title: Easy bruising, thrombocytopenia, and elevated platelet immunoglobulin G in Graves' disease and Hashimoto's thyroiditis.
abstract: Platelet IgG levels, count, and function and easy bruising or bleeding were studied in 25 patients with Graves' disease and 12 with Hashimoto's thyroiditis (normal value for platelet IgG 10.7 +/- 4.5 ng [SD]/10(6) platelets). Eight of 22 patients with Graves' disease and normal platelet counts had elevated platelet IgG averaging 38 +/- 4.0 ng (SEM) (range, 24 to 60). Four of 10 patients with Hashimoto's thyroiditis and normal platelet counts ahd elevated platelet IgG averaging 45 +/- 7.2 ng (range, 27 to 66). Five patients with thrombocytopenia had platelet counts averaging 53000 +/- 12000/microL (SEM) and elevated platelet IgG averaging 154 +/- 40 ng (range, 27 to 300). Twelve of 15 patients with a history of easy bruising or bleeding had elevated platelet IgG compared to five of 22 without easy bruising (p < 0.001). Four of six with elevated platelet IgG had one or more abnormal in-vitro platelet aggregation measurements (particularly with epinephrine) compared to none of six with normal platelet IgG levels (p = 0.03). We conclude that elevated platelet IgG is associated with easy bruising and thrombocytopenia in about half of patients with Graves' disease or Hashimoto's thyroiditis.
mesh_terms: D001778:Blood Coagulation Disorders / Q000150:complications*; D001792:Blood Platelets / Q000276:immunology; D003288:Contusions; D005260:Female; D006111:Graves Disease / Q000097:blood* / Q000150:complications; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis*; D008297:Male; D010974:Platelet Aggregation; D013921:Thrombocytopenia / Q000150:complications*; D013967:Thyroiditis, Autoimmune / Q000097:blood* / Q000150:complications
chemical_list: D007074:Immunoglobulin G