| Abstract: | Background: Although most HIV-1 infections in Brazil are due to subtypeB, Southern Brazil has a high prevalence of subtype C and recombinant forms, such asCRF31_BC. This study assessed the impact of viral diversity on clinical progressionin a cohort of newly diagnosed HIV-positive patients.Methods: From July/2004 to December/2005, 135 HIV-infected patients wererecruited. The partial pol region was subtyped by phylogeny. Ageneralized estimating equation (GEE) model was used to examine the relationshipbetween viral subtype, CD4+ T cell count and viral load levels before antiretroviraltherapy. Hazard ratio (Cox regression) was used to evaluate factors associated withviral suppression (viral load < 50 copies/mL at six months).Results: Main HIV-1 subtypes included B (29.4%), C (28.2%), and CRF31_BC(23.5%). Subtypes B and C showed a similar trend in CD4+ T cell decline. Comparisonof non-B (C and CRF31_BC) and B subtypes revealed no significant difference in theproportion of patients with viral suppression at six months (week 24). Higher CD4+ Tcell count and lower viral load were independently associated with viralsuppression.Conclusion: No significant differences were found between subtypes;however, lower viral load and higher CD4+ T cell count before therapy were associatedwith better response. |
