COMPARISON OF 2 MEASURES OF HUMAN-IMMUNODEFICIENCY-VIRUS (HIV) TYPE-1LOAD IN HIV RISK GROUPS

Levels of viral burden were compared across risk group and gender popu lations among 485 human immunodeficiency virus type 1 (HIV-1)-infected participants consisting of 190 male injection drug users (IDUs), 92 f emale IDUs, and 203 homosexual men. Viral burden was quantified by a m icroculture technique to determine cell-associated infectious units pe r 10(6) peripheral blood mononuclear cells (IUPM) and by reverse trans criptase PCR (Amplicor) to determine plasma HIV RNA levels. Adjusting for CD4(+) cell count, females had a lower infectious HIV load than al l males combined (0.33 log(10) lower; P = 0.004), and homosexual men h ad a 0.29 log(10) higher infectious viral load than all IDUs combined (P = 0.001), For HN RNA levels, females had lower levels than males (0 .19 log(10) lower; P = 0.04), but no differences were observed by risk group. After controlling for percent CD lt cells, no differences were found by risk group for either assay, but females still had a 0.25 lo g,, lower infectious viral load than males (P = 0.04) and a viral RNA load similar to that of males (P = 0.25), The correlation between infe ctious viral load and HIV RNA load was 0.58 overall, which did not dif fer by gender or risk group, Our data suggest that differences in vira l load may exist by gender and that any differences observed by risk g roup are driven predominantly by gender or percent CD4+ cell differenc es. These data also confirm a moderate correlation between cell-associ ated infectious viral load and plasma HIV RNA load, which appears to b e similar by gender and across risk groups.