Detection of Anti-Le^a in Le(a-b+) Individuals by Kinetic ELISA

Utilizing a kinetic enzyme-linked antiglobulin binding assay, eight examples of anti-Le^a were detected in individuals whose Lewis phenotype is Le(a-b+). These antibodies were not detectable by routine hemagglutination techniques, but were indistinguishable from anti-Le^a made by Le(a-b-) individuals in terms of their immunologic fine specificity. However, unlike most anti-Lea antibodies from Le(a-b-) individuals, none of the anti-Lea antibodies had an IgG component. Anti-Le^a antibodies in Le(a-b+) individuals may represent immune responses on the continuum between autoimmunity and alloimmunity.