Objective: To evaluate the clinical usefulness of direct monoclonal antibody immobilization of platelet antigen (MAIPA) technique in the differential diagnosis of immune and non-immune thrombocytopenia.
Methods: Platelet-bound autoantibodies in thrombocytopenic patients (immune and non-immune) were measured by direct MAIPA. Monoclonal antibodies against GP II b/III a, GPIb and GP I a/II a were used.
Results: The positive rates of platelet-bound GP-specific autoantibodies between immune (76.4%) and non-immune thrombocytopenia (3.6%) were significantly different (P < 0.05). The direct MAIPA had a sensitivity of 76.4%, a specificity of 96.4%, and a positive predictive value of 97.1% for the diagnosis of immune thrombocytopenia. There was a significant inverse correlation between platelet-bound GP II b/III a specific autoantibody levels and platelet counts (r = -0.338, P < 0.05).
Conclusion: The direct MAIPA technique can be used to differentiate immune from non-immune thrombocytopenias.