Methods

before their second cohort visit (group B). In group A, predictors for low initial CD4 cell counts were examined with a median regression. In group B, we studied predictors for CD4o200 cells/mL without ART despite cohort follow-up. Results Median initial CD4 cell count in group A was 331 cells/mL; 31 % and 10 % wereo200 ando50 cells/mL, respectively. Risk factors for low CD4 count were age and non-White race. Homosexual transmission, intravenous drug use and living alone were protective. In group B, 30 % initiated ART with CD4 200 cells/mL; 18 % and 2 % dropped to CD4 o200 and o50 cells/mL without ART, respectively. Sub-Saharan origin was associated with lower probability of CD4 o200 cells/mL without ART during follow-up. Median CD4 count at ART initiation was 207 and 253 cells/mL in groups A and B, respectively. Conclusions CD4o200 cells/mL and, particularly, CD4o50 cells/mL before starting ART are predominantly cause