Clinical Infectious Diseases

Pediatric Diagnostic Cohort

Diagnosing pediatric tuberculosis is highly important due to challenges posed by nonspecific symptoms. Timely diagnosis enables prompt treatment, reducing morbidity and mortality risks. Prioritizing innovation in pediatric TB diagnostics is essential to address these factors. Tailored diagnostic tools can enhance accuracy, speed, and accessibility of TB diagnosis in children, improving their treatment outcomes. Innovations like collecting bacilli in the breath or using stool and urine to enhance the diagnostic confirmation in children can improve detection and outcomes. Using next generation sequencing for drug susceptibility testing can help in adapting the treatment to the resistance pattern of each child. Finally, following children with TB and analyzing the changes in lung function testing before and after TB treatment can bring much needed knowledge on post TB lung disease in children.

Therapeutic Drug Monitoring (TDM)

This project investigates the potential for using therapeutic drug monitoring (TDM) in tuberculosis (TB) treatment at the Eastern European Study Site (EESS) of the German Center for Infection Research (DZIF) in Romania. The focus is on surveying existing structures and testing practical strategies that enable a stepwise and locally adapted introduction of TDM. First, a comprehensive overview of the current TDM landscape in Romania will be compiled. This includes the systematic identification of laboratories offering TDM for TB medications, including available analytes, costs, sample logistics, and transport routes. This inventory will serve to highlight existing capacities and identify potential regional partners. In parallel, cross-institutional standard operating procedures (SOPs) will be developed in collaboration with Romanian and international partners to harmonize workflows and standardize quality standards. In addition, web-based pharmacokinetic models will be tested using data from the DZIF EESS TB cohort to evaluate the models for the respective target group. Finally, selected TB cases will be discussed in an international expert forum to obtain clinical recommendations, exchange experiences, and sustainably strengthen local expertise.

Risk Score for TB-Associated Mortality

As one of the research projects at the Eastern European Study Site, a clinical risk score to predict mortality in tuberculosis is being developed and validated. The aim is to enable early risk stratification of patients at the time of TB diagnosis based on readily available clinical variables. Conceptually, the approach is modeled on established respiratory risk scores such as the CRB-65 score and transfers this principle to the TB context. The goal is to develop a pragmatic, easy-to-use tool that can be applied particularly in routine clinical practice and in high-burden, resource-limited settings. By enabling early identification of high-risk patients, the score is intended to support clinical decision-making, facilitate targeted intensification of care, and ultimately reduce TB-associated mortality in the region.

Implementation and evaluation of the targeted Next-Generation Sequencing (tNGS) Assay ‘FreezeTB’ for drug-resistant tuberculosis in the Republic of Moldova

By combining speed, affordability, and comprehensive resistance profiling, FreezeTB has the potential to significantly improve molecular drug susceptibility testing (DST) and support individualized treatment of multidrug-resistant and rifampicin-resistant tuberculosis (MDR/RR-TB).

This study aims to establish and evaluate the FreezeTB assay in the Republic of Moldova, a high-priority setting for TB control. The primary objective is to implement FreezeTB in the national TB reference laboratory and assess its performance for detecting resistance to first-line, second-line, and new or repurposed anti-TB drugs. The study will compare FreezeTB results with routine diagnostic methods, including Xpert® MTB/RIF Ultra, Xpert® MTB/XDR, and phenotypic DST, as well as with Illumina-based commercial tNGS platforms. In addition, operational feasibility—including turnaround time, hands-on time, and failure rates—will be evaluated. The generated evidence will support informed decisions on integrating FreezeTB into national TB diagnostic algorithms.

As part of the collaboration with the Nicolae Testemitanu State University of Medicine and Pharmacy and the Chiril Draganiuc Phthisopneumology Institute, the feasibility and clinical utility of targeted next-generation sequencing (tNGS) for the detection of drug resistance in multidrug-resistant and rifampicin-resistant tuberculosis (MDR/RR-TB) is being investigated. While existing rapid molecular tests cannot reliably detect resistance to essential drugs such as bedaquiline, linezolid, and pretomanid, phenotypic drug susceptibility testing (pDST) is associated with long waiting times, significantly delaying the early initiation of effective therapy. tNGS offers a solution by delivering comprehensive resistance profiles within just two days, thus enabling rapid, precise, and personalized treatment decisions. This study will compare the resistance profiles of MDR/RR-TB patients using tNGS and pDST to evaluate the diagnostic accuracy, applicability, and benefits of tNGS. By validating tNGS as a practical and effective diagnostic tool, the project will provide fundamental data for the integration of this technology into routine TB diagnostics, thus closing existing gaps in current testing methods. Expected outcomes include faster and more precise resistance determination, optimized treatment outcomes for patients, and valuable epidemiological insights contributing to global TB control.

The Research Center Borstel – Leibniz Lung Center, V. N. Karazin Kharkiv National University (Ukraine), and additional Ukrainian institutions are partners in the clinical partnership BREATHE. The initiative aims to sustainably strengthen medical education and clinical capacities in respiratory and infectious diseases in Ukraine during the ongoing war.

Since the beginning of the Russian invasion, Ukraine’s higher education and healthcare systems have been under immense pressure. Medical education has been severely disrupted, while at the same time the burden of communicable and non-communicable diseases has increased. BREATHE addresses these challenges by promoting medical education, stabilizing clinical structures, and supporting healthcare professionals working under wartime conditions.

The project is implemented within the framework of the Hospital Partnerships funding program by the Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) and is financed by the German Federal Ministry for Economic Cooperation and Development (BMZ) and the Else Kröner-Fresenius Foundation (EKFS).

BREATHE includes an expanded online lecture series on pulmonology and infectious diseases, weekly international multidisciplinary case discussions on complex tuberculosis (TB) and non-tuberculous mycobacterial (NTM) cases, an annual advanced clinical training course in Ukraine, and regular training opportunities for Ukrainian physicians as part of international courses in Borstel. The partnership promotes continuous knowledge exchange, ensures patient care, and contributes to the long-term resilience and recovery of Ukraine’s healthcare system.

UNITE4TB (academia and industry united innovation and treatment for tuberculosis) is a public-private partnership consisting of academic institutions, small and medium-sized enterprises (SMEs), public organizations and pharmaceutical companies.

Over a period of seven years (2021-2028), the consortium will be active in around 40 trial sites on four continents (Europe, Asia, Africa and South America) to conduct novel phase 2 clinical trials. These are intended to help accelerate the development of new TB drugs and therapies.

With a financial volume of 180 million euros, UNITE4TB is the largest study in the history of drug development for tuberculosis in history.

The project aims to develop better tolerated drug regimens with shorter treatment duration that can be used to combat tuberculosis with different drug resistance patterns and comorbidities.

Through Professor Lange, the Research Center Borstel is represented in the 4-member steering committee of UNITE4TB. Ms. Ohanna Kirakosyan from the Clinical Infectiology Research Group coordinates the study centers of the consortium in Europe and Mr. Collins Musia is co-leader of the work package on biomarkers. Ms. Nika Zielinski is involved in data analysis and biomarker evaluation.

Further information can be found at: https://www.unite4tb.org/

TBnet e.V. is a German non-governmental organization (NGO) with offices in Riga, Latvia and at the Research Center Borstel. TBnet promotes clinically oriented tuberculosis research in Europe through the exchange and development of ideas and research protocols. It is a European research network that brings together clinicians and researchers in the fight against tuberculosis and aims to improve the quality of care for tuberculosis patients by addressing health inequalities, conducting multicenter clinical trials and training European clinicians and scientists.

In recent years, TBnet has made important contributions to tuberculosis research in the fields of epidemiology, prevention, diagnostics and therapy. A list of TBnet publications can be found here.

TBnet currently has over 640 active members from more than 50 countries (as of May 2024). Ongoing studies focus on improving methods for diagnosis and therapy monitoring, among other things.

Specifically, this involves urinary metabolome analyses, the evaluation of a miniMDR TB test and the improvement of the diagnostic quality of the interferon-gamma release assay (IGRA) in immunosuppressed patients. More general studies are concerned with TB management in organ transplant patients or with the question of the extent to which drug levels in the blood influence specific therapy markers.

Training includes the TBnet Academy, which is aimed at young scientists and doctors to provide them with comprehensive knowledge. In recent years, the TBnet Academy has been held in Athens, Tbilisi and Riga.

TBnet member meetings take place annually on the friday before the ERS conference, where there is an opportunity to exchange ideas, present and discuss the status of projects and initiate new research.

Membership is open to anyone who wishes to make a charitable contribution to tuberculosis research. TBnet does not charge a membership fee

One branch of TBnet is the Nontuberculous Mycobacteria Network (NTMnet). Originally, the Pediatric Tuberculosis Network (pTBnet) was also part of TBnet, but is now independent.

This network emerged in 2011 from the Clinical Infectiology Department of the Research Center Borstel. The current chair is held by Dr. Liga Kuksa from Riga in Latvia. The TBnet secretariat at the Research Center Borstel is headed by Anne Oleischeck (aoleischeck@fz-borstel.de).

Global migration has increased in recent decades due to wars, conflicts, persecution, human rights violations and natural disasters, but also due to work or study opportunities. The risk of tuberculosis among migrants depends on the reasons for migration, socio-economic status, the nature of the journey and the risk of tuberculosis in the transit country, as well as the healthcare in the country of origin and the host country.

Despite advancements in TB care for migrants and new treatment strategies, decisions about treatment are often based on expert opinion rather than clinical evidence.

This document summarizes the current state of knowledge on TB diagnosis, TB treatment strategies in migrants, MDR-TB in migrants and HIV/TB co-infection in migrants arriving in Europe. Studies were summarized by meta-analysis when appropriate, otherwise a narrative summary was used.

Based on a systematic review, consensus recommendations were made by experts on all aspects of migrant care.

Developing a REDCap (Research Electronic Data Capture) database for TBnet research projects is important in order to centralize the data collection and management process and offers customizable data entry forms, facilitating efficient and standardized data entry. Having an operational data collection and management system will provide TBnet with the opportunity of mutualizing research data from different projects and having a more powerful platform for proposals and publications.

DetecTB, a study on biomarker-based diagnostics for tuberculosis, investigates non-invasive diagnostic methods for identifying TB patients. The aim is to identify biomarkers from blood, urine, stool, and sputum that enable a reliable TB diagnosis, particularly in patients without sputum production or with extrapulmonary TB.

At the University Medical Center Hamburg-Eppendorf, patients with suspected TB and control subjects with other pulmonary infections are enrolled in the study. A single collection of various biomaterials is performed and analyzed using modern methods such as mRNA signatures, cellular immunology, PATHFAST-LAM, EclLAM, CRISPR-Cas, stool PCR, and Xpert MTB-HR. The feasibility and diagnostic value of these approaches are systematically evaluated.

The primary goal is to identify novel biomarkers or biomarker combinations that enable non-invasive, rapid, and accurate TB diagnosis. Secondary goals include comparisons between pulmonary and extrapulmonary TB, gender-specific differences, and associations with disease course and prognosis.This prospective, single-center observational study includes 120 patients whose participation offers no direct medical benefit but can contribute to the long-term development of improved TB diagnostics. Data and samples are stored pseudonymously and shared only in anonymized form. The results could help reduce invasive diagnostic procedures and enable earlier initiation of therapy.

As part of a multicenter, prospective research project, the role of a symptom diary in pulmonary infections caused by non-tuberculous mycobacteria (NTM) is being investigated. The study is conducted across numerous specialized centers throughout Europe and is embedded within the NTMnet network. The objective of the project is to systematically capture changes in symptoms over the course of disease and treatment and to assess the extent to which these changes correlate with microbiological and radiological findings. By using a standardized symptom diary, the study aims to evaluate whether patient-reported outcomes can serve as early markers of disease progression or treatment response. In the long term, the NTM Diary initiative seeks to improve monitoring of NTM diseases and to more strongly integrate patient-centered endpoints into clinical decision-making processes.

Immune checkpoints are regulatory pathways of the immune system that play a central role in controlling, modulating, and maintaining the immune response. They help prevent excessive immune reactions and ensure immunological homeostasis. Among the best-characterized immune checkpoint molecules are programmed cell death protein 1 (PD-1) and its ligand PD-L1, which are involved in regulating T-cell activation, proliferation, and effector function.

The PD-1/PD-L1 signaling pathways represent immunoregulatory mechanisms in chronic infectious diseases such as tuberculosis. Persistent antigen exposure can lead to increased expression of PD-1 and PD-L1, which is associated with functional changes in T cells and a diminished antimycobacterial immune response. Simultaneously, this immunoregulatory axis represents an important mechanism for limiting inflammatory tissue damage.The aim of this study is to investigate the immunological mechanisms of disease progression and to identify potential immunological biomarkers and therapeutic targets in the context of tuberculosis.

The aim of the TBpredict study is to evaluate novel molecular and immunological markers that enable an earlier and more precise assessment of treatment success in multidrug-resistant tuberculosis. These include MBLA and LAM measurements in sputum, as well as RNA sequencing in blood. For the first time, these methods are being tested simultaneously in this study, allowing for a direct comparison. In addition, lung function tests and physical performance parameters are being examined to predict performance decline following recovery from the infectious disease. Approximately 50% of tuberculosis patients are affected by post-tuberculosis disease. They experience persistent reduced physical capacity as a result of lung tissue damage caused by tuberculosis, even after the infectious disease has been overcome.

The Republic of Moldova is a high-incidence area for antibiotic-resistant tuberculosis worldwide. The project is part of a long-standing, close scientific collaboration between the Borstel Research Center, the Nicolae Testemitanu State University of Medicine and Pharmacy (USMF) in Chișinău, and the Institute of Pneumology in Chișinău.

The study will prospectively enroll 50 patients with rifampicin-resistant or multidrug-resistant tuberculosis (RR-/MDR-TB) in Chișinău. Extensive data will be collected at five time points during the early phase of TB therapy, as well as 12 and 18 months after the start of treatment.

The study on CRISPR-based detection of tuberculosis (TB) investigates the diagnostic value of an assay for detecting the mobile genetic element IS 6110 in blood. The gold standard for detecting TB is the culture of mycobacteria from sputum. This procedure is costly and time-consuming. Diagnosis is not possible in patients from whom sputum cannot be obtained, e.g., in children or in extrapulmonary TB. In cases of existing HIV coinfection, sputum often yields false-negative results. Detection using CRISPR-dependent fluorescence from blood samples is possible within a few hours. In initial studies, the test has demonstrated good diagnostic value even in cases of extrapulmonary TB, children, and HIV coinfection.

The primary objective of this study is to validate the test for sputum-free detection of tuberculosis. Using samples from biomarker studies, the assay's suitability for monitoring disease progression will be evaluated. Due to their properties, CRISPR-based detection methods have the potential to be implemented in point-of-care devices, so the validation of these assays could make a significant contribution to faster and decentralized tuberculosis diagnostics. Researchers at Tulane University (New Orleans, Louisiana) have developed a lab-in-tube device that enables the detection of cell-free tuberculosis DNA from sputum in 2 hours. An evaluation of the lab-in-tube device is planned for the near future.

As part of the collaboration with the Nicolae Testemitanu State University of Medicine and Pharmacy and the Chiril Draganiuc Phthisopneumology Institute, the feasibility and clinical utility of targeted next-generation sequencing (tNGS) for the detection of drug resistance in multidrug-resistant and rifampicin-resistant tuberculosis (MDR/RR-TB) is being investigated. While existing rapid molecular tests cannot reliably detect resistance to essential drugs such as bedaquiline, linezolid, and pretomanid, phenotypic drug susceptibility testing (pDST) is associated with long waiting times, significantly delaying the early initiation of effective therapy. tNGS offers a solution by delivering comprehensive resistance profiles within just two days, thus enabling rapid, precise, and personalized treatment decisions. This study will compare the resistance profiles of MDR/RR-TB patients using tNGS and pDST to evaluate the diagnostic accuracy, applicability, and benefits of tNGS. By validating tNGS as a practical and effective diagnostic tool, the project will provide fundamental data for the integration of this technology into routine TB diagnostics, thus closing existing gaps in current testing methods. Expected outcomes include faster and more precise resistance determination, optimized treatment outcomes for patients, and valuable epidemiological insights contributing to global TB control.

Drug-resistant (DR) tuberculosis (TB) cases pose a challenge in the care for TB patients and remain a significant epidemiological issue. Globally, rifampicin- and multidrug-resistant (RR/MDR) cases caused an estimated 160 000 deaths in 2022. In low-incidence countries and regions, foreign-born individuals are often more commonly affected by DR TB. 

Ukraine is one of the countries in the European region with the highest incidence of tuberculosis (TB) and is also globally one of the countries with the highest burden of drug-resistant TB (1 - 3). Further, Ukraine has recently been affected by two unprecedented challenges to the national healthcare system with the COVID-19 pandemic and the outbreak of an armed conflict. The annually reported notification rates for infections caused by Mycobacterium tuberculosis across the European Union and the European Economic Area (EU/EEA) have been gradually declining in the last decades. In 2022, both the total TB notification rates (49.3 versus 8.0/ 100 000) and the proportion of DR TB among bacteriologically confirmed pulmonary cases (4.9% versus 28.3%) in the EU/EEA were substantially lower than the level reported in Ukraine. As of December 2023, about 5 million displaced Ukrainians had received temporary protection status in the countries of the EU/EEA. As a result of this substantial population size increase, the total number of notified TB cases in Ukrainians in the region rose almost four-fold in 2022. The proportion of the DR TB cases of Ukrainian origin amounted to almost 20% of all DR TB cases in the region and over 30% of the laboratory confirmed Ukrainian TB cases were affected by DR TB . In this context we aim to explore the DR TB epidemiology in Ukrainian and other foreign-born TB cases notified in the EU/EEA.

The OPAT-NTM project addresses the application and evaluation of so-called sOPAT (self-administered outpatient parenteral antimicrobial therapy) for infections with non-tuberculous mycobacteria (NTM). The focus is on the question of how practical and safe long-term intravenous antibiotic therapy can be outside of an inpatient setting.

We analyze the clinical data of 26 patients of the Borstel Lung Clinic with pulmonary and non-pulmonary infections caused by various mycobacterial species (including M. avium, M. chimaera, M. abscessus, and M. chelonae). A central goal is to describe the duration and composition of the antibiotic regimens used and to determine the reasons for treatment discontinuation or modification. In addition to efficacy, side effects, complications of the port system, and the management of adverse events are being investigated.

Overall, we aim to contribute to the evidence base for a treatment concept that enables patients to have greater autonomy while supporting the long-term treatment of difficult-to-treat infections.

Adverse events can make the treatment of tuberculosis more difficult and can be associated with a reduction in the patient's quality of life. The underlying mechanisms are not yet known for all drugs, meaning that adverse events cannot be completely prevented to date.

The aim of this project is therefore to identify and validate gene signatures using machine-learning algorithms to predict severe adverse events before the start of tuberculosis treatment. Transcriptome-based signatures are particularly suitable here. In addition, possible explanatory approaches for the development of severe adverse events are to be generated by identification and biological interpretation of genes and pathways. This would be a possible foundation for further research aimed at gaining a better understanding of the mechanismsand, if necessary, taking preventive countermeasures.

With the help of this work, it will hopefully be possible in the near future to identify an increased risk of serious adverse events before exposure to medication and thus make a contribution to personalised medicine in tuberculosis treatment.

In a subproject, the gene expression of suprabasin (SBSN) has already been identified as a potential biomarker for the prediction of severe linezolid-associated neuropathies.

doi: 10.1016/S1473-3099(21)00586-7

DRAMATIC is a prospective, Duration-Randomized, Partially Blinded, Phase 2 Study. The objectives are
1) to demonstrate a defined relationship between duration and the proportion of successful outcomes,
2) to determine which durations of the oral experimental regimen can be expected to be as effective as the current validated (but recently de-prioritized) 9-11-month injectable-containing regimen and
3) to define the safety profile of the experimental regimen.

The study randomizes 220 participants, including adults (18 years of age or older) and children (12-17 years of age) with MDR-TB, to 16, 24, 32 or 40 weeks of treatment with a 5-drug oral experimental regimen (bedaquiline, delamanid, linezolid, levofloxacin and clofazimine).

Four experimental treatment durations allow the study to estimate the efficacy of multiple durations of treatment, maximizing the probability to identify the shortest effective experimental regimen. With this design it can be avoided that the duration selected is either too short (thus not effective enough) or too long (thus incurring excess toxicity). By following patients to observe relapse, important information for the optimal treatment duration in a large Phase 3 trial is gathered.

Many biological markers (including metabolic products, proteins, RNA in sputum, blood or urine) will be analyzed to identify new alternatives to traditional culture-based methods for determining the bactericidal activity of a drug or drug combination to predict treatment failure and relapse.

The study is conducted at trial centers in Philippines and Vietnam and is sponsored by the University of California (UCS), and Novartis, Otsuka and Pfizer as industry collaborators. It involves scientists from USA (Boston University, University of Colorado, UCS, Harvard), Philippines, Vietnam and Borstel.

If a new and more effective standard regimen comes into use by the time DRAMATIC has been completed, DRAMATIC will still be able to identify a duration of the experimental regimen that is non-inferior to the new standard of care. This will facilitate moving promptly to a confirmatory Phase 3 trial.

The diagnosis of tuberculosis poses a major challenge, especially in vulnerable patient groups such as children, the elderly, or HIV-infected individuals. The current gold standard for tuberculosis diagnosis is the cultural detection of Mycobacterium tuberculosis in sputum samples. However, this method requires patients to be able to produce sufficient sputum, which is often problematic, especially in children, the elderly, and immunocompromised patients. Lipoarabinomannan (LAM), which is released by Mycobacterium tuberculosis and can be detected in body fluids, offers the possibility of non-invasive and faster diagnosis.

The Electrochemiluminescence LAM Research Assay (EclLAM, MSD, Rockville, Maryland, USA) is a highly sensitive immunoassay that uses an ELISA-like platform with electronic luminescence detection to accurately quantify even the lowest concentrations of LAM.

The aim of this research project is to evaluate the diagnostic accuracy of LAM-based detection methods in urine samples for the diagnosis of TB.

At the Research Center Borstel, a new biomarker (TB22) was identified that enables the individualization of the duration of tuberculosis therapy. For this purpose, a signature was identified from RNA sequences in the peripheral blood of patients. For further validation, access to blood samples from very well characterized tuberculosis patients from Mozambique, Uganda and eSwatini is available through participation in an  EU project.

The TB22 signature will be applied to transcriptome data to determine whether it can accurately diagnose tuberculosis in African children and PLHIV at the start of treatment. In addition, the dynamics of TB22 during treatment will be assessed to determine if the model can accurately predict the time at which the patient has achieved a relapse-free cure.

Transcriptome data may also enable the discovery of new RNA signatures that are not yet known, such as signatures to predict disease progression, detect active tuberculosis, distinguish between tuberculosis and non-tuberculous lung disease, monitor response to treatment, or predict tuberculosis relapse in early stages.

In a longitudinal cohort, samples were taken at various points during treatment to obtain DNA and epigenetic data, and clinical data on disease severity in the form of culture data and imaging procedures, treatment results, medication and any side effects were collected. These data will be used to determine whether and which TB-relevant RNA expressions identified in previous studies can be attributed to DNA mutations or epigenetic disorders in order to draw conclusions about supplementary epigenetic or immunomodulatory therapy. In addition, it will be investigated whether there is a correlation between epigenetic disorders and the clinical manifestations, therapy results and immune cell activity or with existing concepts of personalized TB therapy (e.g. endotypes). Furthermore, it will be investigated whether the epigenetic profile is altered by certain drugs used in TB therapy.

Antibiotic resistance is making the treatment of tuberculosis increasingly difficult. Cultural methods to determine antibiotic resistance are complex and time-consuming. It usually takes several months between the diagnosis of tuberculosis and the receipt of an antibiogram. New methods of gene sequencing allow rapid and comprehensive information on mutations in the genome of tuberculosis bacteria that are associated with antibiotic resistance. These molecular predictions of antibiotic resistance using targeted sequencing technologies (t-NGS) have been officially recommended by the WHO since summer 2023 for the prediction of antibiotic resistance and the composition of treatment regimens. The Research Center Borstel is significantly involved in this process and the preparation of the WHO recommendations.

Whether the treatment results of patients affected by multidrug-resistant tuberculosis (MDR-TB) can actually be improved by using the new technologies is plausible, but has never been proven in a clinical study.

The Research Center Borstel has entered into a strategic partnership with the University of Cape Town, South Africa, to jointly address these and other questions. Our research group is supporting colleagues from the University of Cape Town (Prof. Dr. Keertan Dheda, MD PhD) in the T3 Study 2024, which is investigating the impact of tNGS technology on treatment outcomes of patients with MDR-TB in South Africa. The first patients were enrolled in spring 2024.

The overall endpoint of the study is to determine the impact of t-NGS information-based treatment regimens on treatment outcomes of patients with MDR-TB.

Phase 1 primary endpoint:
proportion of patients initiated on treatment with ≥4 likely effective drugs within 14 days of diagnosis of rifampicin-resistant TB in each group (n=120).

Phase 2 primary endpoint:
rate of unfavorable outcomes 6 months after treatment initiation in each group (n=240 including phase 1 patients)

Phase 3 primary endpoint:
rate of unfavorable outcomes in each group 12 months after treatment initiation (n=300 including phase 2 patients).

The Xpert MTB/RIF Ultra is a rapid molecular assay in cartridge format, first introduced in 2017 as an upgrade of the Xpert MTB/RIF assay for diagnosing tuberculosis. While trace-positive results may represent detection of residual DNA from prior TB, sample cross-contamination, or laboratory error, they may also represent opportunities to detect active TB disease at an early stage. Stool is a clinical sample recommended by the WHO for the diagnosis of TB in children and gaining increasing evidence for adults. We are analyzing trace results from stool in a case-control study of TB patients paired with healthy controls.

A transcriptome model has been developed at the Borstel Research Centre to monitor treatment response in patients with pulmonary tuberculosis. The model uses the response of the human body to an infection with tuberculous mycobacteria to determine whether someone is infected. It could also be used to determine very precisely when someone has been treated with antibiotics long enough to be cured. This means that treatment durations could one day be adapted to each patient and overall shortened.

The model, which is based on 22 genes (TB22 for short), can also be used for diagnostics. This is particularly interesting for children, as many laboratory methods fail to detect tuberculosis in children. There is then no clear evidence of M. tuberculosis, so the diagnosis can only be made clinically. The aim of this research project is to test whether the TB22 model can help in the diagnosis of children or people with HIV infection. In close collaboration with Baylor College of Medicine, Houston, USA, we have been able to obtain RNA samples from children with tuberculosis in Eswatini in southern Africa. The first samples are currently on their way to Borstel and we are starting the measurements for the TB22 transcriptome model.

2023-2024 INSIGHT Scholars with the Baylor Program PI, Dr. Anna Mandalakas (third from right) at orientation in Washington, DC.

The Integrated Network of Scholars in Global Health Research Training (INSIGHT) consortium comprises four U.S. academic institutions (Baylor College of Medicine’s Global TB Program, University of Alabama at Birmingham, University of Maryland Baltimore, University of Pittsburgh) and their affiliated international institutions in Africa, Asia, and the Americas. The program is sponsored by the Fogarty International Center (FIC) and several collaborating Institutes and Centers at the U.S. National Institutes of Health (NIH) and is one of the seven consortia in the NIH Fogarty Launching Future Leaders in Global Health (LAUNCH) Research Training Program. INSIGHT aims to:

1. Create collaborative, multidisciplinary global health research that integrates cross institutional pairing of mentors
2. Provide one year of mentored research training for 105 scholars
3. Promote and support diversity, equity, and inclusion in global health research training
4. Support the transition of scholars into successful and sustainable research careers

This opportunity supports mentored research training in global health for eligible U.S. doctoral candidates and U.S. and LMIC postdoctoral (MD, MD/PhD, ScD or equivalent degree) fellows. Successful applicants spend 12 months abroad at one of 27 affiliated institutions across 20 countries, where they gain experience conducting research in international settings. LMIC postdocs have short-term training at the affiliated U.S. institution. Trainee research projects are supported by experienced and dedicated mentors with expertise in clinical, public health, laboratory, and implementation research.

More information on the INSIGHT training program can be found on the INSIGHT website.

Background: 
In vitro, animal model and clinical evidence suggests that tuberculosis is not a monomorphic disease, and that host response to tuberculosis is protean with multiple distinct molecular pathways and pathologies (endotypes). We applied unbiased clustering to identify separate tuberculosis endotypes with classifiable gene expression patterns and clinical outcomes.

Methods: 
A cohort comprised of microarray gene expression data from microbiologically confirmed tuberculosis patients was used to identify putative endotypes. One microarray cohort with longitudinal clinical outcomes was reserved for validation, as were two RNA-sequencing (seq) cohorts. Finally, a separate cohort of tuberculosis patients with functional immune responses was evaluated to clarify stimulated from unstimulated immune responses.

Results: 
A discovery cohort, including 435 tuberculosis patients and 533 asymptomatic controls, identified two tuberculosis endotypes. Endotype A is characterised by increased expression of genes related to inflammation and immunity and decreased metabolism and proliferation; in contrast, endotype B has increased activity of metabolism and proliferation pathways. An independent RNA-seq validation cohort, including 118 tuberculosis patients and 179 controls, validated the discovery results. Gene expression signatures for treatment failure were elevated in endotype A in the discovery cohort, and a separate validation cohort confirmed that endotype A patients had slower time to culture conversion, and a reduced cure rate. These observations suggest that endotypes reflect functional immunity, supported by the observation that tuberculosis patients with a hyperinflammatory endotype have less responsive cytokine production upon stimulation.

