Determination of the levels and possible associations of alpha2-macroglobulin with autoantibodies in the serum of patients with various forms of autoimmune thyroiditis.

Antibodies to thyroid peroxidase (AB-TPO), antibodies to thyroglobulin (AB-TG), and the content of α2-macroglobulin (α2-MG) have been studied in serum samples of patients with autoimmune thyroiditis (AIT). All the patients were divided into 3 groups depending on age: 25-35, 36-50, 51-65 years. We found a significant change in the thyroid panel parameters in AIT, but without significant changes in the average concentration of α2-MG in the age groups of patients. This may be due to the accumulation and retention of complexes of defective forms of α2-MG in the circulation associated with their decreased ability to bind to receptors.

[Molecular mimicry between human thyroid peroxidase, thyroglobulin, cosinophil peroxidase, IL-24 and microorganisms antigens]. / Mimetismo molecular entre peroxidasa tiroidea humana, tiroglobulina, peroxidasa de eosinófilos, IL-24 y antígenos de microorganismos.

OBJECTIVE: Identify molecular mimicry between TPO, eosinophil peroxidase (EPX), thyroglobulin and IL24 and microorganism antigens. METHODS: Through in silico analysis, we performed local alignments between human and microorganism antigens with PSI-BLAST. Proteins that did not present a 3D structure were modeled by homology through the Swiss Modeller server and epitope prediction was performed through Ellipro. Epitopes were located in the 3D models using PYMOL software. RESULTS: A total of 38 microorganism antigens (parasites, bacteria) had identities between 30% and 45%, being the highest with Anisakis simplex. The alignment between 2 candidate proteins from A. simplex and EPX presented significant values, with identities of 43 and 44%. In bacteria, Campylobacter jejuni presented the highest identity with thyroglobulin (35%). 220 linear and conformational epitopes of microorganism antigens were predicted. Peroxidasin-like proteins from Toxocara canis and Trichinella pseudospiralis presented 10 epitopes similar to TPO and EPX, as possible molecules triggering cross-reactivity. No virus presented identity with the human proteins studied. CONCLUSION: TPO and EPX antigens shared potential cross-reactive epitopes with bacterial and nematode proteins, suggesting that molecular mimicry could be a mechanism that explains the relationship between infections and urticaria/hypothyroidism. In vitro work is needed to demonstrate the results obtained in the in silico analysis.

OBJETIVO: Identificar mimetismo molecular entre TPO, eosinofil peroxidasa (EPX), tiroglobulina e IL24 y antígenos de microorganismos. MÉTODOS: A través de análisis in silico, realizamos los alineamientos locales entre los antígenos humanos y de microorganismos con PSI-BLAST. Las proteínas que no presentaban estructura 3D, fueron modeladas por homología a través del servidor Swiss Modeller y se realizó una predicción de epítopes a través de Ellipro. Los epítopes se localizaron en los modelos 3D utilizando el software PYMOL. RESULTADOS: Un total de 38 antígenos de microorganismos (parásitos y bacterias), tuvieron identidades entre 30 y 45%, siendo los más altos con Anisakis simplex. El alineamiento entre dos proteínas candidatas de A. simplex y EPX presentaron valores importantes, con identidades de 43 y 44%. En las bacterias, Campylobacter jejuni presentó la mayor identidad con tiroglobulina (35%). Se predijeron 220 epítopes lineales y conformacionales de antígenos de microorganismos. Las proteínas similares a la peroxidasina de Toxocara canis y Trichinella pseudospiralis presentaron diez epítopes similares a TPO y EPX, como posibles moléculas desencadenantes de una reactividad cruzada. Ningún virus presentó identidad con las proteínas humanas estudiadas. CONCLUSIÓN: Los antígenos TPO y EPX compartieron potenciales epítopes de reacción cruzada con proteínas bacterianas y nematodos, lo que sugiere que el mimetismo molecular podría ser un mecanismo que explique la relación entre infecciones y la urticaria/hipotiroidismo. Se necesitan trabajos in vitro que demuestren los resultados obtenidos en el análisis in silico.

The expression of anti-protein disulfide isomerase A3 autoantibody is associated with the increased risk of miscarriage in euthyroid women with thyroid autoimmunity.

