Influence of the secretor and Lewis genes on susceptibility to duodenal ulcer.

Human duodenal mucosal cells have been examined by mixed-cell agglutination for the presence of bloodgroup antigens. The secretor status of the patients has been determined, and in a proportion of cases gastric juice as well as saliva has been studied. Mixed-cell agglutination has also been performed on the buccal cells from a percentage of subjects as a control of technique. The results indicate that antigen is present in secretor subjects, but is absent or very scanty in at least a proportion of non-secretor individuals. The possible relevance of this finding to the problem of duodenal ulcerogenesis is examined.