title: Platelet-associated immunoglobulins IgG, IgM, IgA and complement C3c in chronic idiopathic autoimmune thrombocytopenia: relation to the sequestration pattern of 111indium labelled platelets.
abstract: Levels of platelet-associated immunoglobulins (PAIg) IgG, IgM, IgA and complement C3c were related to parameters of 111Indium-labelled platelet kinetics in 17 patients with chronic idiopathic autoimmune thrombocytopenia (cAITP). Elevated levels of PAIg/C3c were found in 14 patients (82%) (PAIgG n = 13, PAIgM n = 11, PAIgA n = 1, PAC3c n = 5). Only PAIgG correlated with platelet counts (RS = -0.71, p less than 0.01). Mean platelet life span (MLS) was shortened in all patients (median 12.0 h, range 0.3-45.6 h) and correlated with the platelet counts (RS = 0.49, p less than 0.05). MLS was correlated with PAIgG (RS = -0.52, p less than 0.05), but not with PAIgM, PAIgA, or PAC3c. The site of sequestration was splenic in 10 patients and splenic-hepatic in 7 patients. Although no significant correlation between either site of platelet sequestration and any of the investigated PAIg/C3c was demonstrable, platelets coated with higher PAIgG levels were more readily sequestrated in the spleen, while elevations of PAC3c were found in 4 out of 7 patients with hepatic involvement.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000276:immunology*; D002470:Cell Survival; D002648:Child; D003176:Complement C3 / Q000276:immunology*; D015932:Complement C3c; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D008099:Liver / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D013154:Spleen / Q000503:physiopathology; D013921:Thrombocytopenia / Q000276:immunology* / Q000503:physiopathology
chemical_list: D001323:Autoantibodies; D003176:Complement C3; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D015932:Complement C3c