The interference of anti-TSH autoantibody on clinical TSH detection.

Objective: It is well known that macro-thyroid-stimulating hormone (macro-TSH) could interfere with the detection of TSH. The anti-TSH autoantibody is an essential component of macro-TSH. However, the epidemiological characteristics and the clinical interference of the anti-TSH autoantibody are unclear. Methods: In this study, the radioimmunoprecipitation technique was used to detect the anti-TSH autoantibody. Platforms with different detection mechanisms were applied to measure the TSH in patients with the anti-TSH autoantibody. Polyethylene glycol (PEG) precipitation was used to determine the immunoassay interference. Results: The prevalence of the anti-TSH autoantibody in patients with mild subclinical hypothyroidism (SCH) and autoimmune thyroiditis, but normal thyroid function, was 4.78%. All 10 patients with anti-TSH antibodies had autoimmune diseases, with five of them having significant clinical test interference. Conclusion: The appearance of the anti-TSH antibody is not associated with thyroid autoantibodies. The presence of the anti-TSH autoantibody can interfere with the detection of TSH and can affect clinical diagnosis and treatment.

Pseudo Elevation of TSH and ACTH Caused by Heterophilic Antibodies: a Case Report and Literature Review.

BACKGROUND: TSH and ACTH are crucial hormones for diagnosing thyroid and adrenal diseases, and incorrect test reports can cause significant harm to patients. METHODS: The TSH and ACTH levels on the testing system of our laboratory were measured using "sandwich" assays. The patient had heterophilic antibodies in their body, causing a false increase in TSH and ACTH levels. RESULTS: TSH on the Abbott platform was 59.7 µIU/mL and on the Roche platform it was 4.33 µIU/mL. After pretreatment with HBR it was 3.95 µIU/mL; ACTH on the SIEMENS platform was 263.5 pg/mL, on the Abbott platform it was 47.6 pg/mL. After pretreatment with HBR it was 36.5 pg/mL. CONCLUSIONS: The patient's serum contains heterophilic antibodies, which interfere with the TSH and ACTH tested by this method.

TSH-TSHR axis promotes tumor immune evasion.

BACKGROUND: Hormones are identified as key biological variables in tumor immunity. However, previous researches mainly focused on the immune effect of steroid hormones, while the roles that thyroid-stimulating hormone (TSH) played in the antitumor response were far from clear. METHODS: The source of TSH was determined using single-cell transcriptomic, histologic, quantitative PCR, and ELISA analysis. The influence of TSH on tumor proliferation, invasion, and immune evasion was evaluated in multiple cell lines of thyroid cancer, glioma, and breast cancer. Then transcriptomic sequencing and cellular experiments were used to identify signaling pathways. TSH receptor (TSHR) inhibitor was injected into homograft mouse tumor models with or without anti-programmed cell death protein-1 antibody. RESULTS: Monocyte-derived dendritic cells (moDCs) highly expressed TSHα and TSHß2 and were the primary source of TSH in the tumor microenvironment. TSH released by moDCs promoted proliferation and invasion of tumors with high TSHR expressions, such as thyroid cancers and glioma. TSH also induced tumor programmed death-ligand 1 (PD-L1) expression through the TSHR-AC-PKA-JNK-c-JUN pathway. TSHR inhibitors reversed tumor immune evasion by inhibiting PD-L1 expression in tumor and myeloid cells and enhancing Teff activation. CONCLUSIONS: TSH-TSHR axis promotes tumor evasion in thyroid cancers and glioma. TSH suppression therapy is an effective therapeutic strategy for combination in immune checkpoint blockades.

Fetal and Neonatal Thyroid Dysfunction.

