HLA-B5 associated with duodenal ulcer.

In a search for further genetic factors contributing to ulcer disease we undertook a study of the frequency of HLA antigens in patients with duodenal ulcer. Seventy-seven male patients (of two races) were typed for the HLA-A and-B loci. Thirteen of the 54 (24%) white males were found to have antigen B5 compared to 10% of controls. These results have a P value of 0.0016 which remains significant even when multiplied by the number of antigens tested (28). These results demonstrate a significant association between duodenal ulcer and HLA antigen B5 in white males, with a relative risk of 2.9, greater than that associated with the combination of blood group O and nonsecretor status.