Elevated thyroid manganese reduces thyroid iodine to induce hypothyroidism in mice, but not rats, lacking SLC30A10 transporter.

Elevated manganese (Mn) accumulates in the brain and induces neurotoxicity. SLC30A10 is an Mn efflux transporter that controls body Mn levels. We previously reported that full-body Slc30a10 knockout mice (1) recapitulate the body Mn retention phenotype of humans with loss-of-function SLC30A10 mutations and (2) unexpectedly develop hypothyroidism induced by Mn accumulation in the thyroid, which reduces intra-thyroid thyroxine. Subsequent analyses of National Health and Nutrition Examination Survey data identified an association between serum Mn and subclinical thyroid changes. The emergence of thyroid deficits as a feature of Mn toxicity suggests that changes in thyroid function may be an underappreciated, but critical, modulator of Mn-induced disease. To better understand the relationship between thyroid function and Mn toxicity, here we further defined the mechanism of Mn-induced hypothyroidism using mouse and rat models. Slc30a10 knockout mice exhibited a profound deficit in thyroid iodine levels that occurred contemporaneously with increases in thyroid Mn levels and preceded the onset of overt hypothyroidism. Wild-type Mn-exposed mice also exhibited increased thyroid Mn levels, an inverse correlation between thyroid Mn and iodine levels, and subclinical hypothyroidism. In contrast, thyroid iodine levels were unaltered in newly generated Slc30a10 knockout rats despite an increase in thyroid Mn levels, and the knockout rats were euthyroid. Thus, Mn-induced thyroid dysfunction in genetic or Mn exposure-induced mouse models occurs due to a reduction in thyroid iodine subsequent to an increase in thyroid Mn levels. Moreover, rat and mouse thyroids have differential sensitivities to Mn, which may impact the manifestations of Mn-induced disease in these routinely used animal models.

Managing the Adverse Events Associated with Pembrolizumab and Lenvatinib Therapy in Endometrial Cancer.

Endometrial cancer (EC) is the most common gynaecological cancer. The combination of lenvatinib and pembrolizumab has exhibited efficacy as the second line treatment for advanced EC, with a significant benefit in terms of progression free survival (PFS) and overall survival, but the adverse events (AE) profile is complex. AEs associated with the treatment may represent a limitation to this combination. Here, we report the case of a 38-year-old female patient diagnosed with stage IV EC elsewhere, whose disease progressed after the first line of treatment and was referred to a specialised cacncer centre in Muscat, Oman, in 2021. We treated her with the combination of lenvatinib and pembrolizumab. During the course of the treatment, she developed hand-foot syndrome grade III and hypothyroidism grade II. The AEs were managed with supportive medications, dose interruptions, dose reductions and multidisciplinary care, which allowed the continuation of the treatment. The patient achieved a good partial response and an ongoing PFS of more than 12 months.

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.

Immune Checkpoint Inhibitors-Induced Endocrinopathies: Assessment, Management and Monitoring in a Comprehensive Cancer Centre.

OBJECTIVES: To determine the incidence, presentation, frequency and management of immune checkpoint inhibitors (ICI)-related endocrinopathies in a comprehensive cancer centre in Oman, particularly with programme death 1/programme death-ligand 1 (PD-1/PD-L1) inhibitors. BACKGROUND: A high number of patients treated with PD-1/PD-L1 inhibitors for the management of solid tumours developed endocrinopathies. METHODS: This is a retrospective study of patients admitted to Sultan Qaboos Comprehensive Cancer Care and Research Centre (SQCCCRC) from August 2021 to December 2022. All adults diagnosed with solid cancers and have received at least one dose of ICIs were included. Patients with incomplete data were excluded from the analysis. Data regarding the ICI-induced endocrinopathy were collected. RESULTS: A total of 139 patients were included in the study of which 58% were females. The median age of the cohort was 56 years. The incidence of endocrine-related adverse events was 28%. The mean time for the development of endocrine adverse events after treatment initiation was 4.1 ± 2.8 months. Of the patients who developed toxicity, 90% had hypothyroidism. Ten patients developed hyperthyroidism, two patients were diagnosed with secondary adrenal insufficiency/hypophysitis and one patient developed Type 1 diabetes mellitus (DM). Using univariable logistic regression weight and body mass index (BMI) significantly impacted the development of endocrine immune-related adverse events (irAEs). CONCLUSIONS: This is the first study from the Sultanate of Oman to assess PD-1/PDL-1 ICI-induced endocrinopathies. The most common endocrine adverse event is thyroid dysfunction, mainly hypothyroidism followed by hyperthyroidism. Hypophysitis, primary adrenal insufficiency and CIADM occur less frequently, but have a more significant effect on the patient's health. The treating physician should be aware of ICI-induced endocrinopathies, screening and treatment. Furthermore, our study showed that patients with a higher BMI have a greater risk of developing irAES. Further studies are needed to establish the predictors of endocrine irAEs.

