Search

BackgroundInterleukin-17-producing CD4 T cells contribute to the control of Mycobacterium tuberculosis (Mtb) infection in humans; whether infection with human immunodeficiency virus (HIV) disproportionately affects distinct Th17-cell subsets that respond to Mtb is incompletely defined.MethodsWe performed high-definition characterization of circulating Mtb-specific Th17 cells by spectral flow cytometry in people with latent TB and treated HIV (HIV-ART). We also measured kynurenine pathway activity by liquid chromatography-mass spectrometry (LC/MS) on plasma and tested the hypothesis that tryptophan catabolism influences Th17-cell frequencies in this context.ResultsWe identified two subsets of Th17 cells: subset 1 defined as CD4+Vα7.2-CD161+CD26+and subset 2 defined as CD4+Vα7.2-CCR6+CXCR3-cells of which subset 1 was significantly reduced in latent tuberculosis infection (LTBI) with HIV-ART, yet Mtb-responsive IL-17-producing CD4 T cells were preserved; we found that IL-17-producing CD4 T cells dominate the response to Mtb antigen but not cytomegalovirus (CMV) antigen or staphylococcal enterotoxin B (SEB), and tryptophan catabolism negatively correlates with both subset 1 and subset 2 Th17-cell frequencies.ConclusionsWe found differential effects of ART-suppressed HIV on distinct subsets of Th17 cells, that IL-17-producing CD4 T cells dominate responses to Mtb but not CMV antigen or SEB, and that kynurenine pathway activity is associated with decreases of circulating Th17 cells that may contribute to tuberculosis immunity.

BackgroundExpanding access to shorter regimens for tuberculosis (TB) prevention, such as once-weekly isoniazid and rifapentine taken for 3 months (3HP), is critical for reducing global TB burden among people living with HIV (PLHIV). Our coprimary hypotheses were that high levels of acceptance and completion of 3HP could be achieved with delivery strategies optimized to overcome well-contextualized barriers and that 3HP acceptance and completion would be highest when PLHIV were provided an informed choice between delivery strategies.Methods and findingsIn a pragmatic, single-center, 3-arm, parallel-group randomized trial, PLHIV receiving care at a large urban HIV clinic in Kampala, Uganda, were randomly assigned (1:1:1) to receive 3HP by facilitated directly observed therapy (DOT), facilitated self-administered therapy (SAT), or informed choice between facilitated DOT and facilitated SAT using a shared decision-making aid. We assessed the primary outcome of acceptance and completion (≥11 of 12 doses of 3HP) within 16 weeks of treatment initiation using proportions with exact binomial confidence intervals (CIs). We compared proportions between arms using Fisher's exact test (two-sided α = 0.025). Trial investigators were blinded to primary and secondary outcomes by study arm. Between July 13, 2020, and July 8, 2022, 1,656 PLHIV underwent randomization, with equal numbers allocated to each study arm. One participant was erroneously enrolled a second time and was excluded in the primary intention-to-treat analysis. Among the remaining 1,655 participants, the proportion who accepted and completed 3HP exceeded the prespecified 80% target in the DOT (0.94; 97.5% CI [0.91, 0.96] p < 0.001), SAT (0.92; 97.5% CI [0.89, 0.94] p < 0.001), and Choice (0.93; 97.5% CI [0.91, 0.96] p < 0.001) arms. There was no difference in acceptance and completion between any 2 arms overall or in prespecified subgroup analyses based on sex, age, time on antiretroviral therapy, and history of prior treatment for TB or TB infection. Only 14 (0.8%) participants experienced an adverse event prompting discontinuation of 3HP. The main limitation of the study is that it was conducted in a single center. Multicenter studies are now needed to confirm the feasibility and generalizability of the facilitated 3HP delivery strategies in other settings.ConclusionsShort-course TB preventive treatment was widely accepted by PLHIV in Uganda, and very high levels of treatment completion were achieved in a programmatic setting with delivery strategies tailored to address known barriers.Trial registrationClinicalTrials.gov NCT03934931.

