Background: Maternal plasma and/or serum levels of anti-HPA-1a at delivery were compared to neonatal platelet (PLT) counts.
Study design and methods: Samples from HPA-1bb women who gave birth to children with thrombocytopenia or had anamnestic information about a previous child with neonatal alloimmune thrombocytopenia (NAIT) were collected at delivery. A modified monoclonal antibody immobilization of PLT antigen method was used for quantification of anti-HPA-1a.
Results: The anti-HPA-1a level in women with severely thrombocytopenic children was higher than the corresponding level in mothers of children born with moderate thrombocytopenia or normal PLT counts.
Conclusion: Our data show a significant correlation between maternal anti-HPA-1a level and the neonatal PLT count and indicate strongly that this may be a reliable predictive measure for NAIT. Suitable test systems for quantitative measurements of anti-HPA-1a must be developed and evaluated for this particular purpose.