HLA antigens in patients with interferon-alpha-induced autoimmune thyroid disorders in chronic hepatitis C

Analysis of clinical characteristics of thyroid disorders in patients with chronic hepatitis B treated with pegylated-interferon alpha

BACKGROUND

Thyroid disorders (TD) is a common complication of pegylated-interferon alpha (Peg-IFNα) therapy. Few studies have investigated the relationship between TD and the efficacy of interferon therapy for chronic hepatitis B (CHB). Therefore, we analyzed the clinical characteristics of TD in patients with CHB treated with Peg-IFNα, and evaluated the correlation between TD and Peg-IFNα treatment efficacy.

METHODS

In this retrospective study, the clinical data of 146 patients with CHB receiving Peg-IFNα therapy were collected and analyzed.

RESULTS

During the course of Peg-IFNα therapy, positive conversion of thyroid autoantibodies and TD occurred in 7.3% (85/1158) and 8.8% (105/1187) patients, respectively, and was diagnosed more often in women. The most common thyroid disorder was hyperthyroidism (53.3%), followed by subclinical hypothyroidism (34.3%). We found that thyroid function returned to normal in 78.7% of patients with CHB, and thyroid antibody levels returned to the negative range in approximately 50% of patients after interferon treatment cessation. Only 25% of patients with clinical TD required treatment. Compared with patients with hypothyroidism/subclinical hypothyroidism, patients with hyperthyroidism/subclinical hyperthyroidism showed greater reduction and seroclearance of hepatitis B surface antigen (HBsAg) levels.

CONCLUSIONS

TD are not an absolute contraindication for interferon therapy; however, patients should be monitored closely during interferon therapy. In pursuit of functional cure, a balance between efficacy and safety must be achieved.

A systematic review and meta-analysis of endocrine-related adverse events associated with interferon

OBJECTIVES

To perform a systematic review and meta-analysis of interferon and endocrine side effects, including their incidence, evaluation, and management.

METHODS

PubMed was searched through March 7th, 2021, by 2 authors independently (LH Wang and H Zhao). Early phase I/II, phase III experimental trials, prospective and retrospective observational studies were included. Stata 16.0 (StataCorp LLC, 16.0) was the main statistical software for meta-analysis. The weighted incidence and risk ratio were estimated for primary thyroid disease and diabetes mellitus.

RESULTS

A total of 108 studies involving 46265 patients were included. Hypothyroidism was the most common thyroid disorder, followed by hyperthyroidism. IFN α+RBV treated patients experienced hypothyroidism in 7.8% (95%CI, 5.9-9.9), which was higher than IFN α (5.2%; 95%CI, 3.7-6.8) and IFN β (7.0%; 95%CI, 0.06-23.92). IFN α+RBV treated patients experienced hyperthyroidism in 5.0% (95%CI, 3.6-6.5), which was higher than IFN α (3.5%; 95%CI, 2.5-4.8) and IFN β (3.4%; 95%CI, 0.9-7.5). The summary estimated incidence of painless thyroiditis was 5.8% (95%CI, 2.8-9.8) for IFN α, and 3.5% (95%CI,1.9-5.5) for IFN α+RBV. The summary estimated incidence of diabetes was 1.4% (95%CI, 0.3-3.1) for IFN, 0.55% (95%CI, 0.05-1.57) for IFN α, 3.3% (95%CI,1.1-6.6) for IFN α+RBV.

CONCLUSIONS

Our meta-analysis shows a high incidence of endocrine adverse events provoked by IFN, further reinforced by combined RBV treatment.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/, identifier CRD42022334131.

The association of hepatitis C virus infection and thyroid disease: A systematic review and meta-analysis

Previous studies have reported that hepatitis C virus (HCV) infection may increase the risk of thyroid disease (TD) even thyroid cancer (TC), but quantitative assessments of risk were rare and the results were not consistent. The purpose of this study was to evaluate the impact of HCV infection on TD and TC, and provide clues to explore the relationship between HCV infection and TD and TC. The literature retrieval was performed up to August 20th, 2021 in the database of PubMed, Cochrane library, Web of Science, China National Knowledge Infrastructure and Wang Fang. The risk of HCV for TD or TC was expressed with odds ratio (OR) and 95% confidence intervals (CI). Subgroup analysis was used to explore the source of heterogeneity. Six articles (three studies published as article and three studies published as abstract) were included in this meta-analysis, with a total of 5398 controls and 1925 cases of hepatitis C. The results of meta-analysis found that HCV infection were significantly associated with an increased risk of TD (sum OR = 1.80, 95% CI = 1.54-2.10, P <  0.001, I² = 74.3%) and TC (sum OR = 16.36, 95% CI = 4.65-57.62, P < 0.001, I² = 0%). HCV infection may increase the risk of TD and TC. More work is needed in the future to establish a causal role, however an awareness of the possibility of increased risk of TD and TC may lead to earlier diagnosis and better outcomes in patients with hepatitis C.

The impact of familial predisposition on the development of Hashimoto's thyroiditis

Objectives: Hashimoto's thyroiditis (HT) is a common autoimmune disease. Available data show that HT develops as a result of interaction between genetic susceptibility and environmental factors, but the exact pathogenesis of the disease is not yet fully understood. The aim of this investigation is to evaluate the potential relationship between family history of HT and the development of HT.Methods: Data regarding family history of all patients who were referred for a diagnostic evaluation of thyroid function for any reason between May 2014 and May 2018 was analyzed. Only first-degree relatives were considered significant, whereas the data of distant relatives was not collected.Results: A total of 39 patients with positive family history of HT were extracted (Hashimoto group). As a control group, 39 patients with negative family history of HT were randomly chosen from the same database for the final analysis. When analyzing cytological diagnoses, there were 17 patients with confirmed HT in the Hashimoto group, and 7 in the control group (p = 0.0262).Conclusion: To the best of our knowledge, this is the first study directly showing that there is genetic predisposition for the development of HT in patients with positive family history of the disease (43.59% of patients with positive family history developed HT themselves). Assessment of a patient's family history in detail should become a standard procedure when a patient with any thyroid disorder is referred for diagnostic evaluation.

