Activating Antibodies to The Calcium-sensing Receptor in Immunotherapy-induced Hypoparathyroidism

Comparative study of insulin resistance surrogate indices to predict mild cognitive impairment among Chinese non-diabetic adults

OBJECTIVE

The study aims to investigate the associations of triglyceride glucose (TyG), TyG combined with body mass index (TyG-BMI), metabolic score for insulin resistance (METS-IR), the triglyceride to high-density lipoprotein cholesterol ratio (TG/HDL-C), and the risk of mild cognitive impairment (MCI) in individuals without diabetes aged 45 and above.

METHODS

The most recent data in this study were from a cohort study, which sourced samples from the China Health and Retirement Longitudinal Study, spanning 2011 to 2018. The four indices' associations with MCI risk were analyzed using logistic regression. The predictive capacity was measured using the receiver operating characteristic (ROC) curve.

RESULTS

Over a 7-year follow-up, 1,261 individuals (31.34%) of the 4,027 participants developed MCI. Logistic regression analysis revealed significant associations between these surrogate indices and MCI. The findings for the highest quartile compared with the lowest quartile were as follows: TyG: 1.24 (95% CI: 1.02, 1.49); TyG-BMI: 1.38 (95% CI: 1.13, 1.68); METS-IR: 1.50 (95% CI: 1.09, 2.06); TG/HDL-C: 1.34 (95% CI: 1.10, 1.64). ROC analysis revealed that TyG, TyG-BMI, TG/HDL-C, and METS-IR demonstrated excellent discriminatory power for MCI, with area under the curve (AUC) values of 0.82 (95% CI: 0.80, 0.83), 0.82 (95% CI: 0.80, 0.83), 0.83 (95% CI: 0.80, 0.84), and 0.83 (95% CI: 0.80, 0.84), respectively. The four indices showed stronger ability to predict MCI risk in females compared to males.

CONCLUSION

Elevated levels of four indices are positively correlated with MCI risk. TyG-BMI and METS-IR demonstrate stronger capabilities in identifying MCI across both male and female populations. This suggests that early intervention in patients with elevated IR surrogate indices may help reduce the MCI.

Life-Threatening Endocrinological Immune-Related Adverse Events of Immune Checkpoint Inhibitor Therapy

Malignant neoplasms are currently one of the leading causes of morbidity and mortality worldwide, posing a major public health challenge. However, recent advances in research in cancer biology and immunity have led to the development of immunotherapy, which is now used on an everyday basis in cancer treatment in addition to surgical treatment, classical cytostatics, and radiotherapy. The efficacy of immunotherapy has promoted the great popularity of this treatment among patients, as well as significant research interest. The increasing number of patients being treated with immunotherapy not only reassures physicians of the efficacy of this technique but also shows the wide spectrum of side effects of this therapy, which has not been considered before. Immune-related adverse events may affect many systems and organs, such as digestive, cardiovascular, respiratory, skin, or endocrine organs. Most complications have a mild or moderate course, but there are life-threatening manifestations that are essential to be aware of because if they are not properly diagnosed and treated on time, they can have fatal consequences. The purpose of this paper was to present the results of a literature review on the current state of knowledge on life-threatening endocrine side effects (such as adrenal crisis, thyroid storm, myxoedema crisis, diabetic ketoacidosis, and severe hypocalcaemia) of immune checkpoint inhibitors to provide information on symptoms, diagnostics, and management strategies.

Endocrine immune-related adverse effects of immune-checkpoint inhibitors

INTRODUCTION

Immune-checkpoint inhibitor therapy modulates the response of the immune system acting against cancer. Two pathways impacted by this kind of treatment are the CTLA4 and the PD-1/PD-L1 pathways. ICI therapy can trigger autoimmune adverse effects, known as immune-related Adverse Events (irAEs).