The weekly rifapentine plus isoniazid for 3 months (3HP) improves completion rate of latent tuberculosis infection treatment, but flu-like symptoms are common. The novel 1HP regimen, involving daily rifapentine plus isoniazid for 28 days, has demonstrated low toxicity in HIV-infected populations. We aimed to investigate whether 1HP has a lower incidence rate of systemic drug reaction (SDR) compared with 3HP during treatment in non-HIV populations. This randomized, multicentre trial compared the completion rate and risks of SDRs of 1HP and 3HP in aged ≥13 years non-HIV subjects with latent tuberculosis infection between September 2019 and September 2023 (ClinicalTrials.gov: NCT04094012). We also investigated associations between SDRs and plasma levels of drugs and their metabolites. A total of 251 and 239 individuals were randomly assigned to 1HP and 3HP groups, respectively, with completion rates of 82.9% (208/251) and 84.5% (202/239), respectively. Among them, 12.7% (32/251) and 10.9% (26/239) of 1HP and 3HP groups experienced SDRs, respectively (p 0.522), predominantly urticaria in 1HP group (59.4% [19/32]) and flu-like syndrome in 3HP group (80.8% [21/26]). Among participants experiencing SDRs, 43.8% (14/32) and 34.6% (9/26) in 1HP and 3HP groups, respectively, completed treatment (p 0.470). Cutaneous reactions were more common in 1HP than 3HP group (32.7% [82/251] vs. 13.0% [31/239], p < 0.001). In 1HP group, urticaria was associated with a higher plasma desacetyl-rifapentine level (ug/mL) at both 2 (median [interquartile range]: 36.06 [17.46–50.79] vs. 22.94 [14.67–31.65], p 0.018) and 6 hours (26.13 [15.80–53.06] vs. 29.83 [18.13–34.01], p 0.047) after dosing. In non-HIV population, the incidence rate of SDR under 1HP is not lower than 3HP. Notably, urticaria, rather than flu-like syndrome, was the predominant SDR associated 1HP. The findings of this study underscore the feasibility of 1HP regimen in non-HIV populations with a high-completion rate exceeding 80%. [ABSTRACT FROM AUTHOR]

Purpose: Isoniazid, a first-line antitubercular drug, is associated with nervous system adverse drug reactions such as seizures, peripheral neuropathy, and psychosis. This systematic review of case reports and case series aimed to characterize the demographic, social, and clinical factors associated with isoniazid-induced psychosis in patients with active tuberculosis (TB) and those who received isoniazid for latent TB infection (LTBI). Methods: We comprehensively searched the Embase, PubMed, and Scopus databases to identify relevant studies published between the date of inception of the database and June 2024. Results: A total of 28 studies, including 21 case reports and 7 case series involved 37 patients who developed isoniazid-induced psychosis. A higher frequency of isoniazid-induced psychosis was observed during the first 2 months of treatment, with a relatively early onset observed among patients aged 18 years or less. Delusions and/or hallucinations are the common symptoms of isoniazid-induced psychosis. Psychomotor disturbances, disorganized speech or formal thought disorder, disorganized or abnormal behaviour, and neuropsychiatric symptoms (sleep disturbances, hostility or aggression, confusion, affective symptoms, anxiety symptoms, and cognitive difficulties) were the other symptoms observed in the included studies. More than 80% of cases rechallenged with isoniazid resulted in the recurrence of psychotic symptoms. Conclusion: Patients with TB and LTBI should be assessed for psychotic and neuropsychiatric symptoms during isoniazid therapy, mainly in the first 2 months. Further research is required to understand the impact of underlying risk factors, such as genetic predisposition and isoniazid pharmacokinetics, as well as the clinical utility and dosage recommendations of pyridoxine for managing isoniazid-induced psychosis. [ABSTRACT FROM AUTHOR]

Background: Efforts to eradicate tuberculosis (TB) are threatened by diabetes mellitus (DM), which confers a 3-fold increase in the risk of TB disease. The changes in the memory phenotypes and functional profiles of Mycobacterium tuberculosis (Mtb)-specific T cells in latent TB infection (LTBI)-DM participants remain poorly characterised. We, therefore, assessed the effect of DM on T-cell phenotype and function in LTBI and DM clinical groups. Methods: We compared the memory phenotypes and function profiles of Mtb-specific CD4+ and CD8+ T cells among participants with LTBI-DM (n=21), LTBI-only (n=17) and DM-only (n=16). Peripheral blood mononuclear cells (PBMCs) were stimulated with early secretory antigenic 6 kDa (ESAT-6) and culture filtrate protein 10 (CFP-10) peptide pools or phytohemagglutinin (PHA). The memory phenotypes (CCR7/CD45RA), and functional profiles (HLA-DR, PD-1, CD107a, IFN-γ, IL-2, TNF, IL-13, IL-17A) of Mtb-specific CD4+ and CD8+ T cells were characterised by flow cytometry. Results: Naive CD4+ T cells were significantly decreased in the LTBI-DM compared to the LTBI-only participants [0.47 (0.34-0.69) vs 0.91 (0.59-1.05); (p<0.001)]. Similarly, CD8+ HLA-DR expression was significantly decreased in LTBI-DM compared to LTBI-only participants [0.26 (0.19-0.33) vs 0.52 (0.400.64); (p<0.0001)], whereas CD4+ and CD8+ PD-1 expression was significantly upregulated in the LTBI-DM compared to the LTBI-only participants [0.61 (0.530.77) vs 0.19 (0.10-0.28); (p<0.0001) and 0.41 (0.37-0.56) vs 0.29 (0.17-0.42); (p=0.007)] respectively. CD4+ and CD8+ IFN-γ production was significantly decreased in the LTBI-DM compared to the LTBI-only participants [0.28 (0.19-0.38) vs 0.39 (0.25-0.53); (p=0.030) and 0.36 (0.27-0.49) vs 0.55 (0.41-0.88); (p = 0.016)] respectively. CD4+ TNF and CD8+ IL-17A production were significantly decreased in participants with LTBI-DM compared to those with LTBI-only [0.38 (0.33-0.50) vs 0.62 (0.46-0.87); (p=0.004) and 0.29 (0.16-0.42) vs 0.47 (0.29-0.52); (0.017)] respectively. LTBI-DM participants had significantly lower dual-functional (IFN-γ+IL-2+ and IL-2+TNF+) and mono-functional (IFN-γ+ and TNF+) CD4+ responses than LTBI-only participants. LTBI-DM participants had significantly decreased dual-functional (IFN-γ+IL-2+, IFN-γ+ TNF+ and IL-2+TNF+) and mono-functional (IFN-γ+, IL-2+ and TNF+) central and effector memory CD4+ responses compared to LTBI-only participants. Conclusion: Type 2 DM impairs the memory phenotypes and functional profiles of Mtb-specific CD4+ and CD8+ T cells, potentially indicating underlying immunopathology towards increased active TB disease risk. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) is a devastating and rapidly spreading disease. Despite years of scientific research and numerous efforts, it is still a major and resurgent health problem worldwide, with high mortality rates. Added to the concern is that TB persists as a latent infection, an occult face of TB, that becomes a potential reservoir for active tuberculosis. Since latent TB‐infected patients may eventually advance to the active form of TB, an accurate diagnosis and effective treatment of latent tuberculosis are essential for TB control. Latent tuberculosis infection (LTBI) treatment is a prominent component of TB control in low‐prevalence countries like the United States; however, its implication in high‐incidence countries like India is still challenging. Therefore, the present study aimed to evaluate the impact of implementing diagnosis and treatment of LTBI in high‐incidence countries using a mathematical model‐based approach. Through our model, we predicted the incidence rate based on the current treatment regimen in India for the year 2035, which is one of the milestones of WHO for a substantial reduction in TB incidence. We observed demographic variability in the effects of various parameters on the TB incidence rate. Finally, we formulated the putative treatment strategies to reduce the TB burden in high‐incidence scenarios. Further, we estimated the impact of these proposed treatment strategies on the drug‐resistant population in high‐incidence scenarios. The model predictions suggested molding the current treatment strategies and focused implementation of LTBI diagnosis and treatment in high‐incidence scenarios. [ABSTRACT FROM AUTHOR]

