A Comparison of Lewis X and Lewis Y Expression inHelicobacter pyloriObtained from Children and Adults

There are no reports, to our knowledge, on the expression of Lewis (Le) antigens in Helicobacter pylori isolates from children. The aim of this study was to compare the expression of Le antigens by H. pylori isolates from children and from adults. Totals of 278 clones from 22 children with recurrent abdominal pain and 293 clones from 22 adults with (n=10) or without (n=12) duodenal ulcer were studied. Expression of Lex and Ley antigens was determined by ELISA, using monoclonal anti-Le antibodies. The Le phenotype of the patients was determined in gastric juice with a hemagglutination assay. Clones expressing Lex were more common in children than in adults (55.4% vs. 33.4%, respectively; P<.001), and Ley was more common in adults than in children (81.6% vs. 66%, respectively; P<.01). A trend analysis showed a significant decline in frequency of clones expressing Lex with age (P=.021). In this community, expression of Le antigens differs in H. pylori isolates obtained from children versus adults