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.

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.

Long-term percutaneous triclosan exposure induces thyroid damage in mice: Interpretation of toxicity mechanism from metabolic and proteomic perspectives

Triclosan (TCS) is an antiseptic incorporated in consumer goods and personal care products that can be absorbed via the skin, raising public health concerns for its continuous detection in human biofluids and tissues. Epidemiology has associated TCS exposure with thyroid function disturbances and decreasing serum thyroid hormone (TH) levels, but the underlying mechanism remains unclear. In this study, we revealed hypothyroidism and histological alternation in the thyroid of mice with chronic percutaneous exposure to TCS, indicating a TCS-caused thyroid impairment. Subsequently, multi-omics approaches were performed to investigate the molecular mechanism of the thyroid in response to long-term dermal TCS exposure. We discovered that TCS interfered with the TH synthesis as indicated by the changes in the levels of the synthetic materials for TH (iodide, Tg, and H2O2) and affected TH release by the downregulation of lysosomal enzymes. The upregulation of glycolysis, tricarboxylic acid cycle, fatty acid, amino acid metabolism, and adenine salvage in the thyroid was also observed after TCS exposure. All these changes led to the elevation of ATP, serving as a rescue for the decreasing thyroid functions. Together, our study demonstrated TCS-induced thyroid damage and identified the interrupted pathways, providing meaningful insight into the molecular mechanisms underpinning the potential health influence of TCS in humans.

The Evaluation and Management of Visceral Complications in Radiation Fibrosis Syndrome Part 1

Abstract

External beam ionizing radiation is a fundamental component of cancer treatment and is incorporated into approximately 50% of cancer treatments. Radiation therapy causes cell death directly by apoptosis and indirectly by disruption of mitosis.

Purpose of Review

This study aims to inform rehabilitation clinicians of the visceral toxicities of radiation fibrosis syndrome and how to detect and diagnose these complications.

Recent Findings

Latest research indicates that radiation toxicity is primarily related to radiation dose, patient co-morbidity, and concomitant use of chemotherapies and immunotherapies for the treatment of cancer. While cancer cells are the primary target, surrounding normal cells and tissues are also affected. Radiation toxicity is dose dependent, and tissue injury develops from inflammation that may progress to fibrosis. Thus, radiation dosing in cancer therapy is often limited by tissue toxicity. Although newer radiotherapeutic modalities aim to limit delivery of radiation to non-cancerous tissues, many patients continue to experience toxicity.

Summary

To ensure early recognition of radiation toxicity and fibrosis, it is imperative that all clinicians are aware of the predictors, signs, and symptoms of radiation fibrosis syndrome. Here, we present part 1 of the visceral complications of radiation fibrosis syndrome, addressing radiation-related toxicity in the heart, lungs, and thyroid gland.

Graphical abstract

In silico analysis decodes transthyretin (TTR) binding and thyroid disrupting effects of per- and polyfluoroalkyl substances (PFAS)

Transthyretin (TTR) is a homo-tetramer protein involved in the transport of thyroid hormone (thyroxine; T4) in the plasma and cerebrospinal fluid. Many pollutants have been shown to bind to TTR, which could be alarming as disruption in the thyroid hormone system can lead to several physiological problems. It is also indicated that the monomerization of tetramer and destabilization of monomer can lead to amyloidogenesis. Many compounds are identified that can bind to tetramer and stabilize the tetramer leading to the inhibition of amyloid fibril formation. Other compounds are known to bind tetramer and induce amyloid fibril formation. Among the pollutants, per- and polyfluoroalkyl substances (PFAS) are known to disrupt the thyroid hormone system. The molecular mechanisms of thyroid hormone disruption could be diverse, as some are known to bind with thyroid hormone receptors, and others can bind to membrane transporters. Binding to TTR could also be one of the important pathways to alter thyroid signaling. However, the molecular interactions that drive thyroid-disrupting effects of long-chain and short-chain PFASs are not comprehensively understood at the molecular level. In this study, using a computational approach, we show that carbon chain length and functional group in PFASs are structural determinants, in which longer carbon chains of PFASs and sulfur-containing PFASs favor stronger interactions with TTR than their shorter-chained counterparts. Interestingly, short-chain PFAS also showed strong binding capacity, and the interaction energy for some was as close to the longer-chain PFAS. This suggests that short-chain PFASs are not completely safe, and their use and build-up in the environment should be carefully regulated. Of note, TTR homologs analysis suggests that thyroid-disrupting effects of PFASs could be most likely translated to TTR-like proteins and other species.

