This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immune system, Subject name: Medicine
[{'content': 'Cause of nephrocalcinosis in granulomatous disorders \nSelect and explain. \nA. Increased calcium in diet, B. Dysregulated production of 1,25-(OH2), C. Dystrophic calcification, D. Mutation in calcium sensing receptor', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Hypercalcemia occurs in most granulomatous disorders. High serum calcium levels are seen in about 10% of patients with sarcoidosis; hypercalciuria is about three times more frequent. Tuberculosis, fungal granulomas, berylliosis, and lymphomas are other conditions that are associated with disorders of calcium metabolism. These abnormalities of calcium metabolism are due to dysregulated production of 1,25-(OH2)D3 (calcitriol) by activated macrophages trapped in pulmonary alveoli and granulomatous inflammation. Undetected hypercalcemia and hypercalciuria can cause nephrocalcinosis, renal stones, and renal failure. Coicosteroids cause prompt reversal of the metabolic defect. Chloroquine, hydroxychloroquine, and ketoconazole are the drugs that should be used if the patient fails to respond or develops dangerous side effects to coicosteroid therapy. Ref - pubmed.com', 'role': 'assistant'}]