Residual Hiv Viremia and its role in Microbial Translocation and Immune Activation

ABSTRACT Introduction: The presence of an inflammatory status has been linked to a worse clinical course of HIV infection. Previous studies showed that the presence of residual HIV replication, not detected by standard methods, as well as alterations in T regulatory cells and in bacterial translocation markers might be a trigger of such inflammatory condition. Aim of this study was to compare HIV-RNA values obtained by a standard and ultrasensitive method and to correlate them with marker of chronic inflammation and bacterial translocation. Methodology: A cross-sectional study was conducted on 40 subjects including HIV-monoinfected (n = 20), and HIV/HCV-co-infected (n = 20) patients. HIV-RNA was measured in peripheral blood by a standard and an ultrasensitive method and levels obtained were compared in the two groups. Foxp3+, CD14 (soluble and surface), IL17 and bacterial DNA products (bacterial DNA 23S, 23S spike, both expression of bacterial translocation) levels were also measured, compared between the groups, and correlated to level of HIV viremia measured by both tests. Main Findings: HIV-RNA values obtained by ultrasensitive test were significantly different from that measured by the standard test (p = 0,0097). Significantly higher levels were found in coinfected patients for FoxP3+ cells (p <0,001), IL17 (p <0,001), CD14sol (p=0,0167), CD14s (p=0,0043), DNA23S (p=0,0033), DNA23S Spike (p<0,01). We did not observe any significant statistical correlation between HIV-RNA ultrasensitive levels and levels of FoxP3+ cells, CD14sol, CD14s and markers of translocation in the two groups of patients. In patients infected only by HIV, we observed a statistical significative correlation between ultrasensitive HIV-RNA levels and IL-17. Conclusions: The use of an ultrasensitive method allowed us to detect levels of residual HIV viremia in a significative number of patients. HIV infected patients showed higher levels of bacterial translocation markers and proinflammatory cytokines . The presence of ongoing viral replication does not correlate with marker of bacterial translocation, whereas levels of HIV correlated with those of IL17. These results seem to show that levels of marker of translocation are not affected by ongoing viral replication, whereas it may correlate with increased immune activation.