Hepatitis C virus infection and thyroid autoimmune disorders: A model of interactions between the host and the environment

The hepatitis C virus (HCV) infection is an important public health problem and it is associated with hepatic and extrahepatic manifestations. Autoimmune thyroid diseases are common in HCV infected patients and the standard interferon-based treatment is associated with an increase of the immune-mediated thyroid damage. Recent evidence in the literature analyzed critical points of the mechanisms of thyroid damage, focusing on the balance between the two sides of the interaction: The environment (virus infection with potential cross-reaction) and the host (susceptibility genes with consistent immune response). The spectrum of antiviral treatment for chronic HCV infection is rapidly expanding for the development of dual o triple therapy. The availability of interferon-free combined treatment with direct antiviral agents for HCV is very promising, in order to ameliorate the patient compliance and to reduce the development of thyroid autoimmunity.

Diabetes and Hepatitis C: A Two-Way Association

Diabetes and hepatitis C infection are both prevalent diseases worldwide, and are associated with increased morbidity and mortality. Most studies, but not all, have shown that patients with chronic hepatitis C are more prone to develop type 2 diabetes (T2D) compared to healthy controls, as well as when compared to patients with other liver diseases, including hepatitis B. Furthermore, epidemiological studies have revealed that patients with T2D may also be at higher risk for worse outcomes of their hepatitis C infection, including reduced rate of sustained virological response, progression to fibrosis and cirrhosis, and higher risk for development of hepatocellular carcinoma. Moreover, hepatitis C infection and mainly its treatment, interferon α, can trigger the development of type 1 diabetes. In this review, we discuss the existing data on this two-way association between diabetes and hepatitis C infection with emphasis on possible mechanisms. It remains to be determined whether the new curative therapies for chronic hepatitis C will improve outcomes in diabetic hepatitis C patients, and conversely whether treatment with Metformin will reduce complications from hepatitis C virus infection. We propose an algorithm for diabetes screening and follow-up in hepatitis C patients.

Patterns of interferon-alpha-induced thyroid dysfunction vary with ethnicity, sex, smoking status, and pretreatment thyrotropin in an international cohort of patients treated for hepatitis C

BACKGROUND

Interferon-alpha (IFNα)-induced thyroid dysfunction occurs in up to 20% of patients undergoing therapy for hepatitis C. The diversity of thyroid disease presentations suggests that several different pathological mechanisms are involved, such as autoimmunity and direct toxicity. Elucidating the relationships between risk factors and disease phenotype provides insight into the mechanisms of disease pathophysiology.

METHODS

We studied 869 euthyroid patients from the ACHIEVE 2/3 trial, a randomized international clinical trial comparing pegylated-IFNα2a weekly or albumin-IFNα2b every 2 weeks for up to 24 weeks in patients with hepatitis C, genotype 2 or 3, from 136 centers. The study population was 60% male and 55% white. Serum thyrotropin (TSH) and free thyroxine were measured before therapy, monthly during treatment from week 8, and at 4- and 12-week follow-up visits.

RESULTS

Overall, 181 (20.8%) participants had at least one abnormal TSH during the study. Low TSH occurred in 71 (8.2%), of whom 30 (3.5%) had a suppressed TSH below 0.1 mU/L. Hypothyroidism occurred in 53 patients (6.1%), with peak TSH above 10 mU/L in 12 patients (1.4%). Fifty-seven patients had a biphasic thyroiditis (6.6%), with extreme values for the nadir and/or peak TSH in all but one. Medical therapy was given to one thyrotoxic patient, four hypothyroid patients, and 26 biphasic thyroiditis patients. Multivariate logistic regression analysis demonstrated that biphasic thyroiditis is associated with being female and higher pretreatment serum TSH, whereas being Asian or a current smoker decreased the risk of thyroiditis. Hypo- and hyperthyroidism are most strongly predicted by the pretreatment TSH.

CONCLUSIONS

Biphasic thyroiditis accounted for the majority (58%) of clinically relevant IFNα-induced thyroid dysfunction. We confirmed our recent findings in a related cohort that female sex is a risk factor for thyroiditis but not hypothyroidism. Further, in this large multiethnic study, the risk of thyroiditis is dramatically increased, specifically for white women. Smoking was found to be protective of thyroiditis. These results support closer monitoring of women and those with a serum TSH at the extremes of the normal range during therapy so that prompt intervention can mitigate the consequences of thyroid dysfunction associated with IFNα treatment.

Genetic analysis of interferon induced thyroiditis (IIT): evidence for a key role for MHC and apoptosis related genes and pathways

Autoimmune thyroid diseases (AITD) have become increasingly recognized as a complication of interferon-alpha (IFNα) therapy in patients with chronic Hepatitis C virus (HCV) infection. Interferon-induced thyroiditis (IIT) can manifest as clinical thyroiditis in approximately 15% of HCV patients receiving IFNα and subclinical thyroiditis in up to 40% of patients, possibly resulting in either dose reduction or discontinuation of IFNα treatment. However, the exact mechanisms that lead to the development of IIT are unknown and may include IFNα-mediated immune-recruitment as well as direct toxic effects on thyroid follicular cells. We hypothesized that IIT develops in genetically predisposed individuals whose threshold for developing thyroiditis is lowered by IFNα. Therefore, our aim was to identify the susceptibility genes for IIT. We used a genomic convergence approach combining genetic association data with transcriptome analysis of genes upregulated by IFNα. Integrating results of genetic association, transcriptome data, pathway, and haplotype analyses enabled the identification of 3 putative loci, SP100/110/140 (2q37.1), HLA (6p21.3), and TAP1 (6p21.3) that may be involved in the pathogenesis of IIT. Immune-regulation and apoptosis emerged as the predominant mechanisms underlying the etiology of IIT.

Autoantibodies in liver disease: important clues for the diagnosis, disease activity and prognosis

It has been well established that numerous kinds of autoantibodies have been detected in liver disease. Some kinds of autoantibodies may be helpful in the diagnosis of autoimmune liver diseases including autoimmune hepatitis, primary biliary cirrhosis or primary sclerosing cholangitis. However, these autoantibodies are present even in sera of patients with viral hepatitis, drug-induced hepatitis, alcoholic liver disease, non-alcoholic fatty liver disease and hepatocelluar carcinoma as well as in sera of patients with autoimmune liver diseases. Other kinds of autoantibodies are recognized as predictive hallmarks for disease activity or prognosis in liver diseases. On the other hand, treatment with interferon initiates the production of several types of autoantibodies in patients with chronic hepatitis C virus infection. Some of autoantibodies induced by interferon may postulate the treatment outcome in those patients. Recent studies also revealed the close correlation between oxidative stress and the production of autoantibodies in liver diseases. This article primarily reviews the recent advances of autoantibodies in the liver diseases and discusses the clinical significance of these autoantibodies.

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.

