Flow cytometry-based method using diversity of cytokine production differentiates between Mycobacterium tuberculosis infection and disease.

Authors present a pilot study of the development of innovative flow cytometry-based assay with a potential for use in tuberculosis diagnostics. Currently available tests do not provide robust discrimination between latent tuberculosis infection (TBI) and tuberculosis disease (TB). The desired application is to distinguish between the two conditions by evaluating the production of a combination of three cytokines: IL-2 (interleukin-2), IFNɣ (interferon gamma) and TNFɑ (tumor necrosis factor alpha) in CD4+ and CD8+ T cells. The study was conducted on 68 participants, divided into two arms according to age (paediatric and adults). Each arm was further split into three categories (non-infection (NI), TBI, TB) based on the immune reaction to Mycobacterium tuberculosis (M.tb) after a close contact with pulmonary TB. Each blood sample was stimulated with specific M.tb antigens present in QuantiFERON tubes (TB1 and TB2). We inferred TBI or TB based on the predominant cytokine response of the CD4+ and/or CD8+ T cells. Significant differences were detected between the NI, TBI and the TB groups in TB1 in the CD4+TNFɑ+parameter in children. Along with IL-2, TNFɑ seems to be the most promising diagnostic marker in both CD4+and CD8+ T cells. However, more detailed analyses on larger cohorts are needed to confirm the observed tendencies.

Availability of drugs and resistance testing for BPaLM regimen for rifampicin-resistant tuberculosis in Europe.

OBJECTIVES: Multidrug-resistant/Rifampicin-resistant tuberculosis (TB) is a major obstacle to successful TB control. The recommendation by the World Health Organization to use bedaquiline, pretomanid, linezolid and moxifloxacin (BPaL(M)) for 6 months, based on results of three trials with high efficacy and low toxicity, has revolutionized treatment options. METHODS: In this study, representatives of the Tuberculosis Network European Trialsgroup (TBnet) in 44/54 countries of the WHO Europe region document the availability of the medicines and drug susceptibility testing (DST) of the BPaL(M) regimen through a structured questionnaire between September to November 2023. RESULTS: 24/44 (54.5%), 42/44 (95.5%), 43/44 (97.7%), and 43/44 (97.7%) had access to pretomanid, bedaquiline, linezolid, and moxifloxacin, respectively. Overall, 23/44 (52.3%) had access to all the drugs composing the BPaL(M) regimen. 7/44 (15.9%), 28/44 (63.6%), 34/44 (77.3%) and 36/44 (81.8%) had access to DST for pretomanid, bedaquiline, linezolid and moxifloxacin, respectively. DST was available for all medicines composing the BPaL(M) regimen in 6/44 (13.6%) countries. CONCLUSION: Only in about half of the countries participating in the survey clinicians have access to all the BPaL(M) regimen drugs. In less than a fifth of countries, a complete DST is possible. Rapid scale up of DST capacity to prevent unnoticed spread of drug resistance and equal access to new regimens are urgently needed in Europe.