Conclusion: 
These findings provide evidence that metabolic and immune profiling could inform optimisation of endotype-specific host-directed therapies for tuberculosis.

doi: 10.1183/13993003.02263-2021D

Development of a tuberculosis therapeutic drug monitoring platform

The treatment of drug-resistant Mycobacterium tuberculosis relies on complex antibiotic therapy. Inadequate antibiotic exposure can lead to treatment failure, acquired drug resistance, and an increased risk of adverse events. Therapeutic drug monitoring (TDM) can be used to optimize the antibiotic exposure. Therefore, we aimed to develop a single-run multiplex assay using high-performance liquid chromatography-mass spectrometry (HPLC-MS) for TDM of patients with multidrug-resistant, pre-extensively drug-resistant and extensively drug-resistant tuberculosis. A target profile for sufficient performance, based on the intended clinical application, was established and the assay was developed accordingly. Antibiotics were analyzed on a zwitterionic hydrophilic interaction liquid chromatography column and a triple quadrupole mass spectrometer using stable isotope-labeled internal standards. The assay was sufficiently sensitive to monitor drug concentrations over five half-lives for rifampicin, rifabutin, levofloxacin, moxifloxacin, bedaquiline, linezolid, clofazimine, terizidone/cycloserine, ethambutol, delamanid, pyrazinamide, meropenem, prothionamide, and para-amino salicylic acid (PAS). Accuracy and precision were sufficient to support clinical decision making (≤±15% in clinical samples and ±20-25% in spiked samples, with 80% of future measured concentrations predicted to fall within ±40% of nominal concentrations). The method was applied in the TDM of two patients with complex drug-resistant tuberculosis. All relevant antibiotics from their regimens could be quantified and high-dose therapy was initiated, followed by microbiological conversion. In conclusion, we developed a multiplex assay that enables TDM of the relevant first- and second-line anti-tuberculosis medicines in a single run and was able to show its applicability in TDM of two drug-resistant tuberculosis patients.

doi: 10.3390/pharmaceutics15112543

Molecular prediction of treatment regimens in drug -resistant tuberculosis

Background:
Comprehensive and reliable drug susceptibility testing (DST) is urgently needed to provide adequate treatment regimens for patients with multidrug-resistant/rifampicin-resistant tuberculosis (MDR/RR-TB). We determined whether next-generation sequencing (NGS) analysis of Mycobacterium tuberculosis complex isolates and genes implicated in drug resistance can guide the design of effective MDR/RR-TB treatment regimens.

Methods:
NGS-based genomic DST predictions of M. tuberculosis complex isolates from MDR/RR-TB patients admitted to a TB reference center in Germany between 1 January 2015 and 30 April 2019 were compared with phenotypic DST results of mycobacteria growth indicator tubes (MGIT). Standardized treatment algorithms were applied to design individualized therapies based on either genomic or phenotypic DST results, and discrepancies were further evaluated by determination of minimal inhibitory drug concentrations (MICs) using Sensititre MYCOTBI and UKMYC microtiter plates.

Results:
In 70 patients with MDR/RR-TB, agreement among 1048 pairwise comparisons of genomic and phenotypic DST was 86.3%; 76 (7.2%) results were discordant, and 68 (6.5%) could not be evaluated due to the presence of polymorphisms with yet unknown implications for drug resistance. Importantly, 549 of 561 (97.9%) predictions of drug susceptibility were phenotypically confirmed in MGIT, and 27 of 64 (42.2%) false-positive results were linked to previously described mutations mediating a low or moderate MIC increase. Virtually all drugs (99.0%) used in combination therapies that were inferred from genomic DST were confirmed to be susceptible by phenotypic DST.

Conclusions:
NGS-based genomic DST can reliably guide the design of effective MDR/RR-TB treatment regimens.

doi: 10.1093/cid/ciab359

Long-term treatment outcomes in patients with multidrug-resistant tuberculosis

Objectives:
To describe long-term treatment outcomes in patients with multi-drug-resistant/rifampicin resistant tuberculosis (MDR/RR-TB) and validate established outcome definitions for MDR/RR-TB treatment.

Methods:
Among patients with MDR/RR-TB admitted to a German MDR/RR-TB referral centre from 1 September 2002 to 29 February 2020, we compared long-term treatment outcomes derived from individual patient follow-up with treatment outcomes defined by WHO-2013, WHO-2021 and the Tuberculosis Network European Trials Group-2016.

Results:
In a total of 163 patients (mean age, 35 years; standard deviation, 13 years; 14/163 [8.6%] living with HIV; 109/163 [66.9%] men, 149/163 [91.4%] migrating to Germany within 5 years), the treatment of culture-confirmed MDR/RR-TB was initiated. Additional drug resistance to a fluoroquinolone or a second-line injectable agent was present in 15 of the 163 (9.2%) Mycobacterium tuberculosis strains; resistance against both the drug classes was present in 29 of the 163 (17.8%) strains. The median duration of MDR/RR-TB treatment was 20 months (interquartile range, 19.3-21.6 months), with a medium of five active drugs included. The median follow-up time was 4 years (47.7 months; interquartile range, 21.7 65.8 months). Among the 163 patients, cure was achieved in 25 (15.3%), 82 (50.3%) and 95 (58.3%) patients according to the outcome definitions of WHO-2013, WHO-2021, and the Tuberculosis Network European Trials Group-2016, respectively. The lost to follow-up rate was 17 of 163 (10.4%). Death was more likely in patients living with HIV (hazard ratio, 4.28; 95% confidence interval, 1.26e12.86) and older patients (hazard ratio, 1.08; 95% confidence interval, 1.05e1.12; increment of 1 year). Overall, 101/163 (62.0%) patients experienced long-term, relapse-free cure; of those, 101/122 (82.8%) patients with a known status (not lost to-follow-up or transferred out) at follow-up.

Conclusion:
Under optimal management conditions leveraging individualized treatment regimens, long-term, relapse-free cure from MDR/RR-TB is substantially higher than cure rates defined by current treatment outcome definitions.

doi: 10.1016/j.cmi.2023.02.013

The impact of migration related to the Russia-Ukraine conflict on the epidemiology of tuberculosis infections in the European Union and the European Economic Area

The tuberculosis notification rate in Ukraine is around six times higher than the overall notification rate in the European Union (EU) and the European Economic Area (EEA). Ukraine is also a high priority country for the World Health Organization in terms of antibiotic-resistant tuberculosis. According to Eurostat, around 5 million Ukrainians have been displaced to EU and EEA countries since the beginning of the war between Russia and Ukraine.

In close collaboration with the European Center for Disease Prevention and Control (ECDC), we assessed the epidemiology of tuberculosis in cases of Ukrainian origin reported in the EU/EEA from 2019 to 2022 using routinely collected data.

Our results showed that the number of reported tuberculosis cases among Ukrainians in the region almost quadrupled in 2022 (n = 780, compared to an average of n = 201 in the three previous years). However, cases of Ukrainian origin continued to account for only a small proportion (2.2% in 2022) of all cases reported in the EU/EEA. In addition, notification rates among Ukrainian citizens in the EU/EEA were lower than those reported in Ukraine and remained below 20 per 100,000. The proportion of antibiotic-resistant forms of tuberculosis among cases of Ukrainian origin in the EU/EEA was high, reflecting the high proportion of resistant cases in Ukraine. In 2022, almost one in five antibiotic-resistant TB cases in the EU/EEA was of Ukrainian origin.

These results underline the importance of migrant-sensitive and patient-centered healthcare to ensure early presentation, initiation and continuation of treatment. Due to the high rate of antibiotic-resistant cases, pathogen detection and susceptibility testing in TB patients from Ukraine is crucial.

doi: 10.2807/1560-7917.ES.2024.29.12.2400094

Unmask-TB

The aim of the Unmask-TB research project is to develop and test modified FFP2 masks as a diagnostic test for pulmonary tuberculosis in children. Even today, tuberculosis in children can often only be diagnosed clinically, i.e. there is no reliable detection of tuberculous mycobacteria in a laboratory test. In children, failure to recognize tuberculosis is dangerous; up to 40% of children under the age of five die of tuberculosis if undiagnosed and therefore untreated.

Tongue swabs, stool, urine, and the modified masks could be promising new sample types: Obtaining these samples is less burdensome for children compared to conventional methods, such as aspirating gastric liquid. Initial studies also indicate that some of these new methods can better detect tuberculosis in children. At the Borstel Research Centre, we have therefore adapted face masks that have been successfully tested on adults for children. These contain a 3D-printed polyvinyl alcohol strip that is designed to capture bacterial DNA in exhaled breath Our method is also part of the large ‘TB GAPS’ study conducted by Baylor College of Medicine, Houston, USA, in several countries in southern Africa. The German Centre for Infection Research has repeatedly provided us with extensive support in the development of the method.

