Hepatitis C Infection, Treatment Regimens, and Thyroid Function Abnormalities:

Thyroid disease in chronic hepatitis C infection treated with combination interferon-α and ribavirin: management strategies and future perspective

OBJECTIVE

Hepatitis C virus (HCV) infection is one of the major epidemics afflicting young people in both developed and developing countries. The most common endocrine disorder associated with this infection, especially in conjunction with interferon-α (IFN-α)-based therapy, is thyroid disease (TD). This review examines the development of TD before, during, and after the completion of treatment with combination IFN-α and ribavirin (RBV) for chronic HCV infection. We also summarize the current understanding of the natural history of the condition and propose management and follow-up guidelines.

METHODS

PubMed was searched up to June 30, 2011 for English-language publications that contained the search terms "hepatitis C virus," "chronic hepatitis C," "HCV," "thyroid disease," "thyroiditis," "autoimmunity," "interferon-alpha," and "ribavirin." Additional publications were identified from the reference lists of identified papers. The included studies were original research publications and included combination IFN-α and RBV use in patients that developed TD.

RESULTS

The prevalence of TD before combination IFN-α and RBV therapy ranges from 4.6 to 21.3%; during therapy, 1.1 to 21.3%; and after therapy, 6.7 to 21.3%. The most common TD is thyroiditis. Thyroid function testing (TFT) frequency and diagnostic criteria for various thyroid conditions are not standardized, and many of the existing studies are retrospective.

CONCLUSION

Patients undergoing this therapy should be assessed with a standardized protocol to appropriately detect and manage developed TD. Based on the currently available literature, we recommend that patients receiving combination interferon-α and RBV therapy undergo monthly thyrotropin (TSH) level testing.

Thyroid disease is a favorable prognostic factor in achieving sustained virologic response in chronic hepatitis C undergoing combination therapy: A nested case control study

BACKGROUND

Interferon-α in combination with ribavirin is the current gold standard for treatment of chronic hepatitis C. It is unknown if the development of autoimmune thyroid disease (TD) during treatment confers an improved chance of achieving sustained virologic response. The aim of this study is to assess the chance of achieving sustained virologic response (SVR) in patients who developed TD during treatment when compared with those who did not.

METHODS

We performed a tertiary hospital-based retrospective nested case-control analysis of 19 patients treated for hepatitis C who developed thyroid disease, and 76 controls (matched for age, weight, gender, cirrhosis and aminotransferase levels) who did not develop TD during treatment. Multivariate logistic-regression models were used to compare cases and controls.

RESULTS

The development of TD was associated with a high likelihood of achieving SVR (odds ratio, 6.0; 95% confidence interval, 1.5 to 24.6) for the pooled group containing all genotypes. The likelihood of achieving SVR was increased in individuals with genotype 1 HCV infection who developed TD (odds ratio, 5.2; 95% confidence interval, 1.2 to 22.3), and all genotype 3 patients who developed TD achieved SVR.

CONCLUSIONS

Development of TD during treatment for hepatitis C infection is associated with a significantly increased chance of achieving SVR. The pathophysiogical mechanisms for this observation remain to be determined.

TRIAL REGISTRATION

The Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRB12610000830099.

Development of thyroid diseases in the treatment of chronic hepatitis C with alpha-interferon may be a good prognosticator in achieving a sustained virological response: a meta-analysis

BACKGROUND AND AIM

Thyroid dysfunction is the most common endocrinopathy associated with hepatitis C and its interferon-based treatment. When undergoing treatment, interferon and ribavirin synergize to potently stimulate the immune system in order to eradicate the virus. One of the innocent bystanders in this accentuated response is the thyroid. The present study investigated whether thyroid dysfunction while undergoing combination treatment for hepatitis C is a favorable prognostic maker for a sustained virological response.

METHODS

We carried out a prospective clinical audit in 201 patients treated with combination ribavirin and alpha-interferon and determined the prevalence of sustained virological response in patients in association with thyroid disease. A meta-analysis was also carried out pooling 741 patients from four previous studies on this topic.

RESULTS

There was positive and significant association between thyroid disease and viral clearance. This was not supported by the meta-analysis, however, and some plausible explanations are proffered for this inconsistency.

CONCLUSION

Despite lacking supportive evidence from the meta-analysis, it is important that this information is confirmed (or refuted) in future studies.

The natural history of interferon-alpha2b-induced thyroiditis and its exclusivity in a cohort of patients with chronic hepatitis C infection

BACKGROUND

Interferon-alpha2b (IFN-alpha2b) is well known to cause both hyper- and hypo-thyroidism. In the former, the commonest aetiology is thyroiditis. As there is no previous data to fully characterize the entity of IFN-related thyroiditis, the aim of this study is to document in detail its evolution in a cohort of hepatitis C patients treated with pegylated IFN-alpha2b and Ribavirin (RBV).

METHODS

A prospective observational study was conducted in patients who developed thyroid diseases whilst receiving combination of pegylated IFN-alpha2b and RBV for hepatitis C. The patients were followed with monthly thyrotropin (TSH). Where TSH was undetectable, free tetra- (fT4) and tri-iodothyronine (fT3) were added. Anti-thyroperoxidase (TPO), anti-thyroglobulin (Tg) and thyroid stimulating immunoglobulin (TSI) levels were also performed at diagnosis, during and at the end of IFN therapy. All patients were assessed and followed up closely with monthly TSH, fT4 and fT3 levels until the completion, after 6 and 12 months of treatment.

RESULTS

There were seven females and four males over a 30-month period. All patients were found to have thyroiditis. On average, the time to the development of thyroid disease was 10 weeks and duration of disease 9 weeks. All patients eventually recovered normal biochemical thyroid function although two required short-term supplementation.

CONCLUSION

Thyroiditis was found exclusively in our patients. Both the hyper- and hypo-thyroid phase can be short lived, extreme and transient in nature which warrants strict monthly TSH monitoring. Careful follow-up of all patients is mandatory as complete recovery is expected.

The Spectrum of Autoimmune Thyroid Disease in the Short to Medium Term Following Interferon-alpha Therapy for Chronic Hepatitis C

Autoimmune thyroid diseases are common manifestations of hepatitis C infection, exacerbated by interferon-based treatment. However, the occurrence and pattern of thyroid disease in the short/medium term following the completion of IFN-based therapy is relatively unknown and there are very few previous reports regarding the specific spectrum of autoimmune thyroid disease that may follow such therapy. We hereby report 3 cases which demonstrate the range of thyroid diseases that may occur following interferon therapy. The hypothesis advanced is that in the pathogenesis of these conditions there must be both triggering and sustaining mechanisms as thyroid diseases occur well outside the immediate effect window of pegylated interferon. This paper suggests the need to continue thyroid surveillance in IFN-treated HCV patients following the completion of therapy, perhaps for the first 6 months.

Exacerbation of hepatitis C induced subclinical hypoadrenalism by Interferon-alpha2beta: A case report

Adrenal disease is an uncommon manifestation of hepatitis C infection and its related treatment regimen. This is a case of subclinical hypoadrenalism, probably induced by hepatitis C infection and further exacerbated by interferon-α2β and Ribavirin therapy. The adrenal deterioration during the treatment course was observed closely with 24-hour salivary profiles and 250 μg adrenocorticotropin stimulation tests using parallel serum and salivary cortisol concentrations. A number of possible pathogenic mechanisms are discussed, and the controversy over its management is emphasized.