Objective: To investigate a specific and sensitive assay for the diagnosis of autoimmune thrombocytopenic purpura (AITP).
Methods: Glycoprotein specific autoantibodies in platelet eluate and plasma were detected by a modified monoclonal antibody immobilization of platelet antigens assay (MAIPA).
Results: The overall positive rate of specific autoantibodies against platelet GPIIb/IIIa and GPIb/IX in plasma was 38.89% and in eluated platelet membrane was 68.52%. The difference between them was significant (corrected chi(2) = 19.39, P < 0.005). The proportion of positive MAIPA results between primary AITP and secondary AITP was not significantly different. There was a significant inverse correlation between antibody level and platelet count.
Conclusion: Detection of eluated GP-specific autoantibodies by MAIPA is highly specific and much more sensitive as compared with the measurement of their plasma counterparts in the diagnosing and therapeutic monitoring of AITP.