The impact of environmental factors and contaminants on thyroid function and disease from fetal to adult life: current evidence and future directions.

The thyroid gland regulates most of the physiological processes. Environmental factors, including climate change, pollution, nutritional changes, and exposure to chemicals, have been recognized to impact thyroid function and health. Thyroid disorders and cancer have increased in the last decade, the latter increasing by 1.1% annually, suggesting that environmental contaminants must play a role. This narrative review explores current knowledge on the relationships among environmental factors and thyroid gland anatomy and function, reporting recent data, mechanisms, and gaps through which environmental factors act. Global warming changes thyroid function, and living in both iodine-poor areas and volcanic regions can represent a threat to thyroid function and can favor cancers because of low iodine intake and exposure to heavy metals and radon. Areas with high nitrate and nitrite concentrations in water and soil also negatively affect thyroid function. Air pollution, particularly particulate matter in outdoor air, can worsen thyroid function and can be carcinogenic. Environmental exposure to endocrine-disrupting chemicals can alter thyroid function in many ways, as some chemicals can mimic and/or disrupt thyroid hormone synthesis, release, and action on target tissues, such as bisphenols, phthalates, perchlorate, and per- and poly-fluoroalkyl substances. When discussing diet and nutrition, there is recent evidence of microbiome-associated changes, and an elevated consumption of animal fat would be associated with an increased production of thyroid autoantibodies. There is some evidence of negative effects of microplastics. Finally, infectious diseases can significantly affect thyroid function; recently, lessons have been learned from the SARS-CoV-2 pandemic. Understanding how environmental factors and contaminants influence thyroid function is crucial for developing preventive strategies and policies to guarantee appropriate development and healthy metabolism in the new generations and for preventing thyroid disease and cancer in adults and the elderly. However, there are many gaps in understanding that warrant further research.

Thyroid dysfunction caused by immune checkpoint inhibitors improves cancer outcomes.

A common immune-related adverse event (irAE) with immune checkpoint inhibitors (ICIs) is thyroid dysfunction (TD-irAEs). The clinical presentation can be varied, and its association with prognosis remains unclear. We investigated the characteristics of TD-irAEs and their association with clinical outcomes among cancer patients treated with ICIs in a real-life setting. Response to treatment was assessed using RECIST v1.1. We calculated the probability of recurrence and survival associated with TD-irAEs using multivariable-adjusted regression and Cox proportional hazards models. In this single-center retrospective analysis, we included 238 patients (72% male) with a median age of 69.5 years. Primary tumors were melanoma (23.1%), lung (60.5%), or urothelial cancer (16.4%), treated with atezolizumab (23.1%), pembrolizumab (44.5%), ipilimumab (0.4%), and/or nivolumab (25.6%). Seventy (29%) patients developed TD-irAEs in a median time of 69 days (41-181). The incidence of TD-irAEs with combination therapy was higher than with monotherapy (67% vs 6.3%, P = 0.011). TD-irAE patients showed a higher objective response rate (ORR) than those without TD-irAEs (60% vs 42.3%, P = 0.013) and longer overall survival (OS) 45 vs 16 months, P < 0.006. Patients who developed TD-irAEs had a relative reduction of 77% (OR 0.23, 95% CI 0.11-0.47) in the risk of progression and of 47% in the risk of mortality (HR 0.53, 95% CI 0.36-0.80), independent of age, sex, primary tumor, or ICI regimen. TD-irAEs occur in nearly 30% of our patients receiving ICIs. In our analysis, TD-irAEs appeared to be associated with higher ORR and longer OS and showed a reduction in the risk of progression and mortality.

Combined use of tyrosine kinase inhibitors with PD-(L)1 blockade increased the risk of thyroid dysfunction in PD-(L)1 blockade: a prospective study.

BACKGROUND: Anti-programmed cell death-1 (ligand-1) antibody [PD-(L)1-Ab] can cause destructive thyroiditis and/or hypothyroidism. In addition, tyrosine kinase inhibitors (TKIs) frequently induce hypothyroidism. The aim of this prospective study is to examine the incidence and clinical characteristics of thyroid dysfunction induced by combination therapy of a PD-(L)1-Ab and TKI [PD-(L)1-Ab/TKI]. METHODS: A total of 757 patients treated with PD-(L)1-Ab or PD-(L)1-Ab/TKI were evaluated for anti-thyroid antibodies (ATAs) at baseline and for thyroid function for 48 weeks after treatment initiation and then observed until the last visit. RESULTS: The cumulative incidences of destructive thyroiditis [4/23 (17.4%) vs. 45/734 (6.1%) patients, p < 0.001], isolated hypothyroidism [10/23 (43.5%) vs. 29/734 (4.0%) patients, p < 0.001], and all thyroid dysfunction [14/23 (60.9%) vs. 74/734 (10.1%) patients, p < 0.001] were significantly higher in the PD-(L)1-Ab/TKI group than PD-(L)1-Ab group, respectively. All patients positive for ATAs at baseline developed thyroid dysfunction after PD-(L)1-Ab/TKI treatment, a significantly higher incidence than that in those negative for ATAs at baseline [4/4 (100%) vs. 10/19 (52.6%) patients, p = 0.026]. CONCLUSIONS: The addition of TKIs increased the risk of thyroid dysfunction induced by PD-(L)1-Ab, with the risk being higher in patients positive for baseline ATAs.

