Determinants of thyroid autoantibody production in Hashimoto's thyroiditis

Association of Pro-Inflammatory Cytokines with Vitamin D in Hashimoto's Thyroid Autoimmune Disease

Background and objectives: Hashimoto's thyroiditis is an important autoimmune thyroid condition. It is characterized by lymphocytic congestion of the thyroid gland followed by progressive deterioration and fibrous substitution of the thyroid in the parenchymal structure. This study has provided insight into the variations of blood pro-inflammatory cytokine levels in patients with Hashimoto's disease and the key role of vitamin D levels among selected patients. Materials and Methods: A total of 144 participants including healthy controls and patients were studied in the current study in which 118 were female and 26 were male. The thyroid profile was evaluated in patients with Hashimoto's thyroiditis and healthy controls. Results: The mean ± SD Free T4 in the patients was recorded as 14.0 ± 4.9 pg/mL, and TSH was 7.6 ± 2.5 IU/L, whereas the median ± IQR thyroglobulin antibodies (anti-TG) were 285 ± 142. Thyroid peroxidase antibodies (anti-TPO) were 160 ± 63.5, whereas in the healthy controls, the mean ± SD Free T4 was recorded as 17.2 ± 2.1 pg/mL, and TSH was 2.1 ± 1.4 IU/L, whereas the median ± IQR anti-TGs were 56.30 ± 46.06, and anti-TPO was 5.6 ± 5.12. The assessment of pro-inflammatory cytokines (pg/mL) and total Vitamin D levels (nmol/L) in patients with Hashimoto's thyroiditis was recorded with values IL-1B 6.2 ± 0.8, IL-6 9.4 ± 0.4, IL-8 7.5 ± 0.5, IL-10 4.3 ± 0.1, IL-12 3.8 ± 0.5, TNF-α 7.6 ± 1.1, and total vitamin D 21.89 ± 3.5, whereas in healthy controls the mean ± SD IL-1B was 0.6 ± 0.1, IL-6 2.6 ± 0.5, IL-8 3.0 ± 1.2, IL-10 3.3 ± 1.3, IL-12 3.4 ± 0.4, TNF-α 1.4 ± 0.3 and total vitamin D was 42.26 ± 5.5. Conclusions: It was found that individuals with Hashimoto's thyroiditis had raised serum levels of IL-1B, IL-6, IL-8, IL-10, IL-12, and TNF-α as compared to the healthy controls, whereas the total vitamin D levels were remarkably low as compared to health controls. Serum TSH, anti-TG, and anti-TPO levels were typically lower in controls and much higher in individuals with Hashimoto's thyroiditis. The current study's findings might aid in future studies and in the diagnosis and management of autoimmune thyroid disease.

The significance of Hashimoto's thyroiditis for postoperative complications of thyroid surgery: a systematic review and meta-analysis

INTRODUCTION

Hashimoto's thyroiditis (HT) is one of the most common immune-mediated diseases. It makes thyroid surgery more complicated and difficult because there may be adhesions between the thyroid gland and surrounding structures. However, it is still controversial whether HT patients carry a high risk for postoperative complications of thyroid surgery. The purpose of this study was to investigate the significance of HT for the postoperative complications of thyroid surgery.

METHODS

A search for studies assessing the postoperative complication risks of HT patients compared with that of patients with benign nodules (BNs) was performed in PubMed, EMBASE and Web of Science. Nine studies (20,118 cases, 1,582 cases of HT and 18,536 cases of BN) were identified, and the data from the relevant outcomes were extracted and analysed.

RESULTS

There were no significant differences between the HT group and BN group in recurrent laryngeal nerve palsy (RLNP) and permanent hypoparathyroidism (PHP). The rate of transient hypocalcaemia (THC) was significantly higher in the HT group (16.85%) than in the BN group (13.20%).

CONCLUSIONS

The meta-analysis showed that HT only increased the risk of the postoperative complication THC compared to BN. Understanding the significance of HT in postoperative hypoparathyroidism after thyroid surgery would help clinicians perform sufficient preoperative (and postoperative) assessments and to optimise surgical planning.

