A Case of Neonatal Alloimmune Thrombocytopenia Associated with anti-HPA-4b Antibody in an Infant Delivered from a Mother with Gestational Thrombocytopenia

Abstract

A male infant was transferred to our neonatal intensive care unit (NICU) on the first day of life because of thrombocytopenia of the cord-blood sample. His mother had developed thrombocytopenia at a gestational age of 28 weeks and 5 days, and her platelet counts were around 10 × 10⁴/μl thereafter. However, her platelet count spontaneously recovered after the delivery. The blood examination of the infant on admission showed thrombocytopenia of 4.4 × 10⁴/μl. The serum from the mother contained an antibody that reacted with the infant and his father's platelets. An anti-HPA-4b antibody was found in the mother's serum. Infants who are borne from a mother who has exhibited thrombocytopenia during her pregnancy, might also develop thrombocytopenia, which could be a possible cause of neonatal aloimmue thrombocy-topenia.