Red cell distribution width in patients with HIV infection

Objective: To examine the association between elevated levels of red cell distribution width (RDW) and cardiovascular risk factors (CVRF) and metabolic syndrome (MS) in HIV-patients. Methods: Cross-sectional study including all asymptomatic HIV-outpatients under follow-up during 2007. Patients completed a questionnaire about CVRF, underwent a physical examination, and an 8-hour fasting blood analysis. Elevated RDW was defined as ≥75th percentile. Patients with and without an elevated RDW were compared. Results: 666 patients (79.3% men) were included: mean age 44.7 years, mean CD4 506/mm3 and 87.5% on antiretroviral therapy (85.3% with undetectable viral load). Mean RDW was 13.7% (range: 7.7% - 33.6%;75th percentile, 14.1%). The prevalence per quartile of MS was 15.7%, 9.3%, 18.8% and 16.6% and of patients with CVRF > 20% was 8.4%, 4.0%, 4.4%, and 6.4%, respectively (p > 0.05);23.4% of the patients had an elevated RDW (>14.1%). The top percentile of RDW was associated with AIDS (OR 1.6;95% CI, 1.0 - 2.4;p = 0.02), detectable viral load (OR 1.5;95% CI, 1.01 - 2.4;p = 0.04) and hypertension (OR 2.3;95% CI, 1.4 - 4.0;p = 0.001). Conclusions: In HIV-outpatients, higher RDW is related with detectable viral load and with AIDS. Although it was associated with hypertension, we found no relation with MS nor with higher cardiovascular risk.

Whole blood platelet aggregometry in HIV-infected patients on treatment with abacavir

Purpose: To assess platelet activity in HIV-patients with and without antiretroviral therapy (ART), analysing the influence of the presence or absence of ABC in the regimen. Methods: Observational, pilot study, including 30 asymptomatic HIV-patients: 20 on ART for at least 24 weeks and with undetectable HIV viral load - 10 on ABC, 10 on tenofovir (TDF) - and 10 na?ve patients, and a control group of 10 HIV-negative subjects. No subject was receiving drugs with antiagregant activity. Platelet activity was assessed by measuring time-dependent platelet aggregometry (electrical impedance on fasting whole blood), induced by ADP (1.25, 2.5 μM), collagen (0.5, 1 μg/mL), arachidonic acid (100, 200 μM), and U46619 (receptor agonist of the tromboxano A2) (1.25, 2.5 μM). Statistic program: SPSS, 16.0. Results: Demographic, anthropometric data, and cardiovascular risk factors were similar in all groups, but older age and longer time of HIV infection in the ABC group (50.4 vs 36.1, 34.2 and 42.7 years, respectively;p < 0.05, and 140.3 vs 88.1 and 48.3 months in the two other groups of HIV patients;p < 0.05). Mean CD4 cells count was 564/mm3. Platelet aggregation with exposure to U46619 was higher in the ABC compared with the TDF group (11.1 vs 4.4%;p = 0.007), na?ve patients (11.1 vs 5.7%;p = 0.014), and the HIV-negative group (11.1 vs 6.5%;p = 0.04). These differences remained significant when controlled for age and time of HIV infection. Conclusions: ABC increases platelet aggregability possibly in relation with the receptor of tromboxano. Wider studies are needed to confirm this hypothesis.