Miscarriage frequently occurs in euthyroid women with thyroid autoimmunity (TAI), but its mechanisms remain unclear. Our previous study has found that the serum level of anti-protein disulfide isomerase A3 autoantibody (PDIA3Ab) was significantly increased in mice with TAI. This study was aimed to explore whether there could be an association between the expression of PDIA3Ab and the occurrence of miscarriage in euthyroid TAI women. It was found that the serum level of PDIA3Ab was significantly increased in euthyroid TAI women as compared with that of non-TAI controls. Especially, serum PDIA3Ab level was markedly higher in euthyroid TAI women with miscarriage than the ones without miscarriage. Furthermore, binary logistic regression analysis showed that the serum PDIA3Ab level was an independent risk factor for spontaneous abortion in euthyroid TAI women with an odds ratio of 13.457 (95% CI, 2.965-61.078). The receiver operating characteristic (ROC) analysis of serum PDIA3Ab expression for predicting the miscarriage in euthyroid TAI women showed that the area under the curve was 0.707 ± 0.05 (P < 0.001). The optimal cut-off OD450 value of serum PDIA3Ab was 0.7129 with a sensitivity of 52.5% and specificity of 86.3% in euthyroid TAI women. Trend test showed that the prevalence of spontaneous abortion was markedly increased with the rise of serum PDIA3Ab level among TAI women in a titer-dependent manner. In conclusion, serum PDIA3Ab expression may imply an increased risk of spontaneous abortion in euthyroid TAI women, and it can be used as a new predictive bio-marker.

The association between subclinical hypothyroidism and TPOAb positivity with infertility in a population-based study: Tehran thyroid study (TTS).

BACKGROUND: Thyroid autoimmunity(TAI) is the most prevalent autoimmune condition in women of fertile age. There are increasing data regarding the association of thyroid dysfunction and thyroid autoimmunity with adverse pregnancy outcomes but there is no consensus regarding infertility and TPOAb positivity; thus we aimed to evaluate the association between thyroid TPOAb positivity and infertility in females and males in a population-based study (TTS). METHODS: Cross-sectional study of 3197 female and male participants in Tehran Thyroid Study (TTS) at the framework of the Tehran Lipid and Glucose Study (TLGS). Data included biochemical measurements and a self-administered questionnaire. RESULTS: A total of 12,823 cases in phase 4, 3719 cases (2108 female and 1611 male) were analyzed. The mean TSH of the infertile female and male was 2.52 ± 2.68 µIU/ml and 3.24 ± 10.26 µIU/ml respectively. The TPO median(IQR) of women with and without a history of infertility were 6.05 (3.30-13.96)and 6.04 (3.17-11.15);(P = 0.613), they were 5.08 (3.20-125.68) and 5.31 (3.93-125.68);(P = 0.490) in male participants, respectively. Results of crude and adjusted logistic regression analysis of the development of infertility by thyroid function and TPOAb, except for fT4 in male subjects, depicted no association between infertility and other variables in both crude and adjusted models. CONCLUSION: Based on the result, thyroid autoimmunity was not associated with infertility in both females and males.

The Influence of Reducing Diets on Changes in Thyroid Parameters in Women Suffering from Obesity and Hashimoto's Disease.

Hashimoto's disease is listed among the most common endocrine causes of obesity. As treatment of obesity in women with Hashimoto's disease is frequently unsuccessful, the aim of this study was to evaluate the effectiveness of two different reducing diets and their influence on changes in thyroid parameters in female patients. A six-month observational/interventional study was performed on 100 women aged 18-65 years, previously diagnosed with Hashimoto's disease and obesity and receiving L-thyroxine. The women were randomly assigned to the test group (group A, n = 50) following elimination/reducing diets, and the control group (group B, n = 50) following reducing diets with the same caloric content (without elimination). Anthropometric and thyroid parameters were evaluated at the beginning, after 3 months and after 6 months of treatment. In both groups a significant decrease in BMI and body fat percentage was achieved, but in test group A the decrease in BMI and body fat percentage was significantly greater than in control group B (p < 0.002 and p = 0.026, respectively). Serum TSH (thyroid stimulating hormon) levels decreased significantly more in group A than in group B (p < 0.001). Group A exhibited significantly greater increases in fT4 and fT3 levels than the control group (p < 0.001) as well as significantly greater decreases in the levels anti-TPO (thyroid peroxidase) (p < 0.001) and anti-TG (thyreoglobulin) antibodies (p = 0.048). The application of reducing diets with product elimination was found to be a more beneficial tool for changing anthropometric and thyroid parameters in women suffering from obesity and Hashimoto's disease than classic reducing diets with the same energy values and macronutrient content.

