OBJECTIVETo explore the diagnosis and treatment of a case of neonatal alloimmune thrombocytopenia purpura (NAITP) caused by anti HPA-3a antibody.

METHODSThe platelet counts and purpuric symptom in the newborn were clinical examined. The HPA-1-21bw genotypes of the newborn and his parents were detected by multiple DNA-PCR, gene sequencing and genotyping. The HPA specificity antibody in the sera of newborn and his mother were detected by flow cytometry (FCM), and the HPA specificity antibody was identified by monoclonal antibody-specific immobilization of platelet antigens (MAIPA).

RESULTSThe newborn had the typical symptom of NAITP, multiple subcutaneous petechia, hematuria and coffee-like vomitus. The HPA genotype of the newborn was HPA-3ab, while that of his mother and his father were HPA-3bb and HPA-3aa, respectively. The sera of newborn and his mother existed antibody against the platelet of newborn's father. The HPA antibody of the newborn and his mother were identified as anti HPA-3a. The newborn was approved a patient of NAITP caused by anti HPA-3a antibody.

CONCLUSIONThe diagnosis and treatment for NAITP newborn caused by anti HPA-3a antibody in this study was the first domestic report. It could provide successful experiences and references for the similar cases.