Phagocytosis of platelets by Kupffer cells in immune thrombocytopenia.

Phagocytosis of platelets by Kupffer cells has long been suspected in immune thrombocytopenia. We describe a patient with Hodgkin's disease who also had immune thrombocytopenia. Surface localization studies with chromium 51-labeled platelets showed predominant hepatic localization of radioactivity, and the thrombocytopenia did not respond to splenectomy. Subsequent chemotherapy with immunosuppressive drugs led to remission of the thrombocytopenia. In this patient, phagocytosis of platelets by Kupffer cells was demonstrated by electron microscopy, and the degree of platelet phagocytosis in the liver was greater than in the spleen. This provides direct evidence that, at least in some cases of immune thrombocytopenia, platelets are phagocytosed by Kupffer cells.