Role of estrogen receptors in thyroid toxicity induced by mono (2-ethylhexyl) phthalate via endoplasmic reticulum stress: An in vitro mechanistic investigation

Mono(2-ethylhexyl) phthalate (MEHP) can influence the expression of estrogen receptors (ERs) and induce thyroid injury. The expression of ERs can be related to thyroid disease and abnormal expression of ERs has been associated with activation of endoplasmic reticulum stress. This study aimed to clarify the role of ERs in MEHP-induced thyroid damage via endoplasmic reticulum stress. We exposed Nthy-ori 3-1 cells to different doses of MEHP. We found that after the exposure, the cell viability and the expression levels of thyroid hormone metabolism-related proteins decreased, while the apoptosis level and the expression levels of ERs (ERα and GPR30) increased. Three endoplasmic reticulum stress-related signaling pathways were activated by MEHP. After ERα and GPR30 were knocked down, these three pathways were inhibited and the thyroid toxicity was alleviated. Taken together, our results indicate that MEHP can induce thyroid toxicity by upregulating the expression of ERs, further activating endoplasmic reticulum stress.

Perinatal low-dose PBDE-47 exposure hampered thyroglobulin turnover and induced thyroid cell apoptosis by triggering ER stress and lysosomal destabilization contributing to thyroid toxicity in adult female rats

Evidence demonstrates that 2,2',4,4'-tetrabromodiphenyl ether (PBDE-47) is able to disturb thyroid hormones (THs) homeostasis, yet the mechanisms remain unknown. We sought to investigate the effects of PBDE-47 on endoplasmic reticulum (ER) and lysosomes in thyroids. Using female Sprague-Dawley rats orally administered PBDE-47 at environmentally relevant doses (0.1, 1.0, 10 mg/kg/day) beginning ten days before breeding and ending at weaning, we showed that perinatal PBDE-47 exposure resulted in a reduction in serum THs levels and relative thyroid weight in adult female rats. These were accompanied by thyroid structural abnormalities with cell apoptosis. Mechanistically, PBDE-47 caused ER stress and activation of unfolded protein response (UPR). Moreover, PBDE-47 elicited lysosomal membrane permeabilization and the release of cathepsin. Importantly, the apoptotic cells co-localized with IRE1α, a stress sensor protein of UPR branch that mediates ER stress-induced apoptosis, or cathepsin B, a lysosomal cysteine protease that is involved in thyroglobulin, the precursor of THs, degradation and apoptosis induction. Interestingly, thyroglobulin was accumulated and predominantly presented in cells harboring compromised ER or lysosomal activity. Collectively, our findings suggest that perinatal low-dose PBDE-47 exposure hampers thyroglobulin turnover and induces thyroid cell apoptosis by triggering ER stress and lysosomal destabilization contributing to thyroid toxicity in adult female rats.

Influences of dissolved humic acid on Zn bioavailability and its consequences for thyroid toxicity

This study aimed to investigate the effect of dissolved humic acid (dHA) on Zn bioavailability and the subsequent influence on the Zn-induced thyroid toxicity. Zn toxicity was assessed using a yeast bioassay in the presence and absence of dHA. With increasing concentration of dHA, the toxic effects decreased, and the free Zn concentrations detected by the anodic stripping voltammetry (ASV) method also decreased. The high correlation (R = 0.92, p < 0.001) between toxic effects and free Zn concentrations indicated that Zn thyroid toxicity largely comes from the free Zn fraction. Water samples from the Qing River in Beijing were also assayed for thyroid toxicity. The results revealed that the metals might contribute to the toxicity. The known thyroid hormone-disrupting metals, namely, Zn, Cd and Hg, were analyzed. The cause-effect relationship between the observed thyroid toxicity and free Zn concentrations as well as their dose-effect relationships were examined. Our results showed that Zn might be the major contributor to the observed thyroid toxicity caused by metals. These results suggest that the ASV method and the identified major contributor (Zn) may be used in lieu of conventional environmental analyses to follow the progression of a risk assessment or remediation strategy.

