Alessia Uglietti

Emerging mutations at virological failure of HAART combinations containing tenofovir and lamivudine or emtricitabine.

Objective:To compare the emergence of drug-resistant HIV variants at failure of lamivudine (3TC)/tenofovir (TDF)-containing or emtricitabine (FTC)/TDF-containing HAART as a consequence of the different 3TC and FTC intracellular half-lives. Design:Retrospective evaluation of 859 patients selected from an Italian HIV resistance database (Antiretroviral Resistance Cohort Analysis). Methods:Patients were selected for analysis if treated with a HAART whose nucleoside/nucleotide reverse transcriptase inhibitor backbone was either 3TC/TDF or FTC/TDF; if they experienced a virological failure after at least 6 months of plasma HIV-RNA undetectability; and if HIV genotypes before treatment and at failure were available. Univariate and multivariate logistic regression analyses were done to detect predictors of resistance mutations emerging at failure. Results:Of 714 patients failing with 3TC/TDF and 145 with FTC/TDF, 35.8 and 21.1% were in Centers for Disease Control and Prevention stage C, and 8.8 and 15.2% were on first-line HAART, respectively. At multivariate analysis, the emergence of K70R (P = 0.002), M184V (P = 0.031), T215F (P = 0.020) and Y181C (P = 0.005) was significantly more common in 3TC-treated than in FTC-treated patients, with an odds ratio of 4, 1.56, 1.89 and 3.84, respectively. Conclusion:Despite their close structural similarity, 3TC and FTC are associated with a significantly different rate of drug resistance at treatment failure when combined with TDF in HAART regimens independently of the third drug used.

Under Representation of the Inhibitory KIR3DL1 Molecule and the KIR3DL1+/BW4+ Complex in HIV Exposed Seronegative Individuals

The activation of natural killer (NK) cells is modulated by surface molecules. We analyzed NK cells in human immunodeficiency virus (HIV)-exposed seronegative (HESN) individuals by means of molecular typing of HLA B, Cw, and killer cell immunoglobulin-like receptor (KIR) molecules. In HESN individuals, compared with HIV patients, the frequency of the inhibitory KIR3DL1 allele and of the KIR3DL1(+)/Bw4(+) inhibitory complex was reduced, whereas that of the activatory KIR3DS1(+) ligand and the activatory Bw4(+)/3DL1(-)/3DS1(+) complex was increased, resulting in a statistically significant diversion from Hardy-Weinberg equilibrium (KIR3DS1 homozygote) in HESN individuals. The reciprocal equilibrium between inhibitory and activatory NK receptors and their ligands favors NK activation in HESN individuals.

KIR-HLA genotypes in HIV-infected patients lacking immunological recovery despite effective antiretroviral therapy

Background In HIV-infected individuals, mechanisms underlying unsatisfactory immune recovery during effective combination antiretroviral therapy (cART) have yet to be fully understood. We investigated whether polymorphism of genes encoding immune-regulating molecules, such as killer immunoglobulin-like receptors (KIR) and their ligands class I human leukocyte antigen (HLA), could influence immunological response to cART. Methods KIR and HLA frequencies were analyzed in 154 HIV-infected and cART-treated patients with undetectable viral load divided into two groups: ‘immunological non responders’ (INR, N = 50, CD4+ T-cell count <200/mm3) and full responders (FR, N = 104, CD4+ T-cell count >350/mm3). Molecular KIR were typed using polymerase chain reaction-based genotyping. Comparisons were adjusted for baseline patient characteristics. Results The frequency of KIR2DL3 allele was significantly higher in FR than in INR (83.7% vs. 62%, P = 0.005). The functional compound genotype HLA-C1+/KIR2DL3+, even at multivariable analysis, when adjusted for nadir CD4+ T-cell count, was associated with reduced risk of INR status: odds ratio (95% Confidence Intervals) 0.34 (0.13−0.88), P = 0.03. Conclusions Reduced presence of the inhibitory KIR2DL3 genotype detected in INR might provoke an imbalance in NK function, possibly leading to increased immune activation, impaired killing of latently infected cells, and higher proviral burden. These factors would hinder full immune recovery during therapy.

