This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Unknown
[{'content': 'Cryoglobulinemia is associated with: \nSelect and explain. \nA. HAV, B. HBV, C. HCV, D. HDV', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ref. Robbins Pathology. 9th edition. Page.\xa0 602\n\xa0\nCryogloblinemia is a vasculitis of small blood vessels that is caused by deposition of immune complexes.\xa0\n\nSkin, joints, and nerves are commonly affected.\xa0\nThe heart, brain, or gastrointestinal tract each are affected in fewer than 10% of cases.\nMost patients with cryoglobulinemia are chronically infected with hepatitis C virus (HCV).\xa0\nMany of the remaining patients with cryoglobulinemia have lupus, Sjogren’s syndrome, rheumatoid arthritis, or white blood cell cancers (lymphoma, myeloma, or Waldenstrom’s macroglobulinemia) as the underlying cause.\xa0\nThe most common appearance of vasculitis in the skin is purpura (bright red circles, from the size of a pinhead up to half an inch, often painful or itchy), but open sores are also common.\xa0\nDamage to nerves (neuropathy) causes numbness, tingling, severe burning pain, and or weakness in a hand or foot.\xa0\nFor patients with HCV, anti-viral therapy is indicated regardless of the degree of severity.\xa0\nFor less severe cases (e.g., purpura, weakness, and joint pain), anti-viral therapy alone is the treatment of choice.\xa0\nInvolvement of vital organs requires addition of immune-suppressive drugs.\xa0 Prednisone, azathioprine, and cyclophosphamide have been widely used, but recent studies have indicated that rituximab may be superior to these medications.', 'role': 'assistant'}]