Additional Information

This is the best test for Immune (Idiopathic) Thrombocytopenic Purpura (ITP). Approximately 85% of patients with autoimmune thrombocytopenia will have platelet associated IgG, IgM or both. It is the antibody bound to the platelets which is identified; the platelets are washed and the bound antibodies are eluted. The eluate is incubated in microtiter wells coated with platelet glycoproteins llb/llla and lb/lX and la/lla. Only these glycoproteins are detected. The timing of specimen collection is important. Samples collected from patients recently transfused may reflect characteristics of the transfused platelets. It is best to wait 4 days after platelet transfusion to assure that the platelets are from the patient.