Thyroid hormonal disturbances related to treatment of hepatitis C with interferon-alpha and ribavirin

OBJECTIVE

To characterize thyroid disturbances induced by interferon-alpha and ribavirin therapy in patients with chronic hepatitis C.

INTRODUCTION

Interferon-alpha is used to treat chronic hepatitis C infections. This compound commonly induces both autoimmune and non-autoimmune thyroiditis.

METHODS

We prospectively selected 26 patients with chronic hepatitis C infections. Clinical examinations, hormonal evaluations, and color-flow Doppler ultrasonography of the thyroid were performed before and during antiviral therapy.

RESULTS

Of the patients in our study, 54% had no thyroid disorders associated with the interferon-alpha therapy but showed reduced levels of total T3 along with a decrease in serum alanine aminotransferase. Total T4 levels were also reduced at 3 and 12 months, but free T4 and thyroid stimulating hormone (TSH) levels remained stable. A total of 19% of the subjects had autoimmune interferon-induced thyroiditis, which is characterized by an emerge of antithyroid antibodies or overt hypothyroidism. Additionally, 16% had non-autoimmune thyroiditis, which presents as destructive thyroiditis or subclinical hypothyroidism, and 11% remained in a state of euthyroidism despite the prior existence of antithyroidal antibodies. Thyrotoxicosis with destructive thyroiditis was diagnosed within three months of therapy, and ultrasonography of these patients revealed thyroid shrinkage and discordant change in the vascular patterns.

DISCUSSION

Decreases in the total T3 and total T4 levels may be related to improvements in the hepatocellular lesions or inflammatory changes similar to those associated with nonthyroidal illnesses. The immune mechanisms and direct effects of interferon-alpha can be associated with thyroiditis.

CONCLUSION

Interferon-alpha and ribavirin induce autoimmune and non-autoimmune thyroiditis and hormonal changes (such as decreased total T3 and total T4 levels), which occur despite stable free T4 and TSH levels. A thyroid hormonal evaluation, including the analysis of the free T4, TSH, and antithyroid antibody levels, should be mandatory before therapy, and an early re-evaluation within three months of treatment is necessary as an appropriate follow-up.

Visceral involvements and long-term sequelae in drug-induced hypersensitivity syndrome

Drug-induced hypersensitivity syndrome (DIHS) is a severe systemic reaction with several herpesvirus reactivations. Multiple organ failures appear during the course of the disease. The severity of DIHS is determined by the degree of visceral involvement. Autoimmune diseases also develop several months to years after the apparent clinical resolution of DIHS.

Clinical characteristics of thyroid abnormalities induced by sunitinib treatment in Japanese patients with renal cell carcinoma

Sunitinib is a multi-targeted tyrosine kinase inhibitor that is effective for advanced renal cell carcinoma. However, sunitinib often causes hypothyroidism. In this study, we report eight cases with thyroid dysfunction that occurred during sunitinib treatment for advanced renal cell carcinoma. In seven cases, mild hypothyroidism developed early in the first treatment cycle, and recovered spontaneously. Transient hyperthyroidism was observed during the second or third treatment cycles and was preceded by a rapid increase in thyroglobulin levels. (99m)Tc scintigraphy in the hyperthyroid state showed decreased thyroidal uptake of (99m)TcO(4)(-), suggesting destructive thyroiditis. Hypothyroidism subsequently developed, requiring levothyroxine replacement therapy. Ultrasonography showed a hypoechogenic pattern of the parenchyma and decreased intrathyroidal blood flow. The thyroid glands ultimately became atrophic, which may progress to permanent hypothyroidism. These findings suggest that sunitinib-induced hypothyroidism may occur frequently and may be a consequence of thyroiditis with transient thyrotoxicosis. The marked decrease in thyroid size due to reduced capillary blood flow induced by VEGF receptor inhibition may cause delayed and/or permanent hypothyroidism. Therefore, thyroid function should be monitored in all patients treated with sunitinib.

