Co-Infection by HTLV-I/II is Associated With Increased Viral Load in PBMC of HIV-1 Infected Patients in Bahia, Brazil

To evaluate the viral load in peripheral blood mononucler cells (PBMC) of patients infected by HIV-1 we performed 96 quantitative cultures in 74 patients infected by HIV-1, using the co-culture method. The viral load was expressed in tissue culture infectious doses (TCID), and the results were analyzed according to gender, age and clinical stage of patients, duration of previous antiretroviral therapy, detectable p24 antigenemia, CD4(+)/CD8(+) cell counts, co-infection by HTLV-I/II and viral subtype. We detected a statistically significant association between co-infection by HTLV-I/II and viral load higher than >50 TCID (p=0.003). We also found a significant association between co-infection by HTLV-I/II and p24 antigenemia (p=0.028). CD4(+) cell counts were significantly higher for patients presenting negative cultures, but there was no detectable association between lower CD4(+) cell counts and higher TCID. The majority of patients were infected by subtype B virus. The observation in this study that co-infection with HTLV-I/II was significantly associated with higher viral load raises the possibility that these agents act as co-factors of AIDS progression, in doubly-infected patients.