Isoniazid Preventive Therapy Added to ART to Prevent TB: An Individual Participant Data Meta-Analysis

Background: Isoniazid preventive therapy prevents active tuberculosis in people with HIV, but previous studies have found no evidence of benefit in people with HIV who had a negative tuberculin skin test, and a non-significant effect on mortality. We aimed to estimate the effect of isoniazid preventive therapy given with antiretroviral therapy (ART) for the prevention of tuberculosis and death among people with HIV across population subgroups. Methods: We searched PubMed, Embase, the Cochrane database, and conference abstracts from database inception to Jan 15, 2019, to identify potentially eligible randomised trials. Eligible studies were trials that enrolled HIV-positive adults (age ≥15 years) taking ART who were randomly assigned to either daily isoniazid preventive therapy plus ART or ART alone and followed up longitudinally for outcomes of incident tuberculosis and mortality. We approached all authors of included trials and requested individual participant data: coprimary outcomes were relative risk of incident tuberculosis and all-cause mortality. We did a single-stage meta-analysis of individual participant data using stratified Cox-proportional hazards models. We did prespecified subgroup analyses by sex, CD4 cell count, and evidence of immune sensitisation to tuberculosis (indicated by tuberculin skin test or interferon-γ release assays [IGRAs]). We also assessed the relative risk of liver injury in an additional prespecified analysis. This study is registered with PROSPERO, CRD42019121400. Findings: Of 838 records, we included three trials with data for 2611 participants and 8584·8 person-years of follow-up for the outcome of incident tuberculosis, and a subset of 2362 participants with 8631·6 person-years of follow-up for the coprimary outcome of all-cause mortality. Risk for tuberculosis was lower in participants given isoniazid preventive therapy and ART than participants given ART alone (hazard ratio [HR] 0·68, 95% CI 0·49–0·95, p=0·02). Risk of all-cause mortality was lower in participants given isoniazid preventive therapy and ART than participants given ART alone, but this difference was non-significant (HR 0·69, 95% CI 0·43–1·10, p=0·12). Participants with baseline CD4 counts of less than 500 cells per μL had increased risk of tuberculosis, but there was no significant difference in the benefit of isoniazid preventive therapy with ART by sex, baseline CD4 count, or results of tuberculin skin test or IGRAs. 65 (2·5%) of 2611 participants had raised alanine aminotransferase, but data were insufficient to calculate an HR. Interpretation: Isoniazid preventive therapy with ART prevents tuberculosis across demographic and HIV-specific and tuberculosis-specific subgroups, which supports efforts to further increase use of isoniazid preventive therapy with ART broadly among people living with HIV. Funding: National Institutes of Health and National Institute of Allergy and Infectious Diseases

Isoniazid Preventive Therapy Added to ART to Prevent TB: An Individual Participant Data Meta-Analysis

Background: Isoniazid preventive therapy (IPT) prevents active TB in people living with HIV (PLHIV), but prior studies found no evidence of benefit in PLHIV with a negative tuberculin skin test (TST) and non-significant impact on mortality. We conducted an individual participant data meta-analysis of randomized controlled 56 trials to estimate the effect of IPT given with ART to prevent TB and death among PLHIV across population subgroups. Methods: We searched PubMed, Embase, the Cochrane database, and conference abstracts. Eligible studies included trials of HIV-positive adults taking ART randomized to daily IPT versus no IPT. We performed a single-stage individual participant data meta-analysis of the outcomes of incident TB disease and all- cause mortality using stratified Cox-proportional hazards models. Registration: PROSPERO (CRD42019121400). Findings: We found 838 citations and included 2611 participants from three trials in Cote D’Ivoire, Malawi, and South Africa. IPT with ART was associated with lower risk for TB than ART alone (hazard ratio=0·68, 95% CI 0·49–0·95, p=0·02) and non-significantly lower all -cause mortality (hazard ratio=0·69, 95% CI 0·43–1·10, p=0.12). TB risk differed by baseline CD4 <200 cells/mm3, but there was no evidence of varying benefit of IPT with ART by sex, baseline CD4, or results of TST or interferon gamma release assays. Elevated alanine aminotransferase occurred in 65/2611 (2.5%) of participants, but data were insufficient to calculate a hazard ratio. Interpretation IPT with ART prevents TB across demographic and HIV- and TB-specific subgroups, which supports efforts to further increase use of IPT with ART broadly among PLHIV

Plasma Concentrations of Efavirenz and Nevirapine among HIV-Infected Patients with Immunological Failure Attending a Tertiary Hospital in North-Western Tanzania

Background: Sub-therapeutic and supra-therapeutic plasma concentrations of antriretrovirals are the significant causes of treatment failure and toxicity respectively among HIV-infected patients. We conducted this study to determine the pattern of efavirenz and nevirapine plasma drug concentrations among adult HIV-infected patients with immunological failure attending at a tertiary hospital in North-western Tanzania. Materials and Methods: A cross-sectional study was conducted among adult HIV-infected patients with immunological failure who have been on either efavirenz or nevirapine based antiretroviral regimen for more than 6 months. Patients were serially enrolled through routine Care and Treatment Clinic (CTC) activities. Plasma drug concentrations for efavirenz and nevirapine were determined by high performance liquid chromatography (HPLC) and Gas Chromatography (GC) respectively. Demographic, clinical and laboratory data such as viral load and CD4 counts were collected. Data analysis was done using STATA 12. Results: Of the 152 patients with immunological failure enrolled, the sub-therapeutic, therapeutic and supra-therapeutic plasma antiretroviral drug concentrations were found in 43/152 (28.3%), 76/152 (50.0%) and 33/152 (21.7%) respectively. Half of the patients were outside therapeutic window with either sub-therapeutic or supra-therapeutic plasma ARV drug concentrations. There was a significant difference in distribution of ARV adherence (p-value<0.001), NRTI backbone (p-value = 0.039), HIV stage (p-value = 0.026) and viral load (p-value = 0.007) within sub-therapeutic, therapeutic and supratherapeutic ARV plasma drug concentrations. Conclusion: There is a wide inter-individual variability of plasma ARV concentrations among HIV patients with immunological failure, with a large proportion of patients being outside therapeutic window. This variability is significant based on ARV adherence, NRTI backbone, viral load and HIV stage. Routine therapeutic drug monitoring (TDM) could assist identifying these patients early and making timely correction to avoid virological failure, poor immunological outcome and prevent associated drug toxicities. Nonetheless, ARV adherence should be strictly emphasized on HIV patients with immunological failure