Valeria Tirelli

Influence of folate serum concentration on plasma homocysteine levels in HIV-positive patients exposed to protease inhibitors undergoing HAART.

Background: Homocysteinemia (Hcy) increase and risk factors in HIV-positive patients are not clear yet. Methods: HIV-positive patients on stable highly active antiretroviral therapy (HAART) regimens for at least 6 months were enrolled in this cross-sectional study. Among other factors, vitamin B12, folate and length of exposure to protease inhibitors (PIs) were evaluated for their possible correlation with hyper-Hcy (>13 µmol/l in females; >15 µmol/l in males) by logistic regression analysis. Results: Ninety-eight HIV-positive patients were recruited. Twenty-eight (28.6%) had hyper-Hcy. Length of exposure to antiretroviral therapy and PIs did not result to be significantly associated with hyper-Hcy risk. Normal folate level was the only factor associated with the outcome, resulting protective from hyper-Hcy, either at univariate (OR = 0.22; CI 95% = 0.06–0.86; p = 0.029) and multivariable (OR = 0.24; CI 95% = 0.06–0.94; p = 0.04) logistic regression analysis. Folate predictive value of hyper-Hcy risk was driven by levels in the lowest quartiles of the study population (i.e. <10.9 nmol/l). Conclusions: No significant correlations were observed between hyper-Hcy and length of exposure to antiretroviral therapy or PIs. Folate could be a confounding factor in the association between hyper-Hcy and PI exposure found by others. The potential value of folate supplementation, in those who are deficient and in those with hyper-Hcy, merits study.

Immune Correlates of Virological Response in HIV-Positive Patients after Highly Active Antiretroviral Therapy (HAART)

Correlates of immune reconstitution after highly active antiretroviral therapy (HAART) are not completely understood, in particular as far as viro-immunological discordant responses are concerned. HIV-positive patients on stable HAART for > or = 1 year were recruited. Viro-immunological responses were categorized according to positive or negative area under the curve (AUC) variations for HIV plasma viral load (pVL) and CD4+ T-cell counts measured at least every 4 months. The following parameters were evaluated: lymphocyte spontaneous apoptosis (LSA), intracellular Bcl-2 expression in both CD4-CD45RA+ and CD4-CD45R0+, IL-7 and IL-15 plasma concentrations, and lymphocyte TRECs levels. Sixty-one patients were enrolled. A significant inverse correlation was found between CD4+ T-cell count and pVL AUC (r = 0.45; p = 0.0003). Patients with pVL response had higher levels of Bcl-2 in CD4-CD45R0+ (mean 65,409 MESF vs. 54,018 MESF; p = 0.089) and higher IL-15 (mean 1.34 pg/mL vs. 1.05 pg/mL; p = 0.069, respectively). Higher LSA and lower TRECs levels were found in viro-immunological non-responder patients with respect to those who had viro-immunological response (mean 24.84% vs. 14.89%; p = 0.01, and mean 17,796 copies/10(6) cells vs. 29,251 copies/10(6) cells; p = 0.68, respectively). Virological suppression may allow Bcl-2 and IL-15 hyperexpression during incomplete immune-reconstitution phase, while more complete immune reconstitution appeared to be marked by both high TRECs and low LSA levels, possibly indicating both central and peripheral CD4+ T-cell repopulations at this stage.

Observational Study on HIV-Infected Subjects Failing HAART Receiving Tenofovir Plus Didanosine as NRTI Backbone