AREAS COVERED

This review focuses on irAEs which affect the endocrine system. This review elucidates the pathways used by these drugs with a focus on the hypothetical pathogenesis at their basis. In fact, the pathophysiology of irAEs concerns the possibility of an interaction between cellular autoimmunity, humoral immunity, cytokines, chemokines, and genetics. The endocrine irAEs examined are thyroid dysfunctions, immune related-hypophysitis, diabetes, peripheral adrenal insufficiency, and hypoparathyroidism.

EXPERT OPINION

There is still much to investigate in endocrine irAES of checkpoint inhibitors. In the future, checkpoint inhibitors will be increasingly utilized therapies, and therefore it is crucial to find the proper diagnostic-therapeutic program for irAEs, especially as endocrine irAEs are nonreversible and require lifelong replacement therapies.

Seizures in activating calcium-sensing receptor antibodies positive autoimmune hypoparathyroidism and preponderance of steroids therapy: A case report

A 55-year-old female patient presented with generalized tonic-clonic seizures. Laboratory evaluation revealed low calcium (4.9 mg/dl), low PTH (0.9 pg/ml), and positive activating CaSR antibodies. The condition was diagnosed as autoimmune hypoparathyroidism. Calcium and vitamin D supplements did not correct the patient's hypocalcemia. The addition of prednisone to vitamin supplements showed a better response and corrected the hypocalcemia. The patient remained in seizure-free for one year.

Endocrine-related adverse conditions in patients receiving immune checkpoint inhibition: an ESE clinical practice guideline

Immune checkpoint inhibitors (ICI) have revolutionized cancer treatment but are associated with significant autoimmune endocrinopathies that pose both diagnostic and treatment challenges. The aim of this guideline is to provide clinicians with the best possible evidence-based recommendations for treatment and follow-up of patients with ICI-induced endocrine side-effects based on the Grading of Recommendations Assessment, Development, and Evaluation system. As these drugs have been used for a relatively short time, large systematic investigations are scarce. A systematic approach to diagnosis, treatment, and follow-up is needed, including baseline tests of endocrine function before each treatment cycle. We conclude that there is no clear evidence for the benefit of high-dose glucocorticoids to treat endocrine toxicities with the possible exceptions of severe thyroid eye disease and hypophysitis affecting the visual apparatus. With the exception of thyroiditis, most endocrine dysfunctions appear to be permanent regardless of ICI discontinuation. Thus, the development of endocrinopathies does not dictate a need to stop ICI treatment.

Hypoparathyroidism: Genetics and Diagnosis

This narrative report summarizes diagnostic criteria for hypoparathyroidism and describes the clinical presentation and underlying genetic causes of the nonsurgical forms. We conducted a comprehensive literature search from January 2000 to January 2021 and included landmark articles before 2000, presenting a comprehensive update of these topics and suggesting a research agenda to improve diagnosis and, eventually, the prognosis of the disease. Hypoparathyroidism, which is characterized by insufficient secretion of parathyroid hormone (PTH) leading to hypocalcemia, is diagnosed on biochemical grounds. Low albumin-adjusted calcium or ionized calcium with concurrent inappropriately low serum PTH concentration are the hallmarks of the disease. In this review, we discuss the characteristics and pitfalls in measuring calcium and PTH. We also undertook a systematic review addressing the utility of measuring calcium and PTH within 24 hours after total thyroidectomy to predict long-term hypoparathyroidism. A summary of the findings is presented here; results of the detailed systematic review are published separately in this issue of JBMR. Several genetic disorders can present with hypoparathyroidism, either as an isolated disease or as part of a syndrome. A positive family history and, in the case of complex diseases, characteristic comorbidities raise the clinical suspicion of a genetic disorder. In addition to these disorders' phenotypic characteristics, which include autoimmune diseases, we discuss approaches for the genetic diagnosis. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

