Effectiveness of a novel cellular therapy to treat multidrug-resistant tuberculosis

AbstractBackground/objectiveWe urgently need novel treatments for multidrug-resistant tuberculosis (MDR-TB). Autologous mesenchymal stromal cell (MSC) infusion is one such possibility due to its potential to repair damaged lung tissue and boost immune responses. We aimed to assess the safety and effectiveness of MSC to improve treatment outcomes among MDR-TB patients.MethodsWe analyzed treatment outcomes for 108 Belarusian MDR-TB patients receiving chemotherapy. Thirty-six patients (cases) also had MSCs collected, extracted, cultured, and reinfused (average time from chemotherapy start to infusion was 49days) in optimal dose; another 36 patients (without MSC treatment) were “study controls”. We identified another control group: 36 patients from the Belarusian national surveillance database (surveillance controls) 1:1 matched to cases.ResultsSuccessful outcomes were observed in 81% of cases, 42% of surveillance controls, and 39% of study controls. After adjusting for age, odds of a successful outcome were 6.5 (95% confidence interval, 1.2–36.2, p=0.032) times greater for cases than surveillance controls. Adjusting for other potential confounders increased the effect estimate while maintaining statistical significance. Cases were less likely (p=0.01) to be culture negative at 2months than surveillance controls, indicating a poorer initial prognosis in cases before (or shortly after) infusion. Radiological improvement was more likely in cases than in study controls.ConclusionMSC treatment could vastly improve treatment outcomes for MDR-TB patients. Our findings could revolutionize therapy options and have strong implications for future directions of MDR-TB therapy researc

Pharmacokinetic Modeling, Simulation, and Development of a Limited Sampling Strategy of Cycloserine in Patients with Multidrug-/Extensively Drug-Resistant Tuberculosis

BACKGROUND AND OBJECTIVE: Multidrug-resistant tuberculosis has much poorer treatment outcomes compared with drug-susceptible tuberculosis because second-line drugs for treating multidrug resistant tuberculosis are less effective and are frequently associated with side effects. Optimization of drug treatment is urgently needed. Cycloserine is a second-line tuberculosis drug with variable pharmacokinetics and thus variable exposure when programmatic doses are used. The objective of this study was to develop a population pharmacokinetic model of cycloserine to assess drug exposure and to develop a limited sampling strategy for cycloserine exposure monitoring. MATERIAL AND METHODS: Patients with multidrug-/extensively drug-resistant tuberculosis who were treated for > 7 days with cycloserine were eligible for inclusion. Patients received cycloserine 500 mg (body weight ≤ 50 kg) or 750 mg (body weight > 50 kg) once daily. MW/Pharm 3.83 (Mediware, Groningen, The Netherlands) was used to parameterize the population pharmacokinetic model. The model was compared with pharmacokinetic values from the literature and evaluated with a bootstrap analysis, Monte Carlo simulation, and an external dataset. Monte Carlo simulations were used to develop a limited sampling strategy. RESULTS: Cycloserine plasma concentration vs time curves were obtained from 15 hospitalized patients (nine male, six female, median age 35 years). Mean dose/kg body weight was 11.5 mg/kg (standard deviation 2.04 mg/kg). Median area under the concentration-time curve over 24 h (AUC0-24 h) of cycloserine was 888 h mg/L (interquartile range 728-1252 h mg/L) and median maximum concentration of cycloserine was 23.31 mg/L (interquartile range 20.14-33.30 mg/L). The final population pharmacokinetic model consisted of the following pharmacokinetic parameters [mean (standard deviation)]: absorption constant Ka_po of 0.39 (0.31) h-1, distribution over the central compartment (Vd) of 0.54 (0.26) L/kg LBM, renal clearance as fraction of the estimated glomerular filtration rate of 0.092 (0.038), and metabolic clearance of 1.05 (0.75) L/h. The population pharmacokinetic model was successfully evaluated with a bootstrap analysis, Monte Carlo simulation, and an external dataset of Chinese patients (difference of 14.6% and 19.5% in measured and calculated concentrations and AUC0-24 h, respectively). Root-mean-squared-errors found in predicting the AUC0-24 h using a one- (4 h) and a two- (2 h and 7 h) limited sampling strategy were 1.60% and 0.14%, respectively. CONCLUSIONS: This developed population pharmacokinetic model can be used to calculate cycloserine concentrations and exposure in patients with multidrug-/extensively drug-resistant tuberculosis. This model was successfully validated by internal and external validation methods. This study showed that the AUC0-24 h of cycloserine can be estimated in patients with multidrug-/extensively drug-resistant tuberculosis using a 1- or 2-point limited sampling strategy in combination with the developed population pharmacokinetic model. This strategy can be used in studies to correlate drug exposure with clinical outcome. This study also showed that good target attainment rates, expressed by time above the minimal inhibitory concentration, were obtained for cycloserine with a minimal inhibitory concentration of 5 and 10 mg/L, but low rates with a minimal inhibitory concentration of 20 and 32.5 mg/L