Extrahepatic manifestations and autoantibodies in patients with hepatitis C virus infection

Patients with chronic hepatitis C virus (HCV) infection frequently have many extrahepatic manifestations, as persistent HCV infection often triggers lymphoproliferative disorders and metabolic abnormalities. These manifestations primarily include autoimmune disorders such as cryoglobulinemia, Sjögren's syndrome, and autoimmune thyroid disorders. It has been well established that chronic HCV infection plays important roles in the production of non-organ-specific autoantibodies, including antinuclear antibodies and smooth muscle antibodies, and organ-specific autoantibodies such as thyroid autoantibodies. However, the clinical significance of autoantibodies associated with the extrahepatic manifestations caused by HCV infection has not been fully recognized. In this paper, we mainly focus on the relationship between extrahepatic manifestations and the emergence of autoantibodies in patients with HCV infection and discuss the clinical relevance of the autoantibodies in the extrahepatic disorders.

Extrahepatic manifestations and autoantibodies in patients with hepatitis C virus infection

Patients with chronic hepatitis C virus (HCV) infection frequently have many extrahepatic manifestations, as persistent HCV infection often triggers lymphoproliferative disorders and metabolic abnormalities. These manifestations primarily include autoimmune disorders such as cryoglobulinemia, Sjögren's syndrome, and autoimmune thyroid disorders. It has been well established that chronic HCV infection plays important roles in the production of non-organ-specific autoantibodies, including antinuclear antibodies and smooth muscle antibodies, and organ-specific autoantibodies such as thyroid autoantibodies. However, the clinical significance of autoantibodies associated with the extrahepatic manifestations caused by HCV infection has not been fully recognized. In this paper, we mainly focus on the relationship between extrahepatic manifestations and the emergence of autoantibodies in patients with HCV infection and discuss the clinical relevance of the autoantibodies in the extrahepatic disorders.

Extrahepatic manifestations and autoantibodies in patients with hepatitis C virus infection

Patients with chronic hepatitis C virus (HCV) infection frequently have many extrahepatic manifestations, as persistent HCV infection often triggers lymphoproliferative disorders and metabolic abnormalities. These manifestations primarily include autoimmune disorders such as cryoglobulinemia, Sjögren's syndrome, and autoimmune thyroid disorders. It has been well established that chronic HCV infection plays important roles in the production of non-organ-specific autoantibodies, including antinuclear antibodies and smooth muscle antibodies, and organ-specific autoantibodies such as thyroid autoantibodies. However, the clinical significance of autoantibodies associated with the extrahepatic manifestations caused by HCV infection has not been fully recognized. In this paper, we mainly focus on the relationship between extrahepatic manifestations and the emergence of autoantibodies in patients with HCV infection and discuss the clinical relevance of the autoantibodies in the extrahepatic disorders.

Phenotypes of interferon-α-induced thyroid dysfunction among patients treated for hepatitis C are associated with pretreatment serum TSH and female sex

CONTEXT

Thyroid dysfunction is a common complication of interferon-α (IFNα) therapy, with many phenotypic patterns and the potential for significant morbidity.

OBJECTIVE

Our objective was to gain mechanistic insight and predict clinical presentations by determining the risk factors for distinct subtypes of IFNα-induced thyroid dysfunction.

DESIGN

ACHIEVE-1, a randomized trial conducted from 2005-2009, compared long-acting preparations of IFNα in 1323 patients with hepatitis C, genotype 1.

SETTING

A total of 149 outpatient clinics in North America, Europe, and Australia participated.

PATIENTS

We studied 1233 patients who were euthyroid at baseline. This population is 60% male and 82% Caucasian.

INTERVENTIONS

Patients were treated with pegylated IFNα2a weekly or albumin-IFNα2b every 2 wk for 48 wk. Serum TSH and free T(4) were measured before therapy and 12 or more times over 60 weeks.

MAIN OUTCOME MEASURES

Thyroid dysfunction was defined as a TSH outside the normal range during the course of therapy. Low serum TSH indicated thyrotoxicosis, elevated TSH indicated hypothyroidism, and both abnormalities occurred in biphasic thyroiditis.

RESULTS

Of previously euthyroid patients, 16.7% developed abnormal TSH values during therapy, including 24 with TSH below 0.1 mU/liter, 69 with TSH over 5.5 mU/liter, and 76 with biphasic thyroiditis. Biphasic thyroiditis was over 8-fold more common among women than men using multivariate logistic regression analysis [odds ratio (OR) = 8.4; 95% confidence interval (CI) = 4.5-15.8]. Thyrotoxicosis was most strongly associated with a lower pretreatment TSH (OR = 4.1 per -1 mU/liter decline; 95% CI = 1.9-9), whereas hypothyroidism was strongly associated with higher pretreatment TSH (OR = 3.9 per 1 mU/liter increase; 95% CI = 3-5.2).

CONCLUSIONS

Biphasic thyroiditis is common among women treated for hepatitis C with IFNα. Lower and higher pretreatment serum TSH are associated with greater likelihood of thyrotoxicosis and hypothyroidism, respectively. Antithyroid antibody levels were not available for the cohort, and thus we cannot clarify the role of pretreatment thyroid autoimmunity as a risk factor. Our results do show that readily identifiable patient characteristics are risk factors for specific patterns of IFN-induced thyroid dysfunction. These findings suggest that distinct mechanisms may underlie subtypes of thyroid dysfunction associated with immune-modulatory therapy for hepatitis C.

Thyroid dysfunction from antineoplastic agents

Unlike cytotoxic agents that indiscriminately affect rapidly dividing cells, newer antineoplastic agents such as targeted therapies and immunotherapies are associated with thyroid dysfunction. These include tyrosine kinase inhibitors, bexarotene, radioiodine-based cancer therapies, denileukin diftitox, alemtuzumab, interferon-α, interleukin-2, ipilimumab, tremelimumab, thalidomide, and lenalidomide. Primary hypothyroidism is the most common side effect, although thyrotoxicosis and effects on thyroid-stimulating hormone secretion and thyroid hormone metabolism have also been described. Most agents cause thyroid dysfunction in 20%-50% of patients, although some have even higher rates. Despite this, physicians may overlook drug-induced thyroid dysfunction because of the complexity of the clinical picture in the cancer patient. Symptoms of hypothyroidism, such as fatigue, weakness, depression, memory loss, cold intolerance, and cardiovascular effects, may be incorrectly attributed to the primary disease or to the antineoplastic agent. Underdiagnosis of thyroid dysfunction can have important consequences for cancer patient management. At a minimum, the symptoms will adversely affect the patient's quality of life. Alternatively, such symptoms can lead to dose reductions of potentially life-saving therapies. Hypothyroidism can also alter the kinetics and clearance of medications, which may lead to undesirable side effects. Thyrotoxicosis can be mistaken for sepsis or a nonendocrinologic drug side effect. In some patients, thyroid disease may indicate a higher likelihood of tumor response to the agent. Both hypothyroidism and thyrotoxicosis are easily diagnosed with inexpensive and specific tests. In many patients, particularly those with hypothyroidism, the treatment is straightforward. We therefore recommend routine testing for thyroid abnormalities in patients receiving these antineoplastic agents.