Thyroid and parathyroid function disorders induced by short-term exposure of microplastics and nanoplastics: Exploration of toxic mechanisms and early warning biomarkers.

Human exposure to micro- and nano-plastics (MNPs) primarily occurs through respiration and diet in the environment. However, the early effects and warning signs of MNPs exposure on vertebrates are unclear. Here we used intratracheal instillation and intragastric infusion to establish mouse models for MNPs exposure to systematically investigate the toxic mechanisms of MNPs on endocrine organs. Results showed that MNPs induced endocrine disruptions in short-term exposure by both dietary and respiratory pathways. Microplastics (MPs) exposed through dietary route were more toxic to thyroid gland, whereas nanoplastics (NPs) exhibited the highest level of toxicity to parathyroid gland through respiration. The transcriptome and validation of related functional genes revealed that MNPs affected the synthesis of thyroglobulin by interfering with the expressions of PAX8 and CREB. MNPs also impacted the levels of thyroid stimulating hormone, further mediating the secretion of thyroid hormones. Moreover, MNPs modulate the expression of Mafb, thereby exerting regulatory effects on parathyroid hormone (PTH) synthesis and growth development in parathyroid cells. Meanwhile, MNPs interfered with the expression of IP3R in the calcium signaling pathway, indirectly affecting the secretion of PTH. This study reveals the effects and mechanisms of MNPs on thyroid and parathyroid and highlights the significance of early warning of MNPs exposure.

Air pollution exposure, accelerated biological aging, and increased thyroid dysfunction risk: Evidence from a nationwide prospective study.

BACKGROUND: Long-term air pollution exposure is a major health concern, yet its associations with thyroid dysfunction (hyperthyroidism and hypothyroidism) and biological aging remain unclear. We aimed to determine the association of long-term air pollution exposure with thyroid dysfunction and to investigate the potential roles of biological aging. METHODS: A prospective cohort study was conducted on 432,340 participants with available data on air pollutants including particulate matter (PM2.5, PM10, and PM2.5-10), nitrogen dioxide (NO2), and nitric oxide (NO) from the UK Biobank. An air pollution score was calculated using principal component analysis to reflect joint exposure to these pollutants. Biological aging was assessed using the Klemera-Doubal method biological age and the phenotypic age algorithms. The associations of individual and joint air pollutants with thyroid dysfunction were estimated using the Cox proportional hazards regression model. The roles of biological aging were explored using interaction and mediation analyses. RESULTS: During a median follow-up of 12.41 years, 1,721 (0.40 %) and 9,296 (2.15 %) participants developed hyperthyroidism and hypothyroidism, respectively. All air pollutants were observed to be significantly associated with an increased risk of incident hypothyroidism, while PM2.5, PM10, and NO2 were observed to be significantly associated with an increased risk of incident hyperthyroidism. The hazard ratios (HRs) for hyperthyroidism and hypothyroidism were 1.15 (95 % confidence interval: 1.00-1.32) and 1.15 (1.08-1.22) for individuals in the highest quartile compared with those in the lowest quartile of air pollution score, respectively. Additionally, we noticed that individuals with higher pollutant levels and biologically older generally had a higher risk of incident thyroid dysfunction. Moreover, accelerated biological aging partially mediated 1.9 %-9.4 % of air pollution-associated thyroid dysfunction. CONCLUSIONS: Despite the possible underestimation of incident thyroid dysfunction, long-term air pollution exposure may increase the risk of incident thyroid dysfunction, particularly in biologically older participants, with biological aging potentially involved in the mechanisms.

Incidence of thyroid dysfunction caused by immune checkpoint inhibitors combined with chemotherapy: A systematic review and meta-analysis.

BACKGROUND: The combination of immune checkpoint inhibitors (ICIs) and chemotherapy as a first-line treatment for triple-negative breast cancer (TNBC) has been associated with many adverse reactions. Thyroid dysfunction, the most common adverse reaction of the endocrine system, has also attracted significant attention. This study aimed to analyse the effect of ICIs combined with chemotherapy on thyroid function in patients with TNBC. METHODS: As of November 4, 2023, we searched the PubMed, Web of Science, and Cochrane Library databases for clinical trials of ICIs combined with chemotherapy for the treatment of TNBC. The incidence of hypothyroidism and hyperthyroidism was calculated using a random-effects model. RESULTS: In the final analysis, 3,226 patients from 19 studies were included. The total incidence of all-grade hypothyroidism induced by the combination of ICIs and chemotherapy in treating TNBC (12% (95% confidence intervals(CI): 0.10-0.15)) was higher than that of hyperthyroidism (5% (95% CI: 0.04-0.06)). Pembrolizumab combined with chemotherapy caused the highest incidence of all grades of hypothyroidism for 13% (95% CI: 0.05-0.06). Durvalumab combined with chemotherapy caused the highest incidence of all grades of hyperthyroidism, at 7% (95% CI: 0.03-0.11). ICIs combined with chemotherapy caused a higher incidence of all grades of hypothyroidism in advanced TNBC (15% (95% CI: 0.13-0.17)) than in early stage TNBC (10% (95% CI: 0.07-0.13)). CONCLUSION: In TNBC, the incidence of hypothyroidism caused by the combination of ICIs and chemotherapy was significantly higher than that caused by hyperthyroidism. Pembrolizumab combined with chemotherapy resulted in the highest incidence of hypothyroidism. The incidence of hypothyroidism in patients with advanced TNBC was significantly higher than that in patients with early stage TNBC. In addition, ICIs combined with chemotherapy resulted in 16 out of 3,226 patients experiencing grade ≥ 3 thyroid dysfunction. Although the incidence of severe thyroid dysfunction is low, it requires attention. PROSPERO: CRD42023477933.

Thyroid disorders induced by immune checkpoint inhibitors.

Immune checkpoint inhibitors (ICIs) are a revolutionary class of drugs that powerfully contribute to cancer therapy by harnessing the immune system to fight malignancies. However, their successful use as anti-cancer drugs is accompanied by a wide spectrum of immune-related adverse effects (irAEs), including endocrinopathies. Among them, thyroid dysfunction stands out as one of the most common endocrinopathies induced by ICI therapy and surfaces as a prominent concern. Destructive thyroiditis is the pathophysiological basis shared by the most common patterns of thyrotoxicosis followed by hypothyroidism and isolated hypothyroidism. Diagnostic approach is guided by clinical manifestation, laboratory evaluation and imaging modalities. Treatment approaches range from the substitution of levothyroxine to the utilization of beta blockers, depending on the extent of thyroid dysfunction's severity. While the medical community is dealing with the evolution and complexities of immunotherapy, recognizing and effectively managing ICI-induced thyroid dysfunction emerged as crucial for enhancing patient safety and achieving improved outcomes. The aim of this review is to navigate the significance of ICI-induced thyroid dysfunction unraveling the various patterns, underlying mechanisms, diagnostic approaches, and treatment strategies. It, also, highlights the impact of various factors such as cancer subtype, ICI dosage, age, and genetic susceptibility on the risk of experiencing dysfunction.

Thyroid dysfunction caused by exposure to environmental endocrine disruptors and the underlying mechanism: A review.

Thyroid disease has been rapidly increasing, but its causes remain unclear. At present, many studies have focused on the relationship between environmental endocrine disruptors (EEDs) and the pathogenesis of thyroid disease. Herein, we summarize such studies exploring the effects of exposure to common EEDs on thyrotoxicosis, finding that EEDs appear to contribute to the pathogenesis of thyroid-related diseases such as thyroid cancer, goiter, thyroiditis, hyperthyroidism, and hypothyroidism. To explore this causative effect in detail, we have analyzed the following three aspects of how EEDs are believed to exert their impacts on the occurrence and development of thyroid disease: (1) damage to the thyroid tissue structure, including disrupted mitochondria and the stratification of thyroid follicular epithelial cells; (2) disruption of thyroid hormone signaling, including thyroid hormone synthesis and secretion disorders, destruction of normal function of the hypothalamus-pituitary-thyroid axis, disturbed estrogen signaling in the body, alterations to the level of thyroid-stimulating hormone, inhibition of the release of thyroglobulin from thyroid cells, and reductions in the levels of sodium iodide co-transporters, thyroid peroxidase, deiodinase, and transthyretin; and (3) molecular mechanisms underlying the disruption of thyroid function, including competitive binding to T3 and T4 receptors, disturbance of the hypothalamic-pituitary-thyroid axis, activation of the ERK and Akt pathways, oxidative stress, regulation of the expression of the proto-oncogene k-Ras, tumor suppressor gene PTEN, and thyroid TSHR gene, and induction of autophagy in thyroid cells. Overall, this article reviews how EEDs can affect the occurrence and development of thyroid disease via multiple routes, thus providing new ideas to intervene for the prevention, diagnosis, treatment, and prognosis of thyroid disease.

