About 5 percent of patients with hepatitis C develop cryoglobulinemic vasculitis. This syndrome, characterized by inflammation of blood vessels (vasculitis), may involve the skin, joints, kidneys, nerves and other sites, and cause skin rashes, joint pain, weakness, fatigue, and numbness.
About 10 to 30 percent of patients develop kidney disease, which, in some cases, can lead to kidney failure. Although the cause of cryoglobulinemic vasculitis is not known, a critical component is the presence of cryoglobulins-abnormal proteins that white blood cells called B lymphocytes produce in response to the chronic hepatitis C infection. Rituximab decreases the number of B cells.
A phase II study of Rituxan is currenlty ongoing. There are several other reports of effectiveness in case series and reports. However until a randomized study can be conducted, it remains an investigational option.
Zaja F, De Vita S, Mazzaro C, Sacco S, Damiani D, De Marchi G, Michelutti A, Baccarani M, Fanin R, Ferraccioli G.Efficacy and safety of rituximab in type II mixed cryoglobulinemia. Blood. 2003 May 15;101(10):3827-34
Quartuccio L, Soardo G, Romano G, Zaja F, Scott CA, De Marchi G, Fabris M, Ferraccioli G, De Vita S.Rituximab treatment for glomerulonephritis in HCV-associated mixed cryoglobulinaemia: efficacy and safety in the absence of steroids.Rheumatology (Oxford). 2006 Jul;45(7):842-6.
Rheumatology (Oxford). 2006 Jun;45(6):783-4; author reply 784-5