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

Direct-acting antivirals used in HCV-related liver disease do not affect thyroid function and autoimmunity

PURPOSE

It is well known that interferon-α (IFN-α), used for long time as the main therapy for HCV-related disease, induces thyroid alterations, but the impact of the new direct-acting antivirals (DAAs) on thyroid is not established. Aim of this prospective study was to evaluate if DAAs therapy may induce thyroid alterations.

METHODS

A total of 113 HCV patients, subdivided at the time of the enrollment in naïve group (n = 64) and in IFN-α group (n = 49) previously treated with pegylated interferon-α and ribavirin, were evaluated for thyroid function and autoimmunity before and after 20-32 weeks of DAAs.

RESULTS

Before starting DAAs, a total of 8/113 (7.1%) patients showed Hashimoto's thyroiditis (HT) all belonging to IFN-α group (8/49, 16.3%), while no HT cases were found in the naïve group. Overall, 7/113 (6.2%) patients were hypothyroid: 3/64 (4.7%) belonging to naïve group and 4/49 (8.2%) to IFN-α group. Furthermore, a total of 8/113 patients (7.1%) showed subclinical hyperthyroidism: 2/64 (3.1%) were from naïve group and 6/49 (12.2%) from IFN-α group. Interestingly, after DAAs therapy, no new cases of HT, hypothyroidism and hyperthyroidism was found in all series, while 6/11 (54.5%) patients with non-autoimmune subclinical thyroid dysfunction became euthyroid. Finally, the only association between viral genotypes and thyroid alterations was genotype 1 and hypothyroidism.

CONCLUSIONS

This study supports evidence that DAAs have a limited or missing influence on thyroid in patients with HCV-related diseases. Moreover, it provides preliminary evidence that subclinical non-autoimmune thyroid dysfunction may improve after HCV infection resolution obtained by DAAs.

International therapeutic guidelines for patients with HCV-related extrahepatic disorders. A multidisciplinary expert statement

Hepatitis C virus (HCV) is both hepatotrophic and lymphotropic virus that causes liver as well extrahepatic manifestations including cryoglobulinemic vasculitis, the most frequent and studied condition, lymphoma, and neurologic, cardiovascular, endocrine-metabolic or renal diseases. HCV-extrahepatic manifestations (HCV-EHMs) may severely affect the overall prognosis, while viral eradication significantly reduces non-liver related deaths. Different clinical manifestations may coexist in the same patient. Due to the variety of HCV clinical manifestations, a multidisciplinary approach along with appropriate therapeutic strategies are required. In the era of interferon-free anti-HCV treatments, international recommendations for the therapeutic management of HCV-EHMs are needed. This implies the need to define the best criteria to use antivirals and/or other therapeutic approaches. The present recommendations, based on qualified expert experience and specific literature, will focus on etiological (antiviral) therapies and/or traditional pathogenetic treatments that still maintain their therapeutic utility.

Hashimoto's Thyroiditis and Graves' Disease in One Patient: The Extremes of Thyroid Dysfunction Associated with Interferon Treatment

Autoimmune thyroid disease associated with interferon therapy can manifest as destructive thyroiditis, Graves' Hyperthyroidism, and autoimmune (often subclinical) hypothyroidism, the latter persisting in many patients. There are scare reports of a single patient developing extremes of autoimmune thyroid disease activated by the immunomodulatory effects of interferon. A 60-year-old man received 48 weeks of pegylated interferon and ribavirin therapy for chronic HCV. Six months into treatment, he reported fatigue, weight gain, and slowed cognition. Serum thyroid stimulating hormone (TSH) was 58.8 mIU/L [0.27–4.2], fT4 11.1 pmol/L [12–25], and fT3 4.2 pmol/L [2.5–6.0] with elevated anti-TPO (983 IU/mL [<35]) and anti-TG (733 U/mL [<80]) antibodies. He commenced thyroxine with initial clinical and biochemical resolution but developed symptoms of hyperthyroidism with weight loss and tremor 14 months later. Serum TSH was <0.02 mIU/L, fT4 54.3 pmol/L, and fT3 20.2 pmol/L, with an elevated TSH receptor (TRAb, 4.0 U/L [<1.0]), anti-TPO (1,163 IU/mL) and anti-TG (114 U/mL) antibodies. Technetium scan confirmed Graves' Disease with bilateral diffuse increased tracer uptake (5.9% [0.5–3.5%]). The patient commenced carbimazole therapy for 6 months. Treatment was ceased following spontaneous clinical and biochemical remission (TSH 3.84 mIU/L, fT4 17pmol/L, fT3 4.5 pmol/L, and TRAb <1 U/L). This raises the need to monitor thyroid function closely in patients both during and following completion of interferon treatment.

