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Understanding of pandemics depends on the characterization of pathogen collections from well-defined and demographically diverse cohorts. Since its emergence in Congo almost a century ago, Human Immunodeficiency Virus Type 1 (HIV-1) has geographically spread and genetically diversified into distinct viral subtypes. Phylogenetic analysis can be used to reconstruct the ancestry of the virus to better understand the origin and distribution of subtypes. We sequenced two 3.6-kb amplicons of HIV-1 genomes from 3,197 participants in a clinical trial with consistent and uniform sampling at sites across 35 countries and analyzed our data with another 2,632 genomes that comprehensively reflect the HIV-1 genetic diversity. We used maximum likelihood phylogenetic analysis coupled with geographical information to infer the state of ancestors. The majority of our sequenced genomes (n  = 2,501) were either pure subtypes (A–D, F, and G) or CRF01_AE. The diversity and distribution of subtypes across geographical regions differed; USA showed the most homogenous subtype population, whereas African samples were most diverse. We delineated transmission of the four most prevalent subtypes in our dataset (A, B, C, and CRF01_AE), and our results suggest both continuous and frequent transmission of HIV-1 over country borders, as well as single transmission events being the seed of endemic population expansions. Overall, we show that coupling of genetic and geographical information of HIV-1 can be used to understand the origin and spread of pandemic pathogens. [ABSTRACT FROM AUTHOR]

Background: Cotrimoxazole preventive therapy (CPT) in human immunodeficiency virus (HIV) infection is a World Health Organization-recommended standard of care in resource-limited settings, but the mechanism of CPT's beneficial effects is unclear. The COSTOP trial (ISRCTN44723643) evaluated the noninferiority of discontinuing CPT in stabilized patients on antiretroviral therapy. The COSTOP immunology substudy was conducted on a subset of COSTOP participants randomized to continue CPT (n = 86) or discontinue CPT (placebo, n = 86) as daily treatment for 1 year.Methods: We evaluated whether CPT reduces microbial translocation, indicated by the presence of bacterial lipopolysaccharide (LPS) and LPS control factors such as soluble CD14 (sCD14) and endotoxin core antibody (EndoCAb immunoglobulin M [IgM]) in plasma. Intestinal barrier damage as indicated by plasma intestinal fatty acid binding protein (IFABP), T-cell activation, and the inflammatory markers C-reactive protein (CRP), interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α) were also evaluated.Results: We found no significant change in markers of microbial translocation (LPS, IFABP, sCD14, and T-cell activation), with decreased EndoCAb IgM. There was significant increase in inflammation markers (CRP and IL-6) after stopping CPT compared to those who continued CPT.Conclusions: These results add to the evidence of immunological benefits of CPT among HIV-infected populations in resource-limited settings. However, no evidence of reducing microbial translocation was observed. [ABSTRACT FROM AUTHOR]

Background: Lack of viral load monitoring of ART is known to be associated with slower switch from a failing regimen and thereby higher prevalence of MDR HIV-1. Many countries have continued to use thymidine analogue drugs despite recommendations to use tenofovir in combination with a cytosine analogue and NNRTI as first-line ART. The effect of accumulated thymidine analogue mutations (TAMs) on phenotypic resistance over time has been poorly characterized in the African setting.Patients and methods: A retrospective analysis of individuals with ongoing viral failure between weeks 48 and 96 in the NORA (Nevirapine OR Abacavir) study was conducted. We analysed 36 genotype pairs from weeks 48 and 96 of first-line ART (14 treated with zidovudine/lamivudine/nevirapine and 22 treated with zidovudine/lamivudine/abacavir). Phenotypic drug resistance was assessed using the Antivirogram assay (v. 2.5.01, Janssen Diagnostics).Results: At 96 weeks, extensive TAMs (≥3 mutations) were present in 50% and 73% of nevirapine- and abacavir-treated patients, respectively. The mean (SE) number of TAMs accumulating between week 48 and week 96 was 1.50 (0.37) in nevirapine-treated participants and 1.82 (0.26) in abacavir-treated participants. Overall, zidovudine susceptibility of viruses was reduced between week 48 [geometric mean fold change (FC) 1.3] and week 96 (3.4, P  =   0.01). There was a small reduction in tenofovir susceptibility (FC 0.7 and 1.0, respectively, P  =   0.18).Conclusions: Ongoing viral failure with zidovudine-containing first-line ART is associated with rapidly increasing drug resistance that could be mitigated with effective viral load monitoring. [ABSTRACT FROM AUTHOR]

