Blood group incidence and Escherichia coli bacterial sepsis.

Many strains of Escherichia coli possess an antigen that reacts with naturally occurring antibodies to human red cell B antigens. The authors tested the hypothesis that the presence of naturally occurring anti-B isoagglutinins afford protection against the development of E. coli septicemia. The blood groups found in 115 patients with E. coli septicemia were compared with those found in three "control" populations: 138 patients with septicemia due to other organisms, 23,135 hospitalized patients, and 40,038 normal blood donors. The relative incidence of B and AB blood groups (not containing anti-B antibodies) was significantly higher than A and O blood groups (containing anti-B antibodies) in the group with E. coli septicemia. This finding supports the hypothesis.