Thyrotoxicosis induced by alpha-interferon therapy in chronic viral hepatitis.
OBJECTIVE
It has been well documented that treatment of chronic hepatitis B and C infection with interferon alpha (IFN-alpha) can lead to the induction of thyroid autoantibodies and hypothyroidism. Thyrotoxicosis, however, is less frequently observed and less well characterized.


METHODS
We reviewed the medical records of patients who developed thyrotoxicosis while receiving IFN-alpha for either chronic hepatitis B or C infection at Westmead Hospital between 1996 and March 2001.


RESULTS
Ten patients (four males and six females) were found to have biochemical thyrotoxicosis. The patients could be divided into two groups with different characteristics. The first group consisted of six patients who had clinical manifestations consistent with Graves' disease, with either diffuse uptake in thyroid scintigraphy and/or positive thyroid-stimulating antibodies. They all required prolonged treatment with antithyroid medications. The second group included three patients who had transient thyrotoxicosis, with progression to hypothyroidism after resolution of thyrotoxicosis.


CONCLUSIONS
Our study suggests that IFN therapy may provoke two different forms of thyrotoxicosis: a Graves' disease picture or a biphasic thyroiditis pattern. The two entities should be differentiated, as they have different implications for treatment.
Wong
Vincent
V
Department of Diabetes and Endocrinology, Westmead Hospital, NSW, Australia. swavwong@aol.com
Fu
Angela Xi-Li
AX
George
Jacob
J
Cheung
N Wah
NW
D000328:Adult; D000998:Antiviral Agents / Q000009:adverse effects* / Q000627:therapeutic use; D005260:Female; D019694:Hepatitis B, Chronic / Q000150:complications / Q000188:drug therapy*; D019698:Hepatitis C, Chronic / Q000150:complications / Q000188:drug therapy*; D006801:Humans; D018828:Immunoglobulins, Thyroid-Stimulating / Q000032:analysis; D016898:Interferon-alpha / Q000009:adverse effects* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013960:Thyroid Function Tests; D013971:Thyrotoxicosis / Q000139:chemically induced* / Q000175:diagnosis
D000998:Antiviral Agents; D018828:Immunoglobulins, Thyroid-Stimulating; D016898:Interferon-alpha