Genome-wide association analysis suggests novel loci for Hashimoto's thyroiditis

PURPOSE

Hashimoto's thyroiditis (HT) is the most common form of autoimmune thyroid diseases. Current knowledge of HT genetics is limited, and not a single genome-wide association study (GWAS) focusing exclusively on HT has been performed to date. In order to decipher genetic determinants of HT, we performed the first GWAS followed by replication in a total of 1443 individuals from Croatia.

METHODS

We performed association analysis in a discovery cohort comprising 405 cases and 433 controls. We followed up 13 independent signals (P < 10^-5) in 303 cases and 302 controls from two replication cohorts and then meta-analyzed results across discovery and replication datasets.

RESULTS

We identified three variants suggestively associated with HT: rs12944194 located 206 kb from SDK2 (P = 1.8 × 10^-6), rs75201096 inside GNA14 (P = 2.41 × 10^-5) and rs791903 inside IP6K3 (P = 3.16 × 10^-5). Genetic risk score (GRS), calculated using risk alleles of these loci, accounted for 4.82% of the total HT variance, and individuals from the top GRS quartile had 2.76 times higher odds for HT than individuals from the lowest GRS quartile.

CONCLUSIONS

Although discovered loci are implicated with susceptibility to HT for the first time, genomic regions harboring these loci exhibit good biological candidacy due to involvement in the regulation of the thyroid function and autoimmunity. Additionally, we observe genetic overlap between HT and several related traits, such as hypothyroidism, Graves' disease and TPOAb. Our study adds a new knowledge of underlying HT genetics and sets a firm basis for further research.

Genome-wide association analysis suggests novel loci underlying thyroid antibodies in Hashimoto's thyroiditis

Thyroid antibodies against thyroglobulin (TgAb) and thyroid peroxidase (TPOAb) are key markers of Hashimoto's thyroiditis (HT), the most common autoimmune thyroid disorder. Genetic determinants of thyroid antibodies are still poorly known, especially as they were not studied in patients with thyroid diseases. We performed the first genome-wide association analysis of thyroid antibodies in 430 HT patients that may be considered as population extremes for thyroid antibodies distribution. We detected two suggestively associated genetic variants with TgAb, rs6972286 close to ANKRD7 and LSM8 (P = 2.34 × 10^-7) and rs756763 inside CA10 (P = 6.05 × 10^-7), and one with TPOAb, rs12507813 positioned between TRIM61 and TRIM60 (P = 4.95 × 10^-7). Bivariate analysis resulted with three suggestively associated genetic variants that predispose to both antibodies: rs13190616 inside RP11-138J23.1 (P = 2.01 × 10^-6), rs561030786 close to DUBR (P = 7.33 × 10^-6) and rs12713034 inside FSHR (P = 7.66 × 10^-6). All identified genomic regions have a substantial literature record of involvement with female-related traits, immune-mediated diseases and personality traits that are all characterized by increased thyroid antibody levels. Our findings demonstrate the existence of genetic overlap between thyroid autoimmunity in HT and different non-thyroid diseases characterized by the presence of thyroid antibodies. We also suggest that genetic variants that regulate antibody levels may differ between HT patients and individuals with normal thyroid function.

Evaluation of Correlations Between Food-Specific Antibodies and Clinical Aspects of Hashimoto's Thyroiditis

OBJECTIVE

We have comprehensively evaluated an immunologic response to food antigens, mediated by immunoglobulin G (IgG) antibodies, on clinical aspects of Hashimoto's thyroiditis (HT).

METHODS

IgG antibodies to 125 food antigens were measured in serum samples of 74 HT patients and 245 controls using microarray-based enzyme-linked immunosorbent assay (ELISA) test. We analyzed differences in IgG levels between two groups and evaluated correlations between food-specific IgG levels and HT-related clinical phenotypes (thyroid hormones/antibodies, symptoms of hypothyroidism, measures of body size and blood pressure) and food consumption in HT patients.