Environmental triggers of thyroiditis: hepatitis C and interferon-α

Autoimmune thyroid diseases (AITD) are postulated to develop as a result of a complex interplay between several genetic and environmental influences. The pathogenesis of AITD is still not clearly defined. However, among the implicated triggers (e.g. iodine, infections, medications), more recent data confirmed strong associations of AITD with the hepatitis C virus (HCV) infection and interferon-α (IFNα) therapy. Moreover, it is likely that HCV and IFN act in synergism to trigger AITD in patients. Indeed, approximately 40% of HCV patients develop either clinical or subclinical disease while receiving IFNα. Interferon induced thyroiditis (IIT) can manifest as non-autoimmune thyroiditis (presenting as destructive thyroiditis, or non-autoimmune hypothyroidism), or autoimmune thyroiditis [presenting with clinical features of Graves' disease (GD) or Hashimoto's thyroiditis (HT)]. Although not yet clearly understood, it is thought that IFNα can induce thyroiditis via both immune stimulatory and direct toxic effects on the thyroid. In view of the high frequency of IIT, routine screening and surveillance of HCV patients receiving IFNα is recommended to avoid the complications, such as cardiac arrhythmias, associated with thyrotoxicosis. In summary, IIT is a common clinical problem that can be readily diagnosed with routine thyroid function screening of HCV patients receiving IFN. The treatment of IIT consists of the standard therapy for differing clinical manifestations of IIT such as GD, HT, or destructive thyroiditis. However, anti-thyroid medications are not recommended in this setting since they can potentially be hepatotoxic.

Hepatitis C and interferon induced thyroiditis

Autoimmune thyroid diseases (AITDs) are complex diseases that develop as a result of interactions between genetic, epigenetic, and environmental factors. Significant progress has been made in our understanding of the genetic and environmental triggers contributing to AITD. The major environmental triggers of AITD include iodine, smoking, medications, pregnancy, and possibly stress. In this review we will focus on two well-documented environmental triggers of AITD, hepatitis C virus (HCV) infection and interferon alpha (IFNa) therapy. Chronic HCV infection has been shown to be associated with increased incidence of clinical and subclinical autoimmune thyroiditis (i.e. the presence of thyroid antibodies in euthyroid subjects). Moreover, IFNa therapy of chronic HCV infection is associated with subclinical or clinical thyroiditis in up to 40% of cases which can be autoimmune, or non-autoimmune thyroiditis. In some cases interferon induced thyroiditis (IIT) in chronic HCV patients may result in severe symptomatology necessitating discontinuation of therapy. While the epidemiology and clinical presentation of HCV and interferon induced thyroiditis have been well characterized, the mechanisms causing these conditions are still poorly understood.

Opportunistic autoimmune disorders: from immunotherapy to immune dysregulation

Rapid advances in our understanding of the immune network have led to treatment modalities for malignancies and autoimmune diseases based on modulation of the immune response. Yet therapeutic modulation has resulted in immune dysregulation and opportunistic autoimmune sequelae, despite prescreening efforts in clinical trials. This review focuses on recent clinical data on opportunistic autoimmune disorders arising from three immunotherapeutic modalities: (1) systemic immunomodulators, including interferon-alpha (also used to treat hepatitis C patients) and interferon-beta; (2) monoclonal antibodies to CTLA-4 and CD52, and (3) hematopoietic stem cell transplantation. Uncategorized predisposing factors in these patients include major histocompatibility complex and gender genetics, prevalence of different autoimmune diseases, prior chemotherapy, underlying disorder (e.g., hepatitis C), and preconditioning regimens as part of organ and stem cell transplants. Not unexpectedly, the prevalent autoimmune thyroid disease surfaced frequently. Our combination models to study the balance between thyroid autoimmunity and tumor immunity upon regulatory T-cell perturbation are briefly described.

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.

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.

Adverse effects of high-dose interferon-alpha-2a treatment for chronic hepatitis B

The aim of this study was to assess morbidity and the incidence of adverse effects during interferon (IFN)-alpha-2a treatment of patients with chronic hepatitis B. This prospective study included 48 consecutive patients with chronic hepatitis B who underwent IFN-alpha-2a treatment from January 2003 to August 2005. Adverse effects related to IFN treatment were recorded during this period and for 6 mo after treatment. Adverse effects that led to dose reduction or early discontinuation of IFN treatment were examined. Complete response was reported in 25% of patients. At least 1 adverse effect was documented in 88% of patients. Flu-like symptoms were the most frequently observed adverse effects (88%), and thrombocytopenia (63%), leukopenia (54%), and anemia (23%) were also reported. Bleeding occurred in 2 patients. Other adverse effects included neuropsychiatric signs (21%), alopecia (19%), weight loss (17%), thyroid disorders (19%), menstrual cycle irregularities (8%), skin lesions (8%), and dry cough (4%). Adverse effects that led to dose reduction or early discontinuation of IFN treatment occurred in 19% of patients and included impotence, depression, seizure, thyroid disorders, severe thrombocytopenia, and intestinal bleeding. These effects were found to be unrelated to treatment response. No relationship was detected between patient age, duration of treatment, and adverse effects of IFN. Although IFN-alpha-2a treatment induced various adverse effects in patients with chronic hepatitis B, most of these effects were reversible or could be ameliorated. Adverse effects that led to dose reduction or early discontinuation of IFN treatment were found to be unrelated to complete response.

The incidence and evolution of thyroid dysfunction during interferon-alpha therapy in children with chronic hepatitis B infection

AIM

To assess the effect of interferon-alpha (IFN-alpha) therapy on thyroid functions in children with chronic hepatitis B infection (CHB).

METHODS

Sixty-eight children (7.8 +/- 3.6 years) were treated with 5 (n = 37, group I) or 10 MU/m2 (n = 31, group II) IFN for 6 months. Thyroid hormones, thyrotropin, thyrotropin-releasing hormone stimulation test, thyroid peroxidase and thyroglobulin autoantibodies were evaluated.

