Ultrastructural changes in platelet aggregates of HIV patients: a scanning electron microscopy study.

Several hematological abnormalities associated with HIV have been documented, but the mechanisms responsible for the cytopenias in AIDS patients are complex and not always completely understood. Thrombocytopenia, which occurs in about 40% of patients with HIV infection, may be caused by increased peripheral platelet destruction, a defect in platelet production due to the impaired formation of platelets by HIV-infected magakaryocytes, or a combination of these. The aim of this study was to compare the morphology of the platelet aggregates in platelet-rich plasma (PRP) clots prepared from HIV patients with those of controls without HIV. These platelet aggregates were studied using the scanning electron microscope to determine the effect of the virus on platelet ultrastructure. The results showed that although the platelets do aggregate, the morphology was changed with membrane blebbing as well as torn cellular membranes. Membrane blebbing is typically associated with apoptosis. It is concluded that the altered morphology of platelet aggregates in HIV patients may be related to thrombocytopenia as a result of peripheral platelet destruction.