M. De Haas et al., Neutrophil antigen 5b is carried by a protein, migrating from 70 to 95 kDa, and may be involved in neonatal alloimmune neutropenia, TRANSFUSION, 40(2), 2000, pp. 222-227
BACKGROUND: Neutrophil antigen 5b has been described as involved in transfu
sion reactions and not in neonatal alloimmune neutropenia.
CASE REPORT: Anti-5b was found in the serum of a mother of a persistently n
eutropenic newborn, who had several bacterial infections. The neutropenia r
esponded to treatment with recombinant human granulocyte-colony-stimulating
factor. Immunoprecipitation experiments performed with this and three othe
r 5b antisera identified a protein, migrating from 70 to 95 kDa, as carrier
of 5b. The observed pattern of migration may point to heavy glycosylation
of this protein.
RESULTS: Six 5b-negative donors were identified among 54 screened white don
ors, for a 5b gene frequency of 0.66.
CONCLUSION: Alloimmunization to 5b in pregnancy is rare. In the patients wi
th neonatal neutropenia analyzed in the last decade, this was the first cas
e discovered.