HLA-B*57 and IFNL4-related polymorphisms are associated with protection against HIV-1 disease progression in controllers

Background

HIV-1-controllers maintain HIV-1 viremia at low levels (normally <2000 HIV-RNA copies/mL) without antiretroviral treatment. However, some HIV-1-controllers have evidence of immunologic progression with marked CD4⁺T-cell decline. We investigated host genetic factors associated with protection against CD4⁺T-cell loss in HIV-1-controllers.

Methods

We analysed the association of interferon lambda 4 (IFNL4)-related polymorphisms and HLA-B haplotypes within Long Term Non-Progressor HIV-1-controllers ((LTNP-C), defined by maintaining CD4⁺T-cells counts >500 cells/mm³ for more than 7 years after HIV-1 diagnosis) versus non-LTNP-C, who developed CD4⁺T-cells counts <500 cells/mm³ Both a Spanish study cohort (n=140) and an international validation cohort (n=914) were examined. Additionally, in a subgroup of individuals HIV-1-specific T-cell responses and soluble cytokines were analysed RESULTS: HLA-B*57 was independently associated with the LTNP-C phenotype (OR=3.056 (1.029-9.069) p=0.044 and OR=1.924 (1.252-2.957) p=0.003) while IFNL4 genotypes represented independent factors for becoming non-LTNP-C (TT/TT, ss469415590, OR=0.401 (0.171-0.942) p=0.036 or A/A, rs12980275, OR=0.637 (0.434-0.934) p=0.021) in the Spanish and validation cohort, respectively, after adjusting for sex, age at HIV-1 diagnosis, IFNL4-related polymorphisms and different HLA-B haplotypes. LTNP-C showed lower plasma IP-10 (p=0.019) and higher IFN-γ (p=0.02) levels than the HIV-1-controllers with diminished CD4⁺T-cell numbers. Moreover, LTNP-C exhibited higher quantities of IL2⁺CD57^- and IFN-γ⁺CD57^- HIV-1-specific CD8⁺T-cells (p=0.002 and 0.041, respectively) than non-LTNP-C.

Conclusions

We have defined genetic markers able to segregate stable HIV-1-controllers from those who experience CD4⁺T-cell decline. These findings allow for identification of HIV-1-controllers at risk for immunologic progression, and provide avenues for personalized therapeutic interventions and precision medicine for optimizing clinical care of these individuals.

Clinical, Virologic, Immunologic Outcomes and Emerging HIV Drug Resistance Patterns in Children and Adolescents in Public ART Care in Zimbabwe

OBJECTIVE

To determine immunologic, virologic outcomes and drug resistance among children and adolescents receiving care during routine programmatic implementation in a low-income country.

METHODS

A cross-sectional evaluation with collection of clinical and laboratory data for children (0-<10 years) and adolescents (10-19 years) attending a public ART program in Harare providing care for pediatric patients since 2004, was conducted. Longitudinal data for each participant was obtained from the clinic based medical record.

RESULTS

Data from 599 children and adolescents was evaluated. The participants presented to care with low CD4 cell count and CD4%, median baseline CD4% was lower in adolescents compared with children (11.0% vs. 15.0%, p<0.0001). The median age at ART initiation was 8.0 years (IQR 3.0, 12.0); median time on ART was 2.9 years (IQR 1.7, 4.5). On ART, median CD4% improved for all age groups but remained below 25%. Older age (≥ 5 years) at ART initiation was associated with severe stunting (HAZ <-2: 53.3% vs. 28.4%, p<0.0001). Virologic failure rate was 30.6% and associated with age at ART initiation. In children, nevirapine based ART regimen was associated with a 3-fold increased risk of failure (AOR: 3.5; 95% CI: 1.3, 9.1, p = 0.0180). Children (<10 y) on ART for ≥4 years had higher failure rates than those on ART for <4 years (39.6% vs. 23.9%, p = 0.0239). In those initiating ART as adolescents, each additional year in age above 10 years at the time of ART initiation (AOR 0.4 95%CI: 0.1, 0.9, p = 0.0324), and each additional year on ART (AOR 0.4, 95%CI 0.2, 0.9, p = 0.0379) were associated with decreased risk of virologic failure. Drug resistance was evident in 67.6% of sequenced virus isolates.

CONCLUSIONS

During routine programmatic implementation of HIV care for children and adolescents, delayed age at ART initiation has long-term implications on immunologic recovery, growth and virologic outcomes.

Infrequent recovery of HIV from but robust exogenous infection of activated CD4(+) T cells in HIV elite controllers

BACKGROUND. Human immunodeficiency virus (HIV) elite controllers are able to control infection with HIV-1 spontaneously to undetectable levels in the absence of antiretroviral therapy, but the mechanisms leading to this phenotype are poorly understood. Although low frequencies of HIV-infected peripheral CD4(+) T cells have been reported in this group, it remains unclear to what extent these are due to viral attenuation, active immune containment, or intracellular host factors that restrict virus replication. METHODS. We assessed proviral DNA levels, autologous viral growth from and infectability of in vitro activated, CD8(+) T cell-depleted CD4(+) T cells from HIV elite controllers (mean viral load, <50 copies/mL), viremic controllers (mean viral load, <2000 copies/mL), chronic progressors, and individuals receiving highly active antiretroviral therapy. RESULTS. Although we successfully detected autologous virus production in ex vivo activated CD4(+) T cells from all chronic progressors and from most of the viremic controllers, we were able to measure robust autologous viral replication in only 2 of 14 elite controllers subjected to the same protocol. In vitro activated autologous CD4(+) T cells from elite controllers, however, supported infection with both X4 and R5 tropic HIV strains at comparable levels to those in CD4(+) T cells from HIV-uninfected subjects. Proviral DNA levels were the lowest in elite controllers, suggesting that extremely low frequencies of infected cells contribute to difficulty in isolation of virus. CONCLUSIONS. These data indicate that elite control is not due to inability of activated CD4(+) T cells to support HIV infection, but the relative contributions of host and viral factors that account for maintenance of low-level infection remain to be determined.