The calcium-sensing receptor in inflammation: Recent updates

The Calcium-Sensing Receptor (CaSR) is a member of the class C of G-proteins coupled receptors (GPCRs), it plays a pivotal role in calcium homeostasis by directly controlling calcium excretion in the kidneys and indirectly by regulating parathyroid hormone (PTH) release from the parathyroid glands. The CaSR is found to be ubiquitously expressed in the body, playing a plethora of additional functions spanning from fluid secretion, insulin release, neuronal development, vessel tone to cell proliferation and apoptosis, to name but a few. The present review aims to elucidate and clarify the emerging regulatory effects that the CaSR plays in inflammation in several tissues, where it mostly promotes pro-inflammatory responses, with the exception of the large intestine, where contradictory roles have been recently reported. The CaSR has been found to be expressed even in immune cells, where it stimulates immune response and chemokinesis. On the other hand, CaSR expression seems to be boosted under inflammatory stimulus, in particular, by pro-inflammatory cytokines. Because of this, the CaSR has been addressed as a key factor responsible for hypocalcemia and low levels of PTH that are commonly found in critically ill patients under sepsis or after burn injury. Moreover, the CaSR has been found to be implicated in autoimmune-hypoparathyroidism, recently found also in patients treated with immune-checkpoint inhibitors. Given the tight bound between the CaSR, calcium and vitamin D metabolism, we also speculate about their roles in the pathogenesis of severe acute respiratory syndrome coronavirus-19 (SARS-COVID-19) infection and their impact on patients' prognosis. We will further explore the therapeutic potential of pharmacological targeting of the CaSR for the treatment and management of aberrant inflammatory responses.

Immune checkpoint inhibitors and kidney disease

PURPOSE OF REVIEW

Immune checkpoint inhibitors (ICIs) have changed the landscape of cancer treatment. However, use of ICIs can be limited by inflammatory toxicities referred to as immune-related adverse events (irAEs). ICI-associated acute kidney injury (ICI-associated AKI) affects 3-5% of ICI users.

RECENT FINDINGS

With the rapidly growing indication of ICI, knowledge of ICI-associated kidney toxicity has also expanded from case series to large multicentre cohort studies. In this review, we discuss the clinical features, risk factors, clinicopathological correlations and prognosis of ICI-associated AKI from the most recent rigorously conducted retrospective cohort studies. We also discuss recent advances in diagnostic biomarker investigation, treatment and the unique challenge faced in the kidney transplant population.

SUMMARY

With more comprehensive understanding of the clinical features and risk factors, ICI-associated AKI is commonly diagnosed clinically, especially given the inherent challenges performing a kidney biopsy in the cancer population; however, this highlights the urgent need for improved noninvasive diagnostic biomarkers to aid diagnosis and prognosis. Prospective studies are needed to better define the optimal treatment of ICI-associated AKI and to minimize the risk of graft loss in patients with kidney transplant who require ICIs.

Circulating biomarkers of response to immunotherapy and immune-related adverse events

INTRODUCTION

Immune checkpoint blockade has revolutionized cancer treatment. However, response rates vary, and these treatments have a high rate of immune-related side effects, which can be limiting. Thus, tests to predict who will respond and who may experience side effects are of critical importance toward realizing the ultimate goal of precision oncology.

AREAS COVERED

We review several of the most recent advances in circulating biomarkers that have been reported to be useful in predicting response and immune-related adverse events (irAE) to checkpoint blockade immunotherapies (CBI). We focus on high-quality studies published within the last few years. We highlight significant findings, identify areas for improvement, and provide recommendations on how these biomarkers may be translated into clinical utility.

EXPERT OPINION

As newer immunotherapies are developed, there is a pressing need to identify circulating biomarkers that can help predict responses and side effects. Current studies are mostly small-scale and retrospective; there is a need for larger-scale and prospective studies to help validate several of the biomarkers detailed here. As oncology focuses more on precision-based approaches, it is likely that a combination of biomarkers, including circulating ones as detailed here, will have critical utility in guiding clinical decisions.

