Antibodies against human platelet alloantigens and human leucocyte antigen class 1 in Saudi Arabian multiparous women and multi-transfused patients.

Objectives: To determine the frequency of alloimmunization against human platelet antigens (HPAs) and human leucocyte antigen class 1 (HLA1) in multiparous women and multi-transfused patients.  

Methods: This prospective study was conducted between January and August 2013, on 50 multiparous women with no history of previous blood transfusion recruited from the Obstetrics and Gynecology Clinic, and 50 patients, who received multiple platelet transfusions, recruited from the Hematology/Oncology Ward, King Khalid University Hospital, Riyadh, Saudi Arabia.

Results: The frequency of alloimmunization among multiparous pregnant women was 76%, as follows: 16% against HLA1 only, 8% against HPAs only, 52% against both HPAs and HLA1 antigens.