DETERMINATION OF NEUTROPHIL ANTIGEN GENE-FREQUENCIES IN 5 ETHNIC-GROUPS BY POLYMERASE CHAIN-REACTION WITH SEQUENCE-SPECIFIC PRIMERS

Background: The granulocyte antigens NA1 and NA2 are the two recognize d allelic forms of Fc gamma receptor IIIB. These antigens are clinical ly relevant, because they are the most frequent targets of neutrophil antibodies in alloimmune neonatal neutropenia, transfusion-related acu te lung injury, and chronic benign autoimmune neutropenia of infancy. Study Design and Methods: A genotyping assay for NA1 and NA2 using pol ymerase chain reaction with sequence-specific forward and reverse olig onucleotide primers has been developed and validated. Genomic DNA was isolated from the peripheral blood of 478 unrelated individuals of fiv e ethnic groups and used as template for NA genotyping. Results: A val idation study of 22 serologically typed samples (2 NA1/NA1, 10 NA1/NA2 , and 10 NA2/NA2) was performed. A concordance rate of 100 percent (22 /22 samples) was observed between the genotyping assay and serologic t yping. In the genotyping study conducted, the NA1 and NA2 gene frequen cies observed were 0.31 and 0.69 for African Americans, 0.30 and 0.70 for Asian Indians, 0.37 and 0.63 for whites, 0.53 and 0.47 for Hispani cs, and 0.55 and 0.45 for Native Americans, respectively. Conclusion: Polymerase chain reaction with sequence-specific primers provides a si mple and rapid alternative to neutrophil antigen typing by serologic t ests. The NA1 and NA2 gene frequencies observed in Asian Indians and A frican American populations are similar to those observed in white pop ulations, while those observed in Native American and Hispanic populat ions are more similar to those previously reported for Asian populatio ns.