Interferon induced thyroiditis

Interferon-alpha (IFNalpha) is used for the treatment of various disorders, most notable chronic hepatitis C virus (HCV) infection. One of the commonest side effects of IFNalpha therapy is thyroiditis, with up to 40% of HCV patients on IFNalpha developing clinical or subclinical disease. In some cases interferon induced thyroiditis (IIT) may result in severe symptomatology necessitating discontinuation of therapy. IIT can manifest as clinical autoimmune thyroiditis, presenting with symptoms of classical Hashimoto's thyroiditis or Graves' disease, or as non-autoimmune thyroiditis. Non-autoimmune thyroiditis can manifest as destructive thyroiditis, with early thyrotoxicosis and later hypothyroidism, or as non-autoimmune hypothyroidism. While the epidemiology and clinical presentation of IIT have been well characterized the mechanisms causing IIT are still poorly understood. It is likely that the hepatitis C virus (HCV) itself plays a role in the disease, as the association between HCV infection and thyroiditis is well established. It is believed that IFNalpha induces thyroiditis by both immune stimulatory effects and by direct effects on the thyroid. Early detection and therapy of this condition are important in order to avoid complications of thyroid disease such as cardiac arrhythmias.

Glucocorticoids are preferable to thionamides as first-line treatment for amiodarone-induced thyrotoxicosis due to destructive thyroiditis: a matched retrospective cohort study

CONTEXT

Type 2 amiodarone-induced thyrotoxicosis (AIT) is a destructive thyroiditis usually responsive to glucocorticoids; however, recent surveys showed that many expert thyroidologists worldwide use thionamides for type 2 AIT patients.

OBJECTIVE

The objective of the study was to compare the effectiveness of methimazole (MMI) or prednisone (GLU) in type 2 AIT patients who had a short cure time according to a published predictive model.

DESIGN

This was a matched retrospective cohort study.

SETTING

The study was conducted at a university center.

PATIENTS

Forty-two untreated type 2 AIT patients with a predicted cure time < or = 40 d were divided into two groups (MMI and GLU groups). After matching for the predicted cure time, patients in the GLU group were selected in a 1:1 ratio to patients in the MMI group.

INTERVENTION

Patients were treated with GLU or MMI for 40 d. Patients still thyrotoxic after 40 d continued glucocorticoids if in the GLU group or were switched to prednisone (MMI-GLU group) if in the MMI group.

MAIN OUTCOME MEASURE

Time and rate of cure (healing) at 40 d were measured.

RESULTS

Patients still thyrotoxic after 40 d were 23.8 +/- 9.3% in the GLU group and 85.7 +/- 7.6% in the MMI group (P = 0.000). The GLU and MMI-GLU groups did not significantly differ in the nonhealing rate at 40 d (P = 0.730). When patients in the MMI group were treated with glucocorticoids, 94.1% patients achieved euthyroidism within 40 d. However, the global median cure time (MMI period + prednisone period) was longer (60 d, 95% confidence interval 53.5-66.5 d) in the MMI-GLU group than the GLU group (21 d, 95% confidence interval 15.1-26.9 d).

CONCLUSIONS

Glucocorticoids are the first-line treatment in type 2 AIT, whereas thionamides play no role in this destructive thyroiditis.

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.

Drug-induced thyroiditis and papillary carcinoma in a minocycline-pigmented black thyroid gland

We describe a 31-year-old woman who had ingested minocycline for 18 months prior to presenting with hyperthyroidism and a palpable thyroid nodule. There was no evidence of Graves' disease or autonomous nodule on thyroid scintigraphy, and a clinical diagnosis of thyroiditis was made. Fine-needle aspiration biopsy of the palpable lesion suggested papillary carcinoma, and the patient underwent a total thyroidectomy. Intraoperatively, the thyroid gland was found to have a striking black discoloration. Subsequent histological examination revealed the accumulation of pigment globules within the apical cytoplasm of the follicular cells, and associated findings of a drug-induced thyroiditis. The tumor nodule showed features of infarction and was felt to represent a necrotic papillary microcarcinoma. We postulate that in addition to causing black thyroid pigmentation, chronic minocycline use in our patient resulted in thyroiditis and subsequent hyperthyroidism. The papillary microcarcinoma was probably a coincidental finding.

Oxidative stress in the thyroid gland: from harmlessness to hazard depending on the iodine content

In basal conditions, thyroid epithelial cells produce moderate amounts of reactive oxygen species (ROS) that are physiologically required for thyroid hormone synthesis. They are not necessarily toxic because they are continuously detoxified either in the process of hormone synthesis or by endogenous antioxidant systems. Using a rat model of goiter formation and iodine-induced involution, we found that compared with control thyroids, the oxidative stress, assessed by the detection of 4-hydroxynonenal, was strongly enhanced both in hyperplastic and involuting glands. The level of antioxidant defenses (glutathione peroxidases and peroxiredoxins) was also up-regulated in both groups, although somewhat less in the latter. Of note, increased oxidative stress came along with an inflammatory reaction, but only in involuting glands, suggesting that although antioxidant systems can adequately buffer a heavy load of ROS in goiter, it is not necessarily the case in involuting glands. The effects of 15-deoxy-Delta(12,14)-prostaglandin J2 (15dPGJ2), an endogenous ligand of peroxisome proliferated-activated receptor gamma (PPARgamma) with antiinflammatory properties, were then investigated in involuting glands. This drug strongly reduced both 4-hydroxynonenal staining and the inflammatory reaction, indicating that it can block iodine-induced cytotoxicity. When experiments were carried out with the PPARgamma antagonist, bisphenol A diglycidyl ether, 15dPGJ2-induced effects remained unchanged, suggesting that these effects were not mediated by PPARgamma. In conclusion, thyroid epithelial cells are well adapted to endogenously produced ROS in basal and goitrous conditions. In iodine-induced goiter involution, the increased oxidative stress is accompanied by inflammation that can be blocked by 15dPGJ2 through PPARgamma-independent protective effects.

Interferon alpha treatment and thyroid dysfunction

Interferon alpha (IFN alpha) is the cornerstone therapeutic agent for chronic hepatitis C virus (HCV) infection. Prospective studies have shown that up to 15% of HCV patients receiving IFN alpha develop clinical thyroid disease, and up to 40% become thyroid antibody positive. In some cases IFN-induced thyroiditis (IIT) may result in discontinuation of interferon therapy; thus, IIT represents a major clinical problem for hepatitis C patients receiving IFN alpha therapy. Recently, the mechanisms leading to the development of IIT have begun to be unraveled. It is now clear that HCV itself plays a role in the disease. Moreover, recent data suggest the IFN alpha precipitates thyroiditis by both immune modulatory mechanisms and direct thyroid toxic effects. Genetic factors also play a major role in the etiology of IIT. IIT can manifest both as clinical autoimmune thyroiditis (ie, Hashimoto's thyroiditis and Graves' disease) and as nonautoimmune thyroiditis (ie, destructive thyroiditis). Early detection and therapy of these conditions are important to avoid complications of thyroid disease such as cardiac arrhythmias. This article reviews the epidemiology and clinical manifestations of IIT and the mechanisms causing IIT, focusing on the role of HCV.

Sunitinib (sutent)-induced thyrotoxicosis due to destructive thyroiditis: a case report

Numerous drugs have been associated with destructive thyroiditis (subacute thyroiditis). Sunitinib, a tyrosine kinase inhibitor employed in renal cell carcinoma and gastrointestinal stromal tumors, has recently been linked to destructive thyroiditis with resultant hypothyroidism. We report a patient with transient overt thyrotoxicosis followed by hypothyroidism, apparently related to sunitinib therapy.

Transient thyroiditis after treatment with lenalidomide in a patient with metastatic renal cell carcinoma

Lenalidomide, a recently developed immunomodulatory drug, shares the antiangiogenic and antitumor properties of thalidomide. While there is a known association between thalidomide and hypothyroidism, to our knowledge, there have been no prior reports of thyrotoxicosis associated with thalidomide or lenalidomide treatment. Herein, we report the case of a patient who developed transient thyrotoxicosis while receiving lenalidomide in a clinical trial for metastatic renal cell carcinoma. The time course and biochemical features of this patient's presentation are most consistent with immune-mediated subacute destructive thyroiditis. This case highlights the importance of monitoring thyroid function in the growing number of patients being treated with lenalidomide.

[Side effects during interferon-alpha therapy of hepatitis C with special consideration of thyroid dysfunction]

Hepatitis C virus infection is a worldwide problem and its natural, unfavorable course is still a challenge for the hepatologist. The standard of treatment is combined therapy with interferon-alpha and ribavirin. This therapy is related to a wide spectrum of side effects that significantly reduce quality of life. Approximately 90% of patients suffer from at least one adverse effect; 15% will therefore have reduced drug dose and 5% will discontinue treatment. The most common acute side effects are flu-like symptoms and chronic effects are hematological, neuropsychiatric, and endocrinological (mainly the thyroid). The latest classification divides interferon-induced thyroid diseases into two groups: autoimmune (Hashimoto disease, Graves-Basedow disease, positive antithyroid autoantibodies in euthyroid patients) and non-autoimmune (destructive thyroiditis, non-autoimmune hypothyroidism). The most common complication of cytokine therapy is the induction of antithyroid autoantibodies de novo without thyroid dysfunction. It seems that destructive thyroiditis with typical biphasic course is more common in therapeutic regimens with ribavirin than in interferon-alpha monotherapy. Clinically overt pathologies very often have very discrete symptoms which cause diagnostic and therapeutic dilemmas. Interferon-induced thyroid disorders are usually mild and sometimes self-limiting; nevertheless, every overt thyroid disease requires endocrinological consultation and possible treatment. In this review the most important current information related to hepatitis C, interferon alpha and ribavirin therapy, and thyroid disorders is collected. A new classification of interferon-induced thyroid disease is proposed.

