Characteristics of paradoxical tuberculosis-associated immune reconstitution inflammatory syndrome and its influence on tuberculosis treatment outcomes in persons living with HIV.

OBJECTIVE: The influence of tuberculosis (TB)-immune reconstitution inflammatory syndrome (IRIS) on TB treatment outcomes and its risk factors were investigated among people with human immunodeficiency virus (HIV) and co-infected with TB. METHODS: Newly diagnosed, culture-confirmed, pulmonary TB patients with HIV and enrolled in a clinical trial (NCT00933790) were retrospectively analysed for IRIS occurrence. Risk factors and TB outcomes (up to 18 months after initiation of anti-TB treatment [ATT]) were compared between people who experienced IRIS (IRIS group) and those who did not (non-IRIS group). RESULTS: TB-IRIS occurred in 82 of 292 (28%) participants. Significant baseline risk factors predisposing to TB-IRIS occurrence in univariate analysis were: lower CD4+ T-cell count, CD4/CD8 ratio, haemoglobin levels, presence of extra-pulmonary TB focus, and higher HIV viral load; the last two retained significance in the multivariate analysis. After 2 months of ATT commencement, sputum smear conversion was documented in 45 of 80 (56.2%) vs. 124 of 194 (63.9%) (p=0.23), culture conversion was in 75 of 80 (93.7%) vs. 178 of 194 (91.7%) (p=0.57) and the median decline in viral load (log10copies/mm3) was 2.7 in the IRIS vs. 1.1 in the non-IRIS groups (p<0.0001), respectively. An unfavourable response to TB therapy was detected in 17 of 82 (20.7%) and 28 of 210 (13.3%) in the IRIS and non-IRIS groups, respectively (p=0.14). CONCLUSIONS: TB-IRIS frequently occurred in people with advanced HIV infection and in those who presented with extra-pulmonary TB lesions, without influencing subsequent TB treatment outcomes.

Daily vs Intermittent Antituberculosis Therapy for Pulmonary Tuberculosis in Patients With HIV: A Randomized Clinical Trial.

Importance: The benefit of daily over thrice-weekly antituberculosis therapy among HIV-positive patients with pulmonary tuberculosis (TB) who are receiving antiretroviral therapy remains unproven. Objective: To compare the efficacy and safety of daily, part-daily, and intermittent antituberculosis therapy regimens in the treatment of HIV-associated pulmonary TB. Design, Setting, and Participants: This open-label, randomized clinical trial was conducted by the National Institute for Research in Tuberculosis, south India. Adults infected with HIV with newly diagnosed, culture-positive, pulmonary TB were enrolled between September 14, 2009, and January 18, 2016. Interventions: Patients were randomized to daily, part-daily, and intermittent antituberculosis therapy regimens, stratified by baseline CD4 lymphocyte count and sputum smear grade. Antiretroviral therapy was initiated as per national guidelines. Clinical and sputum microbiological examinations of patients were performed monthly until 18 months after randomization. Adverse events were recorded using standard criteria. Main Outcomes and Measures: The primary outcome was favorable response, defined as treatment completion with all available sputum cultures negative for Mycobacterium tuberculosis during the last 2 months of treatment. Unfavorable responses included treatment failures, dropouts, deaths, and toxic effects among regimens. Results: Of 331 patients (251 [76%] male; mean [SD] age, 39 [9] years; mean [SD] HIV viral load, 4.9 [1.2] log10 copies/mL; and median [interquartile range] CD4 lymphocyte count, 138 [69-248] cells/µL), favorable responses were experienced by 91% (89 of 98), 80% (77 of 96), and 77% (75 of 98) in the daily, part-daily, and intermittent regimens, respectively. With the difference in outcome between daily and intermittent regimens crossing the O'Brien-Fleming group sequential boundaries and acquired rifampicin resistance emergence (n = 4) confined to the intermittent group, the data safety monitoring committee halted the study. A total of 18 patients died and 18 patients dropped out during the treatment period in the 3 regimens. Six, 4, and 6 patients in the daily, part-daily, and intermittent regimens, respectively, had TB recurrence. Conclusions and Relevance: Among HIV-positive patients with pulmonary TB receiving antiretroviral therapy, a daily anti-TB regimen proved superior to a thrice-weekly regimen in terms of efficacy and emergence of rifampicin resistance. Trial Registration: clinicaltrials.gov Identifier: NCT00933790.

Role of LTA4H Polymorphism in Tuberculosis-Associated Immune Reconstitution Inflammatory Syndrome Occurrence and Clinical Severity in Patients Infected with HIV.

BACKGROUND: Paradoxical tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) is an inflammatory phenomenon complicating HIV management in coincidental tuberculosis (TB) infection, upon immune reconstitution driven by antiretroviral therapy (ART). Leukotriene A4 hydroxylase (LTA4H), an enzyme which converts LTA4 to LTB4, regulates the balance between the anti-inflammatory lipoxins and pro-inflammatory LTB4, with direct implications in TB-driven inflammation. In humans, a single nucleotide polymorphism (SNP) in the LTA4H promoter which regulates its transcriptional activity (rs17525495) has been identified and described to impact clinical severity of TB presentation and response to corticosteroid therapy. Notably, the role of LTA4H on TB-IRIS has not been previously evaluated. Here, we performed an exploratory investigation testing the association of LTA4H polymorphism with respect to frequency of TB-IRIS occurrence and severity of TB-IRIS presentation in HIV-TB co-infected individuals. METHODS: Genotypic evaluation of the LTA4H enzyme from available samples was retrospectively correlated with clinical data captured in case sheets including IRIS details. The cohort included patients recruited from a prospective cohort study nested within a randomized clinical trial (NCT0933790) of ART-naïve HIV+ patients with newly diagnosed rifampicin sensitive pulmonary TB in South India. Frequency of the wild type genotype (CC), as well as of the mutant genotypes (CT or TT) in the IRIS and non-IRIS patients was estimated. Comparative analyses were performed between wild genotype (CC) and the mutant genotypes (CT or TT) and tested for association between the LTA4H polymorphisms and IRIS incidence and clinical severity. RESULTS: A total of 142 eligible ART-naïve patients were included in the analyses. Eighty-six individuals exhibited the wild genotype (CC) while 56 had mutant genotypes (43-CT and only 13-TT). Variant allele frequency was 0.23 and 0.26 in non-IRIS group and in IRIS group, respectively. Upon ART initiation, 51 patients developed IRIS while 91 did not. IRIS incidence was 34% and 37% in the wild (CC) and mutant type (CT/TT), respectively (p = 0.858) with a higher frequency of severe IRIS presentation in the mutant genotype group compared to the wild type genotype (p = 0.0006). A logistic regression model confirmed the association between the presence of CT/TT genotypes and occurrence of severe IRIS. Corticosteroid therapy successfully resolved IRIS in all cases irrespective of the LTA4H genotype. CONCLUSION: A higher incidence of severe IRIS among patients with mutant LTA4H genotypes (CT and TT) was observed compared to the wild type, despite similar IRIS incidence and immune restoration in both groups. Steroids were effective in alleviating IRIS in all the genotypes.