Serum sCD14 levels are increasing during HIV-1 infection. The highest concentration of serum sCD14 is found in the AIDS patients (CDC group C, n = 41), but symptomatic non-AIDS patients (CDC group B, n = 22) and asymptomatic HIV-1-infected individuals (CDC group A, n = 29) also show increased levels of sCD14 in serum compared with controls (n = 21). Bars represent medians and 25 to 75 percentiles. Differences are highly significant (P < .001) in comparisons between all CDC groups and controls and for comparing CDC group C with groups A and B, respectively.