Long-term outcome of interferon-alpha-induced autoimmune thyroid disorders in chronic hepatitis C

Prevalence of thyroid stimulating hormone dysfunction among sofosbuvir-treated HCV-infected patients: A real-world clinical experience

Thyroid dysfunctions occur frequently among hepatitis C virus (HCV)-infected patients. Accumulating evidence has shown the higher incidence of thyroid dysfunctions in interferon-treated patients that was previously the standard of care therapy. However, the prevalence of thyroid disorders has not been studied in the recently developed interferon-free regimens or direct-acting antiviral (DAA) drugs-treated patients. We recruited 37 patients who had just completed 6 months long sofosbuvir-based treatment, and 26 interferon-treated patients were also included in the study. Serum thyrotropin level of all participants was measured using VIDAS. We observed thyroid dysfunctions in both pegylated interferon-experienced and DAA drug-experienced patients but the prevalence of hyperthyroidism was found significantly higher in patients treated with interferon-based regimen as compared with interferon-free regimens. This high prevalence of hypothyroidism in patients with HCV posttreatment highlights the need for regular periodic screening of patients during the treatment.

New treatments for chronic hepatitis C: an overview for paediatricians

Pegylated interferon (IFN) α-2a or 2b in combination with ribavirin for children aged 3 years and older is the standard treatment for paediatric chronic hepatitis C. This treatment regimen was developed firstly in adults. In recent years, a number of direct-acting antiviral agents (DAAs) are under development for treatment of chronic hepatitis C virus (HCV) infection. These agents block viral replication inhibiting directly one of the several steps of HCV lifecycle. DAAs are classified into several categories based on their molecular target: HCV NS3/4A protease inhibitors, HCV NS5B polymerase inhibitors and HCV NS5A inhibitors. Other promising compounds are cyclophilin A inhibitors, mi-RNA122 and IFN-λ. Several new drugs associations will be developed in the near future starting from the actual standard of care. IFN-based and IFN-free regimens are being studied in adults. In this constantly evolving scenario new drug regimens targeted and suitable for children would be possible in the next future. Especially for children, it is crucial to identify the right combination of drugs with the highest potency, barrier to resistance and the best safety profile.

Impairment of regulatory T-cell function in autoimmune thyroid disease

BACKGROUND

Autoimmune thyroid disease (AITD) pathogenesis may result from a loss of immune tolerance to thyroid antigens. Regulatory T cells (Tregs) control immune responses, prevent excessive inflammation, and may be dysfunctional in AITD. We investigated the role of Tregs in Hashimoto's thyroiditis (HT) and Graves' disease (GD), complicated by Down syndrome (DS). Our goal was to identify differences in CD4(+)CD25(high) Treg function or number in patients with GD and HT, compared to healthy controls (HC).

METHODS

Treg number was assessed by flow cytometric analysis in samples from 20 AITD patients (seven GD, 13 HT), nine HC, and seven individuals with DS, a genetic disorder associated with multiple autoimmune disorders including AITD. Treg function was assessed by the inhibition of proliferation (radioactive thymidine incorporation into DNA) of blood-derived T effector (Teff) cells by Tregs in a coculture. Various methods of stimulation were contrasted. Cytokine levels were determined in conditioned media from the co-cultures.

RESULTS

No differences were found in the frequency of Tregs as a percentage of CD4(+) cells between AITD and HC. AITD Tregs were less capable of inhibiting the proliferation of Teff cells when compared to HC; however, the impairment was dependent on the type of stimulation used. DS patients without AITD exhibited normal Treg function. We observed few differences in cytokine production between HC and AITD patients.

CONCLUSIONS

Tregs from AITD patients are partly dysfunctional, possibly explaining their autoimmunity. Future work will elucidate the diagnostic potential and pathophysiology of Tregs in AITD.

