Virologic factors related to interferon-alpha-induced thyroid dysfunction in patients with chronic hepatitis C

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.

Prevalence of Thyroid Dysfunction in Patients With Hepatitis C

Introduction: Hepatitis C has been linked to a multitude of autoimmune disorders, including rheumatoid arthritis, thyroid disease, cryoglobulinemia, immune thrombocytopenic purpura, systemic lupus erythematosus, and Sjögren’s syndrome. In this study, efforts were made to draw a parallel between hepatitis C and thyroid dysfunction.

Methods: This case-control study was conducted between June 2020 and March 2021 in the gastroenterology ward of a tertiary care hospital. We enrolled 300 hepatitis C-positive patients in this study through consecutive convenient non-probability sampling. In addition, 300 patients without hepatitis C were signed up as a control group. Blood sampling for thyroid function tests was conducted via phlebotomy from the cubital vein and the samples were dispatched to the laboratory for further study.

Results: The control group had more euthyroid patients as compared to patients with hepatitis C (74.6% vs. 89.6%; p-value: <0.01). Hepatitis C patients had more cases of primary hypothyroidism compared to the control group (10.6% vs. 4.6%; p-value: 0.005). Similarly, patients with hepatitis C had a higher prevalence of subclinical hypothyroidism compared to the control group (6.0% vs. 1.3%; p-value: 0.002).

Conclusion: Hepatitis C patients have a high frequency of thyroid dysfunction, particularly primary hypothyroidism and subclinical hypothyroidism. Therefore, it is important to ensure regular screening for early prognosis and avoid treatment modalities that are known to cause thyroid abnormalities.

Hepatic pathological features in naïve patients with chronic hepatitis C who have developed thyroid disorder

Knowing the hepatic pathological features encountered in patients with chronic hepatitis C (CHC) and the fact that extrahepatic manifestations occur only in people with certain characteristics of the immune system, we tried to evaluate, qualitatively and semi-quantitatively, the liver pathological aspects encountered in 96 patients with CHC, previously untreated with Interferon (naïve), who showed or did not show signs of thyroid disorder (TD), hospitalized in the 2nd Medical Clinic of the Emergency County Hospital, Craiova, Romania, within a period of five years (2007-2012). Following hormonal, immunological, and thyroid ultrasound investigations, 14 (14.58%) of the 96 patients showed signs of TD. The main clinical forms of TD in the studied patients with CHC were autoimmune thyroiditis and subclinical hypothyroidism. In the patients with CHC with TD, we found mild chronic hepatitis in 14.28% of cases, the appearance of moderate chronic hepatitis was found in 71.42% patients, and the appearance of severe chronic hepatitis was found in 14.28% patients, while in the patients with CHC without TD we found chronic mild hepatitis in 62.19% of cases, the appearance of moderate chronic hepatitis was met in 32.92% patients, and the appearance of severe chronic hepatitis was found in 4.87% of patients. Mild and moderate fibrosis were found only in CHC patients without TD in a percentage of 25.6% and 65.85%, respectively, while severe fibrosis was found at 12.19% among CHC patients without TD and 92.85% among CHC patients with TD. The pathological aspect of liver cirrhosis was found only in those with TD (7.14%). In conclusion, the pathological features which define the liver necroinflammatory process, as encountered at the pathological examination in CHC patients with TD are the same as in any active chronic hepatitis, the differences being represented by the higher percentage of the periportal and the preseptal necrosis (piecemeal necrosis), as well as by the higher score of portal inflammation. In addition, the severe hepatic fibrosis and the histopathological appearance of the liver cirrhosis have only defined the cases of CHC with TD.

Microorganisms associated to thyroid autoimmunity

Autoimmune thyroid diseases are a group of diseases characterized by a dysfunction of the immune system concerning the thyroid gland, associated with hypothyroidism or hyperthyroidism. The thyroid gland autoimmunity has been recognized as multifactorial. It has been reported that microorganisms may play a role on the pathogenesis of Hashimoto's thyroiditis and Graves´ disease. These could explain the high incidence of the autoimmune thyroid diseases. Helicobacter Pylori (H. pylori) and Hepatitis C virus (HCV) are the microorganisms in which the association with autoimmune thyroid diseases is clearer. The pathophysiologic mechanisms are still not well defined. For H. pylori, molecular mimicry has been the most accepted mechanism. It has been proposed Hepatitis C virus as the trigger of the thyroid autoimmunity by exacerbating the production of thyroid auto-antibodies, while some mention that the real factor that triggers the thyroid autoimmunity is the treatment with Interferon alpha (IFN-alpha) by upregulating MHC class I and inducing ligation of CD40+ cells to thyrocytes. Other microorganisms such as Toxoplasma gondii, Human Immunodeficiency virus, Herpes virus and others have reported information about their association with thyroid autoimmune diseases There are no proposals on how these last microorganisms induce thyroid autoimmunity. There is still a lack of evidence on this topic. Further research must be done to determine the interaction of these microorganisms and the best way to manage these patients.

Positron emission tomography/computed tomography scan of Vogt-Koyanagi-Harada syndrome with associated autoimmune thyroid disease: A case report and literature review

RATIONALE

Vogt-Koyanagi-Harada (VKH) syndrome is a rare disease and could be associated with autoimmune thyroid disease (AITD). This report was aimed to investigate the utility of F-fludeoxyglucose positron emission tomography/computed tomography (F-FDG PET/CT) for the diagnosis of VKH syndrome with AITD and to perform a literature review on the association between the 2 diseases.