The modified FFP2 masks for children had a low detection limit for M. tuberculosis-specific DNA in vitro. However, M. tuberculosis DNA was not detected in any of the 30 masks worn by children with pulmonary tuberculosis. FFP2 masks modified in this way may not be more effective at detecting M. tuberculosis in children than existing methods.

doi: 10.1093/infdis/jiae282

Detection of Mycobacterium tuberculosis from respiratory masks in adults with pulmonary tuberculosis

New tuberculosis treatments are needed to address drug resistance, lengthy treatment duration and adverse reactions of available agents. GSK3036656 (ganfeborole) is a first-in-class benzoxaborole inhibiting the Mycobacterium tuberculosis leucyl-tRNA synthetase. Here, in this phase 2a, single-center, open-label, randomized trial, we assessed early bactericidal activity (primary objective) and safety and pharmacokinetics (secondary objectives) of ganfeborole in participants with untreated, rifampicin-susceptible pulmonary tuberculosis. Overall, 75 males were treated with ganfeborole (1/5/15/30 mg) or standard of care (Rifafour e-275 or generic alternative) once daily for 14 days. We observed numerical reductions in daily sputum-derived colony-forming units from baseline in participants receiving 5, 15 and 30 mg once daily but not those receiving 1 mg ganfeborole. Adverse event rates were comparable across groups; all events were grade 1 or 2. In a participant subset, post hoc exploratory computational analysis of 18F-fluorodeoxyglucose positron emission tomography/computed tomography findings showed measurable treatment responses across several lesion types in those receiving ganfeborole 30 mg at day 14. Analysis of whole-blood transcriptional treatment response to ganfeborole 30 mg at day 14 revealed a strong association with neutrophil-dominated transcriptional modules. The demonstrated bactericidal activity and acceptable safety profile suggest that ganfeborole is a potential candidate for combination treatment of pulmonary tuberculosis.

doi: 10.1038/s41591-024-02829-7

As part of the EDCTP-funded "CLICK TB" project, new therapy regimes for the treatment of tuberculosis (TB), in particular drug-resistant TB (MDR-TB), are to be investigated. The aim is to clinically test new drug combinations using new active substances. The international consortium includes scientists from Spain and England (GSK), South Africa (TASK, UCT), Norway (University of Tromsø) and Borstel.

• Sanfetrinem cilexetil is a safe oral carbapenem with intrinsic stability against TB β-lactamases. The active substance has already been successfully clinically tested in a phase II study as a broad-spectrum antibiotic. This is the prerequisite for testing sanfetrinem in a phase IIa “Early Bactericidal Activity” study with regard to bactericidal activity in TB.
• GSK3036656 is the first compound in a new class of selective mycobacterial LeuRS inhibitors. The compound has successfully completed the Phase I study

The clinical studies are conducted at an experienced study center in South Africa (TASK) and include extensive biomarker testing (PET-CT and biological markers) to identify new alternatives to traditional culture-based methods for determining the bactericidal activity of a drug or drug combination. The biological biomarkers are measured and analyzed in the Clinical Infectiology laboratory. The tests include, for example, transcriptome analyses and the measurement of transrenal mycobacterial DNA. If the new drugs confirm the hopes, the study consortium aims to quickly transfer the drugs to a phase III study in order to make them available to TB patients and to make a contribution to the fight against TB.

The EDCTP funded project Stool4TB aims to evaluate an innovative stool-based qPCR diagnostic platform, under the hypothesis that it will narrow the extremely large Tuberculosis (TB) case detection gap by improving TB confirmation rates in children and people living with HIV (PLHIV). 

Among children and PLHIV, TB continues to be a leading cause of morbidity and mortality. TB laboratory confirmation is particularly challenging in children and PLHIV given the difficulty in obtaining sputum samples and the paucibacillary nature of the disease.

Another target of Stool4TB is to create a TB diagnostic network among African high TB burden countries (Mozambique, eSwatini, and Uganda) with the capacity to conduct clinical studies of novel diagnostics and new drugs with a focus on children and PLHIV. Furthermore, a biobank of comparative specimens will be created.

As one of the project partners, the Research Center Borstel takes active part in establishing a biobank of samples for future TB-related research. Blood is collected into PAXgene and QuantiFERON-TB Gold (QFT) tubes with the specific goal to validate the TB22 signature and the concept of endotypes in TB in children. RNAseq and QFT data from the studies’ samples will be used to affirm TB22 potential to diagnose TB also in children, to prove its capacity to serve as a marker for outcome prediction in children, to show that it might be capable to serve as a marker for individualized therapy duration in children, to further validate the concept of endotypes in TB, and to perform multi-dimensional analysis in RNAseq and QFT data to further define endotypes in children. PAXgene tubes collected on sites will be shipped to Research Center Borstel where transcriptomic RNA analysis will be performed.

More information: https://www.stool4tb.org/

This European multicenter study shows that recipients of solid organ transplants (SOT) have a significantly increased risk of tuberculosis (TB), even in countries with low to moderate TB incidence. More than 5,800 adult transplant recipients from 15 centers across eight European countries were included in the study, conducted by researchers from the Tuberculosis Network European Trials Group (TBnet).

A total of 23 confirmed TB cases were observed, corresponding to an incidence of 68 cases per 100,000 person-years—approximately six times higher than in the general population. The risk was particularly high in Southern Europe, with 252 cases per 100,000 person-years, about nine times higher than in Central Europe. Patients with a migration background also had a significantly elevated risk of developing TB.

The study found that only one-third of transplant recipients were screened for latent TB before transplantation, and only one in ten received preventive therapy. Most TB cases occurred more than two years after transplantation, suggesting a combination of reactivation of latent infections and new infections.

The authors emphasize the importance of a regionally adapted prevention strategy: targeted screening in low-incidence regions and universal screening with preventive therapy in high-incidence regions could significantly reduce TB risk in immunocompromised transplant patients.

Drug-resistant tuberculosis is a substantial health-care concern worldwide. Despite culture-based methods being considered the gold standard for drug susceptibility testing, molecular methods provide rapid information about the Mycobacterium tuberculosis mutations associated with resistance to anti-tuberculosis drugs. This consensus document was developed on the basis of a comprehensive literature search, by the TBnet and RESIST-TB networks, about reporting standards for the clinical use of molecular drug susceptibility testing. Review and the search for evidence included hand-searching journals and searching electronic databases. The panel identified studies that linked mutations in genomic regions of M. tuberculosis with treatment outcome data. Implementation of molecular testing for the prediction of drug resistance in M. tuberculosis is key. Detection of mutations in clinical isolates has implications for the clinical management of patients with multidrug-resistant or rifampicin-resistant tuberculosis, especially in situations when phenotypic drug susceptibility testing is not available. A multidisciplinary team including clinicians, microbiologists, and laboratory scientists reached a consensus on key questions relevant to molecular prediction of drug susceptibility or resistance to M. tuberculosis, and their implications for clinical practice. This consensus document should help clinicians in the management of patients with tuberculosis, providing guidance for the design of treatment regimens and optimising outcomes

doi: 10.1016/S1473-3099(22)00875-1

Anecdotal information suggests that clinical practice regarding the use of putative hepatoprotective agents in tuberculosis treatment varies across countries in the WHO European Region. Between November 2023 and May 2024, we conducted a standardized questionnaire survey among representatives of the Tuberculosis Network European Trials Group (TBnet) in countries in the WHO European Region on the use of putative hepatoprotective agents in the treatment of tuberculosis patients.