RESULTS

Baseline features were not different in the two groups. After therapy, thyroid dysfunction was 27% and 41.9% in groups I and II (n.s.). Subclinical hypothyroidism was 17.9%/ 29%, subclinical hyperthyroidism 5.4%/12.9%, hypothyroidism 2.7%/-, and thyroid antibody positivity 2.7%/- in groups I and II (n.s.). Thyroid dysfunction was 33.8% in the whole group (p = 0.001). Predictors of IFN induced-thyroid dysfunction were female sex and age < 6 years. Thyroid dysfunction resolved within median 6 months in all but three children.

CONCLUSION

Although IFN-induced thyroid dysfunction is mostly subclinical and reversible, this side effect should be kept in mind.

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.

The role of thyroid autoantibodies in the development of thyroid dysfunction in Taiwanese chronic hepatitis C patients with interferon-alpha and ribavirin combination therapy

To investigate the role of thyroid autoantibodies in the development of thyroid dysfunction among chronic hepatitis C (CHC) patients receiving interferon-alpha (IFN-alpha) plus ribavirin (RBV) combination therapy, 95 Taiwanese naïve patients with baseline euthyroidism were enrolled. They were treated with IFN-alpha2b, 6 million units thrice weekly, plus RBV 1,000-1,200 mg daily for 24 weeks. Thyroid function, anti-thyroglobulin and antiperoxidase autoantibodies were tested at enrollment (M0), at the end-of-treatment (M6) and 6 months after end-of-treatment (M12). The percentages of thyroid autoantibodies were 8.4%, 11.6% and 9.5%, at M0, M6 and M12 respectively. Fourteen (14.7%) patients developed thyroid dysfunction at M6 or M12. Thyroid dysfunction occurred during treatment in five (62.5%) of the eight patients with baseline thyroid autoantibodies, which was significantly higher than nine (10.3%) of 87 patients without baseline thyroid autoantibodies (P = 0.0001). Among 14 patients who developed thyroid dysfunction, four (80.0%) of five patients with baseline thyroid autoantibodies recovered at M12, in contrast to two (25%) of eight without baseline thyroid autoantibodies recovered at M12 (P < 0.05). In conclusion, thyroid autoantibodies, either occurred before or during IFN-alpha plus RBV combination therapy, carry a high prediction of subsequent thyroid dysfunction. There also exists difference in the clinical manifestations of thyroid dysfunction in CHC patients treated with combination therapy.

Side effects of interferon-alpha therapy

AIM

Interferon-alpha (IFN-alpha) has been extensively explored for its efficacy in various disease conditions and is currently used as a standard treatment in several of these. Its use is accompanied by a wide variety of possible side effects. These side-effects may hamper reaching and maintaining the dose needed for maximal therapeutic effect while their occurrence can outweigh clinical benefit of IFN-alpha treatment. This review addresses the toxicity profile of IFN-alpha, the presumed pathophysiology of the different side effects and the strategies to handle these.

METHODS

Computerized searches were used and cross-references of articles and books were checked.

RESULTS

Adverse effects due to IFN-alpha have been described in almost every organ system. Many side-effects are clearly dose-dependent. Taken together, occurrence of flu-like symptoms, hematological toxicity, elevated transaminases, nausea, fatigue, and psychiatric sequelae are the most frequently encountered. Although insight in the mechanisms accounting for IFN-alpha-related toxicities has improved in recent years, much remains to be elucidated. Guidelines on the management of these untoward sequelae are mostly based on clinical experience, while many side-effects can only be adequately handled by dose adjustment or cessation of treatment.

CONCLUSION

Further research on the mechanisms underlying both therapeutic effects and adverse events is warranted. Hopefully, this will lead to better identification of those patients who are likely to benefit from treatment without experiencing severe toxicities.

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.

Thyroid dysfunction in patients with chronic hepatitis C receiving a combined therapy of interferon and ribavirin: incidence, associated factors and prognosis

BACKGROUND AND AIMS

Interferon (IFN) plus ribavirin therapy for chronic hepatitis C (CHC) virus infection has been associated with thyroid dysfunction. The goal of our current study was to elucidate predictive factors of: (i) thyroid dysfunction associated with combination therapy; and (ii) long-term reversibility of thyroid dysfunction.

METHODS

In total, 461 patients with CHC and normal baseline thyroid functions were enrolled. All patients received IFN-alpha-2b, 3 or 5 million units thrice weekly, or pegylated (PEG)-IFN-alpha-2b 80 or 100 microg weekly combined with ribavirin 1-1.2 g daily for 24-48 weeks. Assays for serum thyroid stimulating hormone (TSH) and free thyroxine were performed.

RESULTS

By the end of the treatment, thyroid dysfunction (TSH <0.1 or >5 mU/L) had developed in 58 patients (12.6%). Female gender was significantly associated with thyroid dysfunction (P < 0.001 odds ratio (OR) = 2.85; 95% confidence interval (CI) = 1.6-5.1). The incidence of thyroid dysfunction was similar for standard IFN and PEG-IFN-treated patients (49/391 vs 9/70; P = 1.00). Under a nested case-control design, detailed laboratory assessment was carried out on frozen serum samples from patients and age- (+/- 5 years) and sex-matched controls (n = 58). Multivariate analysis revealed significant association between higher positive rates of pretreatment TMA and patients who developed thyroid dysfunction (OR = 5.8, 95% CI = 1.2-27.9). Ten patients ( approximately 2%) remained thyroid dysfunctional at the end of follow up (median, 26.5 months). For these patients, no risk factor can predict the reversibility of thyroid function.

CONCLUSIONS

Female gender and pretreatment TMA positivity are associated with thyroid dysfunction. Long-term thyroid dysfunction may persist in a small group of patients ( approximately 2%).

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

BACKGROUND

Autoimmune thyroid disorders are among the well-known adverse effects of interferon-alpha (IFN-alpha) therapy in patients with chronic hepatitis C. However, there are few reports regarding the long-term outcome of this complication. We aimed to evaluate the natural history of IFN-alpha-induced autoimmune thyroid disorders with long-term follow-up.

METHODS

Four hundred and thirty-nine patients with chronic hepatitis C were treated with IFN-alpha for 24 weeks between March 1993 and April 1998. Seventeen of 439 (3.9%) patients developed symptomatic autoimmune thyroid disorders including nine cases of hyperthyroidism and eight cases of hypothyroidism. The patients with hypothyroidism were all women. These 17 patients were followed up for 71.1 +/- 17.8 months (48-120 months) and were evaluated for long-term outcome.