Serum Detection of Anti-thyroid Peroxidase and Anti-thyroglobulin Antibodies in Chinese Patients With Pemphigus Vulgaris and Pemphigus Foliaceus and Literature Review.

Background: Pemphigus is a rare but life-threatening autoimmune skin disease characterized by blistering on skin and/or mucous membranes. The physiological process of blister formation involves IgG antibodies against the desmogleins (Dsgs) and desmocollins (Dscs). Additional autoAbs have also been suggested to mediate the disease heterogeneity, such as anti-thyroid peroxidase (anti-TPO) and antithyroglobulin (anti-Tg) antibodies, the essential culprits of the immune system in autoimmune thyroid diseases. Purpose: To investigate the levels and antibody positivity of anti-TPO and anti-Tg antibodies in pemphigus patients. Methods: Antibody positivity and levels of anti-TPO and anti-Tg antibodies in pemphigus patients as compared to healthy controls were examined. A meta-analysis was conducted by reviewing six similar studies. Results: 98 Chinese pemphigus patients and 65 healthy controls were enrolled in the study. Our meta-analysis revealed a significant correlation between increased presence of positive anti-TPO and anti-Tg antibodies and pemphigus, particularly for pemphigus vulgaris (PV). Such correlation was also observed in our own hospitalized PV patients, but not in pemphigus foliaceus (PF) patients. In addition, the status of anti-TPO and anti-Tg antibodies were also compared between females and males within PV patients, PF patients or controls, as well as compared for females or males between pemphigus patients and controls. In the analysis of T cell counts, we found abnormal low CD3 + T cell counts (< 690 n/µl) were only detected in patients whose thyroid antibody levels were less than 20 IU/ml. Conclusion: Pemphigus patients showed higher levels and antibody positivity of anti-TPO and anti-Tg antibodies than healthy controls. Further investigations are needed to identify the pathogenic functions of these antibodies in pemphigus, as well as to identify the potential shared susceptibility genes.

Role of the Specialized Pro-resolving Mediator Resolvin D1 in Hashimoto's Thyroiditis.

OBJECTIVE: Resolvins are produced by the catabolism of polyunsaturated fatty acids (PUFAs) and play vital roles in inflammation resolution. Resolvins have been associated with autoimmune disorders. This study aimed to measure the level of Resolvin D1 (RVD1) in the serum of Hashimoto's thyroiditis (HT) patients and healthy controls (HCs) and to further analyse its correlation with thyroid autoantibodies and inflammatory factors. METHODS: Sixty-three participants were recruited, namely, 30 untreated HT patients and 33 sex- and age-matched HCs. Serum RVD1 and inflammatory chemokine (MCP-1 and IP-10) levels were measured by ELISA according to the manufacturer's protocol. Serum total T3 (TT3), TT4, free T3 (FT3), FT4, thyroglobulin antibody (TgAb), thyroid peroxidase antibody (TPOAb) and thyroid-stimulating hormone (TSH) levels were measured using an electrochemiluminescence immunoassay. Thyroid homeostasis parameters, including the thyroid secretory capacity (SPINA-GT), the total deiodinase activity (SPINA-GD), Jostel's TSH index (TSHI) and the thyrotroph thyroid hormone sensitivity index (TTSI), were calculated. RESULTS: Serum RVD1 levels in HT patients (134.76, 85.35-201.36 pg/mL) were significantly lower than those in HCs (187.64, 131.01-326.85 pg/mL) (P=0.004). As the TPOAb level increased, the RVD1 level showed a decreasing trend (P for trend=0.002). Both multinomial and ordinal logistics analyses revealed that serum RVD1 levels were negatively correlated with TPOAb levels in the adjusted models. Moreover, RVD1 showed a negative correlation with the inflammatory chemokine IP-1 0 (r=-0.276, P=0.034), TSHI (r=-0.269, P=0.036) and TTSI (r=-0.277, P=0.031). CONCLUSIONS: Thyroid autoimmunity may be associated with low levels of RVD1. Decreased RVD1 levels indicate impaired resolution of inflammation in HT patients.

