CLINICAL-SIGNIFICANCE OF PLATELET-ASSOCIATED IMMUNOGLOBULINS IN NARCOTIC ADDICTS WITH HUMAN-IMMUNODEFICIENCY-VIRUS INFECTION

Increased amounts of platelet-associated immunoglobulin G (PAIgG) have been reported in human immunodeficiency virus (HIV)-infected patients with thrombocytopenia. We have prospectively investigated PAIgG in 21 asymptomatic (group A; CDC stages IIA-IIB) and 9 symptomatic (group B; CDC stages IIIB-IV) HIV-infected narcotic addicts. In both groups only two subjects presented with a decreased platelet count. By competitive ELISA, we found a 1.8- and 2.3-fold greater total PAIgG (PAIgGtot) as measured on platelet lysates in group A and B, respectively; surface-bound IgG (PAIgGsurf) as measured on intact platelets was 2.5- and 3.0-fold greater in groups A and B, respectively, as compared to 36 controls. The ratio between PAIgGtot and PAIgGsurf was lower in HIV-infected addicts when compared to controls (P < 0.05). This indicates that platelets from HIV-infected subjects not only have increased surface and internal pools of PAIgG, but also present with a distribution between these two pools that differs from that of normal platelets. In addition, levels of circulating immune complexes (CIC) were abnormally raised in 17 21 (81%) subjects of group A in 6 9 (66%) subjects of group B. © 1990.