Prospective study on thyroid autoimmunity and dysfunction related to chronic hepatitis C and interferon therapy

Abstract

This study was designed to assess patients with chronic hepatitis C (CHC) for the presence of thyroid autoimmunity and dysfunction, to evaluate the risk of thyroid disorders associated with interferon (IFN) therapy, and to survey the outcome of possible treatment-related thyroid injury. Out of 104 consecutive untreated patients (30 women and 74 men; mean age, 52.7 years), 8 (7.7%) were found seropositive for thyroid autoantibodies (ThyAb), whereas seropositivity in healthy controls was 1/98 (1.3%). The relative increase in risk of developing thyroid autoimmunity associated with CHC was 760% (95% CI, 220-1300%). No patients had abnormalities of thyroid function tests, but on IFN treatment, 3/3 patients showed a rapid over-range rise in circulating thyrotropin, which returned to normal after therapy discontinuation. In the other 5 seropositive patients who refused treatment, thyroid function remained normal. Out of the 58 initially seronegative patients who consented to IFN treatment, 9 (15.5%) developed thyroid autoimmunity. Seven of them (77.7%) had thyroid dysfunction: hypothyroidism in 4 cases, transient thyrotoxicosis in 2 cases. The last patient developed TSH-receptor antibodies and Graves' disease, requiring methimazole therapy. Thyroid function recovered in the former 6 cases following IFN discontinuation. In the 28 initially seronegative patients who refused IFN and participated in a preliminary tauroursodeoxycholic acid trial, antithyroglobulin antibodies alone appeared in one case, but no thyroid dysfunction was observed. The relative risk of thyroid autoimmune disorder associated with IFN therapy was 342% (28-636%). The patients with CHC were unlikely to develop thyroid dysfunction in the absence of IFN therapy, in spite of being ThyAb seropositive. Moreover, a considerable proportion of seronegative patients, when IFN-treated, developed thyroid autoimmunity and then thyroid dysfunction. Both in seropositive and seronegative patients immediate IFN discontinuation normalized thyroid function and hormone replacement therapy was not necessary.

Thyroid Disturbance in Patients with Chronic Hepatitis C Infection: A Systematic Review and Meta-analysis

“…Among the 12 studies, hypothyroidism was reported in 11 [7,[15][16][17][18][19][20][21][22][23][24], while hyperthyroidism in 5 studies [16,20,21,23,24]. TGAb was covered in 8 studies [7,15,17,18,[20][21][22][23], TPOAb in 6 studies [16,17,[20][21][22][23] and ATMA in 5 studies [6,7,15,19,22].…”

“…TGAb was covered in 8 studies [7,15,17,18,[20][21][22][23], TPOAb in 6 studies [16,17,[20][21][22][23] and ATMA in 5 studies [6,7,15,19,22].…”

“…Study characteristics are shown in Table I. The design of these studies was cross-sectional [17,22], case-control [7,16,[19][20][21]23] or cohort (prospective control) [6,18,24,25]. A total of 1,735 HCV-infected and 1,868 non-HCV infected subjects were involved.…”

“…TGAb was determined in 8 studies [7,17,18,[20][21][22][23]25]. The pooled OR was 2.40 (95%CI 1.85-3.13), suggesting that TGAb was more prevalent in HCV group.…”

“…Eleven studies reported the prevalence of hypothyroidism, which involved 1,605 patients in HCV group and 1,626 in the non-HCV group [7,[15][16][17][18][19][20][21][22][23][24]. The prevalence of hypothyroidism was significantly higher in the HCV group than in the non-HCV group (OR, 3.10; 95% CI 2.19-4.40 [I 2 =0.0%]) (Fig.…”