SERUM IL-10 LEVELS IN HIV-POSITIVE SUBJECTS - CORRELATION WITH CDC STAGES

HIV-1 infection and the HIV gp120 have been shown to induce an IL-10 i ncrease in cultured peripheral blood mononuclear cells. Furthermore, t he expression of this cytokine has been reported to increase in lymphn odes of infected patients along the disease course, and a shift from t he TH-1 towards the TH-0/TH-2 phenotypes (with subsequent In-IO releas e) has been hypothesized to underly AIDS progression. In this study th e serum IL-IO levels found in 30 HIV-negative controls and in 65 HIV-p ositive patients, untreated with AZT and negative for HBsAg and HCV-Ab have been compared, using a commercial, competitive ELISA method base d on a polyclonal anti-IL-10 serum. With this test, HIV-positive sera showed IL-10 levels significantly higher than those found in the contr ols. In addition the IL-10 levels progressively increased in the subse quent CDC stages, without further changes from the stage III to the st age IV Accordingly, patients evaluated two times in CDC stage II, with a time interval of at least one year, showed significant IL-IO increa ses even more pronounced when the same patients passed from CDC stage II to stage III. Furthermore, a significant, negative correlation was observed between the circulating IL-IO levels and the patients' CD4/CD 8 ratios. These data may be important from a clinical point of view si nce IL-10 monitoring could be considered as a surrogate marker for eva luating the disease progression. In addition, several immunological ab normalities present in HN positive patients, such as the monocyte/macr ophage impairment and the hypergammaglobulinemia could be related to t he enhanced IL-10 expression.