Association between urinary organophosphate ester metabolite exposure and thyroid disease risk among US adults: National Health and Nutrition Examination Survey 2011-2014.

Background: Organophosphate esters (OPEs) may interfere with thyroid function, but the relationship between OPEs and thyroid disease remains unclear. This study aims to elucidate the relationship between OPEs exposure and thyroid disease risk in the general population in the United States. Method: Data were obtained from the 2011-2014 National Health and Nutrition Examination Survey cycle. All participants were tested for seven OPE metabolites in their urine and answered questions about whether they had thyroid disease through questionnaires. Logistic regression was employed to analyze the association between exposure to individual OPE metabolites and thyroid disease. Weighted Quantile Sum (WQS) regression modeling was utilized to assess exposure to mixed OPE metabolites and risk of thyroid disease. Bayesian kernel machine regression(BKMR) models to analyze the overall mixed effect of OPE metabolites. Result: A total of 2,449 participants were included in the study, 228 of whom had a history of thyroid disease. Bis(1,3-dichloro-2-propyl) phos (BDCPP), Diphenyl phosphate (DPHP) and Bis(2-chloroethyl) phosphate (BCEP) were the top three metabolites with the highest detection rates of 91.75%, 90.77% and 86.57%, respectively. In multivariate logistic regression models, after adjustment for confounding variables, individuals with the highest tertile level of BCEP were significantly and positively associated with increased risk of thyroid disease (OR=1.57, 95% CI=1.04-2.36), using the lowest tertile level as reference. In the positive WQS regression model, after correcting for confounding variables, mixed exposure to OPE metabolites was significantly positively associated with increased risk of thyroid disease (OR=1.03, 95% CI=1.01-1.06), with BCEP and DPHP having high weights. In the BKMR model, the overall effect of mixed exposure to OPE metabolites was not statistically significant, but univariate exposure response trends showed that the risk of thyroid disease decreased and then increased as BCEP exposure levels increased. Conclusion: The study revealed a significant association between exposure to OPE metabolites and an increased risk of thyroid disease, with BCEP emerging as the primary contributor. The risk of thyroid disease exhibits a J-shaped pattern, whereby the risk initially decreases and subsequently increases with rising levels of BCEP exposure. Additional studies are required to validate the association between OPEs and thyroid diseases.

The prevalence of hepatic and thyroid toxicity associated with imatinib treatment of chronic myeloid leukaemia: a systematic review.

BACKGROUND: Imatinib, a potent inhibitor of targeted protein tyrosine kinases, treats chronic myeloid leukaemia (CML). Data on imatinib-associated changes in hepatic and thyroid functions are limited and conflicting. AIM: To report the prevalence of hepatic and thyroid toxicity associated with the use of imatinib in CML patients. METHOD: Articles for the systematic review were selected from electronic databases (PubMed, CINALH, Web of Science). Readily accessible peer-reviewed full articles in English published 1st January 2000 to 18th July 2023 were included. The search terms included combinations of: imatinib, CML, liver toxicity, hepatic toxicity, thyroid toxicity. Screening of titles, abstracts, full text articles was conducted independently by two reviewers. Inclusions and exclusions were recorded following PRISMA guidelines. Detailed reasons for exclusion were recorded. Included articles were critically appraised. RESULTS: Ten thousand one hundred and twenty-three CML patients were reported in the 82 included studies corresponding to 21 case reports, 2 case series, 39 clinical trials and 20 observational studies were selected. Excluding case studies/reports, 1268 (12.6%; n = 1268/10046) hepatotoxicity adverse events were reported, of which 64.7% were rated as mild grade I & II adverse events, 363 (28.6%) as severe, grade III and IV adverse events; some led to treatment discontinuation, liver transplantation and fatal consequences. Twenty (35.1%) studies reported discontinuation of imatinib treatment due to the severity of hepatic toxicity. Fourteen (8.4%, n = 14/167) thyroid dysfunction adverse events were reported. CONCLUSION: High frequency of mild and severe hepatotoxicity, associated with imatinib in CML patients, was reported in the published literature. Low numbers of mild and manageable thyroid toxicity events were reported.