Fetal and neonatal dysfunctions include rare serious disorders involving abnormal thyroid function during the second half of gestation, which may persist throughout life, as for most congenital thyroid disorders, or be transient, resolving in the first few weeks of life, as in autoimmune hyperthyroidism or hypothyroidism and some cases of congenital hypothyroidism (CH) with the thyroid gland in situ. Primary CH is diagnosed by neonatal screening, which has been implemented for 40 years in developed countries and should be introduced worldwide, as early treatment prevents irreversible neurodevelopmental delay. Central CH is a rarer entity occurring mostly in association with multiple pituitary hormone deficiencies. Other rare disorders impair the action of thyroid hormones. Neonatal Graves' disease (GD) results from the passage of thyrotropin receptor antibodies (TRAbs) across the placenta, from mother to fetus. It may affect the fetuses and neonates of mothers with a history of current or past GD, but hyperthyroidism develops only in those with high levels of stimulatory TRAb activity. The presence of antibodies predominantly blocking thyroid-stimulating hormone receptors may result in transient hypothyroidism, possibly followed by neonatal hyperthyroidism, depending on the balance between the antibodies present. Antithyroid drugs taken by the mother cross the placenta, treating potential fetal hyperthyroidism, but they may also cause transient fetal and neonatal hypothyroidism. Early diagnosis and treatment are key to optimizing the child's prognosis. This review focuses on the diagnosis and management of these patients during the fetal and neonatal periods. It includes the description of a case of fetal and neonatal autoimmune hyperthyroidism.

The Association of TSH and Thyroid Hormones With Lymphopenia in Bacterial Sepsis and COVID-19.

CONTEXT: Lymphopenia is a key feature of immune dysfunction in patients with bacterial sepsis and coronavirus disease 2019 (COVID-19) and is associated with poor clinical outcomes, but the cause is largely unknown. Severely ill patients may present with thyroid function abnormalities, so-called nonthyroidal illness syndrome, and several studies have linked thyrotropin (thyroid stimulating hormone, TSH) and the thyroid hormones thyroxine (T4) and 3,5,3'-triiodothyronine (T3) to homeostatic regulation and function of lymphocyte populations. OBJECTIVE: This work aimed to test the hypothesis that abnormal thyroid function correlates with lymphopenia in patients with severe infections. METHODS: A retrospective analysis of absolute lymphocyte counts, circulating TSH, T4, free T4 (FT4), T3, albumin, and inflammatory biomarkers was performed in 2 independent hospitalized study populations: bacterial sepsis (n = 224) and COVID-19 patients (n = 161). A subgroup analysis was performed in patients with severe lymphopenia and normal lymphocyte counts. RESULTS: Only T3 significantly correlated (ρ = 0.252) with lymphocyte counts in patients with bacterial sepsis, and lower concentrations were found in severe lymphopenic compared to nonlymphopenic patients (n = 56 per group). Severe lymphopenic COVID-19 patients (n = 17) showed significantly lower plasma concentrations of TSH, T4, FT4, and T3 compared to patients without lymphopenia (n = 18), and demonstrated significantly increased values of the inflammatory markers interleukin-6, C-reactive protein, and ferritin. Remarkably, after 1 week of follow-up, the majority (12 of 15) of COVID-19 patients showed quantitative recovery of their lymphocyte numbers, whereas TSH and thyroid hormones remained mainly disturbed. CONCLUSION: Abnormal thyroid function correlates with lymphopenia in patients with severe infections, like bacterial sepsis and COVID-19, but future studies need to establish whether a causal relationship is involved.

Interference of anti-streptavidin antibodies: More common than we thought? In relation to six confirmed cases.

Automated immunoassays are extensively used in routine laboratory diagnostics of endocrine disorders because of their advantages, such as high sensitivity, precision, and specificity. However, these methods are limited by the susceptibility of the immunochemical reaction to various interferences. They may present interferences related to the assay's design, for example, the endogenous presence of anti-streptavidin antibodies (ASA) in platforms that use the biotin-streptavidin interaction. To date, there have been few reports in the literature of interference from endogenous ASA. However, such antibodies would potentially lead to falsely decreased or increased results of hormones that can lead to incorrect diagnoses. We report six patients with unusual thyroid function tests, incongruent to their clinical findings. They present elevated concentrations of total T3 and T4 and TSH values within the reference range when measured at Cobas 8000® e801 module (Roche Diagnostics®). Neither patient had been taking biotin; however, all demonstrated the presence of ASA causing falsely high results on competitive assays and also falsely low results on sandwich assays. The hormone panel was also analyzed in the same samples using a different platform available in our laboratory: Cobas 6000® e601 module (Roche Diagnostics®). Nine samples were sent to an external laboratory to be measured with the chemiluminescent method: ADVIA Centaur® (Siemens® Healthcare Diagnostics). The interference seems to affect e801 module and competitive assays the most without affecting results obtained by this chemiluminescent method. This interference could potentially affect other assays performed on the same platform, such as ATPO and estradiol. Finally, laboratories should suspect the presence of interference when there is no correlation between the hormone profile and the patient's clinic. The biotin neutralization protocol demonstrated its effectiveness to eliminate ASA interference.

