Immunological disorders in C virus chronic hepatitis

Hepatitis C virus infection can be accompanied by a number of systemic, non-specific or autoimmune disorders and by extra-hepatic biological abnormalities. Their exact prevalence remains to be determined, together with their association with certain pathologies such as non-Hodgkin lymphoma. The most frequent biological peculiarity is cryoglobulinaemia, found in more than 50% of patients. It is only symptomatic in less than one-third of cases (as purpura, Raynaud's syndrome, neuropathy or renal failure), and could be the origin of benign lymphoproliferative haematological pathology, then of a malignant one (non-Hodgkin lymphoma). Rheumatoid arthritis may develop in 20-25% of cases. Periarteritis nodosa is a rare but possible occurrence. Autoimmune disorders proper include hepatitis with anti-LKM1 antibodies, thyroiditis, skin manifestations, complex connectivitis and Gougerot-Sjögren's syndrome. This syndrome is histologically detected in 15-50% of patients. It affects women preferentially and is usually not accompanied by anti-SSA or anti-SSB antibodies. Thyroidites are different from those occurring under Interferon-alpha therapy, and should be systematically investigated before initiating that therapy. Lichen planus can be associated to HCV infection. The proven induction of autoimmune disorders by Interferon therapy requires that immune disorders be fully assessed before treatment initiation, and close monitoring for their occurrence is necessary throughout the treatment course. TSH and thyroid hormone in particular should be closely monitored.