Elevated TSH Levels: A Database Study of General Practitioners' Course of Action.

OBJECTIVE: To investigate general practitioners' course of action after detection of elevated thyroid stimulating hormone (TSH) levels regarding repeat testing, direct levothyroxine replacement, or neither. METHODS: We conducted a retrospective study of adults without prior evidence of thyroid disease and with a first detection of elevated TSH levels from January 1, 2015, to December 31, 2020, using data from electronic medical records of a Swiss primary care database. We determined the occurrence of either repeat TSH testing or direct levothyroxine initiation in primary care during 12-month follow-up and determined associations with demographic and clinical factors. RESULTS: Of the 1 591 patients included (median age 65 years, 64.4% female, median TSH 5.7 mIU/L), 34.3% received repeat TSH testing and 12.4% received direct levothyroxine replacement in primary care during follow-up. Repeat TSH testing showed the strongest association with overt hypothyroidism and was more common among patients with high primary care utilization and among patients aged 40-64 years compared to patients aged <40 years. Direct levothyroxine initiation was more likely for TSH levels >7 mIU/L, overt hypothyroidism, female patients, and nonurban practices. CONCLUSIONS: While the degree of thyroid dysfunction was the main driver of follow-up, we identified important gaps in the primary care-based monitoring of elevated TSH levels in young patients and in patients with infrequent consultations. We also observed potential overtreatment of women and patients in nonurban areas. Our findings highlight the need for standardization and dissemination of guidelines for the management of elevated TSH levels among general practitioners.

Prevalence and Associated Factors for Thyroid Dysfunction Among Patients On Targeted Therapy for Cancers: A Single-Center Study from Thailand.

Objective: This study aimed to explore the prevalence and associated factors of thyroid dysfunction among cancer patients treated with tyrosine kinase inhibitors (TKIs) and immune checkpoint inhibitors (ICIs). Methodology: A cross-sectional study was done in patients who received TKIs at Rajavithi Hospital in 2019. For patients treated with ICI, a retrospective chart review for patients seen in 2018 to 2019 was conducted. If there were abnormal thyroid function tests (TFT), thyroid autoantibodies were tested. Results: There were 144 patients on TKIs with a mean age of 56.0 years. Thyroid dysfunction was found in 14.6% of patients and most had subclinical hypothyroidism (n = 16, 11.1%). Imatinib (n = 11, 10.8%) and sunitinib (n = 4, 100%) were the 2 most common TKIs given to patients with thyroid dysfunction. Thyroid dysfunction was associated with male sex, chronic kidney disease and hepatitis B virus infection but not with previous thyroid disease and presence of thyroid autoantibodies.There were 18 patients who received ICIs. The mean age was 63.3 years. Twelve patients (66.7%) used programmed cell death protein-1 antibody (anti-PD1), mainly nivolumab. Thyroid dysfunction was found in 50%, which occurred at a median duration of 46 days. Most patients had overt hypothyroidism and 55.6% needed levothyroxine replacement. Conclusion: Thyroid dysfunctions from TKIs were mostly asymptomatic and mild in severity. Some types of TKIs might be associated with thyroid dysfunction. On the other hand, thyroid dysfunction from ICIs usually occurs within 6 months and requires levothyroxine replacement.

Immune checkpoint inhibitor-induced hypothyroidism predicts treatment response in Japanese subjects.

Background: Immune checkpoint inhibitors (ICIs) cause a variety of immune-related adverse events (irAEs). Among them, thyroid dysfunction is most frequently observed. Patients with irAEs have higher survival rates than those without irAEs, but there is no certainty as to whether the degree of thyroid dysfunction is associated with treatment response or survival with ICIs. Method: This is a single-center, retrospective, observational study. The study included 466 patients who received ICI at Kawasaki Medical School Hospital from September 1, 2014, to May 31, 2022 and evaluated the degree of abnormal thyroid function and survival and remission rates after treatment with ICIs. Primary hypothyroidism of less than 10 µIU/mL TSH was classified as grade 1, and primary hypothyroidism requiring more than 10 µIU/mL TSH or levothyroxine as grade 2-4. Result: The mean age of the study participants was 68.2 ± 10.3 years, and the percentage of male participants was 72.6%. The frequency of ICI-induced thyroid dysfunction in the study participants was 28.2%. TSH levels were significantly higher in Grade 1 and Grades 2-4 when treated with ICI compared to NTF (p<0.0001). The survival rate at 1 year after ICI administration was significantly higher with 64.9% for grade 1 and 88.9% for grades 2-4 compared to 52.1% for NTF (p<0.0001). Cancer stage at the time of ICI administration did not differ among the groups (p=0.68). Nevertheless, the remission rate assessed by RECIST criteria was significantly higher in grades 2-4 compared to NTF (p<0.0001). Conclusion: ICI-induced thyroid dysfunction was significantly correlated with survival, mean observation time, and treatment remission rate. It is important to monitor thyroid hormone levels regularly in patients receiving ICIs.