Low Normal TSH Levels and Thyroid Autoimmunity are Associated with an Increased Risk of Osteoporosis in Euthyroid Postmenopausal Women.

BACKGROUND AND OBJECTIVE: Studies on the relationship of thyroid stimulating hormone (TSH) within the reference range and thyroid autoimmunity with osteoporosis have produced conflicting results. The objective of this study was to investigate the association of thyroid function and thyroid autoimmune bodies (TPOAb and TgAb) with osteoporosis in euthyroid postmenopausal women. METHODS: A total of 174 subjects were retrospectively included. Serum TSH, total T3, total T4, TPOAb, TgAb, vitamin D, calcium and bone mineral density were measured. Correlation and logistic multivariate regression analysis were performed. RESULTS: Levels of TSH were lower in osteoporosis group (TSH: 2.03±1.08 vs 2.40±1.24 mIU/L, p=0.040) while TT3 and TT4 levels were similar between the two groups. The positive percentage of anti-TPO antibodies was higher in osteoporosis group (17.9% vs 6.7%, χ2= 5.13, p=0.024) while no significant difference was observed for anti-Tg antibodies (17.9% vs 8.9%, χ2=3.05, p=0.081). The Spearman correlation analysis showed that TSH levels were significantly correlated with lumbar spine BMD (r= 0.161, P=0.035) and femoral neck BMD (r = 0.152, P= 0.045). Logistical regression analysis revealed that low-normal TSH levels and positive TPOAb was an independent risk factor for osteoporosis (OR: 0.698, 95% CI: 0.505-0.965, p=0.030; OR: 3.961, 95% CI: 1.176-13.345, p=0.026 respectively). CONCLUSION: The results showed that low-normal TSH levels and anti-TPO antibodies were independently associated with the presence of osteoporosis in postmenopausal women.

Recombinant Human Thyroid-Stimulating Hormone Increases the Percentages of Natural Killer T Cells and B Lymphocytes in Human Peripheral Blood In Vivo.

Multiple cellular and humoral components of the immune system play a significant role in the physiology and pathophysiology of various organs including the thyroid. On the other hand, both thyroid hormones and thyroid-stimulating hormone (TSH) have been shown to exert immunoregulatory activities, which are difficult to assess independently in vivo. In our study we employed a unique clinical model for the assessment of TSH biological function in humans. The structure of peripheral blood mononuclear cell populations was investigated, using flow cytometry, in athyroid patients (n = 109) after treatment because of the differentiated thyroid carcinoma (DTC) at two time-points: directly before and five days after recombinant human TSH (rhTSH) administration. The analysis revealed significant increase in the percentage of natural killer T cells and B lymphocytes in the peripheral blood of rhTSH treated patients, whereas, we did not observe any effects on investigated subpopulations of dendritic cells and monocytes, T cells and natural killer cells. The findings of the study indicate the immune regulatory role of TSH, directed specifically on selected cell subtypes.

Effects of Maternal Subclinical Hypothyroidism in Early Pregnancy Diagnosed by Different Criteria on Adverse Perinatal Outcomes in Chinese Women With Negative TPOAb.

Aims: To compare the effects of maternal subclinical hypothyroidism (SCH) diagnosed by the 2011 or 2017 "Guidelines of the American Thyroid Association (ATA) for the diagnosis and management of thyroid disease during pregnancy and the postpartum" during the first trimester on adverse pregnancy outcomes in thyroid peroxidase antibody (TPOAb)-negative pregnant women. Methods: There were 1,556 Chinese singleton pregnant women with negative TPOAb diagnosed with either SCH or euthyroidism who were investigated, and the prevalence and risk of obstetric outcomes were compared between the two groups using 2011 and 2017 ATA standards, respectively. The effects of a mildly elevated thyroid-stimulating hormone (TSH) concentration on adverse pregnancy outcomes were evaluated by binary logistic regression. Results: Maternal SCH identified by the 2011 ATA guidelines correlated with higher rates and risks of pregnancy-induced hypertension (PIH), preeclampsia, and low-birth-weight infants, while maternal SCH diagnosed by the 2017 ATA guidelines was more likely to develop PIH, preeclampsia, cesarean delivery, preterm delivery, placenta previa, and total adverse maternal and neonatal outcomes. Moreover, a mildly elevated TSH level was significantly associated with PIH after adjustment for confounding factors. Conclusions: Compared with the 2011 ATA guidelines, the 2017 ATA guidelines could be more applicable to Chinese pregnant women to screen the effects of SCH on the majority of adverse pregnancy outcomes.

