Association between vitamin B12 level and anti-parietal cells and anti-intrinsic factor antibodies among adult Jordanian patients with Helicobacter pylori infection

OBJECTIVE: Evaluate the association of Helicobacter pylori infection with anti-parietal cell antibodies (APCA) and anti-intrinsic factor antibodies (AIFA) and their impact on vitamin B12 serum level. PATIENTS AND METHODS: One hundred patients (M/F: 43/57; age 46.5 ± 17.5 years) who underwent upper gastrointestinal endoscopy at King Abdullah University Hospital, Irbid, Jordan were enrolled in the study. The patients were grouped as H. pylori-infected (n = 81) or H. pylori negative (n = 19) by histopathological examination. Fasting serum vitamin B12 levels, anti-parietal cell antibodies and anti-intrinsic factor antibodies for patients and controls were determined. RESULTS: Anti-parietal cell antibodies and anti-intrinsic factor antibodies were positive in 9.9% and 18.5% of H. pylori-positive patients respectively. None of the H. pylori negative subjects had anti-parietal cell antibodies or anti-intrinsic factor antibodies. Serum vitamin B12 level was lower in the H. pylori-infected patients (275 ± 70.4 pg/mL) than in controls (322.9 ± 60.7 pg/mL; p < 0.05). H. pylori was positive in 94% of the low-vitamin B12 group compared with 64.6% of the normal-vitamin B12 group (p < 0.5). CONCLUSION: Patients with H. pylori infection are more likely to have anti-parietal cell antibodies and anti-intrinsic factor antibodies. There was an association between H. pylori infection and lower vitamin B12 levels. H. pylori infection might be a significant factor in the pathogenesis of autoimmune gastritis.