Standardized risk of moderate or severe ARDS by ABO genotype grouped by expected expression of A and B antigens in the (A) overall MESSI population, (B) MESSI nonpulmonary sepsis, and (C) MESSI pulmonary sepsis. The dot represents the standardized ARDS risk adjusted for age, sex, RBC transfusion, diabetes, hematologic malignancy, source of sepsis, and population stratification. The bars represent the 95% CI around the standardized risk. ARDS risk generally decreased when comparing ABO genotypes predicted to confer a higher density of A antigens (i.e., A1A1 has the highest A antigen density and ARDS risk, then A1A2/A1O, followed by A2A2/A2O, and finally OO).