PATIENT CONCERNS

A 55-year-old woman without the history of ocular trauma suffered from chronic headache. She was presented with painful blurred vision of both eyes with headache for 2 weeks. Ophthalmic evaluations revealed panuveitis, exudative retinal detachment, and papilloedema in both eyes. The clinical symptoms and presentations are compatible with the diagnosis of VKH syndrome. Other examinations for intraocular infection, malignancy, and lupus choroidopathy were of negative results. The result of contrast-enhanced computed tomography (CT) of the brain was normal. Due to the history of cancer in the patient's families, a F-FDG PET/CT whole-body scan was performed. The result indicated a focal of 2-fluoro-2-deoxy-D-glucose (FDG) uptake at the right upper lobe of the thyroid. Therefore, the patient's thyroid function was examined and the result indicated euthyroidism with detectable thyroid peroxidase/thyroglobulin antibodies.

DIAGNOSES

VKH syndrome with associated AITD.

INTERVENTIONS

Treatment with intravenous pulse systemic methylprednisolone (1000 mg daily) was prescribed for 3 days and then shifted gradually to tapered oral steroid medication.

OUTCOMES

Symptoms of papillitis and serous retinal detachment of VKH syndrome was relieved after steroid treatment LESSONS:: F-fludeoxyglucose positron emission tomography/computed tomography (F-FDG PET/CT) can be used for the effective diagnosis of VKH syndrome with AITD.

[Comorbid autoimmune pathology in patients treated with disease modifying drugs]

Because of intensive growth of the prevalence of multiple sclerosis (MS) and other autoimmune diseases (AID) during the last years, the comorbidity of MS and AID is not a rarity. In this literature review, the development of comorbid AID in patients with MS is considered to be the probable complication of disease modifying therapy with drugs of different groups. The authors present the own data on the prevalence of comorbid autoimmune pathology in patients with MS treated with disease modifying drugs.

Thyroid Dysfunction in Chronic Hepatitis C Patients Treated with the Combined Pegylated Interferon-Ribavirin Therapy

Hepatitis C virus (HCV) is an Egyptian serious national health problem. The combination of pegylated interferon (PEG-IFN) with ribavirin (RIB) was considered the established therapy for chronic hepatitis C (CHC), and it was associated with several adverse effects, including thyroid dysfunction (TD). The aim of this work was to study TD in CHC patients receiving PEG-IFN+ RIB therapy. This retrospective study included 100 adult patients attending the outpatient clinics at AL-Kahera Al-Fatemya hospital and were eligible candidates for PEG-IFN+ RIB therapy. Thyroid hormonal profile (thyroid-stimulating hormone, free triiodothyronine, and free thyroxine) was done before initiation of treatment (week 0) and at weeks 12, 24, 48, and 72. The incidence of TD was more evident by the end of treatment (week 48); it was found to be 35%, mostly in the form of hypothyroidism, while the least incidence was detected by week 12 (2%), all in the form of hyperthyroidism. Generally, hypothyroidism was higher than hyperthyroidism in multiple folds. Thyroid profile was not significantly related to viral load.

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.

Thyroid dysfunction in Chinese hepatitis C patients: Prevalence and correlation with TPOAb and CXCL10

AIM: To investigate the relationship among pretreatment serum CXC chemokine ligand 10 (CXCL10), thyroid peroxidase antibody (TPOAb) levels and thyroid dysfunction (TD) in Chinese hepatitis C patients.

METHODS: One hundred and thirty-nine treatment-naive genotype 1 chronic hepatitis C patients with no history of TD or treatment with thyroid hormones were enrolled in this study. Patients underwent peginterferon alfa-2a/ribavirin (PegIFNα-2a/RBV) treatment for 48 wk, followed by detection of clinical factors at each follow-up point. Hepatitis C virus (HCV) antibodies were analyzed using microsomal chemiluminescence, and serum HCV RNA was measured by real-time PCR assay at 0, 4, 12, 24 and 48 wk after the initiation of therapy and 24 wk after the end of therapy. To assess thyroid function, serum thyroid stimulating hormone (TSH), free thyroxine (FT4), free triodothyronine (FT3) and TPOAb/thyroglobulin antibody (TGAb) levels were determined using chemiluminescent immunoassays every 3 mo. Serum CXCL10 levels were determined at baseline.

RESULTS: The prevalence of TD was 18.0%. Twenty-one (84.0%) out of twenty-five patients exhibited normal thyroid function at week 24 after therapy. The rate of sustained virological response to PegIFNα-2a/RBV in our study was 59.0% (82/139), independent of thyroid function. Pretreatment serum CXCL10 levels were significantly increased in patients with euthyroid status compared with patients with TD (495.2 ± 244.2 pg/mL vs 310.0 ± 163.4 pg/mL, P = 0.012). Patients with TD were more frequently TPOAb-positive than non-TD (NTD) patients (24.2% vs 12.3%, P = 0.047) at baseline. Three of the one hundred and fifteen patients without TPOAb at baseline developed TD at the end of treatment (37.5% vs 2.6%, P = 0.000). Female patients exhibited an increased risk for developing TD compared with male patients (P = 0.014).