Humanized Mouse Model Mimicking Pathology of Human Tuberculosis for in vivo Evaluation of Drug Regimens

Human immune system mice are highly valuable for in vivo dissection of human immune responses. Although they were employed for analyzing tuberculosis (TB) disease, there is little data on the spatial organization and cellular composition of human immune cells in TB granuloma pathology in this model. We demonstrate that human immune system mice, generated by transplanted human fetal liver derived hematopoietic stem cells develop a continuum of pulmonary lesions upon Mycobacterium tuberculosis aerosol infection. In particular, caseous necrotic granulomas, which contribute to prolonged TB treatment time, developed, and had cellular phenotypic spatial-organization similar to TB patients. By comparing two recommended drug regimens, we confirmed observations made in clinical settings: Adding Moxifloxacin to a classical chemotherapy regimen had no beneficial effects on bacterial eradication. We consider this model instrumental for deeper understanding of human specific features of TB pathogenesis and of particular value for the pre-clinical drug development pipeline

Factors contributing to drug-resistant tuberculosis treatment outcome in five countries in the Eastern Europe and Central Asia region

Drug-resistant tuberculosis (DR-TB) is a global challenge and a major contributor of death from anti-microbial resistance. With the main aim to determine factors contributing to treatment outcomes observed among DR-TB patients in the countries in Eastern Europe and Central Asia (EECA), a multi-method study was conducted in: Azerbaijan, Belarus, Romania, Tajikistan and Ukraine. Both quantitative and qualitative methodologies were used for data collection and analysis. The quantitative approaches included a desk review of documents related to the DR-TB responses and an analysis of clinical records of DR-TB patients in selected health facilities of the five countries. Qualitative methods included in-depth interviews with national TB programme (NTP) managers, other healthcare providers and non-governmental organizations (NGOs) workers, as well as interviews and Focus Group Discussions (FGDs) with DR-TB patients. The desk review of 38 reports identified as the main challenges to address DR-TB financial and/or management issues and adverse events of the medicines. The most common recommendations related to treatment outcome focussed on general programme management, treatment regimen composition, clinical management and social support for the patients. In all the five countries the NTPs still have a vertical structure. Some integration into the primary health care system (PHC) already exists but further involvement of PHC facilities is feasible and recommended. Interviews with stakeholders indicated that alcoholism and homelessness and a lack of appropriate response to these issues remain as major challenges for a sub-set of patients. Civil society groups, NGOs and communities are substantially engaged in providing different services to DR-TB patients, especially in Ukraine, Romania and Tajikistan. Data from clinical records of 212 patients revealed that independent risk factors for unfavourable treatment outcome (death, loss to follow-up, failure) were culture-positivity at two months of treatment, history of treatment with second-line drugs and homelessness. More powerful, less toxic and shorter oral treatment regimens as well as comprehensive patient support are needed to improve treatment outcome of patients with DR-TB

