CD46 Genetic Variability and HIV-1 Infection Susceptibility.

CD46 is the main receptor for complement protein C3 and plays an important role in adaptive immune responses. CD46 genetic variants are associated with susceptibility to several infectious and autoimmune diseases. Additionally, CD46 function can be subverted by HIV-1 to evade attack by complement, a strategy shared by viruses of other families. We sought to determine the association between CD46 gene variants and HIV-1 acquired through intravenous drug use (IDU) and sexual routes (n = 823). Study subjects were of European ancestry and were HIV-1 infected (n = 438) or exposed but seronegative (n = 387). Genotyping of the rs2796265 SNP located in the CD46 gene region was done by allele-specific real-time PCR. A meta-analysis merging IDU and sexual cohorts indicates that the minor genotype (CC) was associated with increased resistance to HIV-1 infection OR = 0.2, 95% CI (0.07-0.61), p = 0.004. The HIV-1-protective genotype is correlated with reduced CD46 expression and alterations in the ratio of CD46 mRNA splicing isoforms.

Evaluation of hepatitis C viral RNA persistence in HIV-infected patients with long-term sustained virological response by droplet digital PCR.

Several studies have reported the persistence of HCV RNA in liver and/or peripheral blood mononuclear cells (PBMCs) in spite of undetectable viremia in patients who have achieved sustained virological response (SVR). This event, defined as occult HCV infection, remains controversial and low titers of persistent virus may be underestimated because it has not yet been analyzed by a highly sensitive test such as droplet digital PCR (ddPCR). This method provides an alternate ultra-sensitive detection technique for very low numbers of copies of viral RNA or DNA. The aim of this study was to evaluate the persistence of HCV in HIV-coinfected patients with long-term SVR using ddPCR. For each patient, the presence of HCV RNA in serum and PBMCs at baseline was determined by nested RT-ddPCR. Patients with HCV RNA in PBMCs at baseline were followed until the end of the study. One hundred and twenty-three patients were analyzed for persistence of HCV RNA in serum and PBMCs. Persistence of HCV was not found in serum in any patient. HCV RNA was detected in PBMCs in one patient (0.81%; 95% CI: 0.04-3.94) and resolved spontaneously during follow-up. Persistence of HCV RNA in PBMCs is not a common event in HIV/HCV co-infected patients with long-term SVR evaluated by RT-ddPCR.

A Knockout IFNL4 Variant Is Associated With Protection From Sexually Transmitted HIV-1 Infection.

An interferon λ4 gene (IFNL4) knockout allele (rs368234815; TT) is associated with spontaneous and IFN-α-dependent cure of hepatitis C virus infection. The role of this polymorphism in the susceptibility to human immunodeficiency virus type 1 (HIV-1) infection is controversial. This study aimed to assess the association of this knockout IFNL4 variant and sexually transmitted HIV-1 infection. A total of 228 HIV-1-positive individuals and 136 HIV-exposed seronegative individuals were investigated for their association with IFNL4 rs368234815 genotypes. The IFNL4 ΔG functional allele is associated with increased susceptibility to HIV-1 infection through the sexual route (odds ratio [OR], 2.1; 95% confidence interval [CI], 1.2-3.6; P = .004). A meta-analysis including a population of injection drug users suggests a codominant mode of inheritance of this risk factor (OR, 2.0; 95% CI, 1.3-3.2; P = .001).

Liver stiffness predicts variceal bleeding in HIV/HCV-coinfected patients with compensated cirrhosis.

BACKGROUND: A liver stiffness below 21 kPa has a high negative predictive value to exclude the presence of esophageal varices at risk of bleeding in HIV/hepatitis C virus (HCV)-coinfected patients. Consequently, upper gastrointestinal endoscopy (UGE) for the screening of esophageal varices could be avoided in these patients. However, this strategy has not been widely accepted due to concerns about its safety. OBJECTIVE: To assess the ability of liver stiffness to predict the risk of portal hypertensive gastrointestinal bleeding (PHGB) in HIV/HCV-coinfected patients with compensated cirrhosis. METHODS: Prospective study of 446 HIV/HCV-coinfected patients with a new diagnosis of cirrhosis and no previous decompensation. All patients underwent a UGE for the screening of esophageal varices at entry in the cohort before November 2009. From this date, UGE was not recommended in patients with liver stiffness below 21 kPa. The time from diagnosis of cirrhosis to the emergence of PHGB was evaluated. RESULTS: After a median (quartile1-quartile3) follow-up of 49 (25-68) months, 15 (3.4%, 95% confidence interval 1.7-5%) patients developed a first PHGB episode. In all cases, baseline liver stiffness was at least 21 kPa. Thus, the negative predictive value of a liver stiffness below 21 kPa to predict PHGB during follow-up was 100%. At the time of the bleeding episode, liver stiffness was above this threshold in all patients. CONCLUSIONS: Liver stiffness identifies HIV/HCV-coinfected patients with compensated cirrhosis with a very low risk of PHGB. In fact, no individual with liver stiffness below 21 kPa developed this outcome. Our results confirm that UGE can be safely spared in patients with liver stiffness below 21 kPa.