[A case of peripheral facial nerve palsy with cryoglobulinemia and chronic thyroiditis occurring during interferon plus ribavirin therapy for chronic hepatitis C]

A 42-year-old woman with chronic hepatitis C has visited our hospital since October 2003. Liver biopsy revealed chronic hepatitis (A1/F1) . Therapy was initiated with interferon (IFN) alpha-2b and ribavirin in February 2004. Two months later, the patient developed left facial weakness. Laboratory findings showed cryoglobulinemia and abnormal thyroid function without any evidence of other viral infections. Idiopathic peripheral facial nerve palsy was diagnosed. IFN was discontinued at week 9 of therapy, but she obtained sustained virological response and her symptoms resolved at 6 month after the withdrawal.

Glucocorticoid response in amiodarone-induced thyrotoxicosis resulting from destructive thyroiditis is predicted by thyroid volume and serum free thyroid hormone concentrations

CONTEXT

Amiodarone-induced thyrotoxicosis (AIT) resulting from destructive thyroiditis (type 2) is commonly treated with glucocorticoids, but time needed to restore euthyroidism may be unacceptable for patients with underlying cardiac disorders.

OBJECTIVE

The objective of this prospective study was to identify factors affecting the response to glucocorticoids in a large cohort of patients with type 2 AIT followed prospectively.

SETTING

This study was conducted at university centers.

PATIENTS

Sixty-six untreated patients with type 2 AIT were enrolled in the study.

INTERVENTION

All patients were treated with prednisone (initial dose, 0.5 mg/kg.d) as long as needed to restore euthyroidism, defined as cure of AIT.

MAIN OUTCOME MEASURE

The main outcome measure was cure time.

RESULTS

The median cure time was 30 d (95% confidence interval, 23-37 d). Serum free T4 concentration (picograms per milliliter) and thyroid volume (milliliters per square meter) (and, to a lesser extent, serum free T3 concentration) at diagnosis were the main determinants of response to glucocorticoids, with a cure hazard ratio of 0.97 (95% confidence interval, 0.95-0.99; P = 0.005) and 0.84 (95% confidence interval, 0.77-0.91; P = 0.000) for unit of increment, respectively. AIT was cured in all patients with a complete follow-up; euthyroidism was reached in 30 d or less in 60% of patients but in more than 90 d in 16%. A prompt control of thyrotoxicosis (<or=30 d of treatment) was more frequent (77%) in patients with serum basal free T4 concentration no greater than 50 pg/ml and thyroid volume (normalized for body surface area) no greater than 12 ml/m2. The cure probability and the mean cure time in an individual patient can be obtained using a formula generated by multiple regression models.

CONCLUSIONS

Baseline serum thyroid hormone concentrations and thyroid volume help identify patients with type 2 AIT at risk of a delayed response to glucocorticoids.

Granulomatous Adenohypophysitis after Interferon and Ribavirin Therapy

OBJECTIVE

To describe a case of granulomatous hypophysitis occurring after treatment with interferon alfa-2b and ribavirin for hepatitis C.

METHODS

Clinical, radiologic, laboratory, and pathologic assessments of a woman with granulomatous hypophysitis and interferon-induced thyroiditis are presented.

RESULTS

A 42-year-old woman with hepatitis C was treated with interferon alfa-2b and ribavirin for 5 months. She was referred after symptoms of thyrotoxicosis developed, in conjunction with laboratory and radiographic evidence of thyroiditis. During the initial evaluation, she was weak and hypotensive; biochemical evaluation showed undetectable plasma cortisol and corticotropin concentrations. Magnetic resonance imaging revealed diffuse enlargement of the pituitary gland, which encroached on but did not compress the optic chiasm. Treatment with supraphysiologic doses of prednisone resulted in clinical and radiographic improvement. Once physiologic doses of glucocorticoids were instituted, however, follow-up magnetic resonance imaging showed substantial progression of the diffuse pituitary enlargement and mild compression of the optic chiasm. Surgical debulking of the mass and histologic evaluation showed chronic, noncaseating granulomatous hypophysitis. An extensive evaluation for secondary causes of granulomatous inflammation of the pituitary revealed only an elevated angiotensin-converting enzyme level; no organisms were identified. After 2 courses of high-dose glucocorticoids, she had radiographic evidence of decreased size of the pituitary lesion but continued to have multiple anterior pituitary hormone deficiencies.

