HIV-related thrombocytopenia: four different clinical subsets.

BACKGROUND: Many factors have been considered in the pathogenesis of HIV-related Thrombocytopenia (HIV-rel TP): immunological destruction, retroviral infection of megakaryocytes and altered reticulo-endothelial function. Nevertheless the pathogenesis is still controversial. MATERIALS AND METHODS: We reviewed 52 patients (all intravenous drug users) with HIV-rel TP (< 100 x 10(9)/L) by evaluating bone marrow morphology, antiplatelet antibodies (28/52), kinetic studies with 111In Oxine and response to therapy. RESULTS: Seventeen percent of TP were evaluated as "acute ITP-like", and 40% as "chronic ITP-like"; 35% were evaluated as "pooling" TP and 8% as "hypoplastic" TP. Twenty-four patient with moderate TP (> 30 x 10(9)/L) were followed for a mean time of 27 months and no hemorrhages were seen during the period of observation despite the fact that no treatment was given; twenty-eight others with severe TP (< 30 x 10(9)/L) were treated in different ways: 18% responded to steroids and/or HDIg, 70% to splenectomy and 56% to zidovudine. CONCLUSIONS: The term "HIV-related thrombocytopenia" should include more than one kind of TP: "Acute ITP-like" TP, "chronic ITP-like" TP, "pooling" TP and "hypoplastic" TP have to be evaluated differently for pathogenesis, clinical manifestations and treatment.

[Neuropathology of the acquired immunodeficiency syndrome]. / Neuropatologia della sindrome da immunodeficienza acquisita.

Neuropathology of acquired immunodeficiency syndrome. The Central Nervous System (CNS) has been examined at autopsy in 60 patients who died of AIDS in a 6-year period in our hospital. Most of the patients were intravenous drug abusers, the mean age was of 34 years, with a high prevalence of males. Neurologic symptoms were present in 62% of patients, while histologic lesions have been observed in 51 cases (85%). Opportunistic infections were found in 27 patients, the commonest being T. gondii (12) and Cytomegalovirus (7); Progressive Multifocal Leukoencephalopathy was observed in 2 cases. HIV-associated lesions included 21 cases of Multifocal Giant Cell Encephalitis (MGCE), 15 of Progressive Diffuse Leukoencephalopathy (PDL) and 7 cases of Vacuolar Myelopathy. Primary CNS lymphoma was noted in 8 patients and secondary deposits were observed in 3 cases. Simultaneous CNS lesions by more than one pathogen were frequently encountered. The main pathogenetic mechanisms for characterization of all the lesions and their relationship with clinical features of the disease are discussed. It is supposed that MGCE and PDL represent two different patterns of HIV-encephalopathy.