RESULTS

We observed increased IgG levels to 12 different food antigens in either HT cases or controls, of which plum-specific IgG antibodies were significantly higher (p = 1.70 × 10^-8), and almond-specific IgG antibodies were significantly lower (p = 8.11 × 10^-5) in HT patients in comparison to controls, suggesting their possible roles in HT etiology or symptomatology. There was no significant correlation between any of 12 increased food-specific IgG antibodies, along with gluten-specific IgG, with clinically important phenotypes, such as thyroid hormones/antibodies or symptoms. Among other tested correlations, the most interesting is the negative correlation between coffee and tea combined IgG levels and number of symptoms, suggesting possible beneficial effect of tea and coffee on disease symptoms. We also found that food consumption is not correlated with IgG levels.

CONCLUSIONS

Distribution of food-specific IgG antibodies is comparable between HT patients and controls, with the exception of plum and almond. There is no evidence that increased food-specific IgG antibodies are associated with clinical aspects of HT. Clarification of biology behind formation of these antibodies is needed.

Association of established hypothyroidism-associated genetic variants with Hashimoto's thyroiditis

PURPOSE

Hashimoto's thyroiditis (HT) as a chronic autoimmune disease of the thyroid gland is the most common cause of hypothyroidism. Since HT and hypothyroidism are closely related, the main aim of this study was to explore the association of established hypothyroidism single-nucleotide polymorphisms (SNPs) with HT.

METHODS

The case-control dataset included 200 HT cases and 304 controls. Diagnosis of HT cases was based on clinical examination, measurement of thyroid antibodies (TgAb, TPOAb), hormones (TSH and FT4) and ultrasound examination. We genotyped and analysed 11 known hypothyroidism-associated genetic variants. Case-control association analysis was performed in order to test each SNP for the association with HT using logistic regression model. Additionally, each SNP was tested for the association with thyroid-related quantitative traits (TPOAb levels, TgAb levels and thyroid volume) in HT cases only using linear regression.

RESULTS

We identified two genetic variants nominally associated with HT rs3184504 in SH2B3 gene (P = 0.0135, OR = 0.74, 95% CI = 0.57-0.95) and rs4704397 in PDE8B gene (P = 0.0383, OR = 1.32, 95% CI = 1.01-1.74). The SH2B3 genetic variant also showed nominal association with TPOAb levels (P = 0.0163, β = -0.46) and rs4979402 inside DFNB31 gene was nominally associated with TgAb levels (P = 0.0443, β = 0.41).

CONCLUSIONS

SH2B3 gene has previously been associated with susceptibility to several autoimmune diseases, whereas PDE8B has been associated with TSH levels and suggested to modulate thyroid physiology that may influence the manifestation of thyroid disease. Identified loci are novel and biologically plausible candidates for HT development and represent good basis for further exploration of HT susceptibility.

Unusual Presentation of Tuberculous Thyroid Abscess in a Background of Hashimoto's Thyroiditis in a Chronic Hepatitis B Carrier

Tuberculosis of thyroid gland is a very rare disease. It has variable presentations and may be sometimes associated with autoimmune thyroiditis. We report a case of 45-year-old male, with left sided painless neck swelling, with a purulent discharging sinus over it associated with night sweats and loss of appetite. Thyroid imaging disclosed heterogeneous enhancement of left lobe of thyroid gland with internal vascularity and coarse calcifications. Core needle biopsy revealed caseous necrosis and AFB positivity. Patient had thyroid peroxidase antibody and thyroglobulin antibody positivity and the rest of thyroid function tests were normal. Patient had positive Mantoux test, hepatitis B surface Ag, and low viral DNA. The patient was diagnosed as being a case of tuberculous abscess of thyroid gland and was put on antitubercular therapy for 2 months. Patient subsequently underwent left hemithyroidectomy when there was no response. Histopathological examination revealed tuberculosis of thyroid gland. A final diagnosis of tuberculous abscess of thyroid gland in a background of Hashimoto's thyroiditis in a chronic HBV carrier was made. Therefore, although rare tuberculosis of thyroid should be kept in mind as a differential diagnosis of thyroid swelling.