Frequency of thyroid dysfunctions during interferon alpha treatment of single and combination therapy in hepatitis C virus-infected patients: a systematic review based analysis

BACKGROUND

Thyroid dysfunction is the commonest endocrinopathy associated with HCV infection due to interferon-based treatment. This comprehensive and systematic review presents the available evidence for newly developed thyroid antibodies and dysfunctions during interferon treatment (both single and combination) in HCV patients.

METHODOLOGY/PRINCIPAL FINDINGS

This systematic review was conducted in accordance with the PRISMA guidelines. The data generated were used to analyze the risk for thyroid dysfunctions during interferon (IFN) treatment in HCV patients. There was a wide range in the incidence of newly developed thyroid dysfunctions and thyroid antibodies in HCV patients during IFN treatment (both single and combination). The wide range of incidence also denoted the possibility of factors other than IFN treatment for thyroid-related abnormalities in HCV patients. These other factors include HCV viral factors, genetic predisposition, environmental factors, and patho-physiological factors. Variations in IFN dosage, treatment duration of IFN, definition/criteria followed in each study for thyroid dysfunction and irregular thyroid function testing during treatment in different studies influence the outcome of the single studies and jeopardise the validity of a pooled risk estimate of side effects of thyroid dysfunction. Importantly, reports differ as to whether the thyroid-related side effects disappear totally after withdrawal of the IFN treatment.

CONCLUSIONS/SIGNIFICANCE

The present review shows that there is a wide range in the incidence of newly developed thyroid dysfunctions and thyroid antibodies in IFN treated HCV patients. This is a comprehensive attempt to collate relevant data from 56 publications across several nations about IFN (both mono and combination therapy) related thyroid dysfunction among HCV patients. The role of each factor in causing thyroid dysfunctions in HCV patients treated with IFN should be analyzed in detail in future studies, for a better understanding of the problem and sounder clinical management of the disease.

Association of interferon-alpha and ribavirin-induced thyroid dysfunction with severity of disease and response to treatment in pakistani asian patients of chronic hepatitis C

Objective. To determine the association of thyroid dysfunction with the severity of the disease and response to treatment in patients of chronic hepatitis C. Design. Cohort study. Patients. One hundred and sixty seven noncirrhotic chronic hepatitis C patients were grouped into treatment group (n = 107) and control group (n = 60). Measurements. Baseline S. ALT and S. AST by IFCC and S. TSH, S. free T4, and S.T3 level were measured by chemiluminescence method. The severity of the disease was measured by Knodell histopathological index (HPI) on liver biopsy. Study group patients underwent 24-weeks IFN and ribavirin therapy and thyroid functions were determined at weeks 0, 12, and 24. Response to therapy was determined by PCR-HCV test. Results. 20 treated patients (18.69%) developed thyroid dysfunction with relative risk (RR) of 11.25 and attributable risk (AR) of 91%. Females were at higher risk. Hypothyroidism was common than hyperthyroidism. There was no significant association between thyroid dysfunction and severity of the disease (P = 0.81) and response to therapy (P = 0.79). Conclusion. Interferon-alpha and ribavirin therapy induces thyroid dysfunction in chronic hepatitis C patients. There is no association between severity of disease and response to therapy with interferon-induced thyroid dysfunction.

A prospective study of lymphocyte subpopulations and regulatory T cells in patients with chronic hepatitis C virus infection developing interferon-induced thyroiditis

OBJECTIVE

One of the side effects of interferon-alpha (IFN-α) therapy is interferon-induced thyroiditis (IIT). The role of lymphocyte subpopulations in IIT remains to be defined. The aim of this study was to assess different peripheral blood lymphocyte subpopulations, mainly CD4(+) CD25(+) CD127low/-FoxP3(+) regulatory T cells (Tregs), in patients with chronic hepatitis C virus (HCV) infection who developed IIT.

