Association between HLA and red cell antigens. V. A further study of the nature and behaviour of the HLA antigens on red blood cells and their corresponding haemagglutinins.

The variation in the reactivity of red blood cells (RBC) with HLA haemagglutinins was studied, and the influence of some variable factors evaluated. A comparison of the HLA reactivity of RBC with automated and manual methods, showed the superiority of the Auto-Analyzer technique. The similarity in the nature and behaviour of HLA RBC antigens and the related Chido and Rg antigens is discussed. Inhibition/adsorption experiments were performed, and the results did not support the theory that HLA antigens on RBC originate from serum-HLA-active substance. The strength of the HLA reactivity of RBC from a donor was shown to vary from time to time without evidence of clinical disease.