Locally injected bone marrow-derived mesenchymal stem cells reverts the histopathological changes in the tongue of carbimazole-induced hypothyroidism of male rats.

OBJECTIVE: To decipher the role of locally injected bone marrow mesenchymal stem cells (BM-MSCs) in the tongue of hypothyroid rats. DESIGN: A total 24 male Wister rats were utilized and allocated into 3 groups (n = 8). As for the control group, rats received distilled water via oral gavage. In the hypothyroid group, rats administered carbimazole 5 mg/ 250 g/ day for 6 successive weeks, for hypothyroidism induction. The BM-MSC treated hypothyroid group (BM-MSC group); hypothyroid rats received local injection of 0.5 million BM-MSCs in tongue. Six weeks after BM-MSC injection, tongue samples were processed for Hematoxylin and eosin (H and E) staining, Ki67-immunohistochemistry and histomorphometric analysis. RESULTS: The hypothyroid group revealed degenerative alterations in the lingual papillae, and apparent thinning of the inferior lingual epithelium compared to their controls. Tongues of the BM-MSC group depicted restoration of the normal tongue histology. The Ki67 immunoreaction was apparently decreased in the lingual epithelium of hypothyroid group compared to their controls, however the BM-MSC group regained Ki67 immunostaining. CONCLUSION: Our data suggest that administration of BM-MSCs rescued the degenerative changes in the lingual mucosa and one of the possible underlying mechanisms could be the restoration of cellular proliferation in the lingual epithelium.

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.

Improved overall survival in patients developing endocrine toxicity during treatment with nivolumab for advanced non-small cell lung cancer in a prospective study.

PURPOSE: Immune checkpoint inhibitors (ICPIs) disrupting PD-1/PD-L1 axis have revolutionized the management of advanced non-small cell lung cancer (NSCLC). Some studies identified the development of endocrine toxicity as predictor of better survival in cancer patients treated with ICPIs. The aim of study was to evaluate survival and new onset of immune-related endocrine adverse events (irAEs) in patients treated with nivolumab for advanced NSCLC. METHODS: In a prospective study, 73 patients with previously treated advanced NSCLC received nivolumab in monotherapy. Blood samples were collected at each cycle to monitor thyroid autoimmunity, thyroid, adrenal and somatotroph axes, while thyroid morphology was evaluated by ultrasonography. RESULTS: An impaired thyroid function was recorded in 23.4% of patients (n = 15). Eight patients developed asymptomatic transient thyrotoxicosis (ATT) evolving to hypothyroidism in 50% of cases. In addition, seven patients developed overt hypothyroidism without ATT and with negative autoantibodies. Patients who developed hypothyroidism proved to have better overall survival (OS) as compared with non-developers at both univariate (p = 0.021) and multivariate analyses (p = 0.023). The survival curve of patients with reduced IGF-I at baseline, or displaying its reduction during the follow-up, showed significantly reduced median survival compared to patients with normal/high IGF-I levels (p = 0.031). CONCLUSIONS: Thyroid function abnormalities are the major irAEs in patients treated with nivolumab, and hypothyroidism onset is associated with prolonged survival. Our findings indicate that the development of hypothyroidism is a positive predictive biomarker of nivolumab antitumor efficacy in patients with NSCLC. Low IGF-I levels could represent a negative prognostic factor during nivolumab therapy.

Impact of methimazole-induced hypothyroidism on postnatal swine.