Iodine status and its association with prevalence of thyroid diseases in adults from Jiangxi Province, China.

BACKGROUND: Iodine is an essential element for the biosynthesis of thyroid-stimulating hormone (TSH). Both excessive and deficient iodine are major risk factors for thyroid diseases, including thyroid dysfunction, thyroid nodules, and thyroid autoimmunity (TAI). This study aimed to elucidate the relationship between iodine status and the prevalence of thyroid diseases through a national cross-sectional epidemiological survey in Jiangxi province (China). METHODS: This population-based, cross-sectional study enrolled 2636 Chinese local inhabitants who aged over 18 years old from April to August in 2015. Physical examination was performed and biochemical indices, urinary iodine concentration (UIC), and TSH level were measured. The Chi-square test, nonparametric test, and 4 multivariate logistic regression models adjusted for risk factors were applied to analysis. Spearman correlation coefficients were calculated to investigate the relationship between iodine intake level and the prevalence of thyroid diseases. RESULTS: The median UIC was 176.4 µg/L, and a significant difference was found in median UIC between men (182.45 µg/L) and women (169.25 µg/L) (P = 0.03). Among these study subjects, 14.4%, 44.5%, 26.1%, and 15.0% had deficient, adequate, more than adequate, and excessive iodine concentrations, respectively. The prevalence rates of hyperthyroidism, subclinical hyperthyroidism, hypothyroidism, subclinical hypothyroidism, thyroid nodules, and TAI were 0.91%, 0.57%, 0.34% and 7.89%, 9.45%, and 12.7%, respectively. Significant differences were found in iodine status, waist circumstance, systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol (TC), TSH, thyroid nodules, and TAI between men and women (P < 0.05). Compared with those with adequate UIC, subjects with excessive UIC had higher prevalence rates of thyroid dysfunction (odds ratio (OR) = 1.74, 95% confidence interval (CI): 1.40-2.54) and thyroid nodules (OR = 3.33, 95%CI 1.32-8.42). In addition, subjects with deficient and excessive UIC were at the higher risk of TAI compared with those with adequate UIC (OR = 1.68, 95%CI: 1.19-2.60; OR = 1.52, 95%CI: 1.04-2.96, respectively). UIC was positively correlated with the prevalence rates of thyroid nodules (r = -0.44, P < 0.01) and TAI (r = -0.055, P < 0.01). On the contrary, UIC was negatively correlated with the risk of thyroid dysfunction (r = -0.24, P > 0.05). CONCLUSION: Adult inhabitants from Jiangxi province in the TIDE study were in the adequate iodine status. Excessive iodine status was noted as a risk factor for thyroid dysfunction and thyroid nodules. In addition, both iodine deficiency and excessive iodine were risk factors for TAI.

Exposure of Akwesasne Mohawk women to polychlorinated biphenyls and hexachlorobenzene is associated with increased serum levels of thyroid peroxidase autoantibodies.

Persistent organic pollutants (POPs) including polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and dichlorodiphenyltrichloroethane (p,p'-DDT) were reported to influence immunological activity. As endocrine-disrupting chemicals (EDC), these pollutants may disrupt normal thyroid function and act as catalysts for development of autoimmune thyroid disease by directly and indirectly affecting levels of thyroid peroxidase antibodies (TPOAbs). Native American communities are disproportionately exposed to harmful toxicants and are at an increased risk of developing an autoimmune disease. The aim of this study was to determine the association between POPs and TPOAbs in serum obtained from Native American women. This assessment was used to measure whether increased risk of autoimmune thyroid disease occurred as a result of exposure to POPs. Data were collected from 183 Akwesasne Mohawk women, 21-38 years of age, between 2009 and 2013. Multivariate analyses were conducted to determine the association between toxicant exposure and levels of TPOAbs. In multiple logistic regression analyses, exposure to PCB congener 33 was related to elevated risk of individuals possessing above normal levels of TPOAbs. Further, HCB was associated with more than 2-fold higher risk of possessing above normal levels of TPOAbs compared to women with normal levels of TPOAbs. p,p'-DDE was not associated with TPOAb levels within this study. Exposure to PCB congener 33 and HCB was correlated with above normal levels of TPOAbs, a marker of autoimmune thyroid disease. Additional investigations are needed to establish the causes and factors surrounding autoimmune thyroid disease which are multiple and complex.

