HIV-1 non-R5 tropism correlates with a larger size of the cellular viral reservoir and a detectable residual viremia in patients under suppressive ART

Quantification of Total HIV DNA as a Marker to Measure Viral Reservoir: Methods and Potential Implications for Clinical Practice

The focus of this review is to examine the importance of quantifying total HIV DNA to target the HIV reservoir and the clinical implications and challenges involved in its future application in clinical practice. Despite intrinsic limitations, the quantification of total HIV DNA is currently the most widely used marker for exploring the HIV reservoir. As it allows estimating all forms of HIV DNA in the infected cells, total HIV DNA load is the biomarker of the HIV reservoir that provides most of the insights into HIV pathogenesis. The clinical role of total HIV-DNA in both untreated and treated patients is extensively supported by important lines of evidence. Thus, predictive models that include total HIV DNA load together with other variables could constitute a prognostic tool for use in clinical practice. To date, however, this marker has been primarily used in experimental evaluations. The main challenge is technical. Although the implementation of droplet digital PCR could improve analytical performance over real-time PCR, the lack of standardization has made cross-comparisons of the data difficult. An effort by investigators to compare protocols is needed. Furthermore, the main effort now should be to involve the biomedical industry in the development of certified assays for in vitro diagnostics use.

HIV tropism switch in archived DNA of HIV-HCV subjects successfully treated with direct-acting antivirals for HCV infection

We described short-term HIV tropism changes occurring in peripheral blood mononuclear cells and the correlations with HIV DNA value in HIV-HCV co-infected patients cured for HCV disease and with undetectable HIV viremia or residual viremia (RV). Plasma HIV RNA, cellular HIV DNA and tropism were evaluated pre-HCV treatment (baseline, BL) and at 12(T1) and 24(T2) weeks after HCV treatment start. V3 sequences were interpreted using Geno2pheno and classified as R5 only if all three sequences had an FPR ≥ 10% and as X4 when at least one replicate sequence had an FPR < 10%. Forty-nine patients (21 with X4 and 28 with R5 virus) were enrolled. Five X4 patients and 9 R5 subjects experienced at least one tropism change,11 with RV:1/5 patients with X4 infection at BL switched at T1 versus 8/9 in the R5 group (p = 0.022977) and the difference was confirmed in subjects with RV (p = 0.02);6/9 R5 patients switching at T1 confirmed the tropism change at T2. No significant differences in HIV DNA values between patients with RV starting with a R5 or X4 tropism and experienced tropism switch or not were found. Short-term tropism switch involved almost a third of patients, in all but three cases with HIV RV. Being R5 at BL is associated to a higher instability, expressed as number of tropism changes and confirmed switch at T2.

Brief Report: Association Between Low HIV-1 DNA and Western Blot Reactivity to HIV-1 Pol in Chronically Infected Individuals

BACKGROUND

The aim of the study was to evaluate whether negative HIV-1 pol on Western blot (WB) was associated with low HIV-DNA in adults with chronic HIV-1 infection and suppressive antiretroviral therapy.

METHODS

Cross-sectional parent study of the APACHE trial, conducted in subjects with chronic infection, HIV-1 RNA <50 copies/mL for ≥10 years, no residual viremia for ≥5 years and CD4 >500 cells/µL screened for HIV-1 DNA. HIV-1 DNA was quantified in peripheral blood mononuclear cells (PBMCs) by real-time polymerase chain reaction and HIV-1 serostatus was tested by HIV Blot 2.2 WB assay. Multivariate logistic regression was used to determine factors associated with low HIV-1 DNA.

RESULTS

We evaluated 96 patients: 78 (81%) and 18 (19%) subjects with HIV-1 DNA ≥100 copies/10 PBMCs and with HIV-1 DNA <100 copies/10 PBMCs, respectively. Median age was 32.5 (25.3-38.9), and 61 (64%) were men; moreover, we reported that nadir CD4 was 253 (167-339) cells/µL and HIV-RNA <50 copies/mL for 11.7 (10.6-14.0) years. At multivariate analysis, higher nadir CD4 [adjusted odds ratio (AOR) [95% confidence interval (CI) 1.35 (95% CI: 1.03 to 1.76), P = 0.029], longer years of HIV-1 RNA <50 copies/mL [AOR (95% CI) 2.98 (95% CI: 1.25 to 7.10), P = 0.014], a R5-tropic virus [AOR (R5 vs. non-R5) 0.20 (95% CI: 0.04 to 0.96), P = 0.044], and negative HIV-1 pol [AOR 6.59 (95% CI: 1.47 to 29.54), P = 0.014] were associated with low HIV-1 DNA.

CONCLUSIONS

In patients with chronic HIV-1 infection and suppressive antiretroviral therapy, negative HIV-1 pol on WB was associated with low HIV-1 DNA as well as higher nadir CD4, longer years of HIV-1 RNA <50 copies/mL, and a R5-tropic virus.