[Hepatitis-C-virus-associated cryoglobulinemia. Pathogenesis, diagnosis and treatment].
BACKGROUND
Chronic hepatitis C-virus (HCV) infection is frequently associated with a variety of autoimmune phenomenons. Mixed cryoglobulins appear in up to 50% of chronic HCV-infected patients, mostly asymptomatic.


METHODS
Cryoprecipitates present IgM with rheumatoid factor activity and development of immunocomplexes deposited in small vessels responsible for resulting vasculitis. MANIFESTATIONS: Characteristic clinical findings are weakness, arthralgia and purpura with further complications including glomerulonephritis and neuropathic lesions. Several mechanisms for HCV-induced clinical lymphoproliferation are discussed, such as chronic B-cell stimulation and activation of the antiapoptotic oncogene bcl-2 leading to immunoglobulin synthesis and eventually evolving into B-cell non-Hodgkin's lymphoma (NHL).


METHODS
Conventional treatment of HCV-associated mixed cryoglobulinemia aimes at reducing circulating immunocomplexes and causal therapy with interferon (IFN) and ribavirin. New approaches using the anti-CD20 antibody rituximab have been described recently.
Staak
Jan Oliver
JO
Klinik für Innere Medizin. Universität zu Köln, Germany. Oliver.Staak@uni-koeln.de
Glossmann
Jan-Peter
JP
Diehl
Volker
V
Josting
Andreas
A
D000998:Antiviral Agents / Q000627:therapeutic use; D003449:Cryoglobulinemia / Q000175:diagnosis* / Q000209:etiology / Q000628:therapy; D003937:Diagnosis, Differential; D019698:Hepatitis C, Chronic / Q000150:complications / Q000175:diagnosis* / Q000628:therapy; D006801:Humans; D007075:Immunoglobulin M / Q000378:metabolism; D016898:Interferon-alpha / Q000627:therapeutic use; D010956:Plasmapheresis; D012217:Rheumatoid Factor / Q000378:metabolism
D000998:Antiviral Agents; D007075:Immunoglobulin M; D016898:Interferon-alpha; D012217:Rheumatoid Factor