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Background: Identifying determinants of morbidity and mortality may help target future interventions for human immunodeficiency virus (HIV)-infected children.Methods: CD4(+) T-cell count, HIV viral load, and levels of biomarkers (C-reactive protein, tumor necrosis factor α [TNF-α], interleukin 6 [IL-6], and soluble CD14) and interleukin 7 were measured at antiretroviral therapy (ART) initiation in the ARROW trial (case-cohort design). Cases were individuals who died, had new or recurrent World Health Organization clinical stage 4 events, or had poor immunological response to ART.Results: There were 115 cases (54 died, 45 had World Health Organization clinical stage 4 events, and 49 had poor immunological response) and 485 controls. Before ART initiation, the median ages of cases and controls were 8.2 years (interquartile range [IQR], 4.4-11.4 years) and 5.8 years (IQR, 2.3-9.3 years), respectively, and the median percentages of lymphocytes expressing CD4 were 4% (IQR, 1%-9%) and 13% (IQR, 8%-18%), respectively. In multivariable logistic regression, cases had lower age-associated CD4(+) T-cell count ratio (calculated as the ratio of the subject's CD4(+) T-cell count to the count expected in healthy individuals of the same age; P < .0001) and higher IL-6 level (P = .002) than controls. Clustering biomarkers and age-associated CD4(+) and CD8(+) T-cell count ratios identified 4 groups of children. Group 1 had the highest frequency of cases (41% cases; 16% died) and profound immunosuppression; group 2 had similar mortality (23% cases; 15% died), but children were younger, with less profound immunosuppression and high levels of inflammatory biomarkers and malnutrition; group 3 comprised young children with moderate immunosuppression, high TNF-α levels, and high age-associated CD8(+) T-cell count ratios but lower frequencies of events (12% cases; 7% died); and group 4 comprised older children with low inflammatory biomarker levels, lower HIV viral loads, and good clinical outcomes (11% cases; 5% died).Conclusions: While immunosuppression is the major determinant of poor outcomes during ART, baseline inflammation is an additional important factor, identifying a subgroup of young children with similar mortality. Antiinflammatory interventions may help improve outcomes. [ABSTRACT FROM AUTHOR]

Background Nevirapine, an NNRTI used in HIV treatment, can cause hypersensitivity reactions in 6%–10% of patients. In the most serious cases (1.3%) this can manifest as Stevens–Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN). Methods DNA samples were obtained and analysed from a total of 209 adult patients with nevirapine hypersensitivity (57 from a prospective cohort and 152 routine clinic patients) and compared with 463 control patients on nevirapine without any hypersensitivity. The case group included 70 patients with SJS/TEN. All individuals were genotyped for two SNPs in the CYP2B6 gene [c.516G>T (CYP2B6*9) and c.983T>C (CYP2B6*18)] using the TaqMan real-time genotyping platform. The replication cohort comprised 29 controls and 55 nevirapine hypersensitive patients, including 8 SJS/TEN cases. Results An association between the CYP2B6 c.983T>C polymorphism and nevirapine-induced SJS/TEN was observed. In the SJS/TEN group, 30% of individuals possessed at least one c.983T>C versus 16% in the tolerant group [P = 0.006; OR (95% CI) 2.24 (1.27–3.94)]. This association was not significant in the replication cohort [P = 0.075; OR (95% CI) 4.33 (0.80–23.57)]. Combined analysis resulted in an OR of 2.52 (95% CI 1.48–4.20; P = 0.0005) for the association of c.983T>C with SJS/TEN. No association was observed for c.983T>C with other hypersensitivity phenotypes and for CYP2B6 c.516G>T with any hypersensitivity phenotypes. Conclusions Our data show an association between the c.983T>C polymorphism and nevirapine-induced SJS/TEN. CYP2B6 c.983T>C has a frequency of 5%–10% in a variety of African populations, but is not observed in Caucasians, thus representing an ethnic-specific predisposing factor. [ABSTRACT FROM PUBLISHER]

