Idiopathic thrombocytopenic purpura in patients at risk for acquired immunodeficiency syndrome. Histopathologic study, immunohistochemistry, and ultrastructural study on six spleens.

Some cases of idiopathic thrombocytopenic purpura (ITP) may be related to the prodromal phase of the acquired immunodeficiency syndrome (AIDS). The morphologic features of six spleens removed in this context were studied. In the white pulp, lymphoid follicular hyperplasia was constant but hardly distinguishable from that of control ITP on routine light microscopic grounds. Moreover, its bland appearance contrasted with the major histopathologic changes usually described in lymph node biopsy specimens from patients with AIDS-related complex. Immunohistochemistry and electron microscopy demonstrated, respectively, an excess of cytotoxic-suppressor lymphocytes with a decreased CD4/CD8 ratio in the germinal centers and viral particles of the human immunodeficiency virus. The immunohistochemical and ultrastructural studies were more helpful than light microscopy in presenting histopathologic arguments in favor of the human immunodeficiency virus infection.