Abstract
Neonatal alloimmune thrombocytopenia (NAITP) is a rare and transient disease caused by maternal IgG antibodies that react against the paternally inherited antigens expressed on fetal platelets (PLT). Screening and identification of antibodies in maternal blood sample is the main support in the diagnosis of NAITP. We report 38 cases of NAITP referred over the past 5 years. Immunohematologic study on mothers involved: 1) IgG antibody screening by a solid phase red cell adherence methodology; 2) identification of offending antibody carried out by ELISA; 3) HPA 1, 2, 3, 4, 5, 6 and HLA genotype of both parents and neonates through by PCR-SSP technology. The study protocol on infants included: 1) PLT count, 2) clinical examination, 3) detection of antibodies bound to PLT, 4) ultrasound screens. NAITP was clinically suspected in 50 infants, born by first pregnancy. Only 38 maternal sera were reactive with the following specificity: 8 anti HPA-1a, 2 anti HPA-1b, 2 anti HPA-1a + HLA, 2 anti HPA-3a, 6 anti HPA-5b, 17 anti HLA, 1 auto HPA-5b. Specificity of HPA antibodies was confirmed by HPA genotype of parents. The infants with HPA-1a and HPA-1b immunization suffered from severe and symptomatic NAITP (bleeding and petechiae; PLT 7–12 x 103/ml). They were treated with transfusion of PLT compatible with the maternal alloantibody (10–20 ml/kg) and administration of high doses of intravenous immunoglobulin. On the contrary, NAITP due to HPA-3a, HPA-5b and HLA immunization was characterized by mild and self limiting thrombocytopenia (PLT 50 to 60 x 103/ml); no therapy was administered. No infant had intracranial hemorrhage. Neurodevelopmental outcome was good. Our results confirm that in the caucasian population HPA-1 (1a, 1b) polymorphism is most frequently involved in NAITP (10 out of 38 cases). Early diagnosis and adequate postnatal treatment may be successful in NAITP in the first pregnancy.
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Scarcella, A., Fratellanza, G., Scarpato, N. et al. 329 Neonatal Alloimmune Thrombocytopenia: Laboratory Findings and Clinical Management in 38 Cases. Pediatr Res 58, 411 (2005). https://doi.org/10.1203/00006450-200508000-00358
Issue Date:
DOI: https://doi.org/10.1203/00006450-200508000-00358