Peripheral blood natural killer cells and mild thyroid abnormalities in women with reproductive failure

Abnormalities in peripheral blood natural killer (NK) cells have been reported in women with primary infertility and recurrent spontaneous abortion (RSA) and several studies have been presented to define cutoff values for abnormal peripheral blood NK cell levels in this context. Elevated levels of NK cells were observed in infertile/RSA women in the presence of thyroid autoimmunity (TAI), while no studies have been carried out, to date, on NK cells in infertile/RSA women with non-autoimmune thyroid diseases. The contribution of this study is two-fold: (1) the evaluation of peripheral blood NK cell levels in a cohort of infertile/RSA women, in order to confirm related data from the literature; and (2) the assessment of NK cell levels in the presence of both TAI and subclinical hypothyroidism (SCH) in order to explore the possibility that the association between NK cells and thyroid function is not only restricted to TAI but also to SCH. In a retrospective study, 259 age-matched women (primary infertility [n = 49], primary RSA [n = 145], and secondary RSA [n = 65]) were evaluated for CD56+CD16+NK cells by flow cytometry. Women were stratified according to thyroid status: TAI, SCH, and without thyroid diseases (ET). Fertile women (n = 45) were used as controls. Infertile/RSA women showed higher mean NK cell levels than controls. The cutoff value determining the abnormal NK cell levels resulted ⩾15% in all the groups of women. Among the infertile/RSA women, SCH resulted the most frequently associated thyroid disorder while no difference resulted in the prevalence of TAI and ET women between patients and controls. A higher prevalence of women with NK cell levels ⩾15% was observed in infertile/RSA women with SCH when compared to TAI/ET women. According to our data, NK cell assessment could be used as a diagnostic tool in women with reproductive failure and we suggest that the possible association between NK cell levels and thyroid function can be described not only in the presence of TAI but also in the presence of non-autoimmune thyroid disorders.

Graves' disease following immune reconstitution or immunomodulatory treatment: should we manage it any differently?

Graves' disease and other disorders of thyroid function may occur following treatment with novel anticancer agents or during periods of lymphocyte recovery after lymphopenia. There are three main settings for such lymphocyte reconstitution: recovery after a bone marrow or haematopoietic stem cell transplant, alemtuzumab treatment and the use of highly active antiretroviral therapy (HAART) for human immunodeficiency virus infection. The available evidence suggests that Graves' disease behaves as normal in most of these cases and should be treated conventionally, but it may follow a more favourable course in those receiving alemtuzumab or HAART. As spontaneous or drug-induced remission may be more likely in these two settings, first-line treatment should usually consist of an antithyroid drug.

Autoimmune and neoplastic thyroid diseases associated with hepatitis C chronic infection

Frequently, patients with hepatitis C virus (HCV) chronic infection have high levels of serum anti-thyroperoxidase and/or anti-thyroglobulin autoantibodies, ultrasonographic signs of chronic autoimmune thyroiditis, and subclinical hypothyroidism, in female gender versus healthy controls, or hepatitis B virus infected patients. In patients with "HCV-associated mixed cryoglobulinemia" (MC + HCV), a higher prevalence of thyroid autoimmune disorders was shown not only compared to controls, but also versus HCV patients without cryoglobulinemia. Patients with MC + HCV or HCV chronic infection show a higher prevalence of papillary thyroid cancer than controls, in particular in patients with autoimmune thyroiditis. Patients with HCV chronic infection, or with MC + HCV, in presence of autoimmune thyroiditis, show higher serum levels of T-helper (Th)1 (C-X-C motif) ligand 10 (CXCL10) chemokine, but normal levels of Th2 (C-C motif) ligand 2 chemokine, than patients without thyroiditis. HCV thyroid infection could act by upregulating CXCL10 gene expression and secretion in thyrocytes recruiting Th1 lymphocytes that secrete interferon-γ and tumor necrosis factor-α. These cytokines might induce a further CXCL10 secretion by thyrocytes, thus perpetuating the immune cascade, which may lead to the appearance of autoimmune thyroid disorders in genetically predisposed subjects. A careful monitoring of thyroid function, particularly where nodules occur, is recommended in HCV patients.