RESULTS

Eight patients could discontinue the thyroid medication (2-36 months, median 10 months). Nine patients needed the thyroid medication at the follow-up period. The patients with hyperthyroidism who needed long-term thyroid medication had a significantly high titer of TSH receptor antibody on onset compared with the patients who could discontinue the thyroid medication. There were no significant differences in age, type of IFN, duration from IFN administration to onset, cessation of IFN, genotype of hepatitis C virus and thyroid hormone levels on onset between the patients who needed long-term thyroid medication and the patients who could discontinue the thyroid medication.

CONCLUSION

All patients with IFN-alpha-induced thyroid disorders could be controlled with medication. However, the IFN-alpha-induced thyroid disorders are not always reversible. One must be careful about not only the development of autoimmune thyroid disorders during IFN-alpha therapy but also the outcome of the thyroid disease.

Immunogenetics of Hashimoto's thyroiditis

Hashimoto's thyroiditis (HT) is an organ-specific T-cell mediated disease. It is a complex disease, with a strong genetic component. To date, significant progress has been made towards the identification and functional characterization of HT susceptibility genes. In this review, we will summarize the recent advances in our understanding of the genetic input to the pathogenesis of HT.

Host genetic determinants in hepatitis C virus infection

In addition to viral and environmental/behavioural factors, host genetic diversity is believed to contribute to the spectrum of clinical outcomes in hepatitis C virus (HCV) infection. This paper reviews the literature with respect to studies of host genetic determinants of HCV outcome and attempts to highlight trends and synthesise findings. With respect to the susceptibility to HCV infection, several studies have replicated associations of the HLA class II alleles DQB1(*)0301 and DRB1(*)11 with self-limiting infection predominantly in Caucasian populations. Meta-analyses yielded summary estimates of 3.0 (95% CI: 1.8-4.8) and 2.5 (95% CI: 1.7-3.7) for the effects of DQB1(*)0301 and DRB1(*)11 on self-limiting HCV, respectively. Studies of genetics and the response to interferon-based therapies have largely concerned single-nucleotide polymorphisms and have been inconsistent. Regarding studies of genetics and the progression of HCV-related disease, there is a trend with DRB1(*)11 alleles and less severe disease. Studies of extrahepatic manifestations of chronic HCV have shown an association between DQB1(*)11 and DR3 with the formation of cryoglobulins. Some important initial observations have been made with respect to genetic determinants of HCV outcome. Replication studies are needed for many of these associations, as well as biological data on the function of many of these polymorphisms.

Chronic Hepatitis C Infection in a Rural Medicaid HMO

CONTEXT

Chronic hepatitis C infection (CHCI) is an increasingly common problem, affecting about 2% of the US population. The cost and complexity of treatment and difficulties in communicating with the infected population are of concern to insurers and health planners.

PURPOSE

To describe the clinical features of patients with CHCI in a rural Medicaid-covered population and to describe a method developed for treating CHCI in an underserved rural community.

METHODS

We developed a disease management approach to patients with CHCI receiving insurance coverage through a Medicaid HMO in rural Oregon. A locally based multidisciplinary hepatitis committee was formed to develop a management protocol and a process for selecting patients for treatment. The committee met monthly to develop the treatment plan for individual patients. Day-to-day treatment was provided by a nurse under the supervision of the committee.

FINDINGS

One hundred forty-three adults with CHCI were identified by their primary care physicians. About half the patients had a type 1 genotype. Treatment with pegylated interferon and ribavirin was completed on 21 persons, 11 (52%) of whom had a virologic cure. Problems with treatment toxicity were common. Patient satisfaction with the treatment by the nurse was high.

CONCLUSIONS

CHCI is common in this rural, nonminority Medicaid-insured population. A locally based disease management model was developed that was well received by patients and was successful in delivering a high quality of care for people with CHCI in a rural area.

Interferon induced Autoimmune Thyroid Disease (AITD): a model for human autoimmunity

Interferon (IFN) alpha treatment for various conditions has been associated with thyroid autoimmunity. The incidence of interferon induced thyroid autoimmunity has been reported to range from 2.5% to 42%, possibly depending upon dose and duration of medical therapy and patient characteristics. It is not known whether IFN-alpha initiates autoimmune thyroid disease (AITD) or simply exacerbates AITD in individuals with subclinical AITD.

Interferon-alpha and autoimmune thyroid disease

Interferon-alpha (IFN alpha) is the main therapeutic agent in patients infected with the hepatitis C virus (HCV). It is rather safe, but is known to induce the production of autoantibodies and can lead to the occurrence of autoimmune disease. This minireview focuses on the induction of autoimmune thyroid disease (AITD) in HCV-infected patients treated with IFN alpha. Females carry a higher risk to develop AITD upon IFN alpha treatment, with a relative risk of 4.4 (95% confidence interval 3.2-5.9). The presence of thyroid peroxidase antibodies before therapy has a relative risk for AITD of 3.9 (95% confidence interval 1.9-8.1). IFN alpha-associated AITD can consist of autoimmune primary hypothyroidism, Graves' hyperthyroidism, and destructive thyroiditis, with hypothyroidism being the most common side effect. The clear association between AITD and IFN alpha use suggests that high endogenous IFN alpha levels may also be associated with naturally occurring AITD. High endogenous IFN alpha levels are seen in patients infected with certain viruses. It is concluded that IFN alpha is one of the environmental factors capable of triggering the onset of AITD in genetically susceptible individuals.

Identification and management of hepatitis C patients in primary care clinics

OBJECTIVE

Previous survey-based research suggested that hepatitis C patients receive suboptimal care in primary care settings. The aim of our study was to define the actual level of care hepatitis C patients receive in primary care clinics.

METHODS

Medical records of 229 hepatitis C antibody-positive (group 1), 229 hepatitis C antibody-negative (group 2), and 229 patients not tested for hepatitis C antibody (group 3) were reviewed to assess the indications for hepatitis C testing and the subsequent management and referral of hepatitis C antibody-positive patients diagnosed in primary care clinics. In addition, the compliance of primary care physicians with hepatitis C screening and testing guidelines was assessed.