Clinical Characters and Influence Factors of Immune Checkpoint Inhibitor-related Thyroid Dysfunction.

CONTEXT: Explore the clinical characteristics and influencing factors of immune thyroid dysfunction (ITD) caused by immune checkpoint inhibitors (ICIs) in the treatment of malignant tumors. METHODS: This was a retrospective study of cancer patients treated with ICIs between January 2019 and December 2021 at the Second Affiliated Hospital of Nanchang University. According to the occurrence of thyroid dysfunction, patients were divided into an ITD group and non-ITD group. We describe the clinical characteristics, autoantibody levels, and their impact on prognosis of patients with ICI-related ITD. RESULT: A total of 560 cases meeting the criteria were included, with a median follow-up time of 11.0 months. The incidence of ITD was 50.7%. Baseline TSH levels (OR, 1.935/mcIU/L; 95% CI, 1.613-2.321; P < .001) and combination targeted therapy (OR, 2.101; 95% CI, 1.433-3.079; P < .001) were most strongly associated with the occurrence of ITD. The median time to ITD in patients receiving medication with ICIs was 73 (34.5-149) days. Of the 87 patients initially diagnosed with hyperthyroid ITD, 46 (52.9%) progressed to hypothyroidism over the course of the disease. Baseline anti-thyroglobulin antibody abnormalities were strongly associated with the occurrence of ITD (OR, 67.393; 95% CI, 5.637-805.656; P = .001). Overall survival was significantly lower in patients who did not develop ITD than in those who did (hazard ratio, 0.523; 95% CI, 0.599-0.97; P < .001). CONCLUSION: The incidence of ICI-related ITD is high, and the course of the disease is rapidly changing, and thyroid function in patients treated with immunotherapy should be monitored to detect ITD and permit early intervention.

Analysis of clinical characteristics of thyroid disorders in patients with chronic hepatitis B treated with pegylated-interferon alpha.

BACKGROUND: Thyroid disorders (TD) is a common complication of pegylated-interferon alpha (Peg-IFNα) therapy. Few studies have investigated the relationship between TD and the efficacy of interferon therapy for chronic hepatitis B (CHB). Therefore, we analyzed the clinical characteristics of TD in patients with CHB treated with Peg-IFNα, and evaluated the correlation between TD and Peg-IFNα treatment efficacy. METHODS: In this retrospective study, the clinical data of 146 patients with CHB receiving Peg-IFNα therapy were collected and analyzed. RESULTS: During the course of Peg-IFNα therapy, positive conversion of thyroid autoantibodies and TD occurred in 7.3% (85/1158) and 8.8% (105/1187) patients, respectively, and was diagnosed more often in women. The most common thyroid disorder was hyperthyroidism (53.3%), followed by subclinical hypothyroidism (34.3%). We found that thyroid function returned to normal in 78.7% of patients with CHB, and thyroid antibody levels returned to the negative range in approximately 50% of patients after interferon treatment cessation. Only 25% of patients with clinical TD required treatment. Compared with patients with hypothyroidism/subclinical hypothyroidism, patients with hyperthyroidism/subclinical hyperthyroidism showed greater reduction and seroclearance of hepatitis B surface antigen (HBsAg) levels. CONCLUSIONS: TD are not an absolute contraindication for interferon therapy; however, patients should be monitored closely during interferon therapy. In pursuit of functional cure, a balance between efficacy and safety must be achieved.

A Study to Assess Tyrosine Kinase Inhibitors Induced Thyroid Dysfunction in Newly Diagnosed Chronic Myeloid Leukemia Patients.

INTRODUCTION: The use of TKIs has dramatically improved the prognosis of CML. The aim of this study was to evaluate the effects of TKIs on thyroid function in a prospective manner. MATERIALS: In this prospective study, 55 newly diagnosed adult subjects with positive Philadelphia chromosome in chronic phase of CML without any other apparent underlying diseases were enrolled. Total T3, Free T4, TSH and Anti TPO antibodies were measured at starting and after 12 & 24 weeks of treatment respectively. The study also included a same number control group of sex- and age-matched healthy individuals. RESULT: Approximately 10% of the patients were having subclinical hypothyroidism while the rest were normal regarding thyroid function. There were statistically significant changes within reference ranges in serum concentration of TSH (p = 0.022 and 0.011) 12 weeks and 24 weeks after TKIs initiation, respectively. CONCLUSION: This study showed some significant changes on thyroid function tests.However, without any clinical abnormalities in the course of treatment we didn't initiate replacement. We recommend other studies with larger sample size and longer duration of follow-up. References Singha H, Chakrabarty SK, Sherpa PL, et al. Tyrosine kinase inhibitors induced thyroid dysfunction in newly diagnosed chronic myeloid leukemia patients. Singha H, et al. Thyroid dysfunction caused by tyrosine kinase inhibitors in Philadelphia chromosome-positive chronic myeloid leukemia.