The pathogenic role of circulating Hashimoto's Thyroiditis-derived TPO-positive IgG on fetal loss in naïve mice.

PROBLEM: Antibody-mediated autoimmune diseases, such as autoimmune thyroid diseases (ATD), systemic lupus erythematosus (SLE), and antiphospholipid syndrome (APS), often are associated with recurrent fetal loss. One of the ATD is Hashimoto's thyroiditis which recently showed association with complications of pregnancy with increased levels of circulating autoantibodies reactive with epitopes on thyroid tissue such as thyroid peroxidase (anti-TPO). In retrospective study of sera analyses in patients with Hashimoto's thyroiditis, all patients had mainly elevated circulating anti-TPO autoantibodies. AIM: We assessed the potential of human anti-TPO highly positive IgG, derived from patients with Hashimoto's thyroiditis sera associated with complications of pregnancy, to cause directly complications of pregnancy in murine model. METHOD OF STUDY: Naïve ICR female mice, infused intravenously with 100 µg of anti-TPO-positive IgG, showed increased fetal loss and embryo small for date (P < .001) in comparison with mice passively transferred with commercial IgG or PBS. Moreover, we observed embryos small for date in the mice passively transferred with anti-TPO-positive IgG, exemplified by reduced weight of embryos and placentae (P = .001). Histopathological examination revealed delay in fetal development in 50% cases of anti-TPO-positive IgG-treated mice. Importantly, pathological changes in the transition zone, state of glycogen cells, and significant structural changes in the labyrinth part of placenta were observed in all anti-TPO-positive IgG samples. CONCLUSION: The current study shows in the first time, a direct proof of concept, on the association of human TPO-positive IgG from Hashimoto's thyroiditis patients on fetal loss induction in murine model.

Cepharanthine Blocks Presentation of Thyroid and Islet Peptides in a Novel Humanized Autoimmune Diabetes and Thyroiditis Mouse Model.

Autoimmune polyglandular syndrome type 3 variant (APS3v) refers to an autoimmune condition in which both type 1 diabetes (T1D) and autoimmune thyroiditis (AITD) develop in the same individual. HLA-DR3 confers the strongest susceptibility to APS3v. Previously we reported a unique amino acid signature pocket that predisposes to APS3v. We found that this pocket is flexible and can trigger APS3v by presenting both thyroid (Tg.1571, TPO.758) and islet (GAD.492) peptides to induce autoimmune response. We hypothesized that blocking the specific APS3v-HLA-DR3 pocket from presenting thyroid/islet antigens can block the autoimmune response in APS3v. To test this hypothesis we performed a virtual screen of small molecules blocking APS3v-HLA-DR3, and identified 11 small molecules hits that were predicted to block APS3v-HLA-DR3. Using the baculovirus-produced recombinant APS3v-HLA-DR3 protein we tested the 11 small molecules in an in vitro binding assay. We validated 4 small molecule hits, S9, S5, S53 and S15, that could block the APS3v-HLA-DR3 pocket in vitro. We then developed a novel humanized APS3v mouse model induced by co-immunizing a peptide mix of Tg.1571, TPO.758 and GAD.492. The immunized mice developed strong T-cell and antibody responses to the thyroid/islet peptides, as well as mouse thyroglobulin. In addition, the mice showed significantly lower free T4 levels compared to controls. Using the APS3v mouse model, we showed that one of the 4 small molecules, Cepharanthine (S53), blocked T-cell activation by thyroid/islet peptides ex vivo and in vivo. These findings suggested Cepharanthine may have a therapeutic potential in APS3v patients carrying the specific APS3v-HLA-DR3 pocket.

Thyroid peroxidase in human endometrium and placenta: a potential target for anti-TPO antibodies.

