The Development of Severe Neonatal Alloimmune Thrombocytopenia due to Anti-HPA-1a Antibodies Is Correlated to Maternal ABO Genotypes
The platelet count at delivery in HPA-1a-positive newborns was grouped according to maternal ABO type (A or O). Platelet count ≤150 × 109/L (dashed line) is defined as NAIT and <50 × 109/L (dotted line) as severe NAIT. The mean platelet counts in the three groups are indicated, with error bars representing 95% CI. Mean platelet counts are significantly different (, one-way ANOVA). The mean antibody levels between these groups are not significantly different: 11.6 IU/mL for blood group A mothers, 11.1 IU/mL for O02-positive blood group O mothers, and 1.8 IU/mL O02-negative blood group O mothers.