[Blood group affiliation of patients with duodenal ulcer].

The blood groups of 766 patients with duodenal ulcer were studied. A significant association of the disease was established with blood group O (I), particularly emphasized in hereditary loaded patients. The carriedship of the indicated blood group increases (under the same other conditions) the risk of origination of duodenal ulcer with about 50 per cent. The belonging to blood group A (II), on the other hand, decreases that risk with approximately the same percentage. The rest blood groups from the system ABO (H) appear not to have an essential effect on ulcerogenesis in peptic ulcer of duodenum.