Autoimmune gastritis is common in patients with iron deficiency – Non-invasive evaluation of iron deficiency aside guideline recommendations

Background: Iron deficiency (ID) is the most common nutritional deficiency. Symptoms such as fatigue, hair loss and restless legs syndrome decrease quality of life; furthermore it results in impaired physical and cognitive development and poor pregnancy outcome. Current guidelines recommend as non-invasive test only evaluation of coeliac disease. From our clinical observations we hypothesize that other GI causes such as autoimmune gastritis (AG) are far more common and non-invasive evaluation should be included in the primary workup. Methods: We did a retrospective evaluation of patients who attended an out-patients clinic specialized for ID. Laboratory evaluation included endomysial-antibodies, parietal-cell-antibodies, helicobacter-ag (stool) and fecal occult blood test. Endoscopy was performed if indicated. Symptoms of ID were recorded. Results: We included 409 patients in our analysis. Mean hemoglobin was 11.7 g/dL (SD 1.9), median transferrin saturation 9.4% (range 1 – 39.6) and median ferritin 10 µg/L (range 1 – 91). Four patients (1%) had positive screening for coeliac disease. Increased levels of parietal-cell-antibodies were seen in 72 patients (17.6%), 24 (5.9%) were strongly positive (> 100IU/ml) highly suggestive of AG. Helicobacter-pylori gastritis was found in 31 patients (14.2%). Endoscopy was performed in 84 (20.5%) patients, abnormal findings were present in 37 (9%). The most common symptom was fatigue (92.6%), attentiveness disorder (63.3%) and decline in output (57.2%). Hair loss and brittle nails were seen in about half of patients, sleeping disorder in 36.9% and restless legs syndrome in 24.7%. In patients with parietal cell antibodies > 100IU/ml restless legs syndrome was seen significantly more common (41.7%, p = 0.002). Conclusion: We found a high prevalence of AG which is known to cause ID especially in younger patients. Although there is no treatment of AG, diagnosis is important as patients are at a higher risk for gastric carcinoids and adenocarcinomas. Guidelines for diagnosis of ID should be adapted and include non-invasive evaluation of AG.