Neonatale alloimmunthrombozytopenie mit hämorrhagischer infarzierung der rechten hemisphäre

Alloimmune thrombocytopenia is the most common cause of severe thrombocytopenia (< 2000/μl) in otherwise healthy neonates. The diagnosis is usually made in the diagnostic workup of neonatal hemorrhage. If diagnosis and therapy are delayed the consequences for the affected child can be deleterious. Case report of a full-term neonate with the clinical symptoms of severe hemorrhage and hemorrhagic infarction of the right hemisphere due to neonatal alloimmune thrombocytopenia. While the plasmatic coagulation parameters were unaffected, we detected severe neonatal thrombocytopenia and anemia and identified alloimmune antibodies against the child's thrombocytes in the mother's serum. The antibodies were specific against the platelet antigen HPA-1a. Transfusion of HPA-1a-negative thrombocytes stabilized the platelet count. Anemia was treated by erythrocyte transfusion. Unfortunately, the patient exhibited, most likely intrauterine, intracranial hemorrhage and infarction of the right hemisphere, the most dreaded complication of neonatal alloimmune thrombocytopenia. The identification of severe thrombocytopenia causing the hemorrhage allowed us to start substituting thrombocytes without any delay. The previous diagnosis of alloimmune thrombocytopenia should lead to monitoring a subsequent pregnancy in a specialized unit allowing fetal blood sampling and intrauterine thrombocyte substitution if necessary. This case report exemplifies the symptoms and treatment of neonatal alloimmune thrombocytopenia. The differential diagnosis for a neonate showing clinical signs of hemorrhage should include alloimmune thrombocytopenia which can then be treated adequately. The diagnosis should also lead to careful monitoring of subsequent pregnancies.