The detection of an antibody against IgA allotype A2M 2 and a study of the Am genetic marker among the Han Chinese population

Publisher Website
Google Scholar
Abstract
The serum of a woman was found by the Ouchterlony double‐diffusion and the hemagglutination inhibition (HAI) methods to have immunoglobulin A (IgA) deficiency. Further investigation using the hemagglutination (HA) test with red cells coated with IgA myeloma proteins of different specificities showed that the serum agglutinated only IgA2‐, A2M 1‐, and A2M 2‐coated cells. The patterns of the HAI test with a reference panel confirmed the presence of two specificities. One was anti‐IgA2 and the other was a rare antibody against the allotype A2M 2. The anti‐A2M 2 was used for population studies. Testing of the Han Chinese population, including family studies, confirms that A2M.1 and A2M.2 have an autosomal dominant mode of inheritance and are controlled by a codominant allele. The distribution of the two Am genetic markers among the Han Chinese population demonstrated A2M.1 with a gene frequency of 0.553 and A2M.2 with a gene frequency of 0.447 (χ2= 0.145, 0.80>p>0.70).