Neutrophil-specific antigen HNA-2a, NB1 glycoprotein, and CD177.
OBJECTIVE
Several advances have been made in characterization of the molecule that carries human neutrophil antigen (HNA)-2a, NB1 glycoprotein, the gene that encodes NB1 glycoprotein, CD177, and the role of antibodies to HNA-2a in transfusion reactions.


RESULTS
NB1 glycoprotein binds to the endothelial cell adhesion molecule, platelet endothelial cell adhesion molecule-1 (PECAM-1), and participates in neutrophil transmigration. The overexpression of neutrophil CD177 mRNA has become a useful, but nonspecific biomarker of myeloproliferative diseases, especially polycythemia vera. CD177 mRNA overexpression is also a biomarker of a subset of patients with essential thrombocythemia who are at increased risk of thromboembolic complications. In patients with myeloproliferative disorders CD177 mRNA overexpression is secondary to a gain-of-function mutation in JAK2, JAK2 V617F. NB1 glycoprotein is co-localized on neutrophil plasma membranes with proteinase 3 and a complex of NB1 glycoprotein and proteinase 3 may initiate the activation of neutrophils by antineutrophil cytoplasmic antibodies in patients with Wegener's granulomatosis. The inadvertent transfusion of antibodies to HNA-2a with blood components frequently causes pulmonary transfusion reactions.


CONCLUSIONS
The expression of CD177 is an important biomarker of myeloproliferative diseases, NB1 glycoprotein is a ligand for PECAM-1 and it may have a role in Wegener's granulomatosis, and antibodies to HNA-2a frequently cause pulmonary transfusion reactions.
Stroncek
David F
DF
Department of Transfusion Medicine, Clinical Center, National Institutes of Health, Bethesda, Maryland 20892, USA. dstroncek@cc.nih.gov
D000954:Antigens, Surface / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D002462:Cell Membrane / Q000276:immunology; D058851:GPI-Linked Proteins; D014890:Granulomatosis with Polyangiitis / Q000276:immunology; D006801:Humans; D007519:Isoantigens / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000276:immunology*; D009504:Neutrophils / Q000276:immunology; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000276:immunology; D011087:Polycythemia Vera / Q000276:immunology; D011956:Receptors, Cell Surface / Q000276:immunology*; D013920:Thrombocythemia, Essential / Q000276:immunology; D065227:Transfusion Reaction
D000954:Antigens, Surface; D015415:Biomarkers; C407242:CD177 protein, human; D058851:GPI-Linked Proteins; D007519:Isoantigens; D008562:Membrane Glycoproteins; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D011956:Receptors, Cell Surface