Thyroid hormones regulate metabolic rate, nutrient utilization, growth, and development. Swine are susceptible to thyroid suppression in response to disease or environmental conditions, but the physiological impact of such disruption has not been established. The objective of this study was to evaluate the impact of hypothyroidism induced with the antithyroid medication methimazole (MMI). 10 mg/kg MMI significantly decreased circulating triiodothyronine (T3) for the duration of treatment but had only a transient effect on circulating thyroxine (T4). Thyroid tissue weight was significantly increased by more than 3.5-fold in response to MMI treatment. Histologically, the eosinophilic colloid was largely absent from the thyroid follicle which displayed a disorganized columnar epithelium consistent with goiter. MMI induced hypothyroidism has no effect on growth rate over 28 days. Hepatic expression of genes associated with thyroid metabolism (DIO1, DIO2, and DIO3), lipid utilization (CD36, FASN, and ACACA), apoptosis (TP53, PERP, SIVA1, and SFN) and proliferation (CDK1, CDK2, CDK4, and CDKN1A) were unaffected by treatment. Collectively these results demonstrate that MMI induces mild systemic hypothyroidism and pronounced goiter, indicating a strong homeostatic central regulation within the hypothalamic pituitary thyroid axis. This combined with limited peripheral effects, indicates resilience to hypothyroidism in modern swine.

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.

Changes in TgAb and TPOAb titers are greater in thyrotoxicosis than isolated hypothyroidism induced by PD-1 blockade.

Anti-thyroglobulin antibodies (TgAb) and/or anti-thyroid peroxidase antibodies (TPOAb) positivity at baseline is a risk marker for thyroid immune-related adverse events (thyroid-irAEs) in anti-programmed cell death-1 antibody (PD-1-Ab) treatment; however, it is unknown if TgAb and TPOAb titers are associated with clinical characteristics of thyroid-irAEs. Among 586 patients treated with PD-1-Ab at Nagoya University Hospital between 2 November 2015 and 30 September 2021, 57 patients developed thyroid-irAEs (thyrotoxicosis [n = 38]; hypothyroidism without prior thyrotoxicosis {isolated hypothyroidism} [n = 19]) in whom thyroid function, and TgAb and TPOAb titers were determined at baseline and at the onset. The changes in TgAb (median, 54.8 vs. 0.2 IU/mL; p = 0.002) and TPOAb titers (31.6 vs. 0 IU/mL; p = 0.032) from baseline to onset of developing thyroid-irAEs were greater in patients with thyrotoxicosis than patients with isolated hypothyroidism. Higher TgAb and TPOAb titers, and the TgAb titer at baseline were associated with an earlier onset of thyrotoxicosis and higher peak free thyroxine levels, respectively. Twenty-eight patients who developed hypothyroidism after thyrotoxicosis had higher TgAb (54.5 vs. 10.7 IU/mL; p = 0.011) and TPOAb titers at baseline (46.1 vs. 9.0 IU/mL; p < 0.001) and greater changes in TgAb (61.7 vs. 7.8 IU/mL; p = 0.025) and TPOAb titers (52.8 vs. -0.8 IU/mL; p < 0.001) than patients who did not develop hypothyroidism. The TgAb titer at baseline and changes in the TgAb and TPOAb titers were greater in patients with thyrotoxicosis than patients with isolated hypothyroidism, suggesting that the magnitude of the thyroid autoimmune response reflects the clinical types of thyroid-irAEs.

Tyrosine kinase inhibitor-induced hypothyroidism: mechanism and clinical implications.

INTRODUCTION: Since the first experimentally proven tyrosine kinase inhibitor (TKI) imatinib was introduced in the clinical setting, TKIs have attracted widespread attention because of their remarkable therapeutic effects and improvement of survival rates. TKIs are small-molecule, multi-target, anti-cancer agents that target different tyrosine kinases and block downstream signaling. ADVERSE REACTIONS AND CONCERNS: However, with in-depth research on TKI drugs, the adverse reactions-for example, thyroid dysfunction-have become a concern and thus have attracted the attention of numerous researchers. Thyroid dysfunction, especially hypothyroidism, that occurs in high incidence during TKI therapy has a close relationship with treatment efficacy, but the mechanism of TKI-induced thyroid dysfunction is obscure. DISCUSSION: This review discusses the epidemiology, possible mechanisms, and clinical significance of hypothyroidism in cancer patients treated with TKI.

Profound postinduction hypotension precipitated by immune checkpoint inhibitors: a case report.