We evaluated the efficacy of tenofovir (TDF) – and didanosine (ddI)-containing backbones in HIV-infected experienced subjects. We included in the study 245 subjects who started a TDF/ddI-containing HAART with HIV-RNA > 3 log10 cp/ml and an available genotypic resistance test at baseline. At baseline, median CD4 counts and HIV-RNA were 278 cell/mmc and 4.32 log10 cp/ml, respectively. Seventy-four subjects (30.2%) discontinued TDF and/or ddI, 23 of them for drug-related toxicities or intolerance. One-hundred and twenty-six (51.4%) subjects achieved virologic success (HIV-RNA < 50 copies/ml in two consecutive determinations) in a median time of 6.1 months; higher HIV-RNA levels (HR: 0.66, 95% CI: 0.54– 0.79, p < 0.001 for each additional log10 copies/ml), and the total number of mutations either for PI and NNRTI at baseline (HR: 0.87, 95% CI: 0.81–0.92, p < 0.001 for each additional mutation) were both predictors of virologic success. M184V was marginally associated with virologic success (HR: 1.34, 95% CI: 0.94–1.90, p = 0.10 vs no M184V), whilst the number of TAMs was not associated. One-hundred-thirty-three (54.3%) subjects achieved immunologic success (increase of ≥ 100 cells/mm3 from baseline) in a median time of 7.5 months; immunologic success was associated with HIV-RNA levels at baseline (HR: 0.91, 95% CI: 0.79–0.98, p = 0.04 for each additional log10 copies/ml), the total number of mutations either for PI or NNRTI (HR: 0.91, 95% CI: 0.85–0.98, p = 0.01 for each additional mutation) and CD4 count at baseline (HR: 1.11, 95% CI: 1.00–1.23, p = 0.05 for each additional 100 cells/mm3). Results obtained by the on-treatment analyses were comparable. In our study, HAART containing TDF/ddI seem associated with a virologic and immunologic response, when such regimens are chosen according to a genotypic resistance test.

Risk factors for myocardial infarction in HIV-positive patients

We describe the clinical characteristics of 12 HIV-infected patients who suffered from myocardial infarction (MI) in our clinical cohort. They were compared with a control group matched (1:2) for factors related to cardiovascular risk (age, gender, smoking habit, risk factor for HIV acquisition, hypertension, family history for relevant cardiovascular events, and body mass index) by conditional (fixed-effect) logistic regression analysis. Among patients with MI, 6/12 had never used protease inhibitors (PIs) or were antiretroviral therapy naïve. The only variables marginally associated with MI were nadir CD4+ T-cell count <50/mm3 (odds ratio (OR): 7.2; 95% confidence interval (CI) 0.81–64.2; P: 0.077) and zenith >100,000 HIV RNA copies/mL (OR: 7; 95% CI 0.81–60.2; P: 0.076) at univariate analysis. Moreover, the use of PIs did not result in being associated with the risk of MI. Our data show that in HIV-infected patients, PI use does not seem to have any negative impact on MI while the possible impact of advanced HIV infection itself needs further investigations.

Potential role of SEN virus on liver enzyme abnormalities in patients positive for hepatitis C virus with or without HIV infection

A novel single-stranded DNA virus named SEN virus (SENV), which was initially cloned from the plasma of an HIV-positive patient in a cohort we previously studied [1], has been observed in patients suffering from acute and chronic liver diseases of unknown etiology [2]. However, the possible role of SENV in hepatic inflammation is not clear [3]. Phylogenetic analysis of SENV has demonstrated the existence of eight subtypes (A–H), with the SENV H and D subtypes being associated with liver disease more frequently [4, 5]. The epidemiology and clinical implications of SENV infection are currently being investigated. Recently, we demonstrated a lack of negative impact of SENV on the clinical progression of HIV infection [6] and the apparent dynamism of SENV infection, with both clearance and reinfection appearing over time [7]. In HIV-infected patients, hepatitis C virus (HCV) has become a frequent cause of morbidity and mortality in the era of highly effective antiretroviral therapy, and hepatic impairment is aggravated by toxicity due to antiretroviral drugs [8]. Thus, it seems necessary to investigate whether SENV has an impact on patients coinfected with HCV and HIV with or without antiretroviral therapy. The goals of the retrospective, cross-sectional study reported here were to investigate the influence that SENV infection (subtypes A, B, D, and H) may exert on the biochemical hepatic features of patients affected by HIV and chronic HCV in the presence or absence of antiretroviral treatment. As a secondary objective, we also studied the associated charac