VARIATION IN PLASMA RNA LEVELS, CD4 CELL COUNTS, AND P24 ANTIGEN LEVELS IN CLINICALLY STABLE MEN WITH HUMAN-IMMUNODEFICIENCY-VIRUS INFECTION

Short-term variability in CD4 cell counts, plasma RNA levels, and p24 antigenemia was measured in clinically stable men with human immunodef iciency virus infection. Blood samples were obtained three times in ea ch of 2 weeks 4 weeks apart. Differences between duplicate assays were considered to be due to technical factors; variation among visits was attributed to physiologic factors. Median enrollment values of CD4 ce ll counts, plasma RNA levels, and immune complex-dissociated (ICD) p24 antigenemia were 400 cells/mm(3), 3.4 log(10) copies/mL, and 38 pg/mL , respectively. Median absolute differences between duplicate CD4 cell counts, plasma RNA levels, and ICD p24 antigen were 16 cells/mm(3), 0 .21 log(10) copies/mL, and 9.3 pg/mL. Median intraindividual ranges we re 119 cells/mm(3), 0.83 log(10) copies/mL, and 18 pg/mL. Above 500 co pies/mL, plasma RNA levels have a variability of 0.5 log(10); the test is unreliable below this level.