Pregnancy in patients with tuberculosis: A TBNET cross-sectional survey

BACKGROUND: Objectives: To determine whether the incidence of tuberculosis with pregnancy is more common than would be expected from the crude birth rate; to see whether there is significant delay in the diagnosis of tuberculosis during pregnancy. METHOD: Design: A cross-sectional survey. SETTING: 13 tuberculosis clinics within different European countries and the USA. POPULATION/SAMPLE: All patients with tuberculosis seen at these clinics for a period\u2009>\u20091 year. INSTRUMENT: Questionnaire survey based on continuous data collection. MAIN OUTCOME MEASURES: number and proportion of women with tuberculosis who were pregnant; timing of diagnosis in relation to pregnancy, including those who were pregnant or delivered in the 3 months prior to the diagnosis of TB and those who developed TB within 3 months after delivery. RESULTS: Pregnancy occurred in 224 (1.5 %) of 15,217 TB patients and followed the expected rate predicted from the crude birth rate for the clinic populations. TB was diagnosed more commonly in the 3 months after delivery (n\u2009=\u2009103) than during pregnancy (n\u2009=\u200968; \u3c7 2\u2009=\u200925.1, P\u2009<\u20090.001). CONCLUSIONS: TB is diagnosed more frequently after delivery, despite variations in local TB incidence and healthcare systems

Prevalence and genetic profiles of isoniazid resistance in tuberculosis patients: A multicountry analysis of cross-sectional data.

BACKGROUND: The surveillance of drug resistance among tuberculosis (TB) patients is central to combatting the global TB epidemic and preventing the spread of antimicrobial resistance. Isoniazid and rifampicin are two of the most powerful first-line anti-TB medicines, and resistance to either of them increases the risk of treatment failure, relapse, or acquisition of resistance to other drugs. The global prevalence of rifampicin resistance is well documented, occurring in 3.4% (95% CI 2.5%-4.4%) of new TB patients and 18% (95% CI 7.6%-31%) of previously treated TB patients in 2018, whereas the prevalence of isoniazid resistance at global and regional levels is less understood. In 2018, the World Health Organization (WHO) recommended a modified 6-month treatment regimen for people with isoniazid-resistant, rifampicin-susceptible TB (Hr-TB), which includes rifampicin, pyrazinamide, ethambutol, and levofloxacin. We estimated the global prevalence of Hr-TB among TB patients and investigated associated phenotypic and genotypic drug resistance patterns. METHODS AND FINDINGS: Aggregated drug resistance data reported to WHO from either routine continuous surveillance or nationally representative periodic surveys of TB patients for the period 2003-2017 were reviewed. Isoniazid data were available from 156 countries or territories for 211,753 patients. Among these, the global prevalence of Hr-TB was 7.4% (95% CI 6.5%-8.4%) among new TB patients and 11.4% (95% CI 9.4%-13.4%) among previously treated TB patients. Additional data on pyrazinamide and levofloxacin resistance were available from 6 countries (Azerbaijan, Bangladesh, Belarus, Pakistan, the Philippines, and South Africa). There were no cases of resistance to both pyrazinamide and levofloxacin among Hr-TB patients, except for the Philippines (1.8%, 95% CI 0.2-6.4) and Belarus (5.3%, 95% CI 0.1-26.0). Sequencing data for all genomic regions involved in isoniazid resistance were available for 4,563 patients. Among the 1,174 isolates that were resistant by either phenotypic testing or sequencing, 78.6% (95% CI 76.1%-80.9%) had resistance-conferring mutations in the katG gene and 14.6% (95% CI 12.7%-16.8%) in both katG and the inhA promoter region. For 6.8% (95% CI 5.4%-8.4%) of patients, mutations occurred in the inhA promoter alone, for whom an increased dose of isoniazid may be considered. The main limitations of this study are that most analyses were performed at the national rather than individual patient level and that the quality of laboratory testing may vary between countries. CONCLUSIONS: In this study, the prevalence of Hr-TB among TB patients was higher than the prevalence of rifampicin resistance globally. Many patients with Hr-TB would be missed by current diagnostic algorithms driven by rifampicin testing, highlighting the need for new rapid molecular technologies to ensure access to appropriate treatment and care. The low prevalence of resistance to pyrazinamide and fluoroquinolones among patients with Hr-TB provides further justification for the recommended modified treatment regimen