CONCLUSION

Granulomatous hypophysitis and sarcoidosis of the pituitary are rare disorders. Hypophysitis should be considered in patients receiving interferon and ribavirin therapy who have symptoms consistent with pituitary dysfunction.

Hypothyroidism after sunitinib treatment for patients with gastrointestinal stromal tumors

BACKGROUND

Sunitinib malate is an oral tyrosine kinase inhibitor recently approved for the treatment of gastrointestinal stromal tumors and renal cell carcinoma. Because the ret proto-oncogene is also inhibited by this agent, clinical evaluation of thyroid function was performed.

OBJECTIVE

To describe the prevalence and clinical presentation of thyroid dysfunction related to sunitinib therapy.

DESIGN

Prospective, observational cohort study.

SETTING

Tertiary care hospital.

PATIENTS

42 patients treated for a median of 37 weeks (range, 10 to 167 weeks).

MEASUREMENTS

Following analysis of serial thyroid-stimulating hormone (TSH) measurements collected prospectively during a clinical trial of sunitinib, the authors determined the proportion of patients with thyroid dysfunction.

RESULTS

Abnormal serum TSH concentrations were documented in 26 of 42 patients (62%): 15 (36%) developed persistent, primary hypothyroidism; 4 (10%) developed isolated TSH suppression; and 7 (17%) experienced transient, mild TSH elevations. The risk for hypothyroidism increased with the duration of sunitinib therapy. Six of 15 (40%) hypothyroid patients had suppressed TSH concentrations before developing hypothyroidism, suggesting thyroiditis. Two hypothyroid patients evaluated with thyroid ultrasonography had no visualized thyroid tissue despite normal baseline thyroid function.

LIMITATIONS

The exploratory nature of this study precluded more frequent biochemical and sonographic analysis that may better define the mechanism of sunitinib-associated thyroid dysfunction.

CONCLUSION

Hypothyroidism is a frequent complication of sunitinib therapy. Regular surveillance of thyroid function is warranted in patients receiving the drug. Although the mechanism by which this complication occurs is unknown, the observations of preceding TSH suppression and subsequent absence of visualized thyroid tissue in some patients suggest that sunitinib may induce a destructive thyroiditis through follicular cell apoptosis. This provides a rationale for further investigation of sunitinib treatment in patients with advanced thyroid cancer.

Lack of association between repeated vaccination and thyroiditis in laboratory Beagles

BACKGROUND

Intensive vaccination protocols have been suggested as partially responsible for an increased prevalence of autoimmune diseases in dogs in recent years. The aim of this study was to determine whether repeated routine vaccination in dogs is associated with an increased prevalence of thyroiditis.

METHODOLOGY/PRINCIPAL FINDINGS

We conducted a prospective experimental study with 20 healthy purpose-bred Beagles. Five dogs were vaccinated with a multivalent vaccine and a rabies vaccine. Five dogs received only the multivalent vaccine, and 5 dogs received only the rabies vaccine. Five dogs were unvaccinated controls. The multivalent vaccine was administered at 8, 10, 12, 16, 20, 26, and 52 weeks of age and every 6 months thereafter. The rabies vaccine was administered at 16 and 52 weeks of age and then once a year. Blood samples were collected 1 week before euthanasia for evaluation of thyroid profiles and measurement of antibodies directed against canine thyroglobulin. Dogs were euthanized at 5.5 years of age, and the thyroid glands were evaluated histopathologically. Thyroiditis was present in 8 of 20 (40%) dogs at postmortem examination. No association was found between a dog being vaccinated and the prevalence of thyroiditis at postmortem examination. However, the power of the study to detect such an association was low because of the unexpected high prevalence of thyroiditis in the unvaccinated control dogs. Thyroid function tests were abnormal in 2 of 8 dogs with thyroiditis but were normal in all dogs without thyroiditis.

