Comparative analysis of human leucocyte antigen between idiopathic and anti-PD-1 antibody induced isolated adrenocorticotropic hormone deficiency: A pilot study

A Case in Which HLA-DR4 is Involved in the Development of Complex Immune-Related Endocrinological Adverse Events following Combination Therapy with Nivolumab and Ipilimumab

Immune checkpoint inhibitors (ICIs) have become a focal point in cancer immunotherapy, though their utilization is also linked to the occurrence of diverse immune-related adverse events (irAEs). Herein, we present details of a 42-year-old woman diagnosed with a malignant vaginal melanoma who underwent ICI therapy with the combination of nivolumab and ipilimumab. Approximately two months after initiating therapy, the patient manifested destructive thyroiditis and fulminant type 1 diabetes mellitus, thus necessitating intensive insulin therapy. Following the onset of adrenocorticotropic hormone deficiency, frequent hypoglycemic episodes prompted the initiation of replacement therapy with hydrocortisone. Human leukocyte antigen (HLA)-DNA typing revealed the presence of HLA-DRB1∗04 : 05 and DQB1∗04 : 01. HLA-DR4 has been suggested to be associated with the development of multiple endocrine irAEs. This is the first reported case of three endocrine irAEs occurring within a short period, in which the presence of HLA-DR4 may have contributed to the pathogenesis.

Amino acid polymorphisms in human histocompatibility leukocyte antigen class II and proinsulin epitope have impacts on type 1 diabetes mellitus induced by immune-checkpoint inhibitors

Introduction

Immune-checkpoint inhibitors are effective in various advanced cancers. Type 1 diabetes mellitus induced by them (ICI-T1DM) is a serious complication requiring prompt insulin treatment, but the immunological mechanism behind it is unclear.

Methods

We examined amino acid polymorphisms in human histocompatibility leukocyte antigen (HLA) molecules and investigated proinsulin epitope binding affinities to HLA molecules.

Results and Discussion

Twelve patients with ICI-T1DM and 35 patients in a control group without ICI-T1DM were enrolled in the study. Allele and haplotype frequencies of HLA-DRB1*04:05, DQB1*04:01, and most importantly DPB1*05:01 were significantly increased in patients with ICI-T1DM. In addition, novel amino acid polymorphisms in HLA-DR (4 polymorphisms), in DQ (12 polymorphisms), and in DP molecules (9 polymorphisms) were identified. These amino acid polymorphisms might be associated with the development of ICI-T1DM. Moreover, novel human proinsulin epitope clusters in insulin A and B chains were discovered in silico and in vitro peptide binding assays to HLA-DP5. In conclusion, significant amino acid polymorphisms in HLA-class II molecules, and conformational alterations in the peptide-binding groove of the HLA-DP molecules were considered likely to influence the immunogenicity of proinsulin epitopes in ICI-T1DM. These amino acid polymorphisms and HLA-DP5 may be predictive genetic factors for ICI-T1DM.

Predictive Biomarkers for Immune-Related Endocrinopathies following Immune Checkpoint Inhibitors Treatment

In recent years, in the context of the increase in the life expectancy of cancer patients, special attention has been given to immunotherapy and, indeed, to immune checkpoint inhibitors. The use of immune checkpoint inhibitors has increased rapidly, and approximately 40% of cancer patients are eligible for this treatment. Although their impact is valuable on cancer treatment, immune checkpoint inhibitors come with side effects, known as immune-related adverse effects. These can affect many systems, including cutaneous, musculoskeletal, cardiovascular, gastrointestinal, endocrine, neural, and pulmonary systems. In this review, we focus on immune-related endocