Thrombocytopenia in HIV infected patients. Prevalence and clinical spectrum.

We studied the prevalence, clinical spectrum and epidemiologic features of thrombocytopenia among 442 (333 male, 109 female) HIV infected patients. Thrombocytopenia was defined as a platelet count < 100,000/mmc and severe if platelet count was < or = 30,000/mmc. Intravenous drug abusers were 83% (369/442). At the first clinical evaluation according to Walter-Reed (WR) classification, 90% (396/442) of patients were in stage 1-5 and 10% (45/442) in stage 6. Severe thrombocytopenia (platelet count < or = 30,000/mmc) was present in 24% (11/45) of the entire thrombocytopenic population. Forty percent (18/45) of the thrombocytopenic patients were positive to: HBV (6), HCV (7), HBV+HCV (5). Mild bleeding was present in 16% (7/45) of the patients but one case, with severe thrombocytopenia, died of intracranial hemorrhage. Major hemorrhagic sequelae with even fatal events are possible, especially when a low platelet count is associated with other hemostatic abnormalities (e.g. haemophilia, liver disease, disseminated intravascular coagulation). Zidovudine therapy (range 500-1250 mg/day) is effective in normalizing the platelet count (platelets > 100,000/mmc) only in 29% (9/31) of the patients.