Predictors of thyroid adverse events during cancer immunotherapy: a real-life experience at a single center.

BACKGROUND: Thyroid dysfunction is among the most common immune-related adverse events (irAEs) of immune checkpoint inhibitors (ICIs) therapy. Data regarding potential predictors of the development of thyroid irAEs are still limited and sometimes conflicting. PATIENTS AND METHODS: We assessed potential risk factors and clinical outcomes associated with the onset of thyroid irAEs in a cohort of patients with different types of cancer treated with ICIs at a single center. Clinical and biochemical data, including thyroid function tests and autoantibodies at baseline and during treatment, were collected, and the onset of thyroid irAEs was recorded. Patients with thyroid dysfunction and/or under levothyroxine therapy before starting ICI were excluded. RESULTS: 110 patients (80 M, 30 F, aged 32-85 years; 56.4% non-small-cell lung cancer, 87% treated with anti-PD-1) with complete information were included in the study. Among them, 32 (29%) developed thyroid irAEs during ICIs therapy. Primary hypothyroidism was the most common irAEs, occurring in 31 patients (28.18% of the whole cohort), including 14 patients who experienced a transient thyrotoxicosis. About 60% of irAEs occurred within the first 8 weeks of therapy. At multivariate analysis, anti-thyroid autoantibodies positivity at baseline (OR 18.471, p = 0.022), a pre-existing (autoimmune and non-autoimmune) thyroid disorder (OR 16.307, p < 0.001), and a family history of thyroid diseases (OR = 9.287, p = 0.002) were independent predictors of the development of thyroid irAEs. CONCLUSION: Our data confirm the high frequency of thyroid dysfunctions (mostly hypothyroidism) during ICIs, and provide data on valuable predictors of thyroid toxicities that may help clinicians in identifying patients at risk for developing irAEs.

Risk of Thyroid Dysfunction in PD-1 Blockade Is Stratified by the Pattern of TgAb and TPOAb Positivity at Baseline.

CONTEXT: Positive antithyroglobulin (TgAb) and/or antithyroid peroxidase antibodies (TPOAb) at baseline indicate a high risk of thyroid immune-related adverse events (irAEs) induced by antiprogrammed cell death-1 antibodies (anti-PD-1-Ab). However, whether the positivity patterns of both antibodies are associated with the risk of thyroid irAEs is unknown. OBJECTIVE: The aim of the present study was to clarify the association of the pattern of TgAb and TPOAb positivity at baseline with the risk of thyroid irAEs induced by anti-PD-1-Ab. METHODS: Patients (n = 516) were evaluated for TgAb and TPOAb at baseline and prospectively for thyroid function every 6 weeks for 24 weeks after initiating anti-PD-1-Ab. RESULTS: Fifty-one (9.9%) patients developed thyroid irAEs (thyrotoxicosis in 34, hypothyroidism without prior thyrotoxicosis in 17). Twenty-five patients subsequently developed hypothyroidism following thyrotoxicosis. The cumulative incidence of thyroid irAEs differed among 4 groups classified by the presence of TgAb/TPOAb at baseline (group 1: TgAb-(-)/TPOAb-(-), 4.6% [19/415]; group 2: TgAb-(-)/TPOAb-(+), 15.8% [9/57]; group 3: TgAb-(+)/TPOAb-(-), 42.1% [8/19]; group 4: TgAb-(+)/TPOAb-(+), 60.0% [15/25]) as follows: groups 1 vs 2-4 (P ≤ .001) and groups 2 vs 3 (P = .008) and 4 (P < .001). There were different incidences of thyrotoxicosis (groups 1-4, 3.1%, 5.3%, 31.6%, 48.0%, respectively; P < .001) in groups 1 vs 3 and 4, and groups 2 vs 3 and 4, and of hypothyroidism (groups 1-4: 2.9%, 15.8%, 31.6%, 60.0%, respectively; P < .001) in groups 1 vs 2 to 4, and groups 2 vs 4. CONCLUSION: The risk of thyroid irAEs was affected by the pattern of TgAb and TPOAb positivity at baseline; there were high risks of thyrotoxicosis in patients with TgAb-(+) and of hypothyroidism in patients with TgAb-(+) and those with TPOAb-(+).