Thyrotoxicosis in patients with COVID-19: the THYRCOV study.

OBJECTIVE: This study assessed thyroid function in patients affected by the coronavirus disease-19 (COVID-19), based on the hypothesis that the cytokine storm associated with COVID-19 may influence thyroid function and/or the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may directly act on thyroid cells, such as previously demonstrated for SARS-CoV-1 infection. DESIGN AND METHODS: This single-center study was retrospective and consisted in evaluating thyroid function tests and serum interleukin-6 (IL-6) values in 287 consecutive patients (193 males, median age: 66 years, range: 27-92) hospitalized for COVID-19 in non-intensive care units. RESULTS: Fifty-eight patients (20.2%) were found with thyrotoxicosis (overt in 31 cases), 15 (5.2%) with hypothyroidism (overt in only 2 cases), and 214 (74.6%) with normal thyroid function. Serum thyrotropin (TSH) values were inversely correlated with age of patients (rho -0.27; P < 0.001) and IL-6 (rho -0.41; P < 0.001). In the multivariate analysis, thyrotoxicosis resulted to be significantly associated with higher IL-6 (odds ratio: 3.25, 95% confidence interval: 1.97-5.36; P < 0.001), whereas the association with age of patients was lost (P = 0.09). CONCLUSIONS: This study provides first evidence that COVID-19 may be associated with high risk of thyrotoxicosis in relationship with systemic immune activation induced by the SARS-CoV-2 infection.

An Inverse Relationship Between Iodine Intake and Thyroid Antibodies: A National Cross-Sectional Survey in Mainland China.

Background: Iodine intake is associated with thyroid autoimmunity. In this study, we evaluated the changes in thyroid autoimmunity after 20 years of universal salt iodization (USI) in China. Methods: A total of 78,470 subjects (18 years or older) from 31 provincial regions of mainland China participated in the study. Serum thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TgAb), TSH receptor antibody, thyrotropin (TSH), and urinary iodine concentration (UIC) were measured. Results: Positive TPOAb and TgAb were detected in 10.19% [CI 9.80-10.59] and 9.70% [CI 9.28-10.13] of the subjects, respectively. The prevalence of positive isolated TPOAb (i-TPOAb), positive isolated TgAb (i-TgAb), and double positive TPOAb and TgAb (d-Ab) was 4.52%, 4.16%, and 5.94%, respectively. The prevalence of thyroid antibody positivity was the highest in the iodine-deficient (UIC <100 µg/L) groups. The prevalence of i-TPOAb was inversely associated with more than adequate iodine intake (MAI) and excessive iodine intake (EI); the odds ratio (OR) was 0.89 [CI 0.81-0.98] for MAI and 0.90 [CI 0.81-0.99] for EI. We observed that i-TgAb, like i-TPOAb, was a high-risk factor for subnormal TSH levels (OR = 3.64 [CI 2.62-5.05]) and elevated TSH levels (OR = 1.62 [CI 1.49-1.77]). The prevalence of thyroid antibody positivity varied among five ethnic groups. Conclusions: After two decades of USI, the prevalence of thyroid antibody positivity has remained low. MAI and EI had an inverse relationship with TPOAb positivity, which reveals that UIC between 100 and 299 µg/L is optimal and safe for thyroid autoimmunity. These conclusions need to be confirmed in a follow-up study because this study was a cross-sectional study.

Reusable on-plate immunoprecipitation method with covalently immobilized antibodies on a protein G covered microtiter plate.

Covalent immobilization of antibodies to protein G beads is a basic molecular biology method, although the beads present poor recovery results. Our aim was to reuse the immobilized antibody-protein G complex on a very small scale, therefore we optimized the crosslinking procedure to be used on the wells of a standard 96-well microplate. The method used involves the affinity binding of the antibody to the protein G surface, followed by the immobilization step using different crosslinking reagents, DMP and BS3, quenching the crosslinking reaction, and binding the antibody-specific antigen. By scaling down the procedure, we were able to reuse the anti-EGFR crosslinked wells more than 20 times. This method can be used to perform assays on a wide range of solid supports containing the protein G in an immobilized form, including functionalized nanosensors, for immunoprecipitation, protein and cell lysate purification, target protein enrichment.

