Incidence of neutrophil antigens on human cord neutrophils

Neutrophils isolated from cord blood of healthy newborns (33 blacks and 21 whites) were investigated by EDTA-microagglutination for their expression of neutrophil specific antigens that have been associated with isoimmune neonatal or autoimmune neutropenia. Equal volumes of various neutrophil antisera (2 microliter) and cord neutrophils (3-5 X 10(6)/ml) were mixed in tissue typing microplates under oil and were incubated at room temperature for 6-8 hr, following which the degree of agglutination was noted. Our data revealed that all the currently recognized neutrophil antigens are readily demonstrable by antineutrophil antibodies in cord blood, (NA1, 52-54%; NA2, 81-85%; NB1, 95-96%; NC1, 90%; 9A, 29-30%) suggesting that neutrophil antigens are fully expressed at birth.