Platelet autoantibodies have an impact on the platelet count in patients.

Background: It is widely accepted that autoantibodies directed against platelet glycoproteins (GP) are a major pathophysiological mechanism in immune thrombocytopenia (ITP), but little clinical data is available demonstrating an association between platelet antibodies and platelet counts.

Objectives: We hypothesized that if platelet antibodies are clinically relevant, number of targeted glycoproteins and antibody concentration should be associated with the extent of thrombocytopenia.

Methods: Platelet antibodies were identified in a direct, GP-specific test that detects antibodies against GP IIb/IIIa and GP Ib/IX.