Background: The reactivation of tuberculosis (TB) among kidney transplant (KT) recipients in an endemic area is of general concern. However, the epidemiology of latent TB infection (LTBI) status and its dynamic change responses have not been explored. Methods: Between September 2020 and August 2021, a prospective study was conducted to investigate the status of LTBI in KT recipients who received a 9-month isoniazid universal prophylaxis. This status was measured using the interferon-gamma release assay (IGRA) with T-SPOT.TB before transplant, as well as at one month and nine months post-transplant. Results: Ninety-one KT recipients had a mean (SD) age of 45 (11) years, and 41% were female. Sixty-eight (75%) patients received a deceased donor allograft, and eighty-six (91%) patients received induction immunosuppressive therapy. The IGRA results were positive, borderline, negative, and indeterminate in 14 (15.4%), 6 (6.6%), 64 (70.3%), and 7 (7.8%) patients, respectively. Among 84 evaluable patients, 20 (23.8%) KT recipients were defined as having LTBI. Older age was significantly associated with LTBI (OR 1.06 [95% CI 1.01–1.12], p = 0.03). Among the 77 KT recipients who completed monitoring, 55 had negative IGRA results. Three (5.4%) KT recipients had conversion post-transplant. One of them developed pulmonary TB at 1 week after the transplant. Among the 13 patients with positive results, 8 (61.5%) remained positive, 1 (7.7%) had an indeterminate result at 1-month post-transplant and subsequently tested positive at 9 months post-transplant, and 4 (30.8%) experienced reversion to negative results throughout the study. Conclusions: In a high TB-endemic area, one-quarter of KT recipients were reported to have LTBI, and the dynamic change of IGRA response in KT recipients is plausible post-transplant. [ABSTRACT FROM AUTHOR]

Interferon-gamma release assays (IGRAs) have gained attention for the diagnosis of latent tuberculosis infection (LTBI) due to their higher specificity compared to the tuberculin skin test (TST). However, the IGRA's performance varies across different populations. This study evaluated the diagnostic performance of three IGRAs (TBF-FIA, TBF-ELISA, and QFT-Plus) in Ghana, comparing them among individuals exposed and unexposed to MTB infection. Conducted in TB clinics across three regions, this prospective and cross-sectional study included healthy individuals with no known TB exposure (unexposed group) and patients with confirmed active TB (exposed group). Blood samples were tested using all three assays as per the manufacturers' guidelines. The TBF-ELISA showed 3.4% higher sensitivity but 4.6% lower specificity compared to QFT-Plus. The TBF-FIA had sensitivity of 78.5–87.3% and specificity of 82.9–90.0%. These findings indicate that while the three IGRAs offer similar diagnostic accuracy, the variations in specificity and limited data on assays like TBF-FIA require further investigation. [ABSTRACT FROM AUTHOR]