Neonatal Thrombocytopenia in HLA-DR, -DQ, -DP-Typed Mother due to Rare Anti-HPA-1b (PLA2) (Zwb) Fetomaternal Immunization

Abstract

A new case of rare neonatal alloimmune thrombocytopenia, due to an IgG anti- HPA-1b in a mother HPA-1 (a+, b-), was diagnosed using monoclonal antibody- specific immobilization of platelet antigens. Clinically, it was similar to the 2 previously reported observations and confirmed that, in this particular case of anti-HPA-1b, the treatment with random platelet pools may be as effective as selected single-donor platelet units when maternal platelets are unusable. The HLA-DR, -DQ, -DP genotypes of the family were obtained by PCR-SSO. The mother’s typing, compared to the HLA-DR of the 6 similar cases reported in Europe, suggests that a combined effect of two rare HLA haplotypes might enhance this immunization.