A comparison of Lewis X and Lewis Y expression in Helicobacter pylori obtained from children and adults

There are no reports, to our knowledge, on the expression of Lewis (Le) ant igens in Helicobacter pylori isolates from children. The aim of this study was to compare the expression of Le antigens by H. pylori isolates from chi ldren 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 Le(x) and Le(y) antigens wa s determined by ELISA, using monoclonal anti-Le antibodies. The Le phenotyp e of the patients was determined in gastric juice with a hemagglutination a ssay. Clones expressing Le(x) were more common in children than in adults ( 55.4% vs. 33.4%, respectively; P < .01), and Le(y) was more common in adult s than in children (81.6% vs. 66%, respectively; P < .01). A trend analysis showed a significant decline in frequency of clones expressing Le(x) with age (P = .021). In this community, expression of Le antigens differs in H. pylori isolates obtained from children versus adults.