In a randomized comparison of nevirapine or abacavir with zidovudine plus lamivudine, routine viral load monitoring was not performed, yet 27% of individuals with viral failure at week 48 experienced resuppression by week 96 without switching. This supports World Health Organization recommendations that suspected viral failure should trigger adherence counseling and repeat measurement before a treatment switch is considered. [ABSTRACT FROM AUTHOR]

In low-income countries, children ≥4 years and adults with low CD4 count have equally high mortality risk in the 3 months after initiation of antiretroviral therapy, similar to that of untreated individuals. Bacterial infections play a major role; targeted interventions could have important benefits.Background. Adult mortality in the first 3 months on antiretroviral therapy (ART) is higher in low-income than in high-income countries, with more similar mortality after 6 months. However, the specific patterns of changing risk and causes of death have rarely been investigated in adults, nor compared with children in low-income countries.Methods. We used flexible parametric hazard models to investigate how mortality risks varied over the first year on ART in human immunodeficiency virus–infected adults (aged 18–73 years) and children (aged 4 months to 15 years) in 2 trials in Zimbabwe and Uganda.Results. One hundred seventy-nine of 3316 (5.4%) adults and 39 of 1199 (3.3%) children died; half of adult/pediatric deaths occurred in the first 3 months. Mortality variation over year 1 was similar; at all CD4 counts/CD4%, mortality risk was greatest between days 30 and 50, declined rapidly to day 180, then declined more slowly. One-year mortality after initiating ART with 0–49, 50–99 or ≥100 CD4 cells/μL was 9.4%, 4.5%, and 2.9%, respectively, in adults, and 10.1%, 4.4%, and 1.3%, respectively, in children aged 4–15 years. Mortality in children aged 4 months to 3 years initiating ART in equivalent CD4% strata was also similar (0%–4%: 9.1%; 5%–9%: 4.5%; ≥10%: 2.8%). Only 10 of 179 (6%) adult deaths and 1 of 39 (3%) child deaths were probably medication-related. The most common cause of death was septicemia/meningitis in adults (20%, median 76 days) and children (36%, median 79 days); pneumonia also commonly caused child deaths (28%, median 41 days).Conclusions. Children ≥4 years and adults with low CD4 values have remarkably similar, and high, mortality risks in the first 3 months after ART initiation in low-income countries, similar to cohorts of untreated individuals. Bacterial infections are a major cause of death in both adults and children; targeted interventions could have important benefits. [ABSTRACT FROM AUTHOR]

Background. We investigated virological response and the emergence of resistance in the Nevirapine or Abacavir (NORA) substudy of the Development of Antiretroviral Treatment in Africa (DART) trial. Methods. Six hundred symptomatic antiretroviral-naive human immunodeficiency virus (HIV)-infected adults (CD4 cell count, <200 cells/mm3) from 2 Ugandan centers were randomized to receive zidovudine-lamivudine plus abacavir or nevirapine. Virology was performed retrospectively on stored plasma samples at selected time points. In patients with HIV RNA levels >1000 copies/mL, the residual activity of therapy was calculated as the reduction in HIV RNA level, compared with baseline. Results. Overall, HIV RNA levels were lower in the nevirapine group than in the abacavir group at 24 and 48 weeks (P<.001), although no differences were observed at weeks 4 and 12. Virological responses were similar in the 2 treatment groups for baseline HIV RNA level <100,000 copies/mL. The mean residual activity at week 48 was higher for abacavir in the presence of the typically observed resistance pattern of thymidine analogue mutations (TAMs) and M184V (1.47 log10 copies/mL) than for nevirapine with M184V and nonnucleoside reverse-transcriptase inhibitor mutations, whether accompanied by TAMs (0.96 log10 copies/mL) or not (1.18 log10 copies/mL). Conclusions. There was more extensive genotypic resistance in both treatment groups than is generally seen in resource-rich settings. However, significant residual activity was observed among patients with virological failure, particularly those receiving zidovudine-lamivudine plus abacavir. [ABSTRACT FROM AUTHOR]

