Improved virological outcome in non-B patients: a possible role for baseline coreceptor tropism

Influence of HIV-1 V2 sequence variability on bacterial translocation in antiretroviral naïve HIV-1 infected patients

HIV-1 V2 domain binds α4β7, which assists lymphocyte homing to gut-associated lymphoid tissue. This triggers bacterial translocation, thus contributing to immune activation. We investigated whether variability of V2 179-181 binding site could influence plasma levels of lipopolysaccharide (LPS) and soluble cluster of differentiation 14 (sCD14), markers of microbial translocation/immune activation. HIV gp120 sequences from antiretroviral naïve patients were analyzed for V2 tripeptide composition, length, net charge, and potential N-linked-glycosylation sites. LPS and sCD14 plasma levels were quantified. Clinical/immuno-virologic data were retrieved. Overall, 174 subjects were enrolled, 8% with acute infection, 71% harboring a subtype B. LDV179-181 was detected in 41% and LDI in 27%. No difference was observed between levels of LPS or sCD14 according to different mimotopes or according to other sequence characteristics. By multivariable analysis, only acute infection was significantly associated with higher sCD14 levels. In conclusion, no association was observed between V2 tripeptide composition and extent of bacterial translocation/immune activation.

Increased risk of virologic failure to the first antiretroviral regimen in HIV-infected migrants compared to natives: data from the ICONA cohort

Migrant and Italian HIV-infected patients (n = 5773) enrolled in the ICONA cohort in 2004-2014 were compared for disparities in access to an initial antiretroviral regimen and/or risk of virologic failure (VF), and determinants of failure were evaluated. Variables associated with initiating antiretroviral therapy (ART) were analysed. Primary endpoint was time to failure after at least 6 months of ART and was defined as: VF, first of two consecutive virus loads (VL) >200 copies/mL; treatment discontinuation (TD) for any reason; and treatment failure as confirmed VL >200 copies/mL or TD. A Poisson multivariable analysis was performed to control for confounders. Migrants presented significantly lower CD4 counts and more frequent AIDS events at baseline. When adjusting for baseline confounders, migrants presented a lower likelihood to begin ART (odds ratio 0.80, 95% confidence interval (CI) 0.67-0.95, p 0.012). After initiating ART, the incidence VF rate was 6.4 per 100 person-years (95% CI 4.8-8.5) in migrants and 2.7 in natives (95% CI 2.2-3.3). Multivariable analysis confirmed that migrants had a higher risk of VF (incidence rate ratio 1.90, 95% CI 1.25-2.91, p 0.003) and treatment failure (incidence rate ratio 1.16, 95% CI 1.01-1.33, p 0.031), with no differences for TD. Among migrants, variables associated with VF were age, unemployment and use of a boosted protease inhibitor-based regimen versus nonnucleoside reverse transcriptase inhibitors. Despite the use of more potent and safer drugs in the last 10 years, and even in a universal health care setting, migrants living with HIV still present barriers to initiating ART and an increased risk of VF compared to natives.

X4 viruses are frequently archived in patients with long-term HIV infection but do not seem to influence the "inflamm-aging" process

Background

Co-receptor tropism (CRT) in patients with a long history of HIV-1 infection and antiretroviral treatment has been rarely investigated to date. The aim of this study was to determine the prevalence of X4 and R5 strains in patients with a >15-year follow-up and to investigate the demographical, viral, immunological, clinical and therapeutic determinants of CRT in this population. The possible influence of CRT on the inflammation state related to chronic HIV infection was also examined.

Methods

A total of 118 HIV-1 infected patients with an initial HIV-1-positive test before 1997, and still on follow-up, were enrolled and consecutively submitted to blood sampling. Of these, 111 were on antiretroviral therapy and 89/111 (80.2%) had a plasma viral load (pVL) <25 copies/ml at testing. HIV-1 DNA was extracted and amplified from PBMCs for env gp120 sequencing. CRT was assigned by using geno2pheno and isolates were classified as X4 (FPR ≤20%) or R5 (FPR >20%). Level of serological inflammation biomarkers including IL-6, hsPCR, and D-dimers were measured.

Results

An X4 virus was evidenced in HIV-1 proviral DNA of 50 patients (42%) while the remaining 68 patients were classified as R5. The median follow-up was 19 years (range 15–25). No association was observed between CRT and sex, age, nationality, subtype, HIV risk factor, HBV/HCV co-infection, baseline CD4+ cell count and pVL, overall duration of antiretroviral therapy, past exposure to mono-or dual therapies, and duration of NNRTI or PI-based therapy. The presence of an X4 strain was associated with CD4 nadir (p = 0.005), CD4 absolute count over time (p < 0.001), and cumulative positive (copy/years) viremia (p <0.001) during the whole patient history. No differences were found between R5 and X4 patients regarding inflammation marker levels including Il-6, hsPCR and D-dimers.

Conclusions

An archived X4 virus was demonstrated in 42% of patients with a >15-year-history of HIV infection. This presence was clearly associated with a greater exposure to positive viremia and a poorer CD4 trend over time compared to R5, independent of type and duration of antiretroviral treatment. CRT does not seem to influence the inflammation rate of patients aging with HIV.