Neonatal alloimmune thrombocytopenia due to anti-Nak(a)

BACKGROUND: The accurate diagnosis of neonatal alloimmune thrombocytopenia is essential in the effective treatment of potentially serious bleeding in neonates. CASE REPORT: Reported here is a case of a full-term female baby who was del ivered by Vacuum extraction from a gravida 1 pam 1 healthy mother. She pres ented with generalized petechiae and bilateral cephalhematoma, which she ha d had since birth. At 7 hours of life, she had an upper gastrointestinal he morrhage and was found to have severe anemia and marked thrombocytopenia. C oagulation screening tests were normal. The diagnosis of neonatal alloimmun e thrombocytopenia was suspected, and maternal serum was collected for furt her study. The baby was treated with a single dose of hydrocortisone (10 mg /kg) and IVIG (400 mg/kg) while waiting for irradiated platelets from her m other. After 30 mt of a transfusion of maternal platelets, the baby's plate let count rose dramatically, from 15,000 to 162,000 per muL, and it remaine d stable at that level. She was discharged on the 10th hospital day in good condition. During the follow-up period of 8 months, her growth and develop ment were satisfactorily normal, as well as her platelet count. A high-tite red platelet antibody was detected in the maternal serum by use of a solid phase platelet adherence technique. RESULTS: The specificity of the platelet antibody was identified as anti-Na k(a) by the mixed passive hemagglutination test method. CONCLUSION: These findings suggested a diagnosis of NAIT caused by anti-Nak a.