title: Clinical significance of surface and internal pools of platelet-associated immunoglobulins in immune thrombocytopenia.
abstract: We have investigated serum platelet bindable IgG(SPBIgG) and platelet-associated IgG(PAIgG) in patients with immune thrombocytopenia (IT) to ascertain the significance of the larger amounts of PAIgG reported both in normals and in patients using homogenized (Total:T-PAIgG) instead of intact platelets (Surface:S-PAIgG). 12 patients, during active immune thrombocytopenia (A-IT), and 18 patients in steroid-induced remission (S-IT), were studied. As control we considered 20 patients with non-immune thrombocytopenia (N-IT) and 29 subjects with normal platelet count. The average positivity of SPBIgG was 41% with a higher percentage in A-IT (66%) than in S-IT (16%). The results of PAIgG also indicate a different behaviour in A-IT and S-IT of surface and cytoplasmatic pools. During A-IT both pools are enhanced with prevalence towards the surface one (S-PAIgG). On the contrary, during steroid-induced remission, despite the normal amount of the S-PAIgG present the internal pool still increases, indicating a steady-state of IT and the possible existence of a platelet phagocytic activity.
mesh_terms: D000328:Adult; D001172:Arthritis, Rheumatoid / Q000150:complications / Q000276:immunology; D001327:Autoimmune Diseases / Q000276:immunology*; D001792:Blood Platelets / Q000276:immunology*; D002648:Child; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D008180:Lupus Erythematosus, Systemic / Q000150:complications / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D011696:Purpura, Thrombocytopenic / Q000276:immunology; D011947:Receptors, Antigen, B-Cell / Q000276:immunology*; D013921:Thrombocytopenia / Q000209:etiology / Q000276:immunology*
chemical_list: D007074:Immunoglobulin G; D011947:Receptors, Antigen, B-Cell