We received valid responses from 37 of 53 countries (69.8%), of which 16 (43.2%) reported regular use of putative hepatoprotective agents during TB treatment. Half of these countries (n = 8) are part of the former Soviet Union. In five countries, these agents are recommended in national guidelines. The most commonly used putative hepatoprotective agents were silibin/silymarin (n = 9, 56.3%), ursodeoxycholic acid (n = 5, 31.3%), and soy phospholipids (n = 4, 25.0%). Treatment duration varied: 56.3% (n = 9) took them for less than 1 month, 18.8% (n = 3) for 1-3 months, and 18.8% (n = 3) for 4-6 months. Putative hepatoprotective agents are widely used as an adjunct to tuberculosis treatment in the WHO European Region, particularly in the countries of the former Soviet Union, some of which have incorporated them into their national guidelines.

doi: 10.5588/ijtldopen.24.0498

Background:
European-specific policies for tuberculosis (TB) elimination require identification of key populations that benefit from TB screening.

Aim:
We aimed to identify groups of foreign-born individuals residing in European countries that benefit most from targeted TB prevention screening.

Methods:
The Tuberculosis Network European Trials group (TBnet) collected, by cross-sectional survey, numbers of foreign-born TB patients residing in European Union (EU) countries, Iceland, Norway, Switzerland and the United Kingdom (UK) in 2020 from the 10 highest ranked countries of origin in terms of TB cases in each country of residence. Tuberculosis incidence rates (IRs) in countries of residence were compared with countries of origin.

Results:
Data on 9,116 foreign-born TB patients in 30 countries of residence were collected. Main countries of origin were Eritrea, India, Pakistan, Morocco, Romania and Somalia. Tuberculosis IRs were highest in patients of Eritrean and Somali origin in Greece and Malta (both > 1,000/100,000) and lowest among Ukrainian patients in Poland (3.6/100,000). They were mainly lower in countries of residence than countries of origin. However, IRs among Eritreans and Somalis in Greece and Malta were five times higher than in Eritrea and Somalia. Similarly, IRs among Eritreans in Germany, the Netherlands and the UK were four times higher than in Eritrea.

Conclusions:
Country of origin TB IR is an insufficient indicator when targeting foreign-born populations for active case finding or TB prevention policies in the countries covered here. Elimination strategies should be informed by regularly collected country-specific data to address rapidly changing epidemiology and associated risks.

doi: 10.2807/1560-7917.ES.2023.28.42.2300051

In large parts of Europe, tuberculosis no longer plays a major role, although some people still carry the pathogen. However, for people with weakened immune systems, for example after an organ transplant or in the case of HIV infection, the bacterial infection can still be very dangerous. The QuantiFERON-TB Gold Plus (QFT+) test is often used as the standard diagnostic test. The QFT+ is an indirect test, meaning that it does not detect the pathogen itself, but rather the immune system's response to it. If the immune system is weakened, either deliberately to prevent rejection of a donor organ or by an immune system-weakening pathogen such as HIV, the immune response to the tuberculosis pathogen is also weaker. The QFT+ test may then produce false negative results more frequently.

In order to investigate the validity of the QFT+ test for detecting infection with mycobacteria and active tuberculosis, more than 2,600 patients were examined between 2015 and 2019 in a large-scale multicenter study conducted by TBnet. Additionally the patients were followed-up for two years to assess how well the test can determine the risk of developing tuberculosis. 1,788 people came from one of five groups with weakened immune systems: people who had undergone organ transplants, stem cell transplants, or who had rheumatoid arthritis, chronic renal failure, or HIV infection. A further 861 immunocompetent individuals served as a control group. The patients were treated at 21 medical centers in eleven European countries.

The study showed that the QFT+ test is not sufficiently reliable to be used on its own to diagnose active disease. It does not meet the WHO requirements for a tuberculosis test.

In addition, the test's predictive power for future disease is very low. Even after two years, neither the positive nor the negative test subjects developed active tuberculosis- even if the QFT+ test was positive and no preventive therapy was administered. Only a few HIV-positive persons developed active tuberculosis in individual cases. The QFT+ test is therefore not sufficient to reliably predict the individual risk of tuberculosis in low-incidence countries. In future, additional risk factors – such as HIV status, immune status and origin – should therefore be given greater weight in the decision on preventive treatment.

doi: 10.1016/j.lanepe.2025.101416

In 2021, the World Health Organization changed the definitions for “extensively drug-resistant” tuberculosis (XDR-TB). In this form of the disease, the tuberculosis bacteria exhibit a particularlyhigh level of antibiotic resistance. In addition to the key drug rifampicin, there is also resistance to fluoroquinolones and bedaquiline and/orlinezolid. This form of tuberculosis is still very rare in Europe. 

In an observational retrospective cohort study, at many treatment centers in the WHO European Region data were collected from patients diagnosed with XDR-TB between 2017 and 2023. Of 11.003 patients with rifampicin-resistant tuberculosis, 188 patients (1,7%) from 16 countries had XDR-TB. Only four out of ten patients affected by XDR-TB achieved successful treatment outcomes, one out of ten died from the disease. Compared with other levels of drug resistance, treatment outcomes were significantly worse for XDR-TB. The findings oft he study highlight the need for adequate, individualised treatment regimens and optimised drug susceptibility testing.

doi: 10.1016/j.lanepe.2025.101380

Effectiveness of preventive antibiotic treatment depending on age, tuberculosis prevalence and Mycobacterium tuberculosis infection status

Tuberculosis is a preventable disease. However, there is debate regarding which individuals would benefit most from tuberculosis preventive treatment and whether these benefits vary in settings with a high burden and low burden of tuberculosis. We aimed to compare the effectiveness of tuberculosis preventive treatment in exposed individuals of differing ages and Mycobacterium tuberculosis infection status while considering tuberculosis burden of the settings.

In this systematic review and individual-participant meta-analysis, we investigated the development of incident tuberculosis in people closely exposed to individuals with tuberculosis. We searched for studies published between Jan 1, 1998, and April 6, 2018, in MEDLINE, Web of Science, BIOSIS, and Embase. We restricted our search to cohort studies; case-control studies and outbreak reports were excluded. Two reviewers evaluated titles, abstracts, and full text articles for eligibility. At each stage, two reviewers discussed discrepancies and re-evaluated articles until a consensus was reached. Individual-participant data and a pre-specified list of variables, including characteristics of the exposed contact, the index patient, and environmental characteristics, were requested from authors of all eligible studies; contacts exposed to a drug-resistant tuberculosis index patient were excluded. The primary study outcome was incident tuberculosis. We estimated adjusted hazard ratios (aHRs) for incident tuberculosis with mixed-effects Cox regression models with a study-level random effect. We estimated the number-needed-to-treat (NNT) to prevent one person developing tuberculosis. Propensity score matching procedures were used in all analyses. This study is registered with PROSPERO (CRD42018087022).

After screening 25 358 records for eligibility, 439 644 participants from 32 cohort studies were included in the individual-participantdata meta-analysis. Participants were followed for 1 396 413 person-years (median of 2·7 years [IQR 1·3–4.4]), during which 2496 people were diagnosed with incident tuberculosis. Overall, effectiveness of preventive treatment was 49% (aHR 0·51 [95% CI 0·44–0·60]). Participants with a positive tuberculin-skin-test  (TST) or IFNγ release assay (IGRA) result at baseline benefitted from greater protection, regardless of age (0·09 [0·05–0·17] in children younger than 5 years, 0·20 [0·15–0·28] in individuals aged 5–17 years, and 0·17 [0·13–0·22] in adults aged 18 years and older). The effectiveness of preventive treatment was greater in high-burden (0·31 [0·23–0·40]) versus low-burden (0·58 [0·47–0·72]) settings. The NNT ranged from 9 to 34 depending on age among participants with a positive TST or IGRA in both high-burden and low-burden settings; among all contacts (regardless of TST or IGRA test result), the NNT ranged from 29 to 43 in high-burden settings and 213 to 455 in low-burden settings.

