It is widely accepted that the serum of healthy individuals contains natural antibodies only against those blood group A or B antigens that are not expressed on the individual's red blood cells. The mechanisms involved in tolerance to autologous blood group antigens remain unclear. In the present study, we show that IgM and IgG antibodies reactive with autologous blood group antigens are presen...

This report presents evidence for enteric bacterial adaptation to genetically controlled environmental factors in the individual human host. Human feces contains bacterial enzymes that degrade water-soluble A, B, and H antigens, and both the presence and the specificity of ABH blood group antigens in human gut mucous secretions are genetically determined for each individual. In this study, part...

It is widely accepted that the serum of healthy individuals contains natural antibodies only against those blood group A or B antigens that are not expressed on the individual’s red blood cells. The mechanisms involved in tolerance to autologous blood group antigens remain unclear. In the present study, we show that IgM and IgG antibodies reactive with autologous blood group antigens are presen...