Evaluation of the structure, autoimmunity, and functions of the thyroid gland in familial Mediterranean fever patients.

Objective Familial Mediterranean fever (FMF) is an autosomal recessive autoinflammatory disorder that is frequently seen in the eastern Mediterranean region. The thyroid gland can be affected in FMF patients through autoimmunity or amyloidosis. Here, we aimed to evaluate the structure and functions of the thyroid gland in addition to possible autoimmunity in FMF patients. Subjects and methods The study was conducted by the Endocrinology and Metabolism and Internal Medicine Departments. Thirty FMF patients and 30 age and gender-matched healthy controls were enrolled in the study. Free thyroxin (fT4), free triiodothyronine (fT3), thyroid-stimulating hormone (TSH), and anti-thyroid peroxidase (anti-TPO) autoantibodies were investigated. Detailed thyroid grayscale and Doppler Ultrasonography examinations and shear-wave elastosonography (SWE) were performed in the patient and control groups. Results Anti-TPO was detected in 24% (n = 7) of the patients. On the grayscale US, mean thyroid volumes were similar between the FMF and the control groups (p > 0.05). By Doppler US, thyroid vascularity observed was detected in 10.3% (n = 3) of the patients. SWE revealed that the mean velocity value of right vs. left lobe in the patient group was 1.77 ± 0.45 m/s and 1.95 ± 0.51 m/s, respectively. Compared to the control group, the mean velocity values were significantly higher in the right (p = 0.004) and left (p = 0.01) lobes of the patient group. The mean stiffness value in the patient group was also significantly higher in the right and left lobes [10.13 ± 5.65 kPa (p = 0.005) and 12.24 ± 6.17 kPa (p = 0.02), respectively]. Conclusion Recognizing the complications of FMF early in the course of the disease is as important as the early diagnosis of the disorder. Based on this, thyroid functions and changes in its structure should be evaluated carefully for early diagnosis of a possible coexisting thyroid disorder. Arch Endocrinol Metab. 2020;64(1):66-70.

Evaluation of the structure, autoimmunity, and functions of the thyroid gland in familial Mediterranean fever patients

ABSTRACT Objective Familial Mediterranean fever (FMF) is an autosomal recessive autoinflammatory disorder that is frequently seen in the eastern Mediterranean region. The thyroid gland can be affected in FMF patients through autoimmunity or amyloidosis. Here, we aimed to evaluate the structure and functions of the thyroid gland in addition to possible autoimmunity in FMF patients. Subjects and methods The study was conducted by the Endocrinology and Metabolism and Internal Medicine Departments. Thirty FMF patients and 30 age and gender-matched healthy controls were enrolled in the study. Free thyroxin (fT4), free triiodothyronine (fT3), thyroid-stimulating hormone (TSH), and anti-thyroid peroxidase (anti-TPO) autoantibodies were investigated. Detailed thyroid grayscale and Doppler Ultrasonography examinations and shear-wave elastosonography (SWE) were performed in the patient and control groups. Results Anti-TPO was detected in 24% (n = 7) of the patients. On the grayscale US, mean thyroid volumes were similar between the FMF and the control groups (p > 0.05). By Doppler US, thyroid vascularity observed was detected in 10.3% (n = 3) of the patients. SWE revealed that the mean velocity value of right vs. left lobe in the patient group was 1.77 ± 0.45 m/s and 1.95 ± 0.51 m/s, respectively. Compared to the control group, the mean velocity values were significantly higher in the right (p = 0.004) and left (p = 0.01) lobes of the patient group. The mean stiffness value in the patient group was also significantly higher in the right and left lobes [10.13 ± 5.65 kPa (p = 0.005) and 12.24 ± 6.17 kPa (p = 0.02), respectively]. Conclusion Recognizing the complications of FMF early in the course of the disease is as important as the early diagnosis of the disorder. Based on this, thyroid functions and changes in its structure should be evaluated carefully for early diagnosis of a possible coexisting thyroid disorder. Arch Endocrinol Metab. 2020;64(1):66-70

Abnormal thyroid hormone response to TRH in a case of macro-TSH and the cut-off value for screening cases of inappropriate TSH elevation.