Immune-Related Uncommon Adverse Events in Patients with Cancer Treated with Immunotherapy

Immunotherapy has dramatically changed the therapeutic landscape of oncology, and has become standard of care in multiple cancer types in front or late lines of therapy, with some longstanding responses and outstanding results. Notwithstanding, its use has brought a totally unique spectrum of adverse events, characterized by a myriad of diverse manifestations affecting nearly every organ and system of the body, including the endocrine, nervous, cardiac, respiratory and gastrointestinal systems. Uncommon adverse events, defined as those occurring in less than 1% of patients, comprise an even more heterogeneous group of diseases that are being seen more recurrently as the use of immune check-point inhibitors increases and indications spread in different tumor types and stages. Here, we comprehensively review some uncommon, but exceedingly important, immune-related adverse events, with special emphasis in the clinical approach and diagnostic workup, aiming to reunite the evidence published previously, allowing an increase in awareness and knowledge from all specialists implicated in the diagnosis, treatment, and care of cancer patients treated with immunotherapy.

Steroid treatment in the management of destructive thyrotoxicosis induced by PD1 blockade

Objective

Destructive thyroiditis is the most common endocrine immune-related adverse event (iRAEs) in patients treated with anti-PD1/PD-L1 agents. Given its self-limited course, current guidelines recommend no treatment for this iRAE. Nevertheless, in patients with enlarged thyroid volume and a poor performance status, thyrotoxicosis may be particularly severe and harmful. The aim of the study is to evaluate if steroid treatment might be useful in improving thyrotoxicosis in subjects with a poor performance status.

Methods

We conducted a retrospective study, comparing the course of thyrotoxicosis of four patients treated with oral prednisone at the dosage of 25 mg/day (tapered to discontinuation in 3 weeks) and an enlarged thyroid volume to that of eight patients with similar thyroid volume who were left untreated.

Results

The levels of thyroid hormones were lower in subjects treated compared to those untreated at time of 7, 14, 21, 28, 35, 42, 60 and 90 days (P < 0.05 at each time). The time to remission of thyrotoxicosis was 24 days in patients treated with steroids and 120 days in untreated patients (P < 0.001). At 6 months, the rate of evolution to hypothyroidism was similar in the two groups (4/4 in the steroid group vs 7/8 in the untreated group, P = 0.74) and no difference was found in tumor progression (P = 0.89).

Conclusions

Our preliminary data suggest that in patients with a poor performance status experiencing a severe destructive thyrotoxicosis induced by PD-1 blockade, a short period of administration of oral prednisone is effective in obtaining a quick reduction of the levels of thyroid hormones.

Endocrine immune-related adverse events: Adrenal, parathyroid, diabetes insipidus, and lipoatrophy

Immune checkpoint inhibitors are being prescribed increasingly widely for a range of malignancies. They are effective at treating certain cancers, but also have significant side effects. Evidence suggests that efficacy is greatest in patients who experience one or more immune-related adverse events (irAEs). Common irAEs include skin and hepatic reactions, and a range of immune-related endocrinopathies. These include hypophysitis, thyroid disease, and autoimmune diabetes mellitus, and rarer endocrinopathies such as primary adrenal insufficiency, diabetes insipidus, parathyroid disease, autoimmune polyglandular syndrome, lipodystrophy, and ACTH-dependent Cushing's syndrome. Herein, we review the current literature related to these rarer immunotherapy-induced endocrinopathies.

Increased Risk of Thyroid Dysfunction by PD-1 and CTLA-4 Blockade in Patients Without Thyroid Autoantibodies at Baseline

BACKGROUND

Previous studies showed that although the risk of thyroid dysfunction [thyroid immune-related adverse events (irAEs)] induced by anti-programmed cell death-1 antibodies (PD-1-Ab) was as low as 2% to 7% in patients negative for anti-thyroid antibodies (ATAs) at baseline, it was much higher (30%-50%) in patients positive for ATAs. However, whether a similar increase occurs with combination therapy using PD-1-Ab plus anti-cytotoxic T-lymphocyte antigen-4 antibody (CTLA-4-Ab) is unknown.

METHODS

A total of 451 patients with malignancies treated with PD-1-Ab, CTLA-4-Ab, or a combination of PD-1-Ab and CTLA-4-Ab (PD-1/CTLA-4-Abs) were evaluated for ATAs at baseline and for thyroid function every 6 weeks for 24 weeks after treatment initiation and then observed until the last clinical visit.

