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.

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.

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.

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.

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.

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-(+).

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.

In silico assessment of mixture toxicity mechanisms involved in the pathogenesis of thyroid diseases: The combination of toxic metal(oid)s and decabrominated diphenyl ether.

The current study aimed to assess the connection between the mixture of lead (Pb), cadmium (Cd), arsenic (As), methylmercury (MeHg) and decabrominated diphenyl ether (decaBDE) and thyroid function, by using in silico toxicogenomic data-mining approach. To obtain the linkage between investigated toxic mixture and thyroid diseases (TDs), the Comparative Toxicogenomics Database (CTD) was used, while gene ontology (GO) enrichment analysis was performed by ToppGeneSuite portal. The analysis has shown 10 genes connected to all chemicals present in the mixture and TDs (CAT, GSR, IFNG, IL1B, IL4, IL6, MAPK1, SOD2, TGFB1, TNF), most of which were in co-expression (45.68%), or belonged to the same pathway (30.47%). Top 5 biological processes and molecular functions affected by the investigated mixture emphasized the role of two common mechanisms - oxidative stress and inflammation. Cytokines and inflammatory response was listed as the main molecular pathway that may be triggered by simultaneous exposure to toxic metal(oid)s and decaBDE and connected to TDs. The direct relations between Pb/decaBDE and redox status impairment in thyroid tissue was confirmed by our chemical-phenotype interaction analysis, while the strongest linkage between Pb, As and decaBDE and thyroid disorders was found. The obtained results provide better understanding of molecular mechanisms involved in the thyrotoxicity of the investigated mixture, and can be used to direct further research.

Thyroid dysfunction during treatment with systemic antineoplastic therapy for childhood cancer: A systematic review.

Thyroid dysfunction is known to occur following radiotherapy or chemotherapy for childhood cancer. Thyroid dysfunction during treatment for childhood cancer has, however, not been studied extensively, although thyroid hormones are of utmost importance during childhood. This information is needed to develop adequate screening protocols and may be of special importance with upcoming drugs, such as checkpoint inhibitors, which are highly associated with thyroid dysfunction in adults. In this systematic review we have evaluated the occurrence and risk factors for thyroid dysfunction in children during treatment with systemic antineoplastic drugs, up to three months after the end of therapy. Two review authors independently performed the study selection, data extraction and risk of bias assessment of included studies. After an extensive search (January 2021), in total six heterogeneous articles were included, reporting on 91 childhood cancer patients with a thyroid function test during treatment with systemic antineoplastic therapy for childhood cancer. All studies had risk of bias issues. Primary hypothyroidism was found in 18% of children treated with high dose interferon-α (HDI-α) and in 0-10% after tyrosine kinase inhibitors (TKIs). Transient euthyroid sick syndrome (ESS) was common (in 42-100%) during treatment with systematic multi-agent chemotherapy. Only one study addressed possible risk factors, showing different types of treatment to increase the risk. However, the exact prevalence, risk factors and clinical consequences of thyroid dysfunction remain unclear. Prospective high-quality studies including large study samples are needed to longitudinally assess the prevalence, risk factors and possible consequences of thyroid dysfunction during childhood cancer treatment.

Immune checkpoint inhibitor-related thyroid dysfunction.

Immune checkpoint inhibitors (ICIs) are currently the key therapy for several cancers. Among immune-related adverse events, thyroid dysfunction is the most frequent. We review this thyroid dysfunction, with recent data on epidemiology, diagnostic considerations, management and risk factors.

Endocrine-related adverse conditions induced by tyrosine kinase inhibitors.

Tyrosine kinase inhibitors (TKIs) have improved outcome for many tumors. Although better tolerated than cytotoxic chemotherapy, they may cause several adverse events (AEs) and various endocrine-related toxicities have been reported under TKI treatment. The toxicity profile varies between the different TKI compounds. This review focuses on the main endocrinopathies caused by TKIs. Thyroid dysfunction and, in particular, hypothyroidism are the most frequent and best described. Several potential mechanisms have been hypothesized, including thyroid gland dysfunction, hormone metabolism impairment and hypothalamus-pituitary-thyroid axis imbalance. TKIs have been reported to influence almost all glands. In particular, they are associated with adrenal insufficiency, growth retardation due to growth hormone (GH) and/or insulin-like growth factor-1 (IGF1) deficiency, hypogonadism, and male and female fertility impairment. TKIs may affect bone metabolism, in particular decreasing osteoclastogenesis and bone turnover and, in turn, they may cause secondary hyperparathyroidism. Hypocalcemia has been reported under lenvatinib and vandetanib treatment and parathyroid hormone (PTH)-dependent and PTH-independent mechanisms have been hypothesized. Metabolic alterations during TKI treatment range from hypoglycemia with imatinib and dasatinib to hyperglycemia with nilotinib; dyslipidemia improved with imatinib and worsened with nilotinib, sunitinib, pazopanib, sorafenib, and famitinib. Endocrine-related AEs should be managed by dedicated endocrinologists. Hormone deficiencies are easily managed by replacement therapy, while endocrine hyperfunction may be improved by symptomatic treatment. Severe situations should be managed in coordination with the oncologist, trying to limit the need for TKI dose reduction or interruption.

Thyroid dysfunction after immune checkpoint inhibitor treatment in a single-center Chinese cohort: a retrospective study.

