A 22-year-old male patient presented with epigastric pain and lower back pain three months after successful Helicobacter pylori eradication, revealing early-stage endoscopic features of suspected autoimmune gastritis. The case highlights diagnostic challenges in young adults who lack classic complications such as pernicious anemia or vitamin deficiencies.
Autoimmune gastritis, traditionally referred to as type A gastritis, is characterized by corpus-predominant atrophic gastritis caused by autoimmune mechanisms. Most cases are diagnosed in middle-aged or elderly individuals, as complications such as pernicious anemia and impaired absorption of iron and vitamin B12 typically manifest in advanced stages. Additionally, patients with autoimmune gastritis are often asymptomatic, making reports of early-stage endoscopic findings exceedingly rare.
A 22-year-old male presented to our hospital with complaints of epigastric pain and lower back pain. He had undergone eradication therapy for Helicobacter pylori infection at another hospital three months prior to presentation. A urea breath test confirmed successful eradication of H. pylori.
Endoscopic Findings and Serological Profile in Early-Stage Gastritis
Endoscopic examination revealed extensive, sharply demarcated mucosal atrophy extending orally from the middle of the gastric body, while the gastric antrum showed no evidence of atrophy or intestinal metaplasia. By contrast, autoimmune gastritis (AIG) is characterized by immune-mediated destruction of parietal cells in the oxyntic mucosa, resulting in corpus- and fundus-predominant inflammation and atrophy with relative sparing of the antrum. In H. pylori-associated atrophic gastritis, inflammation and atrophy typically develop in the antrum and incisura and may subsequently extend proximally, producing multifocal atrophic changes.
Laboratory tests revealed a mild elevation in anti-parietal cell antibody levels, with a titer of 1:10, whereas serum gastrin and vitamin B12 levels remained within normal limits. Iron metabolism parameters were also normal. However, histopathological confirmation was unavailable, and thus a definitive diagnosis of autoimmune gastritis could not be established. This report presents a rare case of suspected early-stage autoimmune gastritis with distinctive endoscopic findings in a young male.
The prevalence of AAG has been estimated at between 0.3% and 2.7% in the general population. The diagnosis of AAG is based on a combination of the serologic profile and the histological examination of gastric biopsies. Patients with AAG are often asymptomatic but can also have dyspeptic or reflux symptoms. As AIG progresses, patients may develop iron deficiency, vitamin B12 deficiency, pernicious anemia, and neurological manifestations. Nevertheless, many patients remain asymptomatic, and the condition may be detected incidentally during endoscopic or laboratory evaluation.
In Japan, newly proposed diagnostic criteria for autoimmune gastritis integrate endoscopic, histological and serological markers to facilitate early detection. The guidelines enable stratification of patients into confirmed, early-stage and suspected categories, thereby promoting timely intervention and tailored surveillance for gastric tumours and pernicious anaemia.
Autoimmune gastritis is a chronic, immune‐mediated destruction of gastric parietal cells leading to hypochlorhydria, loss of intrinsic factor and subsequent malabsorption of vitamin B12 and iron. The reduction in gastric acidity predisposes to bacterial overgrowth and alters the gut microbiome, while impaired intrinsic factor secretion culminates in pernicious anaemia. Long‐standing gastric atrophy fosters hypergastrinaemia and enterochromaffin‐like cell hyperplasia, thereby increasing the risk of type I gastric neuroendocrine tumours and, in some cohorts, adenocarcinoma. Autoimmune atrophic gastritis is associated with an increased risk of type I neuroendocrine tumors (NETs) and gastric cancer, with an incidence rate of 2.8% and 0.5% per person/year, respectively.
Surveillance Challenges and Unresolved Questions
Population-based analyses have reinforced the link between systemic autoimmunity and gastric malignancy risk. A large nested case–control study in the United Kingdom demonstrated that individuals with any autoimmune condition exhibit a modestly elevated gastric cancer risk, rising substantially in those with pernicious anaemia. These findings underscore the value of stratifying at-risk patients for endoscopic surveillance.
The progression from intrinsic factor deficiency to cobalamin depletion manifests in neurological, cardiovascular and gastrointestinal complications. A recent review of pernicious anaemia emphasises its multifaceted clinical spectrum beyond classic haematological presentations. The review advocates for a multidisciplinary diagnostic approach, encompassing serology, endoscopy and neurologic assessment, and outlines best practices for long-term management and endoscopic monitoring to prevent irreversible sequelae. Management is directed to reinstate vitamins and iron and to prevent malignancies with endoscopic surveillance.
