Relation of H pylori to gastric mucins and gastric surface mucous gel layer Reply

Helicobacter pylori, Lewis antigens, and inflammationEDITOR,-In a recent issue of Gut, Zheng et al reported that peptic ulcer disease was associated with increased expression of Lewis (Le) antigens but not cagA, iceA, or vacA in Chinese patients infected with Helicobacter pylori (Gut 2000;47:18-22).These data raise as many questions as they answer and add further controversy to an intriguing area of microbiology and gastroenterology.Le x and/or Le y blood group determinants are commonly found on the lipopolysaccharide (LPS) of H pylori isolates.These determinants have been identified on approximately 80-90% of isolates from all patient series examined to date. [1]2][3] In our own series, 74/84 (88%) isolates expressed either Le x or Le y , with 47/84 (56%) of isolates coexpressing both determinants. 4 No diVerence was identified in the prevalence of Le x or Le y expression on H pylori strains isolated from ulcer patients and those strains isolated from patients with chronic gastritis, nor was an association demonstrated between host and bacterial Lewis phenotype.Since the report of Zheng et al we have reviewed our raw data regarding the prevalence of strains expressing two or more Lewis antigens.We found that two or more Le determinants were present in 9/12 (75%) isolates from duodenal ulcer patients and in 4/10 (40%) isolates from gastric ulcer patients.This gives an overall prevalence of 59% (13/22 isolates) for isolates from patients with ulcer disease.Thirty four of 62 (55%) patients with histological evidence of chronic gastritis also had isolates expressing two or more Le antigens.A significant diVerence between H pylori strains isolated from Chinese patients and those from our population is the finding of 48/108 (44%) isolates expressing three or more Le antigens compared with 11/84 (13%) isolates from a homogenous Irish population.In our series, only one strain expressed all class 1 and class 2 Le antigensthat is, Le x , Le y , and their isomers Le a and Le b .This unusually high prevalence of three or more antigenic determinants raises the question of whether or not these diVerences were due to strain variation or relate to antibody specificity.Zheng et al also suggest that blood group A determinants have not been identified on H pylori isolates.We have previously described this determinant on a H pylori strain expressing both Le x and Le y . 4 5However, the role of fucosylated blood group determinants such as blood group A, B, or H type-1 on H pylori LPS is as yet undetermined.This contrasts with the well established role of blood group A in H mustelae mediated gastric autoimmunity in the ferret model of gastric autoimmunity. 6 These observations on the role of expression of multiple Le determinants are interesting, given the nature of our study population where patients with ulcerative disease made up only 26% of the overall study population.These individuals were infected with strains with a relatively well conserved pattern of Le determinant expression.Both genotypic conservation and adaptation of H pylori to host populations is well recognised in H pylori infection.Clonality is a recently described property of this bacterium and merits discussion in relation to Le determinants.In recent studies, H pylori strains isolated from 12