DESIGN, PATIENTS AND METHODS

From 120 patients with chronic HCV who started antiviral treatment, those who developed IIT (IIT patients) were selected and compared with patients who did not develop IIT (Co-HCV). Peripheral blood mononuclear cells were obtained before treatment (BT), mid-treatment (MT), end of treatment (ET), 24 weeks post-treatment (PT) and at appearance of IIT (TT).

RESULTS

Eleven patients developed IIT: three Hashimoto's thyroiditis, one Graves'disease, one positive antithyroidal antibodies, one nonautoimmune hypothyroidism and five destructive thyroiditis. During antiviral treatment, an increase in CD8(+) and in Tregs was observed in both groups. A decrease in CD3(+) , CD19(+) and NKT lymphocyte subpopulations was also observed (all P < 0·05). However, no changes were observed in the percentage of CD4(+) , CD3(+) γδ(+) and iNKT lymphocytes, Th1/Th2 balance and Bcl2 expression on B cells when BT was compared with ET. At the appearance of IIT (TT), IIT patients had a higher Th1 response (CCR5(+) CCR7(-) ) (P < 0·01) and a higher Tregs percentage (P < 0·05) than Co-HCV.

CONCLUSIONS

Our results point to the immunomodulatory effects of IFN-α on different lymphocyte subpopulations and a possible role of Th1 response and Tregs in patients with HCV who developed IIT.

Management of Hepatitis C Antiviral Therapy Adverse Effects

Hepatitis C is one of the leading causes of liver disease in the United States, affecting more than 4 million individuals. The current treatment regimen involves pegylated interferon in combination with ribavirin. Although antiviral treatment has been associated with a greater than 50% sustained viral response rate, the adverse effects have proven to be detrimental to quality of life and therapy adherence, and consequently lead to lower sustained viral response rates. This article identifies the most frequently described complications associated with pegylated interferon and ribavirin. The active management of these complications is discussed, including both preventive and empiric treatments.

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.

Toxicity as a result of immunostimulation by biologics

The immune system has evolved highly effective mechanisms of surveillance and defense against foreign pathogens, and is also thought to act in surveillance and suppression of cancer. Thus, a predominant goal of immune system-based therapies is to normalize or enhance the host immune response in the areas of infectious disease and oncology. This review considers general approaches used for therapeutic immunostimulation, alterations in immune response mechanisms that occur with these treatments and the syndromes that commonly arise as a result of these changes. Because nonclinical studies of these therapies are conducted in animal models as the basis for predicting potential human toxicities, this review also considers the value of nonclinical testing to predict human toxicity.

Syndromes and complications of interferon therapy

PURPOSE OF REVIEW

Interferons are used to treat a variety of medical conditions. They are integral players in immunity and a number of immune-mediated complications can arise during interferon therapy. We have reviewed the occurrence of these complications, and the mechanisms behind them.

RECENT FINDINGS

Case reports and follow-up studies of large cohorts of patients on interferon therapy have confirmed that immune-mediated complications are uncommon but can occur in a number of different organ systems. IFNalpha production is induced by specific autoantibody-nuclear antigen immune complexes, and has a key role in the development and maintenance of autoimmunity in systemic lupus erythematosus.

SUMMARY

Interferon therapy can precipitate immune-mediated abnormalities de novo or can exacerbate an existing autoimmune tendency. This is manifest in the rise in titre of existing antibodies and in the development of clinical disease in patients with preexisting antibodies. Type I interferons have a key role in the development of systemic lupus erythematosus.

Thyroid disorders during interferon alpha therapy in 625 patients with chronic hepatitis C: a prospective cohort study

AIM

to report the prevalence, risk factors, management and long-term outcome of thyroid disorders caused by INFalpha in patients with chronic hepatitis C.

PATIENTS AND METHODS

From January 1991 to December 2004, 625 patients with chronic hepatitis C underwent INFalpha therapy. TSH assay was normal and antithyroperoxidase antibodies (anti-TPO) was performed before onset antiviral treatment; then TSH was performed every 2 months in all patients during therapy, and every 3 months after treatment.