Comparison of glomerular filtration rate estimates vs. 24-h creatinine clearance in HIV-positive patients

Guidelines for kidney function monitoring and antiretroviral drug dosing are available and respectively refer to glomerular filtration rate and creatinine clearance (CrCl).

HIV education and counselling using Facebook: a possible new approach

Almost one third of individuals infected with HIV do not enter health care until late in the course of their infection. This phenomenon, called late presentation, is characterized by individuals who discover their seropositivity when in need of highly active antiretroviral therapy or with an AIDS-defining illness. Late presentation is a major concern, since it is harmful to the infected person and to society as a whole, and it is very costly. Its prevalence ranges from 10% to 45% in Europe. Raising awareness in the general population is crucial and the Internet may be a new way of developing educational and counselling strategies. Social networking sites, such as Facebook, Twitter and MySpace, are well-known Web 2.0 applications (i.e. web sites whose content is mostly driven by the users). Most online information services concerning STDs or HIV operate with a Web 1.0 approach (i.e. information provided by the publisher, with a unidirectional stream). Shifting to Web 2.0 social networking sites may increase the effectiveness of prevention messages. We conducted a multi-centre, prospective communicative intervention involving seven physicians with expertise in infectious diseases (termed “researchers” in what follows) who created their profile on Facebook. It was carried out from December 2009 to May 2010. The researchers created a real profile, which included photographs, lists of interests, contact details and other personal information. They used Facebook like everyone does and had conversations about their personal lives, experiences, emotions and feelings. Chatter concerning STDs and HIV topics were collected as professional messages. The researchers spent at least four hours every week on updating their profiles. They aimed to post replies within one week. We conducted a study in two phases: the first was based on a targeted operation model and was held on Facebook. The objective of this phase was to increase the debate about STDs/HIV. We chose the number of friends and the number of questions that were raised as measures of debate. The target audience was the whole population who use Facebook: neither limitations nor exclusion criteria were defined for the choice of friends, in an attempt to use the social network just as in everyday life. To stimulate the debate, researchers posted messages, links and videos related to STDs/HIV (i.e. video clips from the HIVisible Contest held in Cologne in 2009, or from movies and songs with an AIDS theme; references to newspapers or magazines articles; commentaries to the national campaign launched for the World AIDS day of 2009 or to the Pope’s statements against condom use in Africa). The number of replies was counted by each researcher. Demographic features of friends were collected from their personal pages. The evaluation was through outcome measures. The study was designed to quantify the performance from the user perspective and to measure only the rate of query submission. We are not aware of any previous similar work, so the parameters for measurement were extrapolated from other studies on non-web social networks. The effectiveness of recruitment was measured by the Network Index (the ratio between the number of friends and the number of researchers). The number of questions about STDs/HIV was measured by the Performance Index, a parameter set by analogy with the Network Index, and defined as the ratio between number of messages and the number of researchers. The second phase was based on an open operation model and was held on the official site of the Italian Society of Infectious and Tropical Diseases (SIMIT). The objective of this phase was to analyse the questions and the debates that would develop from the inputs posted by researchers. Topics that needed longer explanation or that were perceived as too personal, were directed from Facebook to specific forums on the SIMIT web site. Technical questions (e.g. concerning new drugs or drug toxicities) were directed to the Expert Online forum, where an Italian physician experienced in the matter would answer. Personal questions (e.g. about risky behaviours or condom use) were directed to a public forum, where the adoption of a nickname could guarantee anonymity. Details about how to log into these forums were explained on the personal pages of the researchers. The researchers were also the coordinators of these forums. During the study period, the number of friends reached 625; demographic features are summarized in Table 1. However, the objective of stimulating debate was not realised. The baseline Network Index was 66 and it increased to a value of 89 at the end of the study. Even though the number of friends increased by 35%, their features reflected mainly those of the researchers, i.e. young women from northern Italy, graduates, who were frequently working in health care as doctors or nurses. Despite the large number of professional postings, professional messages were few and none was followed by a specific debate on the SIMIT forums. The Performance Index was 46 for the personal (private) messages, while it was only three for the professional messages. It was not possible to categorize these messages, because of their small number. Thus the second objective of our study was not realised either. The disappointing outcome of the work is due to some limits inherent in Facebook and to the study design. First, Facebook communication is often a manipulation of the personal virtual image with projections of “Self”, i.e. users sometimes do not write what really happens to them, but manipulate their life experiences to seem nicer, funnier and more appealing. This could lead to unreliable discussions on matters where their image could appear fragile, as in the

