HEAVY-CHAIN SUBCLASS OF BOUND ANTI-PLATELET IGG IN AUTOIMMUNE THROMBOCYTOPENIC PURPURA

  • 1 January 1980
    • journal article
    • research article
    • Vol. 56 (1), 84-87
Abstract
H-chain subclass of bound antiplatelet antibody was examined in 6 patients with autoimmune thrombocytopenic purpura (ATCP) by a solid-phase radioimmunoassay. Monospecific antisera for .gamma.G1, .gamma.G2, .gamma.G3 and .gamma.G4 subclasses were employed in a sandwich technique, utilizing the binding of 125I-staphylococcal protein A. Serum antiplatelet antibody was restricted to the .gamma.G3 subclass in ATCP. In contrast, all 4 Ig[immunoglobulin]G subclasses bound to platelets of ATCP patients in the same distribution as that present in normal serum. The differences noted between serum antiplatelet IgG and platelet-bound IgG may represent different mechanisms of platelet injury.