Comparison of Self-report to Biomarkers of Recent HIV Infection: Findings from the START Trial

The association between single-nucleotide polymorphisms within type 1 interferon pathway genes and human immunodeficiency virus type 1 viral load in antiretroviral-naïve participants

BACKGROUND

Human genetic contribution to HIV progression remains inadequately explained. The type 1 interferon (IFN) pathway is important for host control of HIV and variation in type 1 IFN genes may contribute to disease progression. This study assessed the impact of variations at the gene and pathway level of type 1 IFN on HIV-1 viral load (VL).

METHODS

Two cohorts of antiretroviral (ART) naïve participants living with HIV (PLWH) with either early (START) or advanced infection (FIRST) were analysed separately. Type 1 IFN genes (n = 17) and receptor subunits (IFNAR1, IFNAR2) were examined for both cumulated type 1 IFN pathway analysis and individual gene analysis. SKAT-O was applied to detect associations between the genotype and HIV-1 study entry viral load (log10 transformed) as a proxy for set point VL; P-values were corrected using Bonferroni (P < 0.0025).

RESULTS

The analyses among those with early infection included 2429 individuals from five continents. The median study entry HIV VL was 14,623 (IQR 3460-45100) copies/mL. Across 673 SNPs within 19 type 1 IFN genes, no significant association with study entry VL was detected. Conversely, examining individual genes in START showed a borderline significant association between IFNW1, and study entry VL (P = 0.0025). This significance remained after separate adjustments for age, CD4+ T-cell count, CD4+/CD8+ T-cell ratio and recent infection. When controlling for population structure using linear mixed effects models (LME), in addition to principal components used in the main model, this was no longer significant (p = 0.0244). In subgroup analyses stratified by geographical region, the association between IFNW1 and study entry VL was only observed among African participants, although, the association was not significant when controlling for population structure using LME. Of the 17 SNPs within the IFNW1 region, only rs79876898 (A > G) was associated with study entry VL (p = 0.0020, beta = 0.32; G associated with higher study entry VL than A) in single SNP association analyses. The findings were not reproduced in FIRST participants.

CONCLUSION

Across 19 type 1 IFN genes, only IFNW1 was associated with HIV-1 study entry VL in a cohort of ART-naïve individuals in early stages of their infection, however, this was no longer significant in sensitivity analyses that controlled for population structures using LME.

Stigmatizing Policies Interact with Mental Health and Sexual Behaviours to Structurally Induce HIV Diagnoses Among European Men Who Have Sex with Men

Structural stigma shapes men who have sex with men's (MSM's) mental health and sexual behaviours. The aim of this study was to examine how stigmatizing policies interact with downstream anxiety/depression and sexual behaviours to structurally pattern HIV disparities among European MSM. We conducted a secondary data analysis of the European Men-who-have-sex-with-men Internet Survey (EMIS) from 2017. We included a total of 98,600 participants living in 39 European countries. We used the Rainbow Index, a score given to countries based on their sexual and gender minority policies as the predictor of HIV diagnosis. We conducted adjusted random intercept and slope multi-level logistic regressions. In adjusted models, higher Rainbow Index scores was associated with lower predictive probabilities of diagnosed HIV, regardless of the number of condomless intercourse partners. The predictive probability of HIV diagnosis was also lower, regardless of severity of anxiety/depression, where the Rainbow Index score was better. Country-level policies interact with downstream sexual behaviours and anxiety/depression to structurally influence HIV diagnosis among MSM in Europe.

Association Between Single-Nucleotide Polymorphisms in HLA Alleles and Human Immunodeficiency Virus Type 1 Viral Load in Demographically Diverse, Antiretroviral Therapy-Naive Participants From the Strategic Timing of AntiRetroviral Treatment Trial

The impact of variation in host genetics on replication of human immunodeficiency virus type 1 (HIV-1) in demographically diverse populations remains uncertain. In the current study, we performed a genome-wide screen for associations of single-nucleotide polymorphisms (SNPs) to viral load (VL) in antiretroviral therapy-naive participants (n = 2440) with varying demographics from the Strategic Timing of AntiRetroviral Treatment (START) trial. Associations were assessed using genotypic data generated by a customized SNP array, imputed HLA alleles, and multiple linear regression. Genome-wide significant associations between SNPs and VL were observed in the major histocompatibility complex class I region (MHC I), with effect sizes ranging between 0.14 and 0.39 log10 VL (copies/mL). Supporting the SNP findings, we identified several HLA alleles significantly associated with VL, extending prior observations that the (MHC I) is a major host determinant of HIV-1 control with shared genetic variants across diverse populations and underscoring the limitations of genome-wide association studies as being merely a screening tool.

The benefit of immediate compared with deferred antiretroviral therapy on CD4+ cell count recovery in early HIV infection

OBJECTIVE

To assess the impact of immediate vs. deferred antiretroviral therapy (ART) on CD4 recovery among individuals early in HIV infection.

DESIGN

Using serologic markers of early infection together with self-reported dates of infection and HIV diagnosis, ART-naive participants who were randomized to immediate vs. deferred ART in the Strategic Timing of Antiretroviral Treatment trial were classified into subgroups of duration of HIV infection at baseline. CD4 cell count recovery over follow-up according to duration of HIV infection was investigated.

METHODS

Three subgroups were defined: first, infected 6 months or less (n = 373); second, infected 6-24 months (n = 2634); and third, infected 24 months or longer (n = 1605). Follow-up CD4, CD8, and CD4 : CD8 ratio for the immediate and deferred ART groups were compared by subgroup using linear models. For the deferred ART group, decline to CD4 less than 350 cells/μl or AIDS according to infection duration was compared using time-to-event methods.

RESULTS

Follow-up CD4 cell count differences (immediate minus deferred) were greater for those recently infected (+231 cells/μl) compared with the two other subgroups (202 and 171 cells/μl; P < 0.001). CD4 : CD8 ratio treatment differences varied significantly (P < 0.001) according to duration of infection. In the deferred ART group, decline to CD4 less than 350 cells/μl or AIDS was greater among those recently infected (16.1 vs. 13.2 and 10.5 per 100 person years for those infected 6-24 and ≥24 months; P = 0.002).

CONCLUSION

In this randomized comparison of immediate vs. deferred ART, the CD4 cell count difference was greatest for those recently infected with HIV, emphasizing the importance of immediate ART initiation.