Autoimmune thyroid disease is the most common endocrine disorder during pregnancy. Thyroid autoantibodies (TAs) have been suggested to serve a role in implantation failure and spontaneous abortion. Until now, there are no data on the potential interaction of TAs with human reproductive organs. Here, we set out for the first time to test this hypothesis by studying the expression of thyroid peroxidase (TPO) at gene and protein level in human reproductive organs. Endometrial samples were taken from normal women, and placenta tissues were collected after full-term caesarian section. Expression of TPO messenger RNA (mRNA) was investigated by qRT-PCR. In addition, polyclonal anti-TPO antibodies were produced and the expression of TPO protein in mentioned tissues was evaluated by immunohistochemistry and Western blot analysis. The reactivity of anti-TPO antibody in human embryos was evaluated by immunofluorescent staining. For the first time, our study showed that TPO is expressed at gene and protein levels in endometrium and placenta. TPO expression was mainly localized to glandular and luminal epithelial cells in the endometrium. In placenta, the syncytiotrophoblasts and invasive trophoblast cells were the main cell types that expressed TPO protein. Specific band of approximately 110 kDa was observed in all endometrial and placental tissues by Western blot analysis. However, no expression of TPO protein was observed in human embryo. TPO expression in endometrium and placenta may explain higher frequency of abortion and infertility in patients with thyroid autoimmunity.

Is Waist-height Ratio Associated with Thyroid Antibody Levels in Children with Obesity?

Objective: Obesity is known to affect thyroid function. Recently, waist-height ratio (WHtR) has been considered as a useful marker of subclinical hypothyroidism in obese cases, but its relation with thyroid autoimmunity still remains unclear. We evaluated the effect of body fat mass, WHtR, and metabolic parameters on thyroid autoantibody levels in children with obesity. Methods: This was a cross-sectional study carried out with an obese [n=56, male/female (M/F): 29/26] and a healthy group (n=38, M/F: 19/19). All subjects underwent anthropometric measurements, laboratory investigations for thyroid function tests, thyroid peroxidase (TPO-ab) and thyroglobulin-antibodies (Tg-ab), transaminases, blood glucose, insulin levels, and lipids after overnight fasting; homeostatic model assessment for insulin resistance (HOMA-IR) was calculated for assessment of insulin resistance. Fat mass was estimated by multiple frequency bioimpedance analysis in the obese group, which was further divided into two subgroups according to the median of WHtR. All parameters were compared between the groups/subgroups. Results: In the obese group, weight, height, body mass index (BMI), free triiodothyronine, thyrotropin, TPO-ab, insulin, low density lipoprotein-cholesterol, total cholesterol, alanine aminotransferase levels, and HOMA-IR were significantly higher than the controls group (p<0.05 for all). Median of WHtR was 0.6 in the obese group. In the "WHtR >0.6" subgroup (n=28), weight, BMI, fat mass, TPO-ab, Tg-ab, insulin and triglyceride levels were higher than WHtR ≤0.6 subgroup (p<0.05). A positive correlation was obtained between Tg-ab and WHtR (rho=0.28, p=0.041). Conclusion: Euthyroid children with obesity and a WHtR >0.6 are likely to have higher thyroid antibody levels, and Tg-ab levels have a positive correlation with WHtR, which reveals an association of central adiposity with thyroid autoantibody levels in these cases.

The Clinical Value and Variation of Antithyroid Antibodies during Pregnancy.

Antithyroid antibodies, which include thyroid-stimulating hormone receptor antibodies (TRAbs), thyroid peroxidase antibodies (TPOAbs), and thyroid globulin antibodies (TgAbs), are widely known for their tight association with thyroid autoimmune diseases. The variation in all three kinds of antibodies also showed different trends during and after pregnancy (Weetman, 2010). This article reviewed the the physiological changes, while focusing on the variation of thyroid antibodies concentration in women during and after pregnancy, and adverse consequences related to their elevation. Since abnormal elevations of these antithyroid antibodies may lead to adverse outcomes in both mothers and fetuses, special attention must be paid to the titer of the antibodies during pregnancy. The molecular mechanisms of the variations in those antibodies have yet to be explained. The frequency and timing of thyroid antibody measurement, as well as different reference levels, also remain to be elucidated.

Does thyroid autoimmunity affect the reproductive outcome in women with thyroid autoimmunity undergoing assisted reproductive technology?

