Risk factors and long-term course of thyroid dysfunction during antiviral treatments in 221 patients with chronic hepatitis C

Aim - To identify the predictive factors of dysthyroidism during treatment for chronic viral hepatitis C and to evaluate the long-term outcome of these patients. Methods - Patients treated for chronic viral hepatitis C between 1990 and 2001 were analyzed retrospectively. Patients with dysthyroidism before treatment and patients positive for hepatitis B surface antigen or human immunodeficiency virus antibodies were excluded. Dystkyroidism was defined by an abnormal serum TSH level on two separate occasions. Results - 221 consecutive patients were included. Among them, a hundred were treated twice by interferon alpha, 21 had 3 treatments and 3 had A treatments. Fifteen of these patients (7%) had dysthyroidism during antiviral therapy. There was no significant difference in the frequency of dystkyroidism during the first and the second treatment [respectively 4,1% (N = 9) and 6% (N = 6)]. Female gender and the presence of antimicrosome or antithyroperoxydase (anti-TPO) antibodies before antiviral treatment were predictive factors of dystkyroidism. Treatment by interferon and ribavirin did not increase the risk of dystkyroidism compared to monotherapy with interferon. Pegylated interferon (N = 49) was not a risk factor compared to standard interferon. Thirteen patients had hypothyroidism (2 of them as a result of biphasic thyroiditis) and 2 had hypertkyroidism. The antiviral treatment was continued in 11 patients. Seven out of 13 patients with hypothyroidism required an indefinite treatment (follow-up: 15 to 90 months). Conclusions - In our series, 7% of patients with chronic viral kepatitis C had a dystkyroidism during antiviral therapy. Predictive factors were female gender and positive antimicrosome or anti-TPO antibodies before treatment. Absence of dysthyroidism during a first antiviral treatment did not preclude from the risk of dysthyroidism during a second treatment.