CONCLUSION: Lower pretreatment serum CXCL10 levels are associated with TD, and TD prevalence increases in female patients and patients who are positive for TPOAb at baseline.

Possible factors affecting thyroid dysfunction in hepatitis C virus-infected untreated patients

The present study investigated the association of thyroid dysfunction (TD) with the distribution of chronic hepatitis C virus (HCV) infection in untreated patients. A total of 1,012 cases of HCV-infected patients were collected from different regions, of which 209 patients demonstrated a type of TD (chronic thyroiditis complicated with hyperthyroidism, chronic thyroiditis complicated with hypothyroidism, subclinical hyperthyroidism, subclinical hypothyroidism, hyperthyroidism, hypothyroidism or chronic thyroiditis). The results showed the existence of geographical differences in the types of TD present with HCV infection. The female patients had a higher incidence of autoimmune-related TD than the male patients. High levels of HCV RNA expression were most common in all HCV-infected patients, regardless of the presence of TD. High and medium expression levels of HCV RNA were more prevalent in the patients with autoimmune-related TD. Relative analysis of the HCV RNA levels showed that the pathogenesis of TD was not correlated with the HCV RNA expression levels; however, it may have been associated with autoimmunity. The HCV-infected patients with TD were most commonly middle-aged, whereas young adults were the largest group of patients with HCV and normal thyroid function. Among all HCV genotypes, type 1b was the most common HCV genotype and type 2 was the second most common. Types 3 and 6 were scarce in this study population. No associations were identified between HCV genotypes and thyroid disease. The data of liver function showed that HCV-infected patients with TD had a higher liver dysfunction rate compared with that of the patients with normal thyroid function. Therefore, liver dysfunction may be associated with thyroid disease. This study supports the potential of individualized treatment for HCV-infected 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.

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.

Thyroid dysfunction in chinese patients with chronic hepatitis C treated with interferon alpha: incidence, long-term outcome and predictive factors

BACKGROUND

Thyroid dysfunction (TD) represents an extra-hepatic manifestation of chronic hepatitis C (CHC) and it may also be a side effect of interferon-alpha (IFN-α) based treatment. However, previous studies have shown a wide variation in the incidence of TD in patients with CHC. Furthermore, the long-term outcomes and the predictive factors of TD in patients who receive IFN-α based treatment have still not been fully studied.

OBJECTIVES

The purpose of this study was to describe the incidence and long-term outcomes of TD in Chinese patients with CHC receiving IFN-αbased treatment. We also aimed to identify the predictive factors of TD associated with this type of therapy.

PATIENTS AND METHODS

A retrospective case-series study of 592 consecutive CHC patients with normal baseline thyroid functions, who received IFN-αbased therapy, was performed. Thyroid function was assessed at baseline and every three months during treatment, as well as in the follow-up after cessation of therapy. The incidence and long-term outcomes of TD were observed. The prevalence of pretreatment thyroid peroxidase antibodies (TPOAb) were assayed in a sex- and age-matched nested case-control study. Multivariable stepwise regression analysis was used to explore the independent effects of the baseline factors, on the incidence of TD.

RESULTS

At the end of the IFN-αbased therapy, 68 patients (11.5%) in the study had developed TD, 58 patients (85.3%) presented with subclinical TD, and only 10 patients (14.7%) developed overt thyroiditis. The thyroid function of 46 patients (67.8%) spontaneously returned to normal in the six months of follow-up and only three patients (4.4%) had persistent overt TD symptoms after the 24 month follow-up period. Multivariate stepwise analysis suggested that gender and pretreatment TPOAb were the independent factors related to the incidence of TD. Both female patients (OR, 4.31; 95%CI, 2.06-7.31; P = 1.26×10-4) and participants with a positive pretreatment TPOAb (OR = 3.9, 95%CI, 1.72-8.54, P = 0.008) had an increased risk for the development of TD.

CONCLUSIONS

The incidence of TD in Chinese patients with CHC during IFN-αbased therapy was 11.5%, the majority of which was subclinical, while only a very small group had long-term overt TD requiring ongoing medical therapy. Female gender and pretreatment TPOAb positivity are risk factors for the development of TD during IFN-αbased therapy.

Interferon-associated hepatic steatosis is related to discrepancies in biochemical and virological responses of chronic hepatitis C to IFN-based therapy

BACKGROUND AND AIMS

A discrepancy in virological and biochemical responses may occur throughout interferon-based therapy for hepatitis C virus (HCV). We aimed to explore the risk, associated factors, potential mechanisms, and impact on the treatment outcome of the discrepancy.

SUBJECTS AND METHODS

Consecutive 496, chronic HCV-infected patients receiving interferon/ribavirin or peginterferon/ribavirin for 24 weeks with a 24-week follow-up period were enrolled. Of 433 patients with pretreatment liver biopsy, 46 received serial liver biopsies at the end of treatment and end of follow-up to explore the corresponding change in liver histopathology. A virological/biochemical discrepancy was defined as persistently elevated alanine aminotransferase levels throughout the treatment period, despite the seronegativity for HCV RNA at least at the end of treatment. The sustained virological response (SVR) was defined as seronegativity for HCV RNA 6 months after the end of treatment.

RESULTS

Virological/biochemical discrepancy was observed in 28.7 % (137/478) patients. The SVR rate was comparable between patients with (75.2 %, 103/137) and without discrepancy (81.2 %, 277/341, p = 0.14). For patients with discrepancy and SVR, 78 (75.7 %) had a subsequent normalization of alanine aminotransferase. Hepatic steatosis, advanced fibrosis, obesity, older age, peginterferon preparation, and low viral load were independently predictive of a virological/biochemical discrepancy. Serial liver histology showed that significant transient aggravation of hepatic steatosis during interferon-based therapy was observed among patients with a virological/biochemical discrepancy (difference 0.64 ± 0.93, p = 0.022), but not among those without it (difference 0.09 ± 0.69, p = 0.447).

CONCLUSIONS

A virological/biochemical discrepancy no longer exists after treatment cessation in most patients, and had little impact on the HCV treatment outcome. Treatment-related hepatic steatosis might play an important role in the pathogenesis of the discrepancy.

Thyroid autoantibodies and dysfunction do not impact the treatment efficacy of peginterferon and ribavirin combination therapy in chronic hepatitis C

AIMS

Thyroid disorders, such as the emergence of thyroid autoantibodies (TAs) and thyroid dysfunction (TD), are not uncommon in chronic hepatitis C (CHC) patients. The study aimed to investigate the impact of TAs and dysfunction on the treatment response to pegylated interferon-α plus ribavirin (PegIFN/RBV) combination therapy in CHC patients. The association between interleukin-28B (IL-28B) genetic variants and occurrence of TAs and dysfunction was also analyzed.

METHODS

A total of 449 treatment-naive Taiwanese CHC patients with euthyroid status were consecutively enrolled. They received PegIFN/RBV combination therapy with current recommendation. TAs, TD, and IL-28B genetic variants were measured before treatment. Monitoring of TD was done at 3-month intervals during treatment, at end of treatment, and at end of follow-up (EOF).

RESULTS

The development of TAs was detected in 42 (9.4%) patients before treatment, and the incidence of TD during or at EOF was 20%. Of 287 patients with IL-28B rs8099917 TT genotype, 29 (10.1%) had TAs before treatment, whereas the patients with other genotypes did not have TAs (P = 0.04). There was no significant difference of TD incidence during treatment or at EOF between the patients with different IL-28B genotypes. There was also no significant difference of sustained virologic response according to the presence of TAs, TD, or different manifestations of TD.

CONCLUSION

Taiwanese CHC patients with rs8099917 TT genotype had a higher incidence of TAs. The development of TAs and TD did not impact the treatment efficacy of PegIFN/RBV combination therapy.

NASPGHAN practice guidelines: Diagnosis and management of hepatitis C infection in infants, children, and adolescents

Hepatitis C virus (HCV) is an RNA virus that affects >180 million individuals worldwide with a high propensity for chronic infection. Children with HCV infection differ from adults in several ways including some modes of transmission, rates of clearance, progression of fibrosis, and the duration of potential chronic infection when acquired at birth. Since the discovery of HCV in 1989, there have been significant advances in the understanding of the virology and natural history of chronic HCV infection in children. In addition, there are now several treatment options for children with chronic hepatitis C infection and many new therapies on the horizon. As a consequence, the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition brought together experts in pediatric hepatology to review the available data in children and provide clinicians with approaches to the diagnosis, management, and prevention of HCV infection in children and adolescents. The guideline details the epidemiology and natural history of HCV infection in children, the diagnostic workup, monitoring and treatment of disease, and provides an update on future treatment options and areas of research.

Cutting edge: the etiology of autoimmune thyroid diseases

Significant progress has been made in our understanding of the mechanisms leading to autoimmune thyroid diseases (AITD). For the first time, we are beginning to unravel these mechanisms at the molecular level. AITD, including Graves' disease (GD) and Hashimoto's thyroiditis (HT), are common autoimmune diseases affecting the thyroid. They have a complex etiology that involves genetic and environmental influences. Seven genes have been shown to contribute to the etiology of AITD. The first AITD gene discovered, HLA-DR3, is associated with both GD and HT. More recently, this association was dissected at the molecular level when it was shown that substitution of the neutral amino acids Ala or Gln with arginine at position beta 74 in the HLA-DR peptide binding pocket is the specific sequence change causing AITD. Non-MHC genes that confer susceptibility to AITD can be classified into two groups: (1) immune-regulatory genes (e.g., CD40, CTLA-4, and PTPN22); (2) thyroid-specific genes-thyroglobulin and TSH receptor genes. These genes interact with environmental factors, such as infection, likely through epigenetic mechanisms to trigger disease. In this review, we summarize the latest findings on disease susceptibility and modulation by environmental factors.

Antinuclear antibody titer and treatment response to peginterferon plus ribavirin for chronic hepatitis C patients

Positive serum antinuclear antibody (ANA) is not infrequent in chronic hepatitis C virus (HCV)-infected patients. This prospective study evaluated the impact of ANA on the response to and safety of peginterferon/ribavirin combination therapy for chronic hepatitis C patients in clinical practice. We enrolled 243 consecutive patients who were treated with a 24-week regimen of peginterferon-α plus ribavirin, with a 24-week follow-up period. ANA titer was determined before antiviral treatment. The primary end-point was sustained virological response (SVR), defined as HCV RNA <50 IU/mL throughout the follow-up period. Overall, 187 (77.0%) patients experienced a SVR. In the 105-patient HCV genotype non-1 group, patients with ANA titer ≥1:80 had a significantly lower SVR rate than those with ANA titer <1:80 (67.7% vs. 95.8%, respectively, p = 0.013). In contrast, in the 138-patient HCV genotype 1 group, the SVR rate did not differ between patients with and without ANA titer ≥1:80. Multivariate regressive analyses showed that ANA ≥1:80, age and HCV RNA levels were independent factors associated with SVR in HCV genotype non-1 patients; whereas HCV RNA levels and hepatic fibrosis were prognostic predictors of SVR in HCV genotype 1 patients. The frequencies of adverse events were similar between patients with and without ANA seropositivity. Peginterferon/ribavirin combination therapy is effective and safe in ANA-positive chronic hepatitis C patients. A high ANA titer was a negative prognostic factor for treatment response in HCV genotype non-1 patients.

[Thyroid and hepatitis C]

Autoimmune thyroid diseases are complex diseases that develop as a result of interactions between genetic, epigenetic and environmental factors. IFNa therapy of chronic HCV infection is associated with subclinical or clinical thyroiditis, while the relationship between thyroiditis and virus C infection is still debated.

Thyroid Dysfunction and Long-term Outcome during and after Interferon-alpha Therapy in Patients with Chronic Hepatitis C

Introduction: Thyroid dysfunction (TD) is a well-established adverse effect in chronic hepatitis C virus (HCV)-infected patients, treated with interferon-alpha (IFN-α), with or without ribavirin. However, the long-term outcome is not well-studied. The purpose of this study was to estimate the prevalence and long-term outcome of TD after HCV-therapy. Materials and Methods: Retrospective analysis of 109 HCV-treated patients (for 6 to 12 months, according to HCV genotype), for the period 1996 to 2008. Thyroid function tests were performed every 3 months during therapy and after discontinuation (3 months to 12 years). Routine laboratory tests and virological assessment were performed according to generally accepted practice. Results: TD was observed in 26 patients (23.85%). The positive and negative predictive value for thyroid autoantibodies (ATA) was 80% and 72.7%, respectively. Relative risk for those with positive ATA was 2.9 (95% CI: 1.6 to 5.3, P = 0.014). The median duration of TD was 12.0 months (min: 3; max: 132). The median follow-up period for the patients with TD was 25.5 months (min: 12; max: 144). Finally, 15 patients developed permanent TD (57.69%), compared to 11 with temporary TD (42.31%). Sex is a risk factor for TD, as there were more females than males affected (P = 0.011). Genotype, viral load, time of HCV-exposure prior to therapy, and virological response did not differ between patients with and without TD. Conclusion: TD among HCV-treated patients was more frequent than usually reported, with >50% developing permanent TD. ATA status may play a role in estimating the risk of subsequent TD. Women appear to be more vulnerable to TD than men. Key words: Cirrhosis, Hepatitis C, Interferon, Thyroid autoimmunity, Thyroid disease

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.

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

BACKGROUND AND AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Thyroid dysfunction in patients with chronic hepatitis C: virus- or therapy-related?

BACKGROUND AND AIMS

Thyroid dysfunction (TD) represents an extrahepatic manifestation of chronic hepatitis C (CHC). Moreover, the currently approved treatment of CHC is often associated with TD. However, it remains debatable if TD is mainly virus- or treatment-related. The aim of this study was to assess the incidence and features of TD, and to identify its predictors in treated and untreated CHC patients.

METHODS

Ninety-four patients with CHC and normal thyroid function were evaluated long-term for TD: 33 were untreated (control group) and 61 were treated with pegylated interferon alpha (PEG-IFN-alpha) plus ribavirin (treatment group). Mean follow up was 80.1 and 39.4 months, respectively.

RESULTS

All patients in the control group remained euthyroid, while 13 treated patients (21.3%) developed TD (P < 0.001). Eleven of these were diagnosed with hypothyroidism and two with hyperthyroidism, which then converted to hypothyroidism. In the majority of cases (9/13, 69.2%) TD did not reverse after treatment discontinuation and required hormone replacement therapy. Pretreatment virological parameters did not predict TD, according to multiple logistic regression analysis. TD was not associated with total dose of PEG-IFN-alpha or ribavirin, viral kinetics or with virological outcome, but it was linked to development of other therapy-related autoimmune disorders (odds ratio, 8.29).

CONCLUSION

Antiviral therapy of CHC possibly induces de novo or exacerbates pre-existing silent TD. TD does not seem to correlate with any pretreatment virological parameter; it is probably not related to dose or treatment duration, nor linked to viral kinetics or virological outcome. The role of chronic hepatitis C per se in TD remains to be determined.

Thyroid function and changes in ultrasound morphology during antiviral therapy with pegylated interferon and ribavirin in patients with chronic hepatitis C

Thyroid disease is a common side-effect of interferon-based antiviral therapy for chronic hepatitis C, which may lead to dose reduction or discontinuation of therapy. The aim of this study was to investigate changes in ultrasound morphology, thyroid function, autoimmunity as well as predictive factors for the development of thyroid dysfunction in patients with hepatitis C virus infection treated with pegylated interferon-alpha (PEG-IFN-alpha) and ribavirin. A total of 59 patients with chronic hepatitis C assigned for antiviral treatment with PEG-IFN-alpha and ribavirin were enrolled into the study. All patients were subjected to an ultrasound examination of the thyroid gland before treatment, and after 1, 3 and 6 months of antiviral therapy. In addition, thyroid function and autoimmune status were determined at fixed time-points. Prior and during the course of therapy, 11 patients (19%) developed thyroid dysfunction (one hypothyroidism, nine hyperthyroidism, one hyperthyroidism followed by hypothyroidism). Hyperthyroidism was shown to be Graves' disease in one patient and destructive thyroiditis in nine patients. Power-Doppler ultrasound could differentiate between destructive thyroiditis and Graves' disease. A reduction in echogenicity suggestive for a destructive process of the thyroid gland was observed even before changes in thyroid function of antibody status could be measured. Risk factors for the development of thyroid dysfunction were age, female gender, pre-treatment thyroid volume, pre-existing thyroglobulin/thyroid peroxidase antibodies and viral load. Changes in thyroid function are a common side-effect occurring during antiviral therapy with PEG-IFN-alpha and ribavirin. Ultrasound presents a simple complementary tool for screening and follow-up during antiviral therapy, which helps to differentiate between the common types of hyperthyroidism and gives insight into morphological changes of the thyroid gland during antiviral therapy.

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.

Evolution and predictive factors of thyroid disorder due to interferon alpha in the treatment of hepatitis C

AIM: To study predictive factors of thyroid dysfunction associated with interferon-alpha (IFNα) therapy in chronic hepatitis C (CHC) and to describe its long-term evolution in a large population without previous thyroid dysfunction.

METHODS: We performed a follow-up of thyroid function and detection of thyroid antibodies in 301 patients treated for CHC with IFNα from 1999 to 2004.

RESULTS: Thyroid disorder developed in 30/301 (10%) patients with a mean delay of 6 ± 3.75 mo: 13 patients had hyperthyroidism, 11 had hypothyroidism, and 6 had biphasic evolution. During a mean follow-up of 41.59 ± 15.39 mo, 9 patients with hyperthyroidism, 3 with hypothyroidism, and 4 with biphasic evolution normalized thyroid function in 7.88 ± 5.46 mo. Recovery rate of dysthyroidism was not modified by treatment discontinuation, but was better for patients with negative thyroid antibodies before antiviral treatment (P = 0.02). Women had significantly more dysthyroidism (P = 0.05). Positive thyroid peroxidase and thyroglobulin antibodies were more frequent before antiviral treatment in patients who developed dysthyroidism (P < 0.0003 and P = 0.0003, respectively). In a multivariate model, low fibrosis was found to be a predictive factor of dysthyroidism (P = 0.039).

CONCLUSION: In this monocentric population of CHC, dysthyroidism, especially hyperthyroidism, developed in 10% of patients. Low fibrosis was found to be a predictive factor of dysthyroidism. Thyroid disorder recovered in 16/30 patients (53%) and recovery was better in the non-autoimmune form.

Safety of peginterferon in the treatment of chronic hepatitis C

BACKGROUND

Combination of 'pegylated' interferons (IFNs) plus ribavirin, the standard treatment of chronic hepatitis C (CHC), is frequently associated with side effects. Anticipation, recognition and proper management of these side effects are important to ensure compliance with therapy and achievement of sustained virologic response.

OBJECTIVE

To illustrate the side effect profile of pegIFN-alpha in the treatment of CHC.

METHODS

Studies and abstracts were identified through a computerized, English language literature search. Key search terms included peginterferon and CHC. Information available only in abstract form was retrieved from national and international hepatology associations.

RESULTS

Most adverse events occurring with combination therapy can be anticipated and managed appropriately; therefore, premature discontinuation of therapy owing to side effects is not required in most patients.

Detection of hepatitis C virus in thyroid tissue from patients with chronic HCV infection

Thyroid dysfunctions are common in chronic hepatitis C virus (HCV) infection. HCV-RNA has been detected by reverse-transcription polymerase chain reaction (PCR) in thyroid from HCV infected patients with acquired immunodeficiency syndrome. However, morphological evidence of HCV replication in thyroid cells from immune competent patients has not been provided. In situ hybridization and real-time-PCR were used to analyze HCV-RNA replication in thyroid tissue from 11 patients (3 anti-HCV, serum HCV-RNA positive; 8 anti-HCV negative). Genomic and antigenomic HCV-RNA was detected in the thyroid of the 3 anti-HCV positive patients at concentrations of 2.6 x 10(4), 1.7 x 10(4), and 8.6 x 10(3) copies/microg of total RNA (genomic) and 3.2 x 10(2), 4.3 x 10(3) and 2.9 x 10(2) HCV-RNA copies/microg of total RNA (antigenomic). No HCV-RNA was detected in the thyroid tissue of the 8 anti-HCV negative patients. Presence of genomic/antigenomic HCV-RNA in the 3 anti-HCV positive cases was confirmed by in situ hybridization. Signals were observed in the cytoplasm of the thyroid cells. In conclusion, the data obtained indicate that HCV may infect cells of the thyroid in immune competent patients with chronic HCV infection. The pathogenic implications of this finding merit further research.

Extrahepatic manifestations of hepatitis C virus infection

Hepatitis C virus may cause hepatic and extrahepatic diseases. Extrahepatic manifestations range from disorders for which a significant association with viral infection is supported by epidemiologic and pathogenetic data, to anecdotal observations without clear proof of causality. This article describes the diagnosis and treatment of these diseases.

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.

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.

Extrahepatic manifestations of Hepatitis C Virus infection: a general overview and guidelines for a clinical approach

Hepatitis C Virus is associated with a wide series of extrahepatic manifestations. Based on available data the link between the virus and some of these extrahepatic diseases is only suggested and needs further confirmation. Hepatitis C Virus-related lymphoproliferative disorders, whose prototype is mixed cryoglobulinaemia, represent the most closely related extrahepatic manifestations of Hepatitis C Virus. Other Hepatitis C Virus-associated disorders include nephropathies, thyreopathies, sicca syndrome, idiopathic pulmonary fibrosis, porphyria cutanea tarda, lichen planus, diabetes, chronic polyarthritis, cardiopathy and atherosclerosis. A pathogenetic link between Hepatitis C Virus and some extrahepatic manifestations was confirmed by their responsiveness to antiviral therapy, which is now deemed the first therapeutic option to consider. By contrast, there are diseases where treatment with interferon was ineffective or dangerous. The aim of the present paper is to outline the most recent evidence concerning extrahepatic disorders that are possibly associated with Hepatitis C Virus infection. Special emphasis will be given to discussion of the most appropriate clinical approaches to be adopted in order to diagnose, treat (possibly prevent) and follow-up extrahepathic diseases in patients with Hepatitis C Virus infection.

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.

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%).

Risk factors and long-term course of thyroid dysfunction during antiviral treatments in 221 patients with chronic hepatitis C

AIM

To identify the predictive factors of dysthyroidism during treatment for chronic viral hepatitis C and to evaluate the long-term outcome of these patients.

METHODS

Patients treated for chronic viral hepatitis C between 1990 and 2001 were analyzed retrospectively. Patients with dysthyroidism before treatment and patients positive for hepatitis B surface antigen or human immunodeficiency virus antibodies were excluded. Dysthyroidism was defined by an abnormal serum TSH level on two separate occasions.

RESULTS

221 consecutive patients were included. Among them, a hundred were treated twice by interferon alpha, 21 had 3 treatments and 3 had 4 treatments. Fifteen of these patients (7%) had dysthyroidism during antiviral therapy. There was no significant difference in the frequency of dysthyroidism during the first and the second treatment [respectively 4,1% (N = 9) and 6% (N = 6)]. Female gender and the presence of antimicrosome or antithyroperoxydase (anti-TPO) antibodies before antiviral treatment were predictive factors of dysthyroidism. Treatment by interferon and ribavirin did not increase the risk of dysthyroidism compared to monotherapy with interferon. Pegylated interferon (N = 49) was not a risk factor compared to standard interferon. Thirteen patients had hypothyroidism (2 of them as a result of biphasic thyroiditis) and 2 had hyperthyroidism. The antiviral treatment was continued in 11 patients. Seven out of 13 patients with hypothyroidism required an indefinite treatment (follow-up: 15 to 90 months).

CONCLUSIONS

In our series, 7% of patients with chronic viral hepatitis C had a dysthyroidism during antiviral therapy. Predictive factors were female gender and positive antimicrosome or anti-TPO antibodies before treatment. Absence of dysthyroidism during a first antiviral treatment did not preclude from the risk of dysthyroidism during a second treatment.

Thyroid involvement in patients with overt HCV-related mixed cryoglobulinaemia

BACKGROUND

Mixed cryoglobulinaemia (MC), a systemic vasculitis associated with hepatitis C virus (HCV) infection in >90% of cases, is frequently complicated by multiple organ involvement. The prevalence of thyroid disorders in MC has not yet been studied.

AIM

To investigate the prevalence and clinical features of thyroid involvement in patients with HCV-associated MC (HCV + MC).

DESIGN

Case-control study.

METHODS

HCV + MC patients (n = 93, 17 men and 76 women, mean +/- SD age 63 +/- 10 years, mean disease duration 14 +/- 7 years) consecutively referred to the Rheumatology Unit were matched by sex and age (+/- 2 years) to (i) 93 patients with chronic C hepatitis (CH) without MC and (ii) 93 healthy (HCV-negative) controls from the local population. Measurements included prevalence of hypo- or hyperthyroidism, thyroid autoantibodies, thyroid nodules and thyroid cancer.

RESULTS

By McNemar's chi(2) test, the following thyroid abnormalities were significantly more frequent in HCV + MC patients than in HCV-negative controls: serum anti-thyroperoxidase autoantibody (AbTPO) (28% vs. 9%, p = 0.001); serum AbTPO and/or anti-thyroglobulin autoantibody (31% vs. 12%, p = 0.004); subclinical hypothyroidism (11% vs. 2%, p = 0.038); thyroid autoimmunity (35% vs. 16%, p = 0.006). Serum AbTPO were also significantly more frequent in HCV + MC patients than in CH controls (28% vs. 14%, p = 0.035).

DISCUSSION

The prevalence of thyroid disorders is increased in patients with HCV-related mixed cryoglobulinaemia. We suggest careful monitoring of thyroid function in these patients.

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.

Effect of alpha 2b interferon on inducement of mIL-2R and treatment of HCV in PBMC from patients with chronic viral hepatitis C

AIM: To study the level of membrane interleukin-2 receptor (mIL-2R) on surface of peripheral blood mononuclear cells (PBMC) and the therapeutic efficacy of alpha 2b interferon on the treatment of HCV-RNA in PBMC of patients with chronic hepatitis C and to compare the negative rates of HCV-RNA in PBMC, HCV-RNA and anti-HCV in serum.

METHODS: Before and after treatment of alpha 2b interferon, the level of mIL-2R of patients with chronic hepatitis C was detected by biotin-streptavidin (BSA). The therapeutic group (26 cases) was treated with alpha 2b interferon (3 MU/d) and control therapeutic group (22 cases) was treated with routine drugs (VitC, aspartic acid). The total course of treatment with alpha 2b interferon and routine drug was six months and per course of the treatment was three months. The levels of HCV-RNA in PBMC, HCV-RNA and anti-HCV in serum were detected before and after a course of the treatment.

RESULTS: Before and after treatment of alpha 2b interferon and routine drugs, the levels of mIL-2R in silence stage were (3.44 ± 0.77)% and (2.95 ± 0.72)%, the levels of mIL-2R in inducement stage were (33.62 ± 3.95)% and (30.04 ± 3.73)%. There was a significant difference between two groups (P < 0.01-P < 0.05). After treatment of alpha 2b interferon with 3 MU/d for two courses of the treatment, the total negative rates of HCV-RNA in the PBMC and HCV-RNA, anti-HCV in serum were 42.31% (11/26), 57.69% (15/26), 65.38%(17/26) respectively. After the treatment of routine drug, the negative rates of HCV-RNA in PBMC and HCV-RNA, anti-HCV in serum were 13.64% (3/22), 22.73% (5/22), 27.27% (6/22) respectively. There was high significant difference in the group treated with alpha 2b interferon and the group treated with routine drugs (P < 0.01-P < 0.05).

CONCLUSION: The mIL-2R can be induced by alpha 2b interferon during the treatment. The alpha 2b interferon has a definite effect on the treatment of HCV-RNA in PBMC. The curative effect of alpha 2b interferon is better than that of the routine drugs.

Abrupt onset of diabetes during interferon-alpha therapy in patients with chronic hepatitis C

INTRODUCTION

Interferon-alpha (IFN-alpha) is now widely used in the treatment of chronic hepatitis C. Few patients have been reported as developing impaired glucose tolerance or diabetes mellitus (DM) using this therapy. The explanation for the development of DM in chronic hepatitis C treated with IFN-alpha is unclear. We report two patients who developed an abrupt onset of diabetes during IFN-alpha for chronic hepatitis C.

CASE REPORTS

Two male middle-aged patients were admitted to our hospital for an abrupt onset of diabetes, in diabetic ketoacidosis, with a very short duration of hyperglycaemic symptoms. Their clinical course was similar. Case 1 never demonstrated any markers of pancreatic immunogenicity. Case 2 had high levels of decarboxylase glutamic acid autoantibodies (GADAb), before the IFN-alpha treatment that persisted. We compared initial beta-cell function and metabolic control with a group of middle-aged patients from our hospital who had recently been diagnosed with Type 1 diabetes mellitus (DM1). In contrast to these, the onset of the disease was particularly severe with beta-cell function substantially impaired and displaying unstable short-term metabolic control.

CONCLUSIONS

Type 1 diabetes should be considered as a potential complication if IFN is administered to patients with chronic hepatitis C. Its onset may be severe and result in short-term difficulties in metabolic control.

Incidence and associated factors of neutralizing anti-interferon antibodies among chronic hepatitis C patients treated with interferon in Taiwan

BACKGROUND

The administration of interferon (IFN) could be complicated by the development of neutralizing anti-interferon antibodies (NA). This study evaluates the frequency and associated factors of NA among chronic hepatitis C patients treated with different IFNs.

METHODS

Ninety-five chronic hepatitis C patients were randomized to be treated with recombinant IFN-alpha2a (n = 28), IFN-alpha2b (n = 39) or lymphoblastoid IFN-alpha1 (n = 28) given intramuscularly, 3-6 million units, thrice weekly for 24 weeks. Serum samples collected before, during and after the cessation of treatment were checked for NA.

RESULTS

Three patients were withdrawn from treatment. All patients were negative for NA before treatment and 13 (14%) patients developed neutralizing antibodies. Of the 26 patients treated with IFN-alpha2a, 6 (23.1%) developed NA. whereas NA were detected in only 6 (15.4%) of 39 and 1 (3.7%) of 27 patients treated with IFN-alpha2b and IFN-alphanl, respectively. Age, gender, HCV genotype, ALT level, IFN total dose and liver histology were not associated with the development of NA. By using multivariate logistic regression it was shown that pretreatment HCV RNA level and IFN preparation were the two major factors related to the production of NA. The response of treatment was related to pretreatment viremia but not to the presence of NA.

CONCLUSIONS

The frequency of development of NA among Taiwanese patients with chronic hepatitis C might be related to different IFN preparations and pretreatment HCV RNA level. The response of treatment was related to pretreatment HCV RNA level but not to the presence of NA.