A 74-year-old asymptomatic Japanese man with suspected thyroid dysfunction was referred to our hospital. He had an elevated TSH (53.8 mIU/L; reference interval: 0.5-5.0) despite a free T4 (FT4) level (1.4 ng/dL; reference interval: 0.9-1.6). Further analysis revealed macro-TSH. A notable finding was that a 500-µg TRH stimulation test revealed a blunted free T3 (FT3) response despite a prolonged TSH response. Macro-TSH typically presents with inappropriately marked elevation of serum TSH levels compared with other thyroid hormones, as exhibited in our case. However, the level of TSH elevation that might differentiate macro-TSH from subclinical hypothyroidism is poorly known. We retrospectively analyzed 8,183 concurrent measurements of TSH and FT4 in individuals previously examined in our hospital to define the cut-off value for screening cases of inappropriate TSH elevation. FT4 values were rounded off to one decimal place, and the 97.5th percentile of TSH against each FT4 value was calculated. The data of our patient and that of 30 cases of macro-TSH extracted from the English literature were then assessed. When the approximate curve obtained from the 97.5th percentile of TSH values was defined as the cut-off value [Log10TSH = 0.700 + 1.549/{1 + (FT4/0.844)6.854}], 25 of the 31 (80.6%) macro-TSH cases were identified. In conclusion, we report for the first time a case of macro-TSH demonstrating an abnormal FT3 response to TRH. A cut-off value of TSH adjusted to the FT4 level may be a good method of screening for inappropriate TSH elevation (or inappropriate hyperthyrotropinemia) including those caused by macro-TSH.

Vitamin D deficiency and thyroid autoantibody fluctuations in patients with Graves' disease - A mere coincidence or a real relationship?

PURPOSE: The aim of this study was to evaluate the association between vitamin D (vitD) and changes in the titers of anti-TSH receptor (TSHR-Abs), antithyroglobulin (Tg-Abs), and antiperoxidase (TPO-Abs) autoantibodies. MATERIALS/METHODS: The study involved 269 patients with Graves' disease (GD), divided into four subgroups (1-4), i.e. 65 smokers treated with vitD(+) (1), 76 smokers not treated with vitD(-) (2), 61 non-smokers treated with vitD(+) (3) and 67 non-smokers with vitD(-) (4). All thyroid parameters were analyzed at entry and 1, 3, 6, 9 and 12 months later. RESULTS: The titer of TSHR-Abs in group 3 was significantly lower than in groups 1 and 2 across all time points. At 3, 6 and 12 months, the titers of TSHR-Abs were also lower in group 4 compared to groups 1 and 2. At 9 months, the titers in group 3 were lower than in all other groups. There was a significant inverse correlation between baseline levels of vitD and baseline titers of Tg-Abs (in group 1 only), Tg-Abs after 12 months (in group 1 only), TPO-Abs after 12 months (in groups 1 and 3), fT4 (in group 4 only), and a significant positive correlation with TPO-Abs (in group 2 only). VitD levels at 12 months were inversely correlated with Tg-Abs in group 1. CONCLUSIONS: VitD measurements in patients with GD, especially smokers with an increased TSHR-Ab titers before 131I therapy, are recommended. Immunological remission is more likely in patients with GD who receive vitD, particularly smokers.

Rapid cycling bipolar disorder is associated with antithyroid antibodies, instead of thyroid dysfunction.

BACKGROUND: Conclusions regarding the association between antithyroid antibodies or thyroid dysfunction and rapid cycling bipolar disorder (RCBD) have been conflicting. Previous studies suggest that the impact of antithyroid antibodies on mental wellbeing seems to be independent of thyroid function. Here, we investigated their independent association with RCBD in a large, well-defined population of bipolar disorder (BD). METHODS: Fast serum levels of free thyroxine (FT4), free triiodothyronine (FT3), thyroid Stimulating Hormone (TSH), TPO-abs and Tg-abs were simultaneously measured in 352 patients with BD. Clinical features of BD were collected through semi-structural interview conducted by trained interviewers with background of psychiatric education. RESULTS: Neither hypothyroidism nor hyperthyroidism was significantly associated with RCBD. Both TPO-abs and Tg-abs were significantly related to RCBD, even after controlling for gender, age, marriage status, education, antidepressants treatment, comorbidity of thyroid diseases, and thyroid function (serum levels of FT3, FT4 and TSH). Although TPO-abs and Tg-abs were highly correlated with each other, binary logistic regression with forward LR selected TPO-abs, instead of Tg-abs, to be associated with RCBD. TPO-abs was significantly, independently of Tg-abs, associated with hyperthyroidism, while Tg-abs was marginally significantly related to hypothyroidism at the presence of TPO-abs. CONCLUSION: TPO-abs might be treated as a biomarker of RCBD. Further exploring the underlying mechanism might help understand the nature of RCBD and find out new treatment target for it.

