Increased soluble CD14 serum levels and altered CD14 expression of peripheral blood monocytes in HIV-infected patients

Abstract

SUMMARY Serum levels of soluble CD14 were elevated in HIV-infected asymptomatic patients or those with lymphadenopathy (CDC II/III) 2·9 ± 0·8mg/l compared with normal controls with 2·2 ± 0·47 mg/l P < 0·001. A further rise was seen in patients with ARC (CDCIVA) 3·8±1·1 mg/l, P < 0.01 and patients with AIDS (CDC IVB D) 5·7 ±2·5 mg/l. P < 001. Although absolute numbers of CD14+ cells decrease in the AIDS group, the percentage of CD 14+ monocytes did not change. In contrast, levels of soluble T cell antigens sCD4 and sCD8, which are higher in HIV-infected patients compared with normal subjects, showed no increase with disease progression. Serum levels of sCD14 were correlated positively with β2-microglobulin levels (rs= 0·63, P < 0.0001). Whereas the percentage of CD14+ monocytes did not change, an increase in monocytic CD14 expression in HIV-infected patients was observed (P < 0.01). The percentage of a monocyte subset expressing both CD14 and CD16 increased from 6% in normal healthy persons to 13% in HIV-infected patients (P < 0·001), and did not vary between the HIV patient groups. Incubation of cultured peripheral blood monocytes with azidothymidine had no effect on either normal or EPS-induced or IE-4-inhibited sCDI4 release in vitro. Therefore, an effect of AZT on sCD14 serum values in vivo is considered to be unlikely. Our data further provide evidence that monocytes/macrophages are engaged in HIV infection.