RESULTS

Of the 451 patients, 51 developed thyroid irAEs after immunotherapy [41 of 416 (9.9%) treated with PD-1-Ab, 0 of 8 (0%) treated with CTLA-4-Ab, and 10 of 27 (37.0%) treated with PD-1/CTLA-4-Abs]. The cumulative incidence of thyroid irAEs was significantly higher in patients who were positive vs negative for ATAs at baseline after both PD-1-Ab [28/87 (32.2%) vs 13/329 (4.0%), P < 0.001] and PD-1/CTLA-4-Abs [6/10 (60.0%) vs 4/17 (23.5%), P < 0.05] treatments. The risk of thyroid irAEs induced by PD-1/CTLA-4Abs, which was significantly higher than that induced by PD-1-Ab, in patients negative for ATAs at baseline was not statistically different from that induced by PD-1-Ab in patients positive for ATAs at baseline.

CONCLUSIONS

This study showed that the incidence of thyroid irAEs was high and not negligible after PD-1/CTLA-4-Abs treatment even in patients negative for ATAs at baseline.

Electrolyte and Acid-Base Disorders associated with Cancer Immunotherapy

Novel immunotherapy drugs have changed the landscape of cancer medicine. Immune checkpoint inhibitors and chimeric antigen receptor T cells are being used and investigated in almost all solid cancers. Immune-related adverse events have been associated with immunotherapies. Acute kidney injury has been the most commonly associated kidney adverse event. In this review, we showcase the several associated electrolyte disorders seen with immunotherapy. Immune checkpoint inhibitors can lead to hyponatremia by several mechanisms, with the syndrome of inappropriate antidiuresis being the most common. Endocrine causes of hyponatremia are rare. Hypokalemia is not uncommon and is associated with both proximal and distal renal tubular acidosis. Hypercalcemia associated with immune checkpoint inhibitors has led to some interesting observations including immune checkpoint inhibitor-induced parathyroid hormone - related peptide production, sarcoid-like granulomas, and hyper-progression of the disease. Hypocalcemia and hyperphosphatemia may be seen with immune checkpoint inhibitor-induced tumor lysis syndrome. Chimeric antigen receptor T cell therapy-associated electrolyte disorders are also common. This is associated chiefly with hyponatremia, although other electrolyte abnormalities can occur. Early recognition and prompt diagnosis may help providers manage the mechanistically varied and novel electrolyte disorders associated with immunotherapy.

Hypoparathyroidism: an uncommon adverse effect of treatment with durvalumab

Summary

Immune checkpoint inhibitors (ICIs) are monoclonal antibodies approved for the treatment of numerous cancer types. Toxicities induced by ICIs may affect any organ system and manifest as endocrinopathy. The main side effects related to treatment are immune-related adverse events (irAEs), especially thyroid dysfunction and hypophysitis. Rare endocrine irAEs are diabetes insipidus, hypoparathyroidism, thyrotoxic crisis and hypogonadism. We report a case of hypoparathyroidism induced by ICI treatment with durvalumab, which has not previously been described.

Learning points

Treatment with immune checkpoint inhibitors (ICIs) is associated with many endocrine side effects.It is recommended that patients treated with ICIs are observed by an endocrinologist.If side effects are treated accordingly, ICI therapy can continue.

Calcium-Sensing Receptor Polymorphisms at rs1801725 Are Associated with Increased Risk of Secondary Malignancies

Dysregulation of systemic calcium homeostasis during malignancy is common in most patients with high-grade tumors. However, it remains unclear whether single nucleotide polymorphisms (SNPs) that alter the sensitivity of the calcium-sensing receptor (CaSR) to circulating calcium are associated with primary and/or secondary neoplasms at specific pathological sites in patients of European and African ancestry. Multivariable logistic regression models were used to analyze the association of CASR SNPs with circulating calcium, parathyroid hormone, vitamin D, and primary and secondary neoplasms. Circulating calcium is associated with an increased risk for breast, prostate, and skin cancers. In patients of European descent, the rs1801725 CASR SNP is associated with bone-related cancer phenotypes, deficiency of humoral immunity, and a higher risk of secondary neoplasms in the lungs and bone. Interestingly, circulating calcium levels are higher in homozygous patients for the inactivating CASR variant at rs1801725 (TT genotype), and this is associated with a higher risk of secondary malignancies. Our data suggest that expression of CaSR variants at rs1801725 is associated with a higher risk of developing secondary neoplastic lesions in the lungs and bone, due in part to cancer-induced hypercalcemia and/or tumor immune suppression. Screening of patients for CASR variants at this locus may lead to improved management of high calcium associated tumor progression.