Our findings suggest that a risk-targeted strategy prioritising contacts with evidence of M. tuberculosis infection might be indicated in low-burden settings, and a broad approach including all contacts should be considered in high-burden settings. Preventive treatment was similarly effective among contacts of all ages.

doi.org/10.1016/S2213-2600(24)00083-3

Sputum MBLA as a monitoring marker during pulmonary tuberculosis therapy

Once tuberculosis has been diagnosed, anti-tuberculosis therapy is initiated and the course of treatment is monitored regularly over the next six months or more in order to detect treatment failure as early as possible. The most important proof of a treatment response is culture negation, i.e. the absence of growth of mycobacteria in microbiological culture over eight weeks. A molecular biological method for the rapid detection of Mycobacterium tuberculosis in sputum is the amplification of genomic mycobacterial DNA (e.g. GeneXpert®). However, this test system cannot distinguish between dead and viable TB bacteria, meaning that a positive result cannot reliably predict treatment failure. The determination of the expression of replicating genes in the new test system of the molecular tuberculosis bacterial load test (MBLA) has the advantage that only viable bacteria are detected.

In this prospective observational cohort study with Marit Neumann and Prof Dr Christoph Hölscher (Infection Immunology) the accuracy of TB-MBLA in assessing bacterial load was evaluated for the first time, to monitor treatment response in adults with pulmonary MDR/XDR tuberculosis. TB-MBLA results were compared with microscopy, the GeneXpert method and time to culture positivity (TTP) in Mycobacterial Growth Indicator Tube (MGIT) culture.

MBLA was superior in the early identification of successful culture conversion compared to microscopy and GeneXpert and could be a useful biomarker to evaluate novel entities in Phase IIA early-bactericidal-activity drug trials regardless of the degree of M. tuberculosis drug resistance.

doi: 10.1016/j.jinf.2024.106399

Stool-based diagnosis of pulmonary tuberculosis

Background:
Despite increasing availability of rapid molecular tests for the diagnosis of tuberculosis in high-burden settings, many people with tuberculosis are undiagnosed. Reliance on sputum as the primary specimen for tuberculosis diagnostics contributes to this diagnostic gap. We evaluated the diagnostic accuracy and additive yield of a novel stool quantitative PCR (qPCR) assay for the diagnosis of tuberculosis in three countries in Africa with high tuberculosis burdens.

Methods:
We undertook a prospective diagnostic accuracy study in Eswatini, Mozambique, and Tanzania from Sept 21, 2020, to Feb 2, 2023, to compare the diagnostic accuracy for tuberculosis of a novel stool qPCR test with the current diagnostic standard for Mycobacterium tuberculosis DNA detection from sputum and stool, Xpert-MTB/RIF Ultra (Xpert Ultra). Sputum, stool, and urine samples were provided by a cohort of participants, aged 10 years or older, diagnosed with tuberculosis. Participants with tuberculosis (cases) were enrolled within 72 h of treatment initiation for tuberculosis diagnosed clinically or following laboratory confirmation. Participants without tuberculosis (controls) consisted of household contacts of the cases who did not develop tuberculosis during a 6-month follow-up. The performance was compared with a robust composite microbiological reference standard (CMRS).

Findings:
The cohort of adolescents and adults (n=408) included 268 participants with confirmed or clinical tuberculosis (cases), 147 (55%) of whom were living with HIV, and 140 participants (controls) without tuberculosis. The sensitivity of the novel stool qPCR was 93·7% (95% CI 87·4-97·4) compared with participants with detectable growth on M tuberculosis culture, and 88·1% (81·3-93·0) compared with sputum Xpert Ultra. The stool qPCR had an equivalent sensitivity as sputum Xpert Ultra (94·8%, 89·1-98·1) compared with culture. Compared with the CMRS, the sensitivity of the stool qPCR was higher than the current standard for tuberculosis diagnostics on stool, Xpert Ultra (80·4%, 73·4-86·2 vs 73·5%, 66·0-80·1; p=0·025 on paired comparison). The qPCR also identified 17-21% additional tuberculosis cases compared to sputum Xpert Ultra or sputum culture. In controls without tuberculosis, the specificity of the stool qPCR was 96·9% (92·2-99·1).

Interpretation:
In this study, a novel qPCR for the diagnosis of tuberculosis from stool specimens had a higher accuracy in adolescents and adults than the current diagnostic PCR gold standard on stool, Xpert-MTB/RIF Ultra, and equivalent sensitivity to Xpert-MTB/RIF Ultra on sputum.

Funding:
National Institutes of Health (NIH) Allergy and Infectious Diseases and NIH Fogarty International Center.

doi: 10.1016/S2666-5247(23)00391-9

Lipoarabinomannan (LAM) as a potential marker for tuberculosis treatment monitoring

Lipoarabinomannan (LAM), a glycolipid found in the cell wall of mycobacteria, plays an essential role in the pathogenesis of tuberculosis (TB). LAM can be detected in bodily fluids such as urine, making it a suitable diagnostic biomarker, particularly in HIV-positive patients.

The current gold standard for TB diagnosis is the cultural detection of Mycobacterium tuberculosis in sputum samples. However, some patients are unable to produce sputum or produce insufficient amounts (e.g., children, the elderly, immunocompromised individuals). Various test systems aim to detect LAM in clinical samples to enable rapid and non-invasive diagnosis.

In this retrospective cohort study, the ultrasensitive electrochemiluminescent LAM test (EclLAM) from Meso Scale Discovery, Inc. was evaluated to measure LAM in the urine of HIV-seronegative patients with pulmonary TB, both for the diagnosis of active TB and for monitoring TB treatment. Samples obtained at various time points (before and after the start of therapy) from microbiologically confirmed TB patients in South Africa and Germany were analyzed.

Both antibody pairs used, FDX-01/FIND-28 and S4-20/A194-01, correctly identified patients with active TB. In addition, both antibody pairs correlated with the time to positive culture and were therefore suitable for therapy monitoring. Overall, these results underscore the potential of LAM as a biomarker for both diagnosis and treatment monitoring. Further research should prioritize the development of non-invasive, sensitive, specific, and quantitative LAM tests.

doi: 10.1016/j.tube.2025.102619

Lipoarabinomannan (LAM) as a potential marker for the diagnosis of tuberculosis from sputum

Despite modern therapies, tuberculosis (TB) remains one of the world's leading infectious diseases. A key diagnostic goal is to detect infections as early and reliably as possible. Lipoarabinomannan (LAM), a component of the mycobacterial cell wall, is detectable in various bodily fluids during an active infection.

The PATHFAST™ TB LAM Ag Test (PATHFAST LAM, PHC Corporation, Tokyo, Japan) is an automated in vitro diagnostic test for quantifying LAM. In this research project, sputum samples from 27 individuals with pulmonary tuberculosis and 20 control subjects were analyzed. The diagnostic accuracy of the test, the correlation between LAM concentration and bacterial load, and the reproducibility of the test results were evaluated.

LAM concentrations were higher in sputum samples from individuals with TB (median: 241.5 pg/mL) compared to those from individuals without TB (0 pg/mL), with a sensitivity of 85.2% and a specificity of 100%. LAM concentration correlated with both microscopy and smear findings (rho = 0.86) and with the time to positivity in MGIT culture (rho = −0.65). Sample homogenization improved the reproducibility of the test results (coefficient of variation 4.5% vs. 72.6%).The PATHFAST LAM meets the WHO Target Product Profile criteria for tuberculosis diagnosis from sputum. The LAM concentration correlates with the bacterial load, and the reproducibility of the test results benefits from homogenization of the samples.

doi: 10.1016/j.jinf.2025.106662