Background. We sought to investigate renal function in previously untreated symptomatic human immunodeficiency virus (HIV)-infected adults with CD4+ cell counts of !200 cells/mm3 who were undergoing antiretroviral therapy (ART) in Africa. Methods. The study was an observational analysis within a randomized trial of ART management strategies that included 3316 participants with baseline serum creatinine levels of ⩽360 mmol/L. Creatinine levels were measured before ART initiation, at weeks 4 and 12 of therapy, and every 12 weeks thereafter. We calculated estimated glomerular filtration rate (eGFR) using the Cockcroft-Gault formula. We analyzed the incidence of severely decreased eGFR (<30 mL/min/1.73 m2) and changes in eGFR to 96 weeks, considering demographic data, type of ART, and baseline biochemical and hematological characteristics as predictors, using random-effects models. Results. Sixty-five percent of the participants were women. Median values at baseline were as follows: age, 37 years; weight, 57 kg; CD4+ cell count, 86 cells/mm3; and eGFR, 89 mL/min/1.73 m2. Of the participants, 1492 (45%) had mild (⩾60 but <90 mL/min/1.73 m2) and 237 (7%) had moderate (⩾30 but ⩾60 mL/min/1.73 m2) impairments in eGFR. First-line ART regimens included zidovudine-lamivudine plus tenofovir disoproxil fumarate (for 74% of patients), nevirapine (16%), and abacavir (9%) (mostly nonrandomized allocation). After ART initiation, the median eGFR was 89-91 mL/min/1.73 m2 for the period from week 4 through week 96. Fifty-two participants (1.6%) developed severe reductions in eGFR by week 96; there was no statistically significant difference between these patients and others with respect to first-line ART regimen received (Pp.94). Lower baseline eGFR or hemoglobin level, lower body mass index, younger age, higher baseline CD4+ cell count, and female sex were associated with greater increases in eGFR over baseline, with small but statistically significant differences between regimens (P < .001 for all). Conclusions. Despite screening, mild-to-moderate baseline renal impairment was relatively common, but these participants had greatest increases in eGFR after starting ART. Severe eGFR impairment was infrequent regardless of ART regimen and was generally related to intercurrent disease. Differences between ART regimens with respect to changes in GFR through 96 weeks were of marginal clinical relevance, but investigating longer-term nephrotoxicity remains important. [ABSTRACT FROM AUTHOR]

Background The Strategic Timing of AntiRetroviral Treatment (START) trial demonstrated that immediate (at CD4+ >500 cells/µL) vs deferred (to CD4+ <350 cells/µL or AIDS) antiretroviral therapy (ART) initiation reduced risk for AIDS and serious non-AIDS (SNA). We investigated associations of inflammation, coagulation, and vascular injury biomarkers with AIDS, SNA or death, and the effect of immediate ART initiation. Methods Biomarkers were measured from stored plasma prior to randomization and at month 8. Associations of baseline biomarkers with event risk were estimated with Cox regression, pooled across groups, adjusted for age, gender, and treatment group, and stratified by region. Mean changes over 8 months were estimated and compared between the immediate and deferred ART arms using analysis of covariance models, adjusted for levels at entry. Results Baseline biomarker levels were available for 4299 START participants (92%). Mean follow-up was 3.2 years. Higher levels of IL-6 and D-dimer were the only biomarkers associated with risk for AIDS, SNA or death, as well as the individual components of SNA and AIDS events (HRs ranged 1.37–1.41 per 2-fold higher level), even after adjustment for baseline CD4+ count, HIV RNA level, and other biomarkers. At month 8, biomarker levels were lower in the immediate arm by 12%–21%. Conclusions These data, combined with evidence from prior biomarker studies, demonstrate that IL-6 and D-dimer consistently predict clinical risk across a broad spectrum of CD4 counts for those both ART-naïve and treated. Research is needed to identify disease-modifying treatments that target inflammation beyond the effects of ART. [ABSTRACT FROM AUTHOR]