[Bone marrow biopsy in HIV-positive patients with thrombocytopenia. Light and electron microscopy].

: Isolated thrombocytopenia (platelets less than 100,000 mmc) may be the first clinical symptom in HIV positive patients or occur in all the evolutive phases up to overt AIDS. In this paper bone marrow lesions are evaluated at light and electron microscopy in 32 HIV positive patients with isolated thrombocytopenia (group II and III CDC 1986). At light microscopy an increase in megakaryocytes with small dysplastic changes, plasmacytosis and hypereosinophilia were the bone marrow lesions detected. Electron microscoy revealed megakaryocytes with focal nuclear alterations (hypolobation and dilatation of the perinuclear cisternae) and abnormalities in the maturation of platelets associated with cytoplasmic micro-macrovacuolation, absence of viral particles or of virus correlated structures. About 9% of HIV positive patients presented with isolated thrombocytopenia as a first clinical symptom: thrombocytopenia is not believed to have unfavourable prognostic significance in the evolution to overt AIDS.