BACKGROUND: Thyroid dysfunction is a common adverse event after immune checkpoint inhibitor (ICI) therapy. The clinical manifestations of thyroid immune-related adverse events (irAEs) are variable and the underlying mechanisms remain unclear. PURPOSE: To identify the clinical and biochemical characteristics of Chinese patients with ICI-related thyroid dysfunction. METHODS: We retrospectively reviewed patients with carcinoma who received ICI therapy and underwent evaluation of thyroid function during hospitalization at Peking Union Medical College Hospital between January 1, 2017 and December 31, 2020. Clinical and biochemical features were analyzed in patients who developed ICI-related thyroid dysfunction. Survival analyses were performed to determine the effect of thyroid autoantibodies on thyroid abnormalities and the impact of thyroid irAEs on clinical outcomes. RESULTS: The cohort included 270 patients with a median follow-up of 17.7 months; 120 (44%) of these patients developed thyroid dysfunction on immunotherapy. The most common thyroid irAE was overt hypothyroidism (with/without transient thyrotoxicosis), which occurred in 38% of patients (n = 45), followed by subclinical thyrotoxicosis (n = 42), subclinical hypothyroidism (n = 27), and isolated overt thyrotoxicosis (n = 6). The median time to first clinical presentation was 49 days (interquartile range 23, 93) for thyrotoxicosis and 98 days (interquartile range 51, 172) for hypothyroidism. In patients treated with PD-1 inhibitors, hypothyroidism was strongly associated with younger age (odds ratio [OR] 0.44, 95% confidence interval [CI] 0.29-0.67; P < 0.001), previous thyroid disease (OR 4.30, 95% CI 1.54-11.99; P = 0.005), and a higher baseline thyroid-stimulating hormone level (OR 2.76, 95% CI 1.80-4.23; P < 0.001). Thyrotoxicosis was only associated with the baseline thyroid-stimulating hormone (TSH) level (OR 0.59, 95% CI 0.37-0.94; P = 0.025). Thyroid dysfunction after initiation of ICI therapy was associated with better progression-free survival (hazard ratio [HR] 0.61, 95% CI 0.44-0.86; P = 0.005) and overall survival (hazard ratio 0.67, 95% CI 0.45-0.99; P = 0.046). Anti-thyroglobulin antibody positivity increased the risk of thyroid irAEs. CONCLUSIONS: The occurrence of thyroid irAEs with diverse phenotypes is common. Distinct clinical and biochemical characteristics suggest heterogeneity among different subgroups of thyroid dysfunction, which requires further research to explore the under mechanism.

Basics of prevention and management of iodine-based contrast media-induced thyroid dysfunction - position paper by the Polish Society of Endocrinology.

Medical practice involves a high number of radiological examinations using iodinated contrast media (ICM). Therefore, it is crucial for doctors of different specialties to be aware of possible adverse effects associated with ICM use. The most common and well characterized adverse effect is contrast-induced nephropathy, whereas thyroidal adverse reactions remain a diagnostic and therapeutic dilemma. ICM-induced thyroid dysfunction represents a highly heterogenous group of thyroid disorders. Due to supraphysiological iodine concentration, ICM can induce both hyper- and hypothyroidism. In most cases, the ICM-induced thyroid dysfunction is oligo- or asymptomatic, mild, and transient. In rare cases, however, the ICM-induced thyroid dysfunction may be severe and life threatening. Recently, the European Thyroid Association (ETA) Guidelines for the Management of Iodine-Based Contrast Media-Induced Thyroid Dysfunction were published. The authors advise an individualized approach to prevention and treatment of ICM-induced thyroid dysfunction, based on patient's age, clinical symptoms, pre-existing thyroid diseases, coexisting morbidities, and iodine intake. There is a geographic variation of ICM-induced thyroid dysfunction prevalence, which is linked to iodine intake. The prevalence of ICM-induced hyperthyroidism, which may pose a serious therapeutic challenge, is greater in countries with iodine deficiency. Poland is a region with a history of iodine deficiency, contributing to an increased prevalence of nodular thyroid disease, especially in the elderly. Therefore, the Polish Society of Endocrinology has proposed national, simplified principles of ICM-induced thyroid dysfunction prevention and treatment.

Thyroid autoimmunity following alemtuzumab treatment in multiple sclerosis patients: a prospective study.

Autoimmune thyroid disease (AITD) is the most common adverse effect in alemtuzumab (ALZ) treated relapsing-remitting (RR) multiple sclerosis (MS) patients. The objective of this prospective study was to analyze the occurrence, timing of onset, clinical course, and laboratory characteristics of AITD post-ALZ. We evaluated 35 RRMS patients treated with ALZ at a single academic MS center; clinical and laboratory data were collected before ALZ initiation and thereafter quarterly on follow-up with a median of 43.5 months. Seventeen out of 31 patients (54.8%) with no prior history of thyroid dysfunction developed AITD with a mean onset of 19.4 months ± 10.2 (SD) after the first ALZ cycle; Graves' disease (GD) (n = 9); hypothyroidism with positive stimulating thyrotropin receptor antibodies (TRAb) (n = 1); Hashimoto thyroiditis (HT) (n = 6); HT with hypothyroidism (n = 1). Interestingly, seven of nine (77.7%) GD patients showed a fluctuating course. Three out of four patients with preexisting thyroid disease remained stable, whereas one with prior HT and hypothyroidism developed fluctuating GD. All patients with GD commenced antithyroid drugs (ATDs); five continued on "block and replace" treatment; one required radioactive iodine, and one total thyroidectomy. Our analysis showed earlier onset of ALZ-induced AITD in comparison to most other ALZ cohorts; overall, these patients required complex therapeutic approaches of the AITD. We observed a higher rate of fluctuating GD, with earlier onset and lower remission rate than previously reported, which in the majority of patients required prolonged "block and replace" therapy in the minimum dose of each therapeutic agent or more definitive interventions.