PROBLEM: Our study aims to investigate whether the anti-thyroperoxidase antibody (TPO-Ab) and TSH level in euthyroid women have any association with reproductive outcomes after the ART cycle. METHODS OF STUDY: A total of 1107 patients who were enrolled in the study were divided into four groups based on serum TSH level and TPO-Ab status: group A, 0.3 ≤ TSH < 2.5 mIU/L and TPO-Ab- ; group B, 0.3 ≤ TSH < 2.5 mIU/L and TPO-Ab+ ; group C, 2.5 ≤ TSH < 4.2 mIU/L, and TPO-Ab- ; and group D, 2.5 ≤ TSH < 4.2 mIU/L, TPO-Ab+ . The differences in ART cycles and pregnancy outcomes were analyzed between study groups. RESULTS: The fertilization rate in group D (73%) was significantly lower than that in groups A (83% P < .001), B (84% P = .001), and C (82% P = .002). The biochemical pregnancy rates of groups B (7%) and D (12%) were significantly higher than those of group A (2%) (P = .028 and P = .017, respectively). TPO-Ab was related to a higher biochemical pregnancy rate (P = .002, OR = 5.311, 95% CI 1.859-15.169) and TSH over 2.5 mIU/L was related to higher ICSI rate (P = .001, OR = 1.759, 95% CI 1.250-2.476) by logistic regression analysis. The receiver operating characteristic (ROC) also verified the results. CONCLUSION: The impacts of TSH ≥ 2.5 mIU/L on the intracytoplasmic sperm injection (ICSI) rate, TSH ≥ 2.5 mIU/L and TPO-Ab+ on the fertilization rate, and TPO-Ab+ on the biochemical pregnancy rate, rather than the effect on abortion, clinical pregnancy, and live birth, were emphasized.

Effect of levothyroxine on pregnancy outcomes in women with thyroid autoimmunity: a systematic review with meta-analysis of randomized controlled trials.

OBJECTIVE: To investigate whether levothyroxine is associated with improved live birth and other benefits in women with thyroid autoimmunity. DESIGN: Systematic review and meta-analysis. SETTING: Not applicable. PATIENT(S): Women positive for thyroid peroxidase antibody. INTERVENTION(S): MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched without any language restrictions. Pooled effect sizes were calculated using random-effects models. MAIN OUTCOME MEASURE(S): The primary outcome was the incidence of live birth, miscarriage, preterm birth, clinical pregnancy, ectopic pregnancy, neonatal admission, and birth weight. The summary measures were reported as relative risk (RR) with 95% confidence interval. RESULT(S): Levothyroxine supplementation was not associated with an increased rate of live birth or a decreased risk of miscarriage. Results were similar in subgroup analyses of live birth by age, baseline thyrotropin, baseline thyroid peroxidase antibody, body mass index, and use of assisted conception. For live birth, the effect estimate lay within the futility boundary for RR of 20% and 15%, but at a 10% RR, the effect estimate lay between the futility boundary and the inferior boundary. CONCLUSION(S): High- to moderate-quality evidence demonstrated that the use of levothyroxine was not associated with improvements in clinical pregnancy outcomes among women positive for thyroid peroxidase antibody. REGISTRATION NUMBER: PROSPERO CRD42019132976.

Anti-Thyroid Peroxidase/Anti-Thyroglobulin Antibody-Related Neurologic Disorder Responsive to Steroids Presenting with Pure Acute Onset Chorea.

Background: Pure acute onset chorea without encephalopathy has rarely been reported in anti-thyroid peroxidase (anti-TPO)/anti-thyroglobulin (anti-TG) antibody-related neurologic disorders responsive to steroids (ATANDS). Case report: We report a 16-year-old female who presented with acute chorea without encephalopathy. Anti-TPO antibodies were found to be strongly positive (>1200 IU/ml) along with anti-thyroglobulin and anti-thyroid stimulating hormone receptor antibodies. After pulse intravenous methylprednisolone therapy (1 g/day for five consecutive days), all the movements seized, and she was discharged with oral prednisolone 30 mg/day with gradual tapering over next three months. After one year of follow-up, she is stable, drug-free, and never had any other problems. Discussion: Anti-thyroid antibodies testing should be included in routine/conventional panel that is done for elucidating causes of chorea as ATANDS can be easily missed and is treatable with widely available, relatively low-cost drugs like steroids with a promising outcome.

Thyroid hormone levels are associated with metabolic components: a cross-sectional study.