Emtricitabine/tenofovir in the treatment of HIV infection: current PK/PD evaluation

Introduction: Emtricitabine/tenofovir disoproxil fumarate fixed-dose combination (FTC/TDF FDC) is the co-formulation of a nucleoside and a nucleotide, respectively. After oral administration, both drugs exhibit plasma and intracellular half-lives suitable for once-daily dosing. Within the host cells, active metabolites FTC-TP and TFV-DP act as chain terminators to the newly synthesized proviral DNA, showing synergy at enzymatic level (viral reverse transcriptase). When given in HAART combinations, FTC/TDF FDC has a remarkable effectiveness in controlling HIV replication and securing a significant CD4+ cell recovery. If patients treated with FTC/TDF FDC fail, a lower incidence of TDF-associated K65R resistance mutation seems to develop. Furthermore, cytidine analog-associated M184V is less likely to appear with FTC than with lamivudine when both are given with TDF. FTC and TFV are not metabolized by CYP450 enzymes and are eliminated by the renal route. TFV may accumulate in tubular cells and cause a decrease in GFR and a loss of phosphates. As a onsequence, patients treated with FTC/TDF FCD may experience varied degrees of renal impairment and osteopenia/osteoporosis. Areas covered: This paper has focused on the PK/PD features of FTC and TDF, when given as single agent or when administered as FDC. The interpretation of efficacy/toxicity was guided by PK/PD features. The review of the available literature included also conference presentations and recent guidelines (as of May 2012). Expert opinion: FTC/TDF FDC is a potent and reliable component of most HAART combinations due to its maintained activity across time, as demonstrated in many trials and studies. Toxicity issues (kidney, bone) are still to be entirely elucidated and the drug-induced component well separated from patient- and HIV-related ones. However, the clinical gain associated with the use of FTC/TDF FDC is fully acknowledged by its leading position in most current treatment guidelines.

Correlations between atazanavir Ctrough and hyperbilirubinemia: a case report

IntroductionHyperbilirubinemia is a common side effect of the antiretroviral agent atazanavir but is generally reversible upon discontinuation of treatment. We used therapeutic drug monitoring to investigate the occurrence of hyperbilirubinemia in a 49-year-old Hispanic man infected with HIV, following an overdose of ritonavir in ritonavir-boosted atazanavir therapy.Case presentationA 49-year-old Hispanic man with HIV who had received several highly active antiretroviral therapy regimens over a number of years including atazanavir-containing regimens, was diagnosed with hyperbilirubinemia. An inappropriate doubling of ritonavir boosting resulted in a high atazanavir Ctrough and an initial rise in bilirubin plasma levels. Bilirubin levels later decreased, probably as a consequence of enzyme induction, while atazanavir plasma concentrations remained elevated.ConclusionThis article describes an occurrence of hyperbilirubinemia in a man infected with HIV and supports the importance of therapeutic drug monitoring in investigations of hyperbilirubinemia among patients receiving antiretroviral agents. That the patient tolerated exceptionally high atazanavir levels further strengthens the tolerability profile of this drug.

Comparability of echographic and tomographic assessments of body fat changes related to the HIV associated adipose redistribution syndrome (HARS) in antiretroviral treated patients.

