Prevalence of CCR5-tropic HIV-1 Among Treatment-Experienced Individuals in Spain

Abstract

Objective: To determine the prevalence of CCR5-tropic HIV-1 among treatment-experienced patients in Spain. Design: Epidemiologic, cross-sectional, and non-interventional study between January and June 2008 in HIV-1–infected patients in Spain. Methods: A total of 485 treatment-experienced patients from across Spainand with a plasma viral load of >1000 copies/mL were studied. Viral tropism, CD4+ cell count, plasma viral load, stage of disease, and current treatment strategies were determined. Univariate and multivariate logistic regression analyses were used to determine association of coreceptor use with patients’ characteristics. Results: Coreceptor usage was determined by viral tropism assays: 290 (68.9%) patients had CCR5-tropic HIV-1 virus, and 131 (31.1%) had dual-tropic/mixed or CXCR4 virus variants. Mean CD4+ cell counts in the R5 group (319.4 cells/mm3) were higher than in the non-R5 group (237.9 cells/mm3) (p = .0005). There was an inverse relationship between CD4+ cell counts and plasma viral load, but regression analyses on covariates associated with CCR5 tropism showed that only a higher CD4+ cell number was significantly associated with CCR5 coreceptor usage. Conclusions: The prevalence of CCR5-tropic HIV-1 among treatment-experienced patients in Spain is higher than previously found in other geographical settings. We did not find independent markers predictive of coreceptor usage other than a relationship with CD4+ levels.