AIM: To analyze the association of thyroid function and hormone levels with metabolic syndrome (MetS) and its components. METHODS: This cross-sectional population-based study involved 2183 Croatian individuals with no history of thyroid disease, hypertension, diabetes, and hyperlipidemia. MetS was diagnosed according to the National Cholesterol Education Program's Adult Treatment Panel III criteria. RESULTS: We found no association between thyroid function groups and the prevalence of MetS and its components. Clinically hypothyroid participants showed significantly higher triceps skinfold measurements than subclinically hypothyroid and euthyroid participants. Furthermore, clinically hypothyroid participants had higher abdominal skinfold thickness than subclinically hypothyroid participants. Otherwise, suprailiac and abdominal skinfold measurements were higher in the subclinically and clinically hyperthyroid group of participants compared with euthyroid and subclinically hypothyroid participants. A strong positive association of thyroid-stimulating hormone (TSH) and strong negative association of free triiodothyronine (fT3) and free thyroxine (fT4) levels with HOMA-IR and cholesterol levels were found. Furthermore, the fT4 level also showed a strong negative association with HDL and triceps skinfold thickness. CONCLUSIONS: This study supports the standing that TSH, fT3, and fT4 levels are important variables to determine the association of thyroid function with MetS.

Development and validation of an ELISA for a biomarker of thyroid dysfunction, thyroid peroxidase autoantibodies (TPO-Ab), in dried blood spots.

BACKGROUND: The prevalence of allergic and autoimmune conditions has been steadily increasing in wealthy nations over the past century. One hypothesis put forward to explain this is the Old Friends Hypothesis, which posits that increased hygiene, urbanization, and lifestyle changes have reduced our exposure to parasites and microbes that we co-evolved with, resulting in immune dysregulation. However, research in traditionally living populations, who are exposed to greater parasite and pathogen loads such as those encountered during our evolution, is limited, in part due to a lack of minimally invasive, field-friendly biomarkers of autoimmune disorders. We therefore developed an ELISA to assess positivity for thyroid peroxidase autoantibody (TPO-Ab), an indicator of autoimmune thyroid disease, based on dried blood spot (DBS) samples. RESULTS: We used the Accubind anti-thyroid peroxidase test system to screen our validation samples comprising matched fingerprick DBS, venous DBS, and plasma samples from 182 adults. After confirming that we had TPO-Ab-positive individuals in our validation sample (n = 12), we developed an indirect ELISA to measure TPO-Ab levels from one 3-mm DBS punch. The sensitivity and specificity of our assay for DBS samples ranged from 91.7-100% and 98.2-98.8%, respectively, using a cut-off value of ≥ 26 IU/mL. Intra-assay reliability for duplicate quality control DBS punches was 5.2%, while inter-assay reliability ranged from 11.5-24.4% for high, medium, and low DBS controls. Dilutional linearity ranged from 80 to 120%, and spike and recovery experiments indicated that the DBS matrix does not interfere with the detection of TPO-Ab. TPO-Ab levels remained stable in DBS samples stored at - 28 °C or - 80 °C, but decreased over time in DBS samples kept at 22 °C or at 37 °C. CONCLUSIONS: We developed an in-house, kit-independent indirect ELISA assay to determine individuals' TPO-Ab positivity based on dried blood spots, representing a cost-effective method with potential applications in a range of research settings.

Correlation of IgG autoantibodies against acetylcholine receptors and desmogleins in patients with pemphigus treated with steroid sparing agents or rituximab.

INTRODUCTION: Autoantibodies (autoAbs) against desmoglein-1 (DSG1) and desmoglein-3 (DSG3) have conventionally been studied and well accepted in the pathogenesis of pemphigus vulgaris (PV) and foliaceus (PF). Recent studies have suggested that non-DSG autoAbs may contribute to the pathogenesis of pemphigus, including autoAbs directed at acetylcholine receptors (AChR) and thyroid peroxidase (TPO). The purpose of this study is to retrospectively analyze PV and PF patient sera to better understand the relationship between anti-AChR and -TPO Abs to disease activity and DSG reactivity between patients treated with prednisone and steroid sparing agents (SSA; n = 22) or prednisone and rituximab (n = 21). METHODS: Patients were evaluated at 2 time points, T1 and T2, for disease activity using the Pemphigus Disease Area Index (PDAI), and sera were tested for the presence of TPO, DSG1, DSG3, muscarinic (M3) and nicotinic (n) AChR IgG autoAbs, as well as antibodies against Varicella Zoster Virus (VZV) by ELISA. RESULTS: Disease activity significantly decreased in patients from T1 to T2 (p < .0001). A significant difference was seen in IgG anti-DSG1 (p < .0001) and anti-DSG3 (p = .0049) levels when T1 was compared to T2 in both treatment groups. A significant increase was found between pemphigus patients and normal subjects with nAChR (p < .0001) at T1 but not with m3AChR, TPO or VZV Abs. No significant difference was seen between T1 and T2 values in patients with pemphigus for the non-desmoglein Abs TPO (p = .7559), M3AChR (p = .9003), nAChR (p = .5143) or VZV (p = .2454). These findings demonstrate that although an increase in IgG anti-nAChR autoAbs was found in PV and PF subjects, these Abs did not decrease with treatment. No other non-DSG Abs were increased or significantly changed over time in patients with pemphigus. This suggests that anti -AChR and -TPO Abs may not play a direct role in the pathogenesis of most patients with pemphigus, but does not rule out a role for non-DSG auto antibodies in distinct subsets of pemphigus patient.

