BLOOD-GROUPS LEWIS(B) AND ABH EXPRESSION IN GASTRIC-MUCOSA - LACK OF INTERRELATION WITH HELICOBACTER-PYLORI COLONIZATION AND OCCURRENCE OF GASTRIC MALT LYMPHOMA

Background-Blood group Lewis(b) antigens mediate Helicobacter pylori a ttachment to gastric mucosa with attachment being particularly strong in subjects with ABH blood group O. Aims-To determine whether H pylori colonisation or the occurrence of gastric mucosa associated lymphoid tissue (MALT) lymphomas might be related to gastric Lewis(b) expressio n or occurrence of particular ABH blood groups on gastric mucosa. Pati ents-Gastric resection specimens from 89 cases with gastric MALT lymph oma and gastric mucosal biopsy specimens from 95 patients undergoing u pper endoscopy due to upper gastrointestinal complaints, including fiv e cases with gastric MALT lymphoma, were studied. Methods-H pylori was visualised with the Warthin-Starry stain. Immunostaining (Lewis(b), L ewis(a), A, B) was performed by applying a three step immunoperoxidase technique and indirect immunofluorescence staining on formalin fixed and paraffin wax embedded tissue. In 40 patients red blood cell Lewis phenotype and ABH blood groups were additionally determined by haemagg lutination assay. Results-Gastric surface epithelial cells showed an i mmunoreactivity to blood groups A, B, and AB in 80 (43.5%), 22 (12%), and 11 (6%) cases respectively and no immunoreactivity to any of these blood group substances (blood group O) in 71 (38.5%) patients. Lewis( b) expression of all gastric surface epithelial cells (secretor status ) was found in 130 (70.7%) cases. Lewis(a) expression of all gastric s urface epithelial cells (non-secretor status) was found in 36 (19.6%) cases, secretor status remained unclassified in 18 (9.8%) patients. Co lonisation with H pylori was found in 134 (72.8%) cases. The occurrenc e of H pylori was neither significantly associated with secretor statu s nor with certain ABH blood groups. The infiltration of gastric mucos a with MALT lymphoma was highly significantly associated with H pylori colonisation (p < 0.0003) but neither with secretor status nor with c ertain ABH blood groups. There was no inter-relation between secretor status or ABH blood groups and type, stage, grade of, and survival aft er MALT lymphoma. Conclusion-This study failed to show an inter-relati on between secretor status or particular ABH blood groups and either H pylori infection or the occurrence of gastric MALT lymphomas.