Values of molecular markers in the differential diagnosis of thyroid abnormalities

INTRODUCTION

Thyroid cancer (TC), follicular adenoma (FA) and Hashimoto's thyroiditis (HT) are three of the most frequently reported abnormalities that affect the thyroid gland. A frequent co-occurrence along with similar histopathological features is observed between TC and FA as well as between TC and HT. The conventional diagnostic methods such as histochemical analysis present complications in differential diagnosis when these abnormalities occur simultaneously. Hence, the authors recognize novel methods based on screening genetic defects of thyroid abnormalities as viable diagnostic and prognostic methods that could complement the conventional methods.

METHODS

We have extensively reviewed the existing literature on TC, FA and HT and also on three genes, namely braf, nras and ret/ptc, that could be used to differentially diagnose the three abnormalities. Emphasis was also given to the screening methods available to detect the said molecular markers.

RESULTS AND CONCLUSION

It can be conferred from the analysis of the available data that the utilization of braf, nras and ret/ptc as markers for the therapeutic evaluation of FA and HT is debatable. However, molecular screening for braf, nras and ret/ptc mutations proves to be a conclusive method that could be employed to differentially diagnose TC from HT and FA in the instance of a suspected co-occurrence. Thyroid cancer patients can be highly benefited from the screening for the said genetic markers, especially the braf gene due to its diagnostic value as well as due to the availability of personalized medicine targeted specifically for braf mutants.

Association between genetic mutations and the development of autoimmune thyroiditis in patients with chronic hepatitis C treated with interferon alpha

BACKGROUND

Considerable progress was made by the introduction of interferon to the treatment of chronic hepatitis C virus infection. This treatment, however, is associated with the risk of developing or exacerbating autoimmune diseases, with chronic autoimmune thyroiditis being one of them. The aim of our study was to evaluate the predisposition to autoimmune thyroiditis in patients with chronic hepatitis C virus during IFN-alpha therapy, depending on the presence of polymorphisms in the promoter region of CTLA-4C (-318)T gene and in exon 1 of A49G gene as well as C1858T transition of PTPN22 gene.

METHODS

The study was conducted in 149 patients aged between 18 and 70 years (mean of 43.9 years), including 82 men and 67 women. Control group for the assessment of the distribution of analyzed polymorphism of genotypes consisted of 200 neonates, from whom umbilical blood was drawn for the tests. The patients were divided into three groups: group 1 consisted of 114 patients without thyroid impairment before and during IFN-alpha therapy, group 2 contained 9 patients with AT with the onset prior to IFN-alpha treatment, and group 3 comprised 26 patients with AT starting after the beginning of IFN-alpha therapy.

RESULTS

The frequency of C1858Tand C(-318)T genotypes observed in the study group did not differ significantly from control group. A significant difference, however, was found for A49G polymorphism.

CONCLUSIONS

No association was demonstrated between the occurrence of autoimmune thyroiditis with the onset during IFN-alpha therapy and the presence of polymorphisms within CTLA-4 C(-318)T gene in the promoter region and A49G in exon 1, as well as C1858T transition of PTPN22 gene.

Is thyroidectomy in patients with Hashimoto thyroiditis more risky?

BACKGROUND

Hashimoto thyroiditis (HT) is an organ-specific autoimmune disease characterized by the production of antibodies such as antithyroperoxidase, which leads to the destruction of the thyroid gland and a decrease in normal thyroid function. Thyroidectomy is performed when the patient presents with symptoms or potential neoplastic degeneration occurs; however, surgery can be difficult because of the dense inflammatory process around the thyroid gland. We hypothesized that patients with HT may have a higher rate of complications after thyroid surgery.

METHODS

We identified 1791 consecutive patients who underwent thyroidectomy from May 1994 to December 2009. Patients with HT were compared with those without HT with regard to outcomes with analysis of variance and chi-square test (SPSS, Inc).

