[The Atri system. Immunogenetic lymphocytic system associated with ABO and ABH secretory systems]

The antigen Atri can be detected on the lymphocytes of 5.19% of ABH Secretor A individuals. The Atri substance is present in the plasma of the same individuals and can be fixed on group O erythrocytes. It is also found in the saliva of 30/32 A individuals not secreting substance A. Its existence in the saliva of A Secretor individuals, however, cannot be proved due to the presence of both the A and Atri antigens. The Atri substance is neutralized by the soluble substance A extracted from the gastric mucous of a pig. Yet the A and Atri antigens can be shown to be distinct on lymphocytes by redistribution of the corresponding sites and blocking of the A sites by an immune anti-A. On a genetic level, the Atri specificity might belong to a lymphocyte system comprising three alleles: Atri, RB and W100. These three specificities have the common characteristic of being expressed on a certain percentage of the lymphocytes of group A individuals. This system, provisionally named Atri, is functionally associated with the ABO system and secretor system. Nevertheless, the fact that in several families the Atri antigen is not expressed by the parents shows that its expression on lymphocytes requires the intervention of at least one gene in addition to the A and Se genes.