Abo Blood Groups and Secretor Character in Duodenal Ulcer

Abstract

Part I Recent work has suggested an association between blood group O and duodenal ulcer in several areas of Europe and in the U.S.A. The finding has been obtained by comparing the blood groups of ulcer patients with a control series of unaffected people living in the same area. Such controls can be unsatisfactory in that a population of mixed origin may contain elements with a high frequency both of group O and of duodenal ulcer without the two being causally connected. Sibship studies where the unaffected sibs act as controls are not subject to this criticism. Data are presented for 293 duodenal ulcer sibships. An analysis of these gives no evidence to support the hypothesis that a group O individual is more likely to have a duodenal ulcer than are his A, B, or AB sibs. This result could be regarded as evidence in support of the suggestion that the previously found association was due to racial stratification within the populations concerned. There are, however, considerable objections to this explanation, and an alternative, that the findings are due to a maternal effect, is discussed. Part II The ability to secrete ABO blood group antigens in body fluids is an inherited character, and it seemed possible that secretors and non-secretors might have different susceptibilities to duodenal ulcer. We have therefore investigated the secretor character in the saliva of 514 unrelated duodenal ulcer patients and compared the results with those of 491 controls from the general population. This analysis shows that there is a significantly higher proportion of non-secretors in the duodenal ulcer patients (35.0%) than in the controls (24.2%). This difference is found in both males and females of each of the ABO blood groups and in both macroscopically and radiologically diagnosed cases. These data suggest that non-secretor individuals may be about 45% more likely to develop duodenal ulcer than are secretors. For the same reason as in the association between group O and duodenal ulcer, sibship studies have been carried out, and the results in 262 families suggest that the relationship between non-secretion and duodenal ulcer may hold within families. The possibility that the ABO and Lewis antigens may confer some protection against duodenal ulceration by virtue of their mucoid character is discussed. © 1956, British Medical Journal Publishing Group. All rights reserved.