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Low‐frequency human platelet antigens as triggers for neonatal alloimmune thrombocytopenia
Author(s) -
Peterson Julie A.,
Gitter Maria,
Bougie Daniel W.,
Pechauer Shan,
Hopp Kathleen A.,
Pietz Brad,
Szabo Aniko,
Curtis Brian R.,
McFarland Janice,
Aster Richard H.
Publication year - 2014
Publication title -
transfusion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.045
H-Index - 132
eISSN - 1537-2995
pISSN - 0041-1132
DOI - 10.1111/trf.12450
Subject(s) - neonatal alloimmune thrombocytopenia , serology , antigen , immunology , medicine , typing , antibody , population , human leukocyte antigen , immunization , pregnancy , biology , genetics , fetus , environmental health
Background Twenty‐four low‐frequency human platelet antigens ( LFHPA s) 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 P hase 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 LFHPA s by DNA sequencing. In a P hase 2 study, high‐throughput methods were used to type fathers of 1067 consecutive unresolved NAIT cases for LFHPA s. Mothers of 1338 unresolved cases were also typed to assess the prevalence of LFHPA s in a population racially/ethnically similar to the fathers. Results In P hase 1, LFHPA s were identified in 16 of 244 fathers (6.55%). In P hase 2, LFPA s were found in only 28 of 1067 fathers (2.62%). LFHPA s 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). Conclusions 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 .