Expression of human neutrophil antigen-2a (NB1) is increased in pregnancy.
BACKGROUND
The expression of human neutrophil antigen-2a (HNA-2a) or NB1 is highly variable. This study investigated variations in neutrophil expression of HNA-2a by comparing the expression of epitopes recognized by three HNA-2a-specific CD177 antibodies among healthy adults and pregnant women.


METHODS
Flow cytometry was used to compare the neutrophil reactions of three CD177 antibodies (MEM-166, TAG4, and 7D8) among 52 healthy adults. Because HNA-2a expression is greater in women than men, neutrophils were studied from 21 women early in pregnancy and 23 women late in pregnancy.


RESULTS
All three CD177 antibodies reacted with two populations of neutrophils: a brightly staining population and a dimly staining population. Among the 52 healthy adults, there was no difference in the mean size of the brightly reactive population of neutrophils recognized by each antibody (46 +/- 23% for MEM-166, 49 +/- 23% for TAG4, and 49 +/- 23% for 7D8), and all three antibodies were specific for HNA-2a. For all three antibodies the size of the antigen bright neutrophil population was greater on neutrophils collected both early and late in pregnancy than in healthy adults. There was no difference in the size of the antigen bright population among neutrophils tested early and late in pregnancy.


CONCLUSIONS
HNA-2a antigen expression increases in pregnancy. Some of the variations in neutrophil expression of HNA-2a among individuals is likely due to differences in gene regulation or differences in post-translational protein modifications rather than gene polymorphisms.
Caruccio
Lorraine
L
Department of Transfusion Medicine, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland, USA.
Bettinotti
Maria
M
Matsuo
Kazuhiko
K
Sharon
Victoria
V
Stroncek
David
D
D000328:Adult; D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D000939:Epitopes / Q000032:analysis / Q000276:immunology; D005260:Female; D005434:Flow Cytometry; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D058851:GPI-Linked Proteins; D005865:Gestational Age; D006801:Humans; D007519:Isoantigens / Q000097:blood* / Q000276:immunology; D008297:Male; D008562:Membrane Glycoproteins / Q000097:blood* / Q000276:immunology; D009504:Neutrophils / Q000276:immunology*; D011247:Pregnancy; D011956:Receptors, Cell Surface; D012727:Sex Characteristics
D000911:Antibodies, Monoclonal; C407242:CD177 protein, human; D000939:Epitopes; D005456:Fluorescent Dyes; D058851:GPI-Linked Proteins; D007519:Isoantigens; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; D016650:Fluorescein-5-isothiocyanate