Population structure, biogeography and transmissibility of mycobacterium tuberculosis

Mycobacterium tuberculosis is a clonal pathogen proposed to have co-evolved with its human host for millennia, yet our understanding of its genomic diversity and biogeography remains incomplete. Here we use a combination of phylogenetics and dimensionality reduction to reevaluate the population structure of M. tuberculosis, providing an in-depth analysis of the ancient Indo-Oceanic Lineage 1 and the modern Central Asian Lineage 3, and expanding our understanding of Lineages 2 and 4. We assess sub-lineages using genomic sequences from 4939 pan-susceptible strains, and find 30 new genetically distinct clades that we validate in a dataset of 4645 independent isolates. We find a consistent geographically restricted or unrestricted pattern for 20 groups, including three groups of Lineage 1. The distribution of terminal branch lengths across the M. tuberculosis phylogeny supports the hypothesis of a higher transmissibility of Lineages 2 and 4, in comparison with Lineages 3 and 1, on a global scale. We define an expanded barcode of 95 single nucleotide substitutions that allows rapid identification of 69 M. tuberculosis sub-lineages and 26 additional internal groups. Our results paint a higher resolution picture of the M. tuberculosis phylogeny and biogeography.http://www.nature.com/naturecommunicationsam2022Medical Microbiolog

Multidrug-Resistant Tuberculosis in Europe, 2010-2011

This study (TBNET #30) was supported by the European Commission Seventh Framework Programme (FP7/2007-2013) under grant agreement FP7-223681 and was part of the EU FP7–funded TBPANNET project (http://www.tbpannet.org). C.L. is supported by the German Center for Infection Research

Delayed diagnosis of tuberculosis in persons living with HIV in Eastern Europe: associated factors and effect on mortality-a multicentre prospective cohort study

Background: Early diagnosis of tuberculosis (TB) is important to reduce transmission, morbidity and mortality in people living with HIV (PLWH). Methods: PLWH with a diagnosis of TB were enrolled from HIV and TB clinics in Eastern Europe and followed until 24 months. Delayed diagnosis was defined as duration of TB symptoms (cough, weight-loss or fever) for ≥ 1 month before TB diagnosis. Risk factors for delayed TB diagnosis were assessed using multivariable logistic regression. The effect of delayed diagnosis on mortality was assessed using Kaplan-Meier estimates and Cox models. Findings: 480/740 patients (64.9%; 95% CI 61.3-68.3%) experienced a delayed diagnosis. Age ≥ 50 years (vs. < 50 years, aOR = 2.51; 1.18-5.32; p = 0.016), injecting drug use (IDU) (vs. non-IDU aOR = 1.66; 1.21-2.29; p = 0.002), being ART naïve (aOR = 1.77; 1.24-2.54; p = 0.002), disseminated TB (vs. pulmonary TB, aOR = 1.56, 1.10-2.19, p = 0.012), and presenting with weight loss (vs. no weight loss, aOR = 1.63; 1.18-2.24; p = 0.003) were associated with delayed diagnosis. PLWH with a delayed diagnosis were at 36% increased risk of death (hazard ratio = 1.36; 1.04-1.77; p = 0.023, adjusted hazard ratio 1.27; 0.95-1.70; p = 0.103). Conclusion: Nearly two thirds of PLWH with TB in Eastern Europe had a delayed TB diagnosis, in particular those of older age, people who inject drugs, ART naïve, with disseminated disease, and presenting with weight loss. Patients with delayed TB diagnosis were subsequently at higher risk of death in unadjusted analysis. There is a need for optimisation of the current TB diagnostic cascade and HIV care in PLWH in Eastern Europe