Serum Thyroid Peroxidase Antibody Level and Incident Hypertension in Iranian Men: A Suggestion for the Role of Thyroid Autoimmunity.

BACKGROUND: Dysfunction of the thyroid gland has profound effects on the cardiovascular system. OBJECTIVE: We aimed to explore the relation of serum thyroid peroxidase antibody (TPO-Ab), as a marker of thyroid autoimmunity with incident hypertension among a euthyroid population. METHODS: A total of 3681 participants (1647 men) entered the study. Multivariate Cox proportional hazard models were conducted to estimate the association between TPO-Ab and incident hypertension. RESULTS: The mean age (standard deviation) of the participants was 37.5 (12.8) years. During a median follow-up of 12.2 years, 511 men and 519 women developed hypertension. The multivariable hazard ratios (HRs) and related 95% confidence intervals (CIs) of 1-unit increase in natural logarithm (ln) of TPO-Ab for incident hypertension were 1.09 (1.00-1.19), 1.03 (0.97-1.10), and 1.05 (1.00-1.11) for men, women, and total population, respectively. Moreover, considering the TPO-Ab status as a categorical variable (i.e. TPO-Ab positive or TPO-Ab negative), the multivariate-adjusted HRs (95% CIs) of TPO-Ab positivity for incident hypertension, were 1.33 (0.95-1.85), 1.12 (0.86-1.45) and 1.19 (0.97- 1.46) for men, women, and total population, respectively. CONCLUSION: Elevated serum TPO-Ab level can contribute to the development of hypertension among euthyroid men during a long follow-up; suggesting a role for thyroid autoimmunity.

Abdominal Obesity Phenotypes and Incidence of Thyroid Autoimmunity: A 9-Year Follow-up.

PURPOSE: The association between obesity and autoimmune diseases has been suggested by several previous studies. The objective of our study was to assess the association of abdominal obesity phenotypes with thyroid autoimmunity. MATERIALS AND METHODS: This study was conducted within the framework of a population-based cohort study, Tehran Thyroid Study (TTS) on 4708 subjects without thyroid autoimmunity at baseline. Participants were categorized into four abdominal obesity phenotypes according to waist circumference (WC) and other metabolic syndrome components. Serum concentrations of thyroid peroxidase antibody (TPOAb), free T4 (FT4), thyrotropin (TSH), glucose, and lipid profiles were measured after 3, 6 and 9 years of follow-up. Cox proportional hazard models were used to evaluate associations of different phenotypes with the incidence of thyroid autoimmunity, adjusted for age, sex, FT4, and TSH. RESULTS: Highest and lowest incidence rates of TPOAb positivity were observed among metabolically unhealthy, non-abdominally obese (MUNAO) [8.78 (7.31-10.55) per 1000 person-years of follow-up] and metabolically unhealthy abdominally obese (MUAO) [4.98 (3.88-6.41) per 1000 person-years of follow-up] phenotypes. Considering the metabolically healthy non-abdominal obese (MHNAO) individuals as reference, none of metabolically healthy abdominally obese (MHAO), MUNAO, and MUAO phenotypes were associated with increased risk of developing TPOAb positivity. Compared to individuals with high WC, the incidence rate (95%CI) of TPOAb positivity was higher among those with normal WC: 8.44 (7.13-10.0) vs 5.11 (4.01-6.51) per 1000 person-years, respectively. Higher WC was not associated with incident TPOAb positivity. CONCLUSION: There was no significant association between baseline abdominal obesity phenotype status and development of TPOAb positivity over 9 years of follow-up.