This work was supported by Grant HL-13629 (RHA), 1UL1RR031973 (AS), and AHA 11GRNT7690032 (JAP).
Low-frequency human platelet antigens as triggers for neonatal alloimmune thrombocytopenia
Article first published online: 16 OCT 2013
© 2013 American Association of Blood Banks
Volume 54, Issue 5, pages 1286–1293, May 2014
How to Cite
Peterson, J. A., Gitter, M., Bougie, D. W., Pechauer, S., Hopp, K. A., Pietz, B., Szabo, A., Curtis, B. R., McFarland, J. and Aster, R. H. (2014), Low-frequency human platelet antigens as triggers for neonatal alloimmune thrombocytopenia. Transfusion, 54: 1286–1293. doi: 10.1111/trf.12450
- Issue published online: 12 MAY 2014
- Article first published online: 16 OCT 2013
- Manuscript Accepted: 27 AUG 2013
- Manuscript Revised: 5 AUG 2013
- Manuscript Received: 19 JUN 2013
- AHA 11GRNT7690032
- Howard Hughes Medical Institute
- National Institutes of Health, National Human Genome Research Institute. Grant Numbers: R01-HG00257, P50-HG00098
Twenty-four low-frequency human platelet antigens (LFHPAs) have been implicated as immunogens in neonatal alloimmune thrombocytopenia (NAIT). We performed studies to define more fully how often these antigens trigger maternal immunization leading to NAIT.
Study Design and Methods
In a Phase 1 study, fathers of selected NAIT cases not resolved by serologic testing but thought to have a high likelihood of NAIT on clinical and serologic grounds were typed for LFHPAs by DNA sequencing. In a Phase 2 study, high-throughput methods were used to type fathers of 1067 consecutive unresolved NAIT cases for LFHPAs. Mothers of 1338 unresolved cases were also typed to assess the prevalence of LFHPAs in a population racially/ethnically similar to the fathers.
In Phase 1, LFHPAs were identified in 16 of 244 fathers (6.55%). In Phase 2, LFPAs were found in only 28 of 1067 fathers (2.62%). LFHPAs were identified in 27 of 1338 maternal samples (2.01%). HPA-9bw was by far the most common LFHPA identified in the populations studied and was the only LFHPA that was significantly more common in fathers than in mothers of affected infants (p = 0.02).
Maternal immunization against recognized LFHPAs accounts for only a small fraction of the cases of apparent NAIT not resolved by standard serologic testing. Typing of the fathers of such cases for LFHPAs is likely to be rewarding only when a maternal antibody specific for a paternal platelet glycoprotein is demonstrated and/or there is compelling clinical evidence for NAIT.