RESULTS

58 patients developed thyroid disorder (8.9%). Mean age was 50.6+/-13 years; sex ratio: 1 M/2 F; the anti-TPO antibodies were positive before onset antiviral treatment in 9 patients (13.8%). 26 patients developed hypothyroidism (44.8%), 9 patients developed hyperthyroidism (15.5%) and among them 3 cases of Grave's disease. Biphasic thyroiditis occurred in 21 patients (36.2%), anti-TPO increase during treatment in 2 patients (3.5%) without hypothyroidism. The dysthyroidism was more frequent in risk in female gender (p<0.05) and in the group with positive antiTPO antibodies before treatment (p<0.02).

CONCLUSION

Female gender and positive antiTPO antibodies are the predictive factors of development of the thyroid dysfunction during INFalpha therapy.

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.

Systemic sclerosis after interferon alphacon-1 therapy for hepatitis C

A 66-year-old woman developed systemic sclerosis (SSc) after receiving interferon alphacon-1 (IFNalphacon-1; consensus interferon) therapy for chronic hepatitis C. She suffered from Raynauds phenomenon about 1 year after a course of IFNalphacon-1 therapy. The combination of proximal scleroderma, Raynauds phenomenon, and ANA positivity led to a diagnosis of systemic sclerosis (SSc). IFN has multiple effects on the immune system and is known to trigger the development of autoantibodies, as well as the onset or exacerbation of autoimmune disease. We suspect that the immunomodulatory effects of IFNalphacon-1 triggered the clinical manifestations of SSc in this patient. To our knowledge this is only the third case of SSc after IFNalpha therapy, and it is the first case associated with IFNalphacon-1 therapy.

Adverse side-effects to biological agents

Biological agents-like cytokines, monoclonal antibodies and fusion proteins are widely used in anti-inflammatory and tumour therapy. They are highly efficient in certain diseases, but can cause a great variety of adverse side-effects. Based on the peculiar features of biological agents a new classification of these adverse side-effects of biological agents is proposed - related but clearly distinct from the classification of side-effects observed with chemicals and drugs. This classification differentiates five distinct types, namely clinical reactions because of high cytokine levels (type alpha), hypersensitivity because of an immune reaction against the biological agent (beta), immune or cytokine imbalance syndromes (gamma), symptoms because of cross-reactivity (delta) and symptoms not directly affecting the immune system (epsilon). This classification could help to better deal with the clinical features of these side-effects, to identify possible individual and general risk factors and to direct research in this novel area of medicine.

Central hypothyroidism and hypophysitis during treatment of chronic hepatitis C with pegylated interferon alpha and ribavirin

Thyroid dysfunction is a known complication of interferon treatment in patients with hepatitis C virus (HCV) infection. Other uncommon endocrine complications have been reported during the treatment of viral hepatitis with IFN-alpha, such as hypopituitarism. A 54-year-old female patient with chronic hepatitis C began treatment with pegylated (PEG)-IFN-alpha 2a 180 mug/week plus ribavirin 1,000 mg/day. At week 20 of treatment, her routine laboratory control showed low levels of thyroid-stimulating hormone (TSH) and free serum thyroxine. This was confirmed at week 24, and other laboratory values showed low levels of adrenocorticotrophic hormone (ACTH). A T1-weighted magnetic resonance imaging scan demonstrated high intensity of the anterior pituitary gland and enhancement after intravenous administration of gadolinium. Hypophysitis with hypothalamic-pituitary dysfunction and secondary or central hypothyroidism was diagnosed on the basis of the clinical features, endocrinological assessment, immunological markers and imaging studies. Twenty-four weeks after stopping treatment, HCV RNA was negative by polymerase chain reaction and alanine aminotransferase values were below the upper limits of normal, and ACTH and thyroid values remained within the reference values. This is the first report of central hypothyroidism and hypophysitis during treatment with PEG-IFN-alpha plus ribavirin, and may be included in the potential list of side effects of the combination treatment.