Association of syncytium-inducing phenotype of HIV-1 with CD4 cell count, viral load and sociodemographic characteristics.

Objectives: To study whether syncytium-inducing (Sl)/non-SI (NSI) phenotype of HIV-1 is associated with CD4+ lymphocyte count, plasma HIV RNA level, clinical stage and sociodemographic characteristics in antiretroviral-naive HIV-1-infected patients. Design: Cross-sectional analysis of single centre cohort study data. Methods: SI/NSI phenotype was determined using a cocultivation assay using patients' peripheral blood mononuclear cells and MT2 cells. Standard procedures were used for CD4+ cell counts and viral load measurements in plasma. Univariate and multivariate analyses of association of CD4+ cell counts, viral load, clinical stage, age, sex and mode of HIV transmission were performed. Results: In univariate analysis, SI phenotype was significantly associated with lower CD4+ cell counts, higher HIV RNA plasma levels, symptomatic HIV disease, male sex and age 32-36 years (middle tercile). In multivariate analysis, only lower CD4+ cell counts were associated with SI phenotype (odds ratio per increase of 100 x 10(6)/l, 0.54; 95% confidence interval, 0.38-0.78). Conclusions: HIV-1 SI phenotype was associated with lower CD4+ cell counts but not with higher plasma viral load, clinical stage or sociodemographic variables. (C) 1998 Lippincoit-Raven Publishers.