This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Medicine
[{'content': 'Soluble Transferrin receptor in iron deficiency anemia is \nSelect and explain. \nA. Increased, B. Decreased, C. Normal, D. None', 'role': 'user'}, {'content': 'Answer: A \nExplanation: (A) Increased # The diagnosis of iron deficiency anemia ultimately rests on laboratory studies.> Both hemoglobin and hematocrit are depressed, usually to moderate levels, and are associated with hypochromia, microcytosis, and some poikilocytosis.> The serum iron and serum ferritin are low, and the total plasma iron-binding capacity (reflecting transferrin concentration) is high.> Low serum iron with increased iron-binding capacity results in a reduction of transferrin saturation levels to below 15%.> Transferrin receptor, expressed on the surface of many cells, is required for the transport of iron into cells.> The level of transferrin receptors is inversely related to available serum iron.> With iron deficiency, the level of cell-bound transferrin receptors and their soluble forms that circulate in the blood is elevated.', 'role': 'assistant'}]