<s>[INST] context: Ref. API Textbook of Medicine. Pg. 1851
 
Cryogloblinemia is a vasculitis of small blood vessels that is caused by deposition of immune complexes. 

Skin, joints, and nerves are commonly affected. 
The heart, brain, or gastrointestinal tract each are affected in fewer than 10% of cases.
Most patients with cryoglobulinemia are chronically infected with hepatitis C virus (HCV). 
Many 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. 
The 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. 
Damage to nerves (neuropathy) causes numbness, tingling, severe burning pain, and or weakness in a hand or foot. 
For patients with HCV, anti-viral therapy is indicated regardless of the degree of severity. 
For less severe cases (e.g., purpura, weakness, and joint pain), anti-viral therapy alone is the treatment of choice. 
Involvement of vital organs requires addition of immune-suppressive drugs.  Prednisone, azathioprine, and cyclophosphamide have been widely used, but recent studies have indicated that rituximab may be superior to these medications. [/INST] question: Cryoglobulinemia is associated with which of the following | options: A: Hepatitis C B: Overian cancer C: Diabetes D: Leukemia | answer: A </s>