Management of Thyrotoxicosis Induced by PD1 or PD-L1 Blockade

Context

Thyrotoxicosis is a common immune-related adverse event in patients treated with programmed cell death protein-1 (PD1) or programmed cell death protein ligand-1 (PD-L1) blockade. A detailed endocrinological assessment, including thyroid ultrasound and scintigraphy, is lacking, as are data on response to treatment and follow-up.

Objective

The aim of this study was to better characterize the thyrotoxicosis secondary to immune checkpoint inhibitors, gaining insights into pathogenesis and treatment.

Methods

We conducted a retrospective study of 20 consecutive patients who had normal thyroid function before starting immunotherapy and then experienced thyrotoxicosis on PD1 or PD-L1 blockade. Clinical assessment was combined with thyroid ultrasound, ^99mtechnecium scintiscan, and longitudinal thyroid function tests.

Results

Five patients had normal or increased scintigraphic uptake (Sci+), no serum antibodies against the thyrotropin receptor, and remained hyperthyroid throughout follow-up. The other 15 patients had no scintigraphic uptake (Sci–) and experienced destructive thyrotoxicosis followed by hypothyroidism (N = 9) or euthyroidism (N = 6). Hypothyroidism was more readily seen in those with normal thyroid volume than in those with goiter (P = .04). Among Sci– individuals, a larger thyroid volume was associated with a longer time to remission (P < .05). Methimazole (MMI) was effective only in Sci+ individuals (P < .05).

Conclusion

Administration of PD1- or PD-L1–blocking antibodies may induce 2 different forms of thyrotoxicosis that appear similar in clinical severity at onset: a type 1 characterized by persistent hyperthyroidism that requires treatment with MMI, and a type 2, characterized by destructive and transient thyrotoxicosis that evolves to hypothyroidism or euthyroidism. Thyroid scintigraphy and ultrasound help in differentiating and managing these 2 forms of iatrogenic thyrotoxicosis.

Clinical Characteristics, Management, and Potential Biomarkers of Endocrine Dysfunction Induced by Immune Checkpoint Inhibitors

Immune-related adverse events (irAEs) affecting the endocrine glands are among the most frequent irAEs induced by immune checkpoint inhibitors (ICIs) and include hypopituitarism, primary adrenal insufficiency, thyrotoxicosis, hypothyroidism, hypoparathyroidism, and type 1 diabetes mellitus. Since the incidence and clinical features of endocrine irAEs vary according to the ICI used, it is important to understand the characteristics of these irAEs and to manage each one appropriately. Since some endocrine irAEs, including adrenal crisis and diabetic ketoacidosis, are potentially life-threatening, predicting the risk of endocrine irAEs before their onset is critical. Several autoantibodies have been detected in patients who develop endocrine irAEs, among which anti-thyroid antibodies may be predictive biomarkers of thyroid dysfunction. In this review, we describe the clinical features of each endocrine irAE induced by ICIs and discuss their potential biomarkers, including autoantibodies.

Endocrine complications of immunotherapies: a review

Use of immune checkpoint inhibitors in cancer treatment has increased vastly over the past decade, as both single and combination agent therapies. While having a positive impact on survival rates, adverse effects have been noted, with endocrine effects in around 10% of patients. Thyroid disease and hypophysitis are the most commonly encountered, with diabetes mellitus and primary adrenal insufficiency also reported, as well as more rare endocrinopathies. Patient and clinician education to raise awareness of these effects, as well as regular monitoring to enable early recognition, diagnosis and prompt treatment of the immune side effects, are key. In this review, we discuss the aetiology, presentation and management of the endocrine complications of immunotherapies that are relevant to the general physician, as well as highlighting important areas where further research is still needed.

