[Neonatal alloimmune thrombocytopenia in Croatia in 1997-2007]

Neonatal alloimmune thrombocytopenia (NATP) is caused by maternal sensitization to paternal alloantigens on fetal platelets during pregnancy. Although the disease is rare, the severity of clinical picture and its sequels associated with central nervous system hemorrhage impose the need of an early diagnosis, and timely and specific treatment of the disease. Based on these and literature data on the prevalence of NATP in Caucasians of 1-2 cases per 1000-5000 live births, it is estimated that 10 to 50 serologically verified cases of NATP and approximately a twofold number of requests for serologic testing for suspected NATP could be expected in Croatia per year. In the present study, results of serology testing and clinical laboratory data of twenty five cases of NATP in Croatia during the 1997-2007 period are evaluated. In 20/25 cases platelet antibody screening was positive. Specific platelet antibodies were confirmed in 14/20 (70%) cases with positive screening (anti-HPA-la in 7/14, anti-HPA-5b in 5/14, and anti GP Ib-IX in 2/14 cases). Only fourteen serologically confirmed cases of NATP per -45,000 live births per year in Croatia indicate the prevalence of the disease to be considerably lower than expected.