Is hepatitis C virus a risk factor for thyroid autoimmunity?

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.

Thyroid disturbances in children treated with combined pegylated interferon-alpha and ribavirin for chronic hepatitis C

BACKGROUND

Immunomodulatory properties of interferon (IFN) have been documented. It may induce autoimmune diseases such as autoimmune thyroiditis with hypo- or hyperthyroidism. In addition, it may impair thyroid hormone synthesis through affecting iodide organification in thyroid gland.

PURPOSE

The aim of this study was to describe thyroid function tests disturbances in children with chronic hepatitis C (CHC) receiving pegylated interferon-alpha (PEG IFN-α) plus ribavirin.

METHODS

Fifty children with CHC virus infection who received combined pegylated interferon-alpha with ribavirin were selected. Other 50 apparently healthy children of matched age and sex (considered as control group) were selected. All children (100) were subject to liver function tests, virological studies, and follow-up of thyroid function test during and after the treatment course.

RESULTS

Our study showed that 28% of children received combined PEG IFN-α plus ribavirin showed subclinical hypothyroidism. After 24 weeks treatment with combined therapy of IFN plus ribavirin, the mean level of thyroid stimulating hormone (TSH) was 3.23±88 mU/mL, while TSH was 1.16± 0.77 mU/mL before starting treatment. On the other hand, mean TSH was 1.09±0.92 mU/mL in normal control group.

CONCLUSION

This study revealed an association between subclinical thyroid dysfunction and treatment with IFN-alpha and ribavirin in children. Further studies on larger number of patients and longer follow-up duration are recommended for further confirmation.

Extrahepatic manifestations associated with Chronic Hepatitis C Virus Infection

Chronic hepatitis C virus (HCV) infection has been associated with both organ-specific and systemic autoimmune diseases, with cryoglobulinemia being the most frequent associated disease. Experimental, virologic, and clinical evidence have demon-strated a close association between HCV infection and some systemic autoimmune diseases, especially Sjögren's syndrome, but also rheumatoid arthritis and lupus. A higher prevalence of hematological processes has also been described in patients with HCV infection, including cytopenias and lymphoproliferative disorders (B-cell lymphoma). In addition, patients with chronic HCV infection have a higher frequency of other extrahepatic manifestations including endocrine, metabolic and cardiovascular disorders that may worse the prognosis of patients, along with neuropsychiatric manifestations and general symptoms that have a significant influence on the quality of life of the patient. Direct-acting antiviral therapies (DAAs) that have recently begun to be used are providing the opportunity to effectively cure chronic HCV infection and reduce the burden of both hepatic and extrahepatic complications.

Autoantibodies in chronic hepatitis C: A clinical perspective

Non-organ-specific autoantibodies and thyroid autoantibodies have been frequently found in chronic carriers of hepatitis C virus (HCV). With respect to endomysial antibodies and tissue transglutaminase, it is controversial whether the prevalence of gluten-related seromarkers is higher in patients with HCV. In such cases, in addition to acknowledging any currently existing autoimmune disease, recognizing the risk of the patient developing an autoimmune disease during interferon (IFN)-based treatment must be a principle concern. From a clinical point-of-view, the presence of autoantibodies arouses suspicion that an autoimmune disease may be present or may be precipitated by IFN-based HCV treatment. In this paper, we review the prevalence of autoantibodies in individuals with hepatitis C, the clinical significance of these autoantibodies, and the approach recommended for such situations.

Assessment of the Frequency of Autoantibodies in Chronic Viral Hepatitis

Objective:

To examine the occurrence frequency of auto-antibodies and autoimmune diseases in patients with chronic hepatitis B or C.

Methods:

A total of 67 patients diagnosed with chronic hepatitis B and 77 patients diagnosed with chronic hepatitis C infection based on HBs Ag, Anti HCV, HBe Ag, Anti HBe Ag, HBV DNA, HCV RNA, liver ultrasound, and liver biopsy results as well as 48 healthy individuals were included in this study. ANA, anti dsDNA, anti LKM, Anti-SMA, AMA, C-ANCA, P-ANCA, anti-SSA, anti-SSB, anti-Scl-70, anti Jo-1, anti-U1snRNP, anti-centromere, anti-Jo-1, anti tpo, and anti tg were studied in all individuals in each study group.

