Autoimmune manifestations during interferon therapy in patients with chronic hepatitis C: the hepatologist's view.

In face of numerous benefits induced by therapy based on interferon (IFN) associated with ribavirin for the treatment of chronic hepatitis C, there is an increasing concern regarding its tolerance, which can, in some cases, reduce the quality of life as well as compliance of patients. Among the less common side effects, there are the autoimmune ones which can be globally divided into appearance or increase in titres of auto-antibodies and/or manifestation of overt autoimmune pathologies. Whereas the former may concern more than 50% of treated subjects, the latter is reported in only 1-2% of patients under therapy. Thyroid dysfunction represents the well-studied autoimmune disorder. The presence of pre-existing anti-thyroid antibodies and being of female sex, constitute relevant risk factors for the development of a disease involving this gland. Often the treatment of thyropathy must be continuous in spite of IFN discontinuation because the disturbance usually does not abate with stopping antiviral therapy. Some observations have pointed out to the fact that IFN can lead to the development of insulin-dependent diabetes mellitus. Sometimes, during, as well as after IFN treatment, the appearance of anti-islet cell antibodies has been shown, but its interrelationship with the development of disease is uncertain. While being treated with IFN for chronic hepatitis C, the finding of non-organ specific antibodies at baseline can increase the likelihood of the development of autoimmune hepatitis. However, their presence does not constitute an absolute contraindication to the treatment, except in case of high titre. Other disorders, such as a lupus erythematosus-like syndrome, haemolytic anaemia, and immune-mediated thrombocytopenia have been reported. In conclusion, although the presence of auto-antibodies is considered to be an epiphenomenon without pathogenic significance in most patients suffering from chronic hepatitis C, it poses a problem when they need to be treated with IFN. This antiviral drug can induce or exacerbate a multitude of autoimmune-related disorders, however, clinically overt immune-mediated diseases are rare and affect a subset of subjects who have an underlying autoimmune diathesis.