ANTIPLATELET GRANULE MEMBRANE-PROTEIN (GMP-140) AUTOANTIBODIES DETECTED IN PLASMA FROM PATIENTS WITH IDIOPATHIC THROMBOCYTOPENIC PURPURA

Plasma from 92 patients with idiopathic thrombocytopenic purpura (ITP) was tested for autoantibodies against granule membrane protein 140 (G MP-140) using an antigen specific immunoassay. Results showed that aut oantibodies to GMP-140 existed in 17 of these patients (18.5%). Incuba tion of patient plasma with purified GMP-140, immobilized on nitrocell ulose strips by SDS-PAGE and Western blotting, revealed a staining ban d at the level of GMP-140 in two of 8 plasmas. Autoantibodies to GMP-1 40 often coexisted with other autoantibodies, in particular towards GP Ib/IX (3 cases), GP IIb-IIIa (5 cases) or both (3 cases). This study provides direct evidence for the presence of anti-platelet GMP-140 aut oantibodies in some patients with ITP.