Association of IL6 gene methylation in peripheral blood cells with the development and prognosis of autoimmune thyroid diseases.

Autoimmune thyroid diseases (AITDs), including Hashimoto's disease (HD) and Graves' disease (GD), are archetypes of organ-specific autoimmune diseases, but the prognosis of patients with AITD varies. Autoimmune diseases, including AITDs, are believed to develop in response to both genetic and environmental factors. Interleukin (IL)-6 plays a major role in B cell differentiation and T cell proliferation, and methylation of the IL6 gene is associated with IL-6 production. To clarify the role of IL6 gene methylation in the pathogenesis and prognosis of AITDs, we measured the methylation levels of -666, -664, -610, -491 and -426 CpG sites in the IL6 gene. We measured the methylation levels of 5 CpG sites in 29 patients with HD, 31 patients with GD and 16 healthy volunteers using pyrosequencing. The methylation level at each of the -664, -491 and -426 CpG sites was negatively correlated with the age at the time of sampling. Multiple regression analysis indicated that patients with HD, including severe or mild HD, showed higher methylation levels at the -426 CpG site than control subjects. Patients with intractable GD showed lower methylation levels at the -664 and -666 CpG sites than patients with GD in remission. In conclusion, IL6 gene methylation levels were related to the susceptibility to HD and the intractability of GD.

Generation and characterization of monoclonal antibodies against thyroid-stimulating hormone for newborn screening of congenital hypothyroidism.

Congenital hypothyroidism (CH) is one of the most frequent inherited-metabolic diseases in the world, and the main cause of treatable mental retardation in children. Because signs and symptoms of this disease are often scarce and not easily recognizable, newborns are screened for the early CH detection at birth. The Center of Immunoassay (CIE) has developed the UMELISA® TSH Neonatal and UMELISA® TSH to determine neonatal thyroid-stimulating hormone (TSH) levels in dried blood and serum samples. Both reagent kits use the same polystyrene plates coated with anti-ß-TSH monoclonal antibodies (MAbs), but one of these is commercially acquired. Obtaining appropriate anti-TSH MAbs at the CIE would guarantee economic independence and security in the production of these kits. Immunization of mice with TSH led to the generation of 7G11E3, an anti-ß-TSH IgG1-secreting hybridoma. The high affinity of 7G11E3 MAb and its characteristic epitopic recognition explain its better performance when adsorbed to UMELISA® plates for capturing low amounts of TSH in comparison with the studied MAbs. Performance of assays using polystyrene plates coated with 7G11E3 MAb was studied. Recovery percentages (100.0-106.7% for UMELISA® TSH NEONATAL and 97.3-99.0% for UMELISA® TSH) and intra (5.2-7.9% for UMELISA® TSH NEONATAL and 3.2-5.3% for UMELISA® TSH) and inter (6.6-7.7% for UMELISA® TSH NEONATAL and 5.2-8.0% for UMELISA® TSH) coefficients of variation were similar to the ones described for the commercial kits. Limits of detection and quantification were 1.0 and 3.8 mIU/L for UMELISA® TSH NEONATAL, and 0.3 and 0.6 mIU/L for UMELISA® TSH, respectively. The results also showed high overall concordance between assays (n = 2 019, ρc = 0.90 for UMELISA® TSH NEONATAL and n = 200, ρc = 0.94 for UMELISA® TSH). The 7G11E3 MAb meets the requirements for its use in the plates of UMELISA® TSH kits for CH newborn screening in Cuba. Abbreviations: CECMED, Center for the State Control of Medicaments and Medical Equipment and Devices; CH, congenital hypothyroidism; CIE, Center of Immunoassay; CLSI, Clinical and Laboratory Standards Institute; CV coefficient of variation; DBS, dried blood spots; LOB, limit of blank; LOD, limit of detection; LOQ, limit of quantitation; SD, standard deviation; Sr, repeatability standard deviation; SUMA, Ultra Micro Analytic System; UMELISA, ultramicro enzyme-linked immunosorbent assay.