Case records of the Massachusetts General Hospital. Weekly clinicopathological exercises. Case 39-1978

Successful therapy of sarcoidosis-associated thrombocytopenia refractory to corticosteroids by a single course of human gammaglobulins

Thrombocytopenia developed in a 21-year-old patient with sarcoidosis when corticosteroid therapy was discontinued. Platelet-associated IgGs were elevated. High-dose cortisone did not affect the thrombocytopenia. However, platelet counts remained normal for more than 1.5 years following intravenous treatment with a single course of human gammaglobulins.

Autoimmune thrombocytopenia in sarcoidosis

Severe thrombocytopenia and splenomegaly developed in a young man with sarcoidosis. Platelet-associated immunoglobulin (IgG) was strongly positive, and platelet survival studies revealed a half-life of five and a half hours. Treatment with prednisone and vincristine led to a rise in the platelet count to 100,000/mm3 after two months with no change in the splenomegaly. Five months later, when the platelet count was normal, the level of platelet-associated IgG had fallen to normal. Repeated platelet survival studies showed an initial half-life of three hours with a second half-life of two days, associated with accumulation in the spleen. Although there was evidence for splenic sequestration of platelets, the dominant mechanism of thrombocytopenia appeared to be antibody-mediated destruction, analogous to that seen in idiopathic autoimmune thrombocytopenic purpura and responsive to immunosuppressive therapy.