RESULTS

Patients with HT were significantly younger and more likely to be female. There was no significant difference between the two groups in the rate of malignancy. However, patients undergoing thyroidectomy with HT had a significantly higher postoperative complication rate. Specifically, the rates of overall, transient, and permanent complications were all increased in HT patients.

CONCLUSION

Patients with HT had a higher rate of complications after thyroidectomy compared with those without HT. Therefore, careful consideration must be taken before pursuing operative treatment in patients with HT including providing adequate informed consent regarding the increased risks of surgery.

Hashimoto's Thyroiditis: From Genes to the Disease

Hashimoto's thyroiditis (HT) is the most prevalent autoimmune thyroid disorder. Intrathyroidal lymphocytic infiltration is followed by a gradual destruction of the thyroid gland which may lead to subclinical or overt hypothyroidism. Biochemical markers of the disease are thyroid peroxidase and/or thyroglobulin autoantibodies in the serum which are present with a higher prevalence in females than in males and increase with age. Although exact mechanisms of aetiology and pathogenesis of the disorder are not completely understood, a strong genetic susceptibility to the disease has been confirmed predominantly by family and twin studies. Several genes were shown to be associated with the disease occurrence, progression, and severity. Genes for human leukocyte antigen, cytotoxic T lymphocyte antigen-4, protein tyrosine phosphatase nonreceptor-type 22, thyroglobulin, vitamin D receptor, and cytokines are considered to be of utmost importance. Amongst endogenous factors for the disease development, the attention is focused predominantly on female sex, pregnancy with postpartum period and fetal microchimerism. Environmental factors influencing HT development are iodine intake, drugs, infections and different chemicals. Disturbed self-tolerance accompanied by the increased antigen presentation is a prerequisite for the HT occurrence, whereas proper interaction of thyroid cells, antigen presenting cells, and T cells are necessary for the initiation of thyroid autoimmunity. Secreted cytokines lead predominantly to T-helper type 1 (Th1) response as well as to Th 17 response which has only recently been implicated. Final outcome of HT is thyroid destruction which is mostly a consequence of the apoptotic processes combined with T-cell mediated cytotoxicity.

Should patients with symptomatic Hashimoto's thyroiditis pursue surgery?

BACKGROUND

In this study, patients with Hashimoto's Thyroiditis and significant symptoms were evaluated for improvement or resolution of preoperative symptoms after thyroidectomy. Hashimoto's thyroiditis (HT) is an organ-specific autoimmune disease characterized by production of antibodies such as anti-thyroperoxidase (TPO), which leads to destruction of the thyroid gland and a decrease in normal thyroid function. Thyroidectomy is not generally recommended because the dense inflammatory process that surrounds the thyroid gland can make resection more difficult. However, patients with HT are considered for surgery if they experience persistent symptoms after conservative therapy. We hypothesized that patients with HT and significant compressive and other associated symptoms may benefit from thyroidectomy for palliation.

METHODS

We identified 1791 patients who underwent thyroidectomy from May 1994 to December 2009. Of those 1791 patients, 311 were diagnosed with HT. Of these 311 patients, 133 had 170 significant preoperative symptoms, and served as our sample population. Patients were subjectively evaluated for improvement or relief of symptoms postoperatively.

RESULTS

The mean age of the group was 46 ± 1 y, and 90% were female. Patients underwent lobectomy (33%), subtotal thyroidectomy (6%), or total thyroidectomy (61%). The overall rate of symptomatic improvement for HT patients was 90% after thyroidectomy. The most frequent preoperative symptom was compression, and >93% of patients experienced relief. In addition, we found high rates of improvement for HT patients with other preoperative symptoms including voice problems (77%), hormone imbalance (84%), and other (90%).

CONCLUSION

The overwhelming majority of HT patients with significant symptoms appear to benefit from thyroidectomy. Therefore, HT patients should consider pursuing surgery for palliation if they suffer from persistent symptoms after conservative therapy.