Hepatotoxicity and Recurrent NSTEMI While on Pembrolizumab for Metastatic Giant Cell Bone Tumor

We present the first reported case showing metastatic giant bone cell tumor being treated successfully with pembrolizumab after failing prior tyrosine kinase inhibitor therapy. Of note, the patient developed multiple systemic effects associated with checkpoint inhibitor use. One year after starting the checkpoint inhibitor (ICI), the patient also developed hepatitis that was confirmed by liver biopsy and pathology to be, in part, due to drug-mediated toxicity similar to prior ICI toxicity cases that have been reported. Additionally, although the patient had vascular risk factors (hypertension, diabetes and smoking), it was notable from a cardiology perspective that the patient developed 2 subsequent non-ST-elevation myocardial infarctions, with rapid progression of stenosis of the left circumflex artery 2 months apart. The first left heart catheterization showing minimal disease of the left circumflex, but 2 months later, presenting with chest pain, a repeat left heart catheterization showed significant stenosis of the left proximal circumflex, raising the possibilities that either ICI can promote plaque rupture and/or accelerated atherosclerosis; both phenomena have been shown to occur in animal models. The patient also developed thyroiditis with subsequent hypothyroidism, now on thyroid replacement from checkpoint inhibitor use. This case demonstrates the multiorgan adverse effects this new antioncologic agent can have and yet also its promising antitumor effects. Awareness of the side effects among primary care doctors and all specialists will be helpful in managing these potential side effects and research will help elucidate ways to prevent the adverse effects.

Benchmark dose analysis of multiple thyroid toxicity endpoints in ovariectomized rats exposed to propylthiouracil

Benchmark dose (BMD) analysis is generally recognized superior to generate a point of departure (PoD) to conduct risk assessment on environmental toxicants, comparing with the traditionally employed no observed adverse effect level (NOAEL) or lowest observed adverse effect level (LOAEL) methods. However, only a few studies compared the two on producing PoD of thyroid toxicity caused by environmental chemicals. Here, we presented BMD analyses on several thyroid toxicity endpoints caused by a model chemical - propylthiouracil (PTU). Adult female rats underwent ovariectomy were randomly assigned into groups receiving different doses of PTU (0, 0.1, 0.5, 1.0, and 5.0 mg/kg bw) through gavage for 8 days. Results show that PTU induces significant dose-dependent changes of serum total thyroxine (tT₄), total triiodothyronine (tT₃), thyroid stimulating hormones, liver type I 5'-deiodinonase (5'-DI) and malic enzyme (ME) activity with profound histopathological exacerbation. BMD and BMDL results (0.03 and 0.01 mg/kg bw respectively) from Hill model of liver 5'-DI activity were accepted based on selection criteria in the benchmark dose analysis. In summary, BMD analysis results in much lower PoD (0.01 mg/kg bw) than LOAEL (0.1 mg/kg bw) in PTU induced thyroid toxicity.

Nivolumab-induced thyroid dysfunction in patients with lung cancer

BACKGROUND

Nivolumab is an anti-cancer monoclonal antibody that inhibits PD1 and modulates T-cell response. It has been shown to significantly improve survival in several types of cancer, but clinical trials have also reported an increased risk of developing immune-related adverse events (IRAEs). Endocrine IRAEs may be particularly relevant.

OBJECTIVE

To comprehensively evaluate the clinical presentation of endocrine IRAEs in patients with lung cancer treated with nivolumab. Potential risk factors are analyzed, and strategies for IRAE management are proposed.

METHODS

Forty consecutive patients treated with nivolumab for advanced non-small cell lung cancer (NSCLC) were studied, paying particular attention to development of endocrine IRAEs (thyroid, hypophyseal, adrenal, or pancreatic) and clinical outcome.

RESULTS

Thyroid function changes were found in 9 patients (22.5%), of which six developed hypothyroidism and three had hyperthyroidism after a median of 3.8 and 2.3 cycles of nivolumab respectively. Only one patient had thyroid-related symptoms. Thyroid autoimmunity was negative in all cases. Hyperthyroid patients showed no uptake in iodine scintigraphy, and their hormone values returned to normal in less than six months. Nivolumab was discontinued for toxicity in one patient. One patient with hyperthyroidism also developed autoimmune diabetes, and one patient with hypothyroidism also had hypogonadism. After a median follow-up of 7.6 months, 25 patients (62.5%) showed response to nivolumab. Univariate and multivariate analyses showed no differences between patients who developed thyroid changes and those who did not.

CONCLUSIONS

Thyroid changes after treatment with nivolumab are common and warrant active laboratory monitoring. The underlying mechanisms and their relevance deserve further research.