RESULTS

Only 16% of group 1 and 10% of group 2 patients were tested for hepatitis C based on physician-identified risk factors. Only 1% of group 3 patients had documented discussion of hepatitis C risk factors during their initial visit with a primary care physician. The majority of hepatitis C antibody-positive patients was appropriately evaluated in primary care clinics, and most (77%) hepatitis C RNA-positive patients with elevated liver enzymes were referred for subspecialty care. Of the 59 patients who underwent liver biopsy, 40% had bridging fibrosis or cirrhosis.

CONCLUSIONS

Hepatitis C testing is rarely initiated in primary care clinics based on physician-identified risk factors. Interventions should be developed to optimize early diagnosis of hepatitis C as significant liver disease may be present despite the absence of symptoms.

Thyroid dysfunction during treatment of chronic hepatitis C with interferon alpha: no association with either interferon dosage or efficacy of therapy

OBJECTIVES

Treatment of chronic hepatitis C with interferon-alpha (IFN-alpha) may induce thyroid disorders. We evaluated whether this risk is related to the dosage of IFN-alpha or the virological treatment response. Other possible risk factors as well as the evolution of the thyroid abnormalities were also studied.

METHODS

In this prospective trial (n=254), thyroid-stimulating hormone (TSH), free thyroxin (fT4) and thyroid peroxidase autoantibodies were measured before, during and after treatment for hepatitis C virus (HCV). The patients were randomized to either induction therapy [IFN-alpha 6 million units (MIU) daily for 4 weeks and 3 MIU 3/7 days for 22 weeks] or conventional therapy [IFN-alpha 3 MIU 3/7 days for 26 weeks]. In addition, all patients received ribavirin (1000 or 1200 mg) daily. Sustained virological response was defined as loss of detectable HCV RNA at 6 months follow-up. Thyroid dysfunction was defined as TSH level below or above the normal range (0.2-4.5 MIU L-1).

RESULTS

Biochemical thyroid dysfunction developed in 30 (11.8%) of 254 patients. Hypothyroidism (TSH > 4.5 MIU L-1) was seen in 20 and hyperthyroidism (TSH < 0.2 MIU L-1) in 10 patients. Nine of the 30 patients developed symptomatic thyroid disease and HCV treatment was discontinued because of thyroid dysfunction in three of these patients. Thyroid dysfunction occurred in 15 (11.7%) of 128 patients who received high-dose IFN-alpha induction therapy as compared with 15 (11.9%) of 126 patients who received conventional IFN-alpha therapy (P=0.96). Amongst 231 patients who completed all 6 months of HCV treatment, a sustained virological response was obtained in 19 (66%) of 29 with thyroid dysfunction and 109 (54%) of 202 without (P=0.24). By multivariate analysis female gender and Asian origin were independent predictors of developing biochemical thyroid dysfunction (P < 0.01).

CONCLUSION

Thyroid dysfunction occurred in 11.8% of patients treated for chronic hepatitis C with IFN-alpha and ribavirin. Neither the IFN-alpha dosage nor the virological response to treatment were related to the incidence of thyroid dysfunction.

Knowledge of hepatitis C screening and management by internal medicine residents: trends over 2 years

OBJECTIVES

Over 2 million people in the United States are infected with hepatitis C, and there has been an explosion in knowledge regarding this disease in the last decade. Internal medicine residents must be able to identify patients at risk for hepatitis C and institute appropriate diagnostic testing and referral of these patients.

METHODS

A survey regarding hepatitis C risk factors and the management of hepatitis C patients was administered on three occasions over 15 months (time 0, 1 month, and 15 months) to members of a large university-based internal medicine residency.

RESULTS

During the study period 59 residents completed all three surveys. Less than half of the residents (39%) ask patients about hepatitis C risk factors. Only 58% reported that they would refer a hepatitis C antibody positive patient with elevated liver enzymes to a subspecialist on the initial survey. The residents who did not refer patients cited low response rates, high side-effect profiles, and the high cost of therapy as reasons for not referring the patient. There was significant improvement (58% vs 78%, p < 0.01) in the rate of patient referral during the 15-month study period but no substantial improvement in the other knowledge deficits.

CONCLUSIONS

The knowledge base of the internal medicine residents about hepatitis C screening and management is suboptimal. New, more effective hepatitis C education programs for internal medicine residents should be initiated.

A survey of Australian general practice management of hepatitis C-infected patients from non-English-speaking backgrounds

BACKGROUND

Australia receives many migrants from countries with a high prevalence of hepatitis C infection. General practitioners, who are often the first health professionals consulted, need to be aware of risk factors and complications associated with hepatitis C in this group.

METHODS

Four hundred and forty-seven general practitioners, obtained from registries at two Melbourne teaching hospitals serving large non-English-speaking migrant populations, were sent a questionnaire. Two hundred and forty-one returned a completed questionnaire. The survey attempted to assess knowledge of risk factors, complications, currently recommended antiviral therapy, referral practice to specialists and difficulties encountered by practitioners and patients in accessing information about HCV.

RESULTS

Sexual and vertical transmission were listed as more common risk factors than iatrogenic causes or injecting drug use. Most respondents interpreted basic diagnostic tests correctly but there was a range of estimates regarding progression to cirrhosis and hepatocellular carcinoma with many seriously overestimating these aspects of natural history. Interferon and ribavirin were commonly listed as optimal therapy, but both interferon monotherapy and lamivudine, a treatment for hepatitis B, were stated as optimal therapy by 25% of respondents. Considerable frustration was expressed regarding access to reliable information about treatment outcomes and to linguistically and culturally appropriate patient information.

CONCLUSIONS

The wide response range regarding modes of acquisition of HCV in patients from non-English-speaking backgrounds, rates of progression to cirrhosis and hepatocellular carcinoma and optimal antiviral therapy suggests a need to improve provision of appropriate educational resources that will facilitate general practice management of a common and important public health problem.

The impact of medical informatics on the confidence of rural physicians caring for patients with chronic hepatitis C viral infections

OBJECTIVE

The purpose of the present study was to determine whether CD-based medical informatics enhances rural physicians' confidence in the management of patients with chronic hepatitis C viral infections.

METHODS

A total of 385 Canadian rural physicians were mailed a CD-based medical software programme that outlines all aspects of HCV care including diagnosis, counselling, treatment and follow-up. Accompanying the CD was a brief questionnaire that addressed physicians' confidence in the following areas: (i) identifying HCV patients in their practice; (ii) laboratory use and interpretation; (iii) patient counselling; (iv) selection of candidates for treatment; (v) sharing treatment delivery; and (vi) providing follow-up. Three months thereafter, the same questionnaire was repeated.

RESULTS

Of the 385 mailings, 59 (15%) physicians returned the initial questionnaire and 57 (15%) the follow-up questionnaire. Twenty-five (44%) respondents indicated they had used the CD. Baseline physician confidence was low in three of the six areas addressed. At follow-up, in addition to now being confident in all areas, CD users were significantly more confident than those who had not used the CD. Increases in physician confidence for CD users were approximately 150-300% in the six areas addressed. The value assigned the CD programme was 8/10.

CONCLUSION

The results of this study indicate that: (i) rural physicians are uncomfortable in dealing with many aspects of HCV management; (ii) CD-ROM-based medical informatics can significantly enhance rural physicians' confidence in these areas; (iii) approximately 50% of physicians will employ CD-ROM-based medical informatics in their offices; and (iv) physician level of satisfaction with such programmes is high.

Management of hepatitis C patients by primary care physicians in the USA: results of a national survey

Hepatitis C is a major health problem worldwide, yet very little research has been performed to assess the knowledge base and practice patterns of primary care physicians (PCPs) regarding hepatitis C. The aim of this study is to determine the knowledge base and practice patterns of a nationwide cohort of PCPs. A survey was developed to assess the knowledge of PCPs regarding risk factors for hepatitis C, management of hepatitis C patients and attitude regarding testing for hepatitis C. The survey was mailed to 4000 PCPs in the USA. A total of 1412 (39%) PCPs completed the survey. The vast majority, > 90%, of PCPs correctly identified the most common risk factors for hepatitis C. However, only 59% indicated they ask all patients about hepatitis C risk factors, 70% reported they test all patients with hepatitis C risk factors and 78% test all patients with elevated liver enzymes for hepatitis C. Most (72%) PCPs would refer an HCV-positive patient with elevated aminotransferase but only 28% would refer an HCV-positive patient with normal aminotransferase to a specialist. One-fourth of the PCPs did not know what treatment to recommend for hepatitis C patients. Our data suggest that hepatitis C patients may be underdiagnosed and under-referred. Specific educational initiatives and practice guidelines for PCPs are needed to optimize the recognition of patients at risk for hepatitis C and to ensure appropriate testing and referral.

Autoimmune thyroid dysfunction induced by interferon-alpha treatment for chronic hepatitis C: screening and monitoring recommendations

OBJECTIVE

To analyze the proposed mechanisms of action of recombinant interferon-alpha (IFN-a) in causing autoimmune thyroid dysfunction, to identify pretreatment risk factors, and to provide recommendations for screening and monitoring of thyroid dysfunction during IFN-a therapy for chronic hepatitis C.

METHODS

Selected publications were reviewed to analyze the proposed mechanisms of autoimmune thyroid disorders. In addition, we examined the interrelationship of the thyroid and the liver, the occurrence of thyroid dysfunction in patients with chronic hepatitis C before and after IFN-a therapy, and the presence or absence of antithyroid antibodies in association with thyroid disease. Case reports were selected to demonstrate various IFN-a-induced thyroid dysfunction.

RESULTS

IFN-a induces thyroid dysfunction in 3 to 14% of all treated patients with chronic hepatitis C, leading to hypothyroidism, hyperthyroidism, or thyroiditis. In a few patients, thyroid disease will develop in the absence of antithyroid antibodies, a scenario that suggests a nonimmune-mediated mechanism. More frequently, patients develop antithyroid antibodies, which may progress to overt thyroid dysfunction. Through its immunomodulatory properties, IFN-a seems to act through major histocompatibility complex class I antigens to produce antithyroid antibodies and thyroid disease.

CONCLUSION

In patients receiving IFN-a therapy for chronic hepatitis C infection, identifiable risk factors for developing autoimmune thyroid dysfunction are preexisting overt thyroid or autoimmune disease, subclinical thyroid or autoimmune thyroid disease, and female gender. Pretreatment screening is recommended for all patients in whom IFN-a therapy is being considered, and periodic monitoring should be performed during such therapy. Thyroid disease need not be a contraindication to IFN-a therapy; early detection of subclinical or overt thyroid disease may allow uninterrupted continuation of IFN-a treatment.

Efficacy of interferon alfa-2a in severe and refractory uveitis associated with Behçet's disease

PURPOSE

To evaluate the efficacy of interferon alfa-2a (IFN alfa) in severe uveitis associated with Behçet's disease, that is refractory to steroids and conventional immunosuppressive agents.

PATIENTS AND METHODS

Patients with Behçet's disease (according to the International Study Group criteria), who relapsed despite steroids and immunosuppressive agents, were included in this retrospective study. Ophthalmological examination, laser flare photometry, and fluorescein angiography associated with laboratory tests were performed at regular intervals. IFN alfa (3 millions units thrice a week) was injected subcutaneously.

RESULTS

Eight patients (sex ratio: 1) were included between May 1995 and January 1999. The mean age was 29.1 years (14-54 years) and the disease was present between 11 and 167 months before the administration of IFN alfa. IFN alfa was efficient in all cases with a mean follow-up of 22 months (10-55 months). Steroids were tapered from a mean dosage of 47 mg/d to a mean dosage of 8.5 mg/d. Ocular inflammation was controlled and visual acuity improved in all cases. Treatment was generally well tolerated despite a constant but transient flu-like syndrome. IFN alfa was tapered in three patients and stopped in one case without any relapse after five months.

CONCLUSIONS

Within the limitations of this retrospective study, low-dose IFN alfa seems to be well tolerated, promising in the management of refractory forms of uveitis due to Behçet's disease, and effective in allowing a reduction of steroid dosage. A prospective controlled study is necessary to confirm these preliminary results.

Subacute thyroiditis during treatment with combination therapy (interferon plus ribavirin) for hepatitis C virus

Autoimmune thyroiditis has been frequently reported during interferon monotherapy for hepatitis C, but there are few reports concerning subacute thyroiditis. Recently, combination therapy of IFN plus ribavirin has become the preferred therapeutic schedule for chronic hepatitis C. Similarly to interferon monotherapy, there are no reports concerning subacute thyroiditis during combination therapy. We described four episodes of subacute thyroiditis occurring in three patients during antiviral combination therapy. All patients had symptoms compatible with hyperthyroidism, which could be misdiagnosed as IFN side-effects. The antiviral treatment was continued in all three patients and thyroid function increased progressively with pharmacological treatment for hyperthyroidism. We concluded that subacute thyroiditis may be a complication of combination antiviral therapy and should be investigated in patients presenting with compatible symptoms, in order to differentiate from IFN side-effects.