To assess the comparability of ultrasonographic (US) subcutaneous fat thickness (SFT) measurements in comparison with computed tomography (CT) at reference points (RPs) representative of HIV related adipose redistribution syndrome (HARS) in patients treated with antiretrovirals. US and CT measurements were compared in nine patients with clinical reports of HARS. We obtained the best resolution of facial (at deepest point of Bichat pad), brachial (in the dorsal face of arm) and crural SFT (at mid thigh) by means of minimal transducer pressures avoiding potential biases such as stand off pads pressure on the skin and artefacts due to too abundant quantity of gel. CT scans were obtained in the same RP where US measurements were performed such as identified by means of metallic skin markers. Median US measurement of facial SFT was 8.8 mm (95% CI: 3.1 to 13.4), 3.95 mm (95% CI: 2.62 to 5.84) for brachial SFT and 4 mm (95% CI: 3.4 to 9.4) for crural SFT. Median CT assessments of facial SFT was 8.7 mm (95% CI: 3.5 to 13.5), 4.2 mm (95% CI: 2.6 to 5.88) for brachial SFT and 5 mm (95% CI: 3.9 to 10.3) for crural SFT, with no significant difference at each RP. A linear regression showed good CT/US comparability at each RP, with no significant deviation from linearity (p > 0.10). US shows to be highly comparable with CT, excluding invaliding biases as the transducer pressure on the skin. Given the proven efficacy on the HARS assessments, if well standardized, US could be a reliable method, simpler than CT in the management of body fat changes related to HARS.

Nelfinavir+M8 Plasma Levels Determined with an ELISA Test in HIV Infected Patients with or without HCV and/or HBV Coinfection: The VIRAKINETICS II Study

Virakinetics II was designed as an observational, multicenter cohort study conducted in HIV-positive patients treated with NFV-based combinations. Trough (pre-dose) concentrations of NFV+M8 in plasma were determined using a novel ELISA test (NFV TDM-ELISA) and analyzed using clinical and laboratory parameters. Drug levels were sorted as below, within or above a given interval (<0.8 microg/mL, 0.8-3.5 microg/mL and >3.5 microg/mL, respectively). Longitudinal analysis was performed in a subset of patients who underwent two or more determinations. Ninety patients on NFV-containing HAART were enrolled and 43 were coinfected with HCV and/or HBV. Among coinfected patients, 10 subjects had a clinical or histological diagnosis of cirrhosis. Compared to the HIV-monoinfected, the coinfected patients were significantly older, more treatment-experienced, with higher frequency of lipodystrophy and altered liver function test values (all p values: <0.05). Coinfected patients were also more likely to be on a reduced dose of NFV than monoinfected (p=0.03). No significant difference was observed between the two groups with regard to NFV+M8 trough values and concentration range distribution. Median NFV+M8 C(trough) concentrations were higher in coinfected patients, but without reaching statistical significance (p=0.2). This new ELISA test proved to be a rapid, convenient and reliable tool for assessing NFV+M8 plasma levels in HIV-positive patients. It could be suitable for use within the framework of routine clinical practice even in peripheral centers without specialized laboratories.

Proven Intra and Interobserver Reliability in the Echographic Assessments of Body Fat Changes Related to HIV Associated Adipose Redistribution Syndrome (HARS)

OBJECTIVE To prove intra- and inter-observers reliability of ultrasound (US) in the assessment of lipoatrophic findings related to the HIV associated Adipose Redistribution Syndrome (HARS). PATIENTS AND METHODS In two separated sessions, 2 consecutive measurements of subcutaneous fat thickness (SFT) were performed by each observer at the deepest point of Bichat pad, the dorsal face of arm and the mid thigh for the assessment of facial, brachial and crural lipoatrophy, respectively. We enrolled 20 HIV patients, rotating an experienced and untrained sonologist. The assessments were performed avoiding any stand off pads in the skin and excluding artefacts due to the too abundant quantity of gel to obtaining, with minimal transducer pressure, the best resolution of the reference points. RESULTS Means of facial, brachial and crural SFT showed no significant differences between the workers. Coefficients of variability (SD/mean x100) were similar for facial (ranges: 4.7-5.2% vs 4.9-5.6%, respectively), brachial (ranges: 5.8-8.4% vs 9.7-11.2%) and crural SFTs (ranges: 5.9-6% vs 6.2-8.7%). There was greater consistency in the measurements performed by the experienced vs the untrained worker. Inter-observer agreement, assessed through kappa statistic (k) analysis, confirmed increased measurements agreement in the facial (k ranged from 0.40 to 0.60), brachial (k: 0.23-0.63) and crural SFT assessments (k: 0.58-0.70) from the 1(st) to 2(nd) session. CONCLUSIONS US shows low intra observer variability and good inter observer reliability in the assessment of body fat changes related to the HARS. The different degree of consistency by the workers and the improvement of interobserver agreement, suggest to stating a well defined period of training to obtain better US reliability.