system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 57-year-old woman experiences frequent symptoms of heartburn. She reports no weight loss, diarrhea, or dysphagia symptoms. Past medical history is significant for vitamin B12 deficiency treated with monthly injections. She appears well, and the examination is normal, except for some patches on her arms where she has lost all the skin pigmentation. Her upper endoscopy is normal, except for gastric biopsies commenting on gastritis.For the above patient with gastritis, select the most likely mechanism of injury.
assistant
The correct answer is  Type A chronic gastritis may lead to pernicious anemia. Antibodies to parietal cells and to intrinsic factor are frequently seen in the sera, suggesting an immune or autoimmune pathogenesis. These patients can also have autoimmune thyroid disease and vitiligo.