[Neonatal alloimmune thrombocytopenic purpura caused by anti-HPA-1a alloantibodies. Case report]. / Neonatalna aloimuna trombocitopenijska purpura (NATP) uzrokovana anti-HPA-1a aloprotutijelima. Prikaz bolesnika.

We report the case of serologically proven HPA-1a NATP. The child was born after uneventful 4th pregnancy. Immediately after birth generalized petechiae and signs of gastrointestinal bleeding were present. Isolated thrombocytopenia with the platelet number of 29 x 10(9)/L was observed. Serological investigation (PSIFT and MAIPA) showed high titre anti-HPA-1a antibody and low titre anti-HLA antibody in mother's sera. Mother's platelets were HPA-1a negative and she was HLA DR 52 positive. Father's platelets were HPA-1a positive. Cross-match between mother's sera and father's platelets was positive. 24 hours after the introduction of corticosteroid therapy platelet number increased to 73 x 10(9)/L and 48 hours later to 155 x 10(9)/L. The child was treated by corticosteroids because the NATP was severe and antigen negative platelets (mother or donor) or IVGG were not available. According to data from the literature the efficiency of corticosteroid therapy in NATP is questionable, but in this case it provided sufficient increase of platelet number with the stop of newborn bleeding.