BACKGROUND: With the increasing use of immune checkpoint inhibitors (ICIs) in cancer therapy, perioperative healthcare professionals need to be vigilant about potential immune-related adverse events (irAEs). We report a case of severe postinduction hypotension in a patient undergoing laparotomy due to suspected intraabdominal bleeding from gastric cancer and Krukenberg tumors, caused by unrecognized hypothyroidism precipitated by ICIs. CASE PRESENTATION: A 65-year-old Chinese female with a history of gastric adenocarcinoma and Krukenberg tumors, previously treated with nivolumab, presented to the emergency room with abdominal pain and hypotension. Despite ruling out other causes, including hypovolemia and anaphylaxis, her hypotension persisted. The patient was found to have severe hypothyroidism, likely an irAE from the use of nivolumab. Thyroxine replacement therapy resolved the hypotension, and the patient recovered uneventfully after surgery. CONCLUSIONS: This case underscores the importance of considering irAEs, such as hypothyroidism, in patients treated with ICIs. Perioperative healthcare providers must remain vigilant for potential complications and promptly recognize and manage irAEs to optimize patient outcomes.

[The association between baseline TPOAb and/or TgAb positivity and thyroid immune-related adverse events in patients with malignancies following treatment with immune checkpoint inhibitors].

Objective: To investigate the association between positive anti-thyroid peroxidase antibody (TPOAb) and/or anti-thyroglobulin antibody (TgAb) and the occurrence of thyroid immune-related adverse events (irAEs) in patients with malignant tumors who treated with immune checkpoint inhibitors (ICIs). Methods: A case-control study. A total of 116 patients with malignant tumor who received ICIs treatment and underwent thyroid function evaluation at Peking Union Medical College Hospital from January 2017 to April 2023 were enrolled retrospectively, including 77 males and 39 females, with a median age of (M(Q1, Q3)) 63.0 (55.0, 70.0) years. The patients were divided into the euthyroid group (n=58) and the thyroid irAEs group (n=58) according to whether thyroid irAEs occurred after ICIs treatment. The clinical characteristics and baseline anti-thyroid antibodies associated with the occurrence of thyroid irAEs after ICIs treatment in patients with malignant tumors were evaluated. Variables with statistical significance in univariate analysis were included in multivariate logistic regression model to analyze the risk factors for thyroid irAEs in patients with malignant tumors who received ICIs treatment. Results: In irAEs group, therewore 4 (3.4%) cases of clinical thyrotoxicosis, 23(19.8%) cases of subclinical thyrotoxicosis, 23 (19.8%) cases of clinical hypothyroidism, and 8(6.9%) cases of subclinical hypothyroidism. The positive rate of anti-thyroid antibodies at baseline in the thyrioid irAEs group was higher than that in the euthyroid group［16/58（27.6%）vs 3/58（5.2%），P=0.001］. After at least one course of ICIs treatment, the incidence of thyroid irAEs in patients with positive anti-thyroid antibodies at baseline was 84.2% (16/19), whereas it was 43.3% (42/97) in patients with negative anti-thyroid antibodies(P=0.001). Univariate logistic regression analysis showed that gender (OR=2.812, 95%CI:1.257-6.293), baseline thyroid autoantibodies were positive (OR=6.984, 95%CI: 1.909-25.547), baseline TgAb positivity (OR=8.909, 95%CI: 1.923-41.280), and baseline TPOAb positivity (OR=7.304, 95%CI: 1.555-34.308) were associated with thyroid irAEs (all P<0.05). Multivariate logistic regression analysis indicated that baseline TgAb positivity (OR=7.637, 95%CI: 1.617-36.072) was a risk factor for thyroid irAEs (P=0.01). Conclusions: The incidence of thyroid irAEs is higher in patients who are positive for baseline TPOAb and/or TgAb compared to those who are negative for TPOAb and TgAb. Patients with positive TgAb at baseline are at high risk of developing thyroid irAEs.

Effect of melatonin on reproductive function in propylthiouracil induced hypothyroidism in adult male rats.

OBJECTIVE: Thyroid hormones are essential for regulating metabolism, reproduction, and growth. Hypothyroidism is connected with lower sperm count and motility, leading to male infertility. Oxidative stress is likely to be linked to this interaction. Melatonin, being known as an oxidative scavenger, may offer a feasible treatment method for reproductive dysfunction accompanying hypothyroidism in adult male rats. The purpose of this investigation was to determine the mechanism by which melatonin treatment affected spermatogenic and steroidogenic function in an experimental model-induced hypothyroidism in adult male rats. MATERIALS AND METHODS: Twenty-one male albino adult rats weighing between 150 and 210 g were used in this experiment. Rats were split into three groups and studied for 11 weeks. The control euthyroid group, in which rats received 0.9% Sodium Chloride (NaCl) solution by intraperitoneal injection [solvent for 6-propyl 2-thouracil (PTU)], 6 days/week for 8 weeks; the PTU-induced hypothyroid group, in which chemical thyroidectomy was induced by intraperitoneal injection of PTU at a dose of 10 mg/kg body weight, 6 days/week for 8 weeks; and the melatonin-treated hypothyroid group, which received 3 mg/kg melatonin intraperitoneally daily for 21 days plasma free Triiodothyronine (T3), free Thyroxin (T4), thyroid stimulating hormone (TSH), free testosterone, Follicle Stimulating Hormone (FSH), Luteinizing Hormone (LH) and prolactin were measured. Also, semen analysis, testicular tissue malondialdehyde (MDA), and tumor necrosis factor-α (TNF-α) were accessed. RESULTS: The results indicated that melatonin significantly increased sperm viability and motility compared to the untreated PTU-induced hypothyroid group (p<0.001). Testicular MDA and TNF-α showed a significant decrease in the melatonin-treated hypothyroid group compared with the PTU-induced hypothyroid group (p<0.05). In addition, plasma testosterone levels were significantly increased, accompanied by a significant reduction of plasma prolactin levels compared to the untreated hypothyroid group (p<0.05 for both). CONCLUSIONS: Based on the study findings, melatonin could mitigate gonadal dysfunction induced by hypothyroidism by improving several components of semen analysis, such as sperm motility and sperm viability, as well as by enhancing testosterone production focusing on oxidative and inflammatory stress as the underlying mechanisms.

Thyroid dysfunction after immune checkpoint inhibitors in a single-centre UK pan-cancer cohort: A retrospective study.

PURPOSE: This study investigated thyroid dysfunction with immune checkpoint inhibitors (ICIs) in terms of proportions affected, risk factors, thyroid sequelae, and overall survival (OS). METHODS: Among patients with normal baseline free T4 (fT4) and thyroid stimulating hormone (TSH) receiving ICIs at a large cancer centre, proportions of hyperthyroidism/hypothyroidism were determined (any, subclinical [normal fT4, abnormal TSH], overt [abnormal fT4, abnormal TSH], isolated hyperthyroxinaemia/hypothyroxinaemia and secondary) with onset times and subsequent thyroid statuses. Associations of overt dysfunction with OS were estimated using Cox regression and methods robust to immortal time bias (time-dependent Cox regression and 3- and 6-month landmark analyses). Associations of baseline variables with overt hyperthyroidism and hypothyroidism were estimated using Fine and Gray regression. RESULTS: Of 1349 patients, 34.2% developed hyperthyroidism (10.3% overt), including 54.9% receiving combination ICIs, while 28.2% developed hypothyroidism (overt 9.3%, secondary 0.5%). A third of overt hypothyroidism cases occurred without preceding hyperthyroidism. Subclinical thyroid dysfunction returned directly to normal in up to half. Overt hyperthyroidism progressed to overt hypothyroidism in 55.4% (median 1.6 months). Melanoma treatment in the adjuvant vs. advanced setting caused more overt hyperthyroidism (12.1% vs. 7.5%) and overt hypothyroidism (14.5% vs. 9.7%). Baseline eGFR < 60 mL/min/1.73 m2 (HR=1.68, 1.07-2.63) was associated with overt hyperthyroidism and sex (HR=0.60, 0.42-0.87) and TSH (4th vs. 1st quartile HR=1.87, 1.10-3.19) with overt hypothyroidism. Overt dysfunction was associated with OS in the Cox analysis (HR=0.65, 0.50-0.85, median follow-up 22.2 months) but not in the time-dependent Cox (HR=0.79, 0.60-1.03) or landmark analyses (3-month HR=0.74, 0.51-1.07; 6-month HR=0.91, 0.66-1.24). CONCLUSION: Thyroid dysfunction affects up to half of patients receiving ICIs. The association with OS is unclear after considering immortal time bias. The clinical courses include recovery, thyrotoxicosis and de novo overt hypothyroidism. Adjuvant treatment for melanoma, where longer-term harms are of concern, causes more frequent/aggressive dysfunction.

High-dose exposure to butylparaben impairs thyroid ultrastructure and function in rats.

Parabens (PBs) are a class of preservatives commonly used in cosmetics and pharmaceuticals. Studies have shown that these compounds may act as endocrine disruptors, affecting thyroxine levels in humans. PBs with longer chain substituents, such as butylparaben (BuP), are less prone to complete biotransformation and are therefore more likely to accumulate in the body. In this study, the effect of high-dose exposure to BuP on thyroid microstructure, ultrastructure, and function was investigated in rats. 50 mg/kg bw per day of BuP was injected subcutaneously into the neck of rats for 4 weeks. Rat thyroid weight, microstructure, and ultrastructure were determined, and the levels of thyroid sodium/iodide symporter (NIS), serum thyroid hormones, and thyroid autoantibodies were measured. The human thyroid cell line was used to study the mechanism of BuP on thyroid epithelial cells. The weight of the thyroid gland of BuP-exposed rats was increased, the structure of the thyroid follicles was irregular and damaged, the mitochondria and rough endoplasmic reticulum were swollen and damaged, and the microvilli at the tip of the epithelium were reduced and disappeared. Serum total T3, total T4, free T3, and free T4 were decreased in BuP-exposed rats, and TSH, peroxidase antibody, and thyroglobulin antibody were increased. In vitro, BuP decreased the level of NIS in thyroid epithelial cells, inhibited proliferation and viability, and induced apoptosis in a dose-dependent manner. This study demonstrated that high-dose exposure to BuP induced structural, ultrastructural, and functional impairment to the thyroid gland of rats, which may be one of the factors leading to hypothyroidism.

Histological evidence of hypothyroidism in mice chronically exposed to conventional farming.

Worldwide, disorders of the thyroid gland are a growing concern; such can be caused by exposure to contaminants, including agrochemicals used in conventional agriculture, which act as endocrine disruptors. The purpose of this study is to evaluate whether or not exposure to an environment with conventional agriculture leads to thyroid disruption. Mus musculus were used as bioindicator species, captured in two sites: a farm where conventional agriculture is practiced, and a place without agriculture. Thyroid histomorphometric and morphologic data were analyzed. The impacts of the agricultural environment over the thyroid were revealed, as indications of hypothyroidism were observed in exposed mice: the area and volume of epithelial cells were much lower. Alterations in thyroid histomorphology were also observed: lower follicular sphericity, irregularly delimited epithelium and increased exfoliation into the colloid. These results highlight the need for transition from current conventional agricultural systems towards organic systems.

Hypoxia-inducible Factor Prolyl Hydroxylase Inhibitors and Hypothyroidism: An Analysis of the Japanese Pharmacovigilance Database.

BACKGROUND/AIM: Hypothyroidism induced by roxadustat, a hypoxia-inducible factor prolyl hydroxylase (HIF-PH) inhibitor, was recently reported; however, information regarding roxadustat-associated hypothyroidism is still lacking. We explored the risk and time to onset of hypothyroidism associated with HIF-PH inhibitors using the Japanese Adverse Drug Event Report (JADER), a pharmacovigilance database. PATIENTS AND METHODS: The participants of this study were registered in the JADER database between April 2004 and March 2023. The association between HIF-PH inhibitors and hypothyroidism was evaluated using the reporting odds ratio (ROR) and information component (IC). We also calculated the period from the start of drug administration to the onset of hypothyroidism and determined the onset pattern using Weibull distribution. RESULTS: Roxadustat had positive signals for hypothyroidism among the HIF-PH inhibitors based on the ROR [31.03, 95% confidence interval (CI)=27.81-34.62] and IC (4.51, 95%CI=4.36-4.67) values, and a strong relationship was confirmed. In addition, the median time to roxadustat-associated hypothyroidism onset was 92 days, and over 50% of cases occurred within 100 days of starting treatment. Furthermore, the onset pattern was an early failure type. CONCLUSION: There is a possible association between roxadustat and hypothyroidism. Therefore, enhanced thyroid function testing within 100 days of treatment initiation may help detect roxadustat-associated hypothyroidism. However, further research is required to confirm these findings, considering study limitations using databases of spontaneous adverse event reports.

Monitoring thyroid function during amiodarone use.

Amiodarone is an antiarrhythmic drug used to treat cardiac tachyarrhythmias. It has many adverse effects, with thyroid dysfunction one of the most notable. Through various mechanisms, both thyrotoxicosis and hypothyroidism can occur secondary to amiodarone therapy. There are two types of amiodarone-induced thyrotoxicosis: type 1 occurs in those with pre-existing thyroid disease and is treated with thionamide, whereas type 2 occurs in those without and is treated with glucocorticoids. Patients with amiodarone-induced hypothyroidism may be given levothyroxine to replace thyroid hormone, but in some cases, the appropriate management may be cessation of amiodarone.