The relative incidence of idiopathic and secondary autoimmune thrombocytopenia: a clinical and serological evaluation in 508 patients.
Abnormally elevated levels of platelet-associated immunoglobulins were detected in 508 patients with the clinical and haematological criteria of autoimmune thrombocytopenia (AITP). In 246 patients (48.4%), thrombocytopenia was accompanied by a variety of disease entities, the most commonly associated being autoimmune disorders (21.0%) and lymphoproliferative diseases (14.8%). This group was classified as 'secondary' AITP. There was a female preponderance in both the idiopathic and secondary AITP's and peak age incidences were identified in the 3rd-4th decades and in the 7th-8th decades of life. In 253 patients, only platelet-associated IgG (PAIgG) was quantitated; there being insufficient material for further study. Both platelet associated immunoglobulins (PAIgG and PAIgM) were measured in the remaining 255 patients. When both parameters were quantitated, elevated PAIgM was seen slightly more frequently in the idiopathic group, in contrast to the secondary AITP's when PAIgG was seen more frequently abnormal. Both parameters were found most commonly elevated together in patients with systemic lupus erythematosus (SLE) and in those in whom thrombocytopenia was induced by drug intake or preceding viral illness. PAIgG and PAIgM were quantitated by modification of a previously described enzyme-linked immunoassay (Hegde et al. 1981).
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001327:Autoimmune Diseases / Q000150:complications*; D001792:Blood Platelets / Q000276:immunology; D002648:Child; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D008232:Lymphoproliferative Disorders / Q000150:complications; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D012737:Sex Factors; D013921:Thrombocytopenia / Q000139:chemically induced / Q000209:etiology*; D014777:Virus Diseases / Q000150:complications
D007074:Immunoglobulin G; D007075:Immunoglobulin M