Pembrolizumab-Associated Hypoparathyroidism: A Single Case Report

Objective

To evaluate a case of pembrolizumab-induced hypoparathyroidism leading to hypocalcemia.

Methods

The diagnostic tests performed included calcium and parathyroid hormone level detection and calcium-sensing receptor gene analysis.

Results

A 71-year-old Caucasian man was diagnosed with stage IIIB adenocarcinoma of the lung and received radiation therapy but had no other exposure to radiation. Pembrolizumab 200 mg intravenous every 3 weeks was started 5 years after the initial diagnosis. The patient’s corrected calcium level was 9.2 mg/dL (normal, 8.5-10.5 mg/dL) at the start of pembrolizumab therapy. The calcium level after the 13th dose of pembrolizumab was 8.1 mg/dL (normal, 8.5-10.2 mg/dL), leading to endocrinology referral. The patient’s parathyroid hormone and corrected calcium levels after the 22nd dose were 4.3 mg/dL (normal, 14-72 pg/mL) and 6.5 mg/dL (normal, 8.5-10.2 mg/dL), respectively. He denied symptoms of latent tetany on presentation while on pembrolizumab for 15 months but complained of fatigue and weakness. The patient had no history of autoimmune diseases or neck injuries. Calcium-sensing receptor gene analysis was negative for genetic mutations. Immunotherapy-mediated hypoparathyroidism was diagnosed. He was treated with daily oral calcium carbonate (2000 mg), calcitriol 0.5 μg, 1 dose of calcium gluconate 2 g intravenous, and 3 doses of calcium chloride 1 g intravenous. His fatigue, weakness, and calcium levels improved with therapy.

Conclusion

Pembrolizumab treatment may have resulted in immune-mediated hypoparathyroidism, leading to hypocalcemia. It is important to report such cases to understand its presentation and timing in relation to pembrolizumab, which further facilitates its timely treatment.

Endocrine Adverse Events Caused by Different Types and Different Doses of Immune Checkpoint Inhibitors in the Treatment of Solid Tumors: A Meta-Analysis and Systematic Review

The aim of this meta-analysis was to assess the risks of endocrine adverse events in patients with malignancies treated with different types and different doses of immune checkpoint inhibitors (ICIs). PubMed and Embase were searched for randomized controlled trials on ICIs and endocrine adverse events since 2000, and meta-analysis was carried out. Twenty-six randomized controlled trials comprising 13 824 patients with malignancies were included. Compared with the other tumor therapies (used as a control group), patients treated with programmed death-1 inhibitors appeared to be at higher risks of hypothyroidism, hyperthyroidism, thyroiditis, hypophysitis or hypopituitarism, and type 1 diabetes mellitus, while there was no difference in the risk of primary adrenal insufficiency. It was also found that patients treated with cytotoxic T-lymphocyte-associated protein-4 inhibitors were at higher risk of hypophysitis or hypopituitarism, primary adrenal insufficiency, and hypothyroidism. In comparison, patients treated with programmed death-ligand 1 inhibitors were at higher risk of hyperthyroidism and hypothyroidism. Compared with the control group, both low-dose and high-dose ICI groups were at higher risk of hypothyroidism and hyperthyroidism, and the low-dose group had increased risk of thyroiditis and primary adrenal insufficiency. There was no significant difference in the risk of type 1 diabetes between the low-dose group and the high-dose group. The risk of hypophysitis or hypopituitarism in the high-dose group (relative risk, 20.12; 95% confidence interval, 8.02-50.46) was significantly higher than that in the low-dose group (relative risk, 4.92; 95% confidence interval, 2.11-11.47). The risk of endocrine adverse events was increased in patients treated with ICIs. Different types and doses of ICIs have varying characteristics of endocrine adverse events.