CONCLUSIONS/SIGNIFICANCE

There was no evidence to support an association between routine vaccination and thyroiditis at postmortem examination in beagle dogs after repeated vaccination.

The clinical and physiological spectrum of interferon-alpha induced thyroiditis: toward a new classification

Interferon-alpha (IFNalpha) is a major treatment modality for several malignant and nonmalignant diseases, especially hepatitis C. Prospective studies have shown that up to 15% of patients with hepatitis C receiving IFNalpha develop clinical thyroid disease, and up to 40% were reported to develop thyroid antibodies. Some of these complications may result in discontinuation of interferon therapy. Thus, interferon induced thyroiditis (IIT) is a major clinical problem for patients receiving interferon therapy. IIT can be classified as autoimmune type and non-autoimmune type. Autoimmune IIT may manifest by the development of thyroid antibodies without clinical disease, or by clinical disease which includes both autoimmune hypothyroidism (Hashimoto's thyroiditis) and autoimmune thyrotoxicosis (Graves' disease). Non-autoimmune IIT can manifest as destructive thyroiditis or as hypothyroidism with negative thyroid antibodies. Early detection and therapy of these conditions is important in order to avoid complications of thyroid disease such as cardiac arrhythmias. While it is not clear which factors contribute to the susceptibility to IIT, recent evidence suggests that genetic factors, gender, and hepatitis C virus infection may play a role. In contrast, viral genotype and therapeutic regimen do not influence susceptibility to IIT. The etiology of IIT is unknown and may be secondary to immune modulation by IFNalpha and/or direct effects of interferon on the thyroid. In this review we discuss the clinical and pathophysiological aspects of IIT, and we are proposing a new, etiology-based classification of IIT, as well as an algorithm for diagnosis and treatment of IIT.

[Beta interferon and thyroid]

We report the case of a thyroiditis in a 44-year-old woman with relapsing-remitting multiple sclerosis treated with interferon beta. Before treatment, thyroid function tests were normal and anti-thyroid (anti-thyroglobulin and anti-thyroid peroxidase) antibodies were negative. After 18 months of treatment, the patient presented clinical features of thyroiditis. We noted a rise in TSH values and anti-thyroid antibodies were found positive. Treatment was not discontinued and further surveillance showed an improvement in clinical and biological features. We conclude that thyroid function should be monitored during INF beta treatment. Laboratory tests must be carried out before therapy. Clinical follow-up is indicated before undertaking biological tests.

Interferon-alpha-induced hyperthyroidism: a three-stage evolution from silent thyroiditis towards Graves' disease

Autoimmune thyroid disease is a common side-effect of interferon-alpha (IFN-alpha) treatment of viral hepatitis C. We have described three patients with hepatitis C for whom IFN-alpha and ribavirin were prescribed and who developed two successive phases of silent thyroiditis followed by hyperthryroidism relapse due to Graves' disease. These three men had no known history of familial or personal thyroid disease. Destructive thyrotoxicosis appeared 4-6 months after starting IFN-alpha, followed by Graves' hyperthyroidism within 8 to 11 months. The thyrotropin (TSH) level was normal before IFN-alpha was started. The diagnosis of destructive thyroiditis was confirmed by anti-TSH receptor antibody (TSHRAb) negativity and the absence of radionuclide ((123)I or (99)Tc) uptake on thyroid scintiscans. Eight to eleven months after starting treatment, TSHRAb positivity and intense scintigraphic uptake confirmed the appearance of Graves' disease. IFN-alpha was continued in only one patient. Hence, hyperthyroidism induced by IFN-alpha could correspond to the first phase of silent thyroiditis, to Graves' disease or to the succession of both. Rigorous diagnostic procedures with repeated scintiscans and TSHRAb titering are necessary to avoid a false diagnosis and inappropriate therapy.

[Study of the efficacy of combined therapy with interferon alfacon-1 and ribavirin for chronic hepatitis C]

The results of combined interferon alfacon-1 and ribavirin therapy of 94 patients with chronic hepatitis C were analyzed. Complete data, including sustained viral response (SVR), were obtained in 88 patients. 46.8% of them achieved SVR. The most important factor influencing SVR, was the presence of HCV RNA in serum at weeks 12 and 24 of therapy. SVR in these cases was achieved in 14.3% and 0%, respectively. Eight patients discontinued therapy due to adverse events. Most frequent were depressive reactions due to interferon (3 cases), and severe anemia due to ribavirin (2 cases). 37% of patients developed thyroiditis, significantly more frequent in women (27 versus 9).