Results:

ANA positivity was detected in 8 (12%), 15 (19%) and 2 (4%) individuals in HBV, HCV and control groups, respectively. The difference between the groups was significant (P=0.04). Similarly, anti Tg was positive in one subject in HBV group, in 6 subjects (7%) in HCV group, and in one subject among controls, the difference being significant (P=0.04). There were no significant differences between the study groups in the frequency of other auto-antibodies.

Conclusion:

Similar to studies involving patients who received interferon and/or antiviral agents, an increased frequency of auto-antibodies was also detected in our patient group consisting of interferon and anti-viral naive subjects. The increase in the frequency of auto-antibodies reached statistical significance among individuals with HCV infection. Thus, pre-treatment assessment of auto-antibodies in newly diagnosed cases of chronic hepatitis B or hepatitis C infection may provide beneficial information on the future occurrence of auto-immune responses in these patients.

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.

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.

Clinical, subclinical and potential autoimmune diseases in an Italian population of children with coeliac disease

BACKGROUND Several studies have suggested a link between coeliac disease and other autoimmune diseases. AIM To compare the presence of autoimmune disease in children with coeliac disease and in controls. METHODS When coeliac disease was diagnosed, 267 children were evaluated for clinical autoimmune disease (with signs/symptoms), subclinical autoimmune disease (with autoantibodies and subclinical impairment of the target organ) or potential autoimmune disease (with autoantibodies only) and compared with 220 healthy controls. 170 coeliac disease patients were followed up for a mean 47 +/- 31 months, in complete remission on a gluten-free diet. Ninety-nine controls were followed up for 45 +/- 33 months. RESULTS When coeliac disease was diagnosed, 71 (27%) children had autoimmune disease vs. 1% among the controls (P < 0.001): 31 had clinical autoimmune disease and 40 had subclinical or potential autoimmune disease. During the follow-up, the clinical autoimmune disease cases slightly decreased from 12% to 11%, while the potential autoimmune disease cases increased from 14% to 21%. Of the 99 controls, none had any variation in their autoantibody profile. CONCLUSIONS Gluten-free diet does not modify the natural history of autoimmunity in patients with coeliac disease. However, gluten-free diet seems to produce a favourable effect on the previously present clinical autoimmune disease and to prevent the development of new clinical autoimmune disease, but does not affect the onset of potential autoimmunity, which tends to increase with time.

Thyroid cancer in HCV-related chronic hepatitis patients: a case-control study

OBJECTIVE

The present study prospectively investigated prevalence and features of thyroid cancer in patients with hepatitis C virus-related chronic hepatitis (HCV+) in comparison to two samples from the general population with different iodine intake.

DESIGN

We studied the prevalence of thyroid cancer in 308 unselected HCV+ patients in comparison to two population-based, gender- and age-matched control groups: 1) 616 subjects from an iodine deficient area; 2) 616 subjects from an iodine-sufficient area. Thyroid status was assessed by measurement of circulating thyroid hormones and autoantibodies, thyroid ultrasonography, and when indicated, fine-needle aspiration cytology.

MAIN OUTCOME

Circulating thyrotropin, anti-thyroglobulin, and anti-thyroperoxidase antibodies levels, and the prevalence of hypothyroidism were significantly higher in HCV+ patients (p < 0.001 for all). Six patients with papillary thyroid cancer were detected among HCV+ patients, whereas no case was observed in control 1 (p = 0.001), and only one case was observed in control 2 (p = 0.003). In HCV+ patients 83% with thyroid cancer had evidence of thyroid autoimmunity vs 31% of the other HCV+ patients (p = 0.02).

CONCLUSIONS

These data suggest a high prevalence of thyroid papillary cancer in HCV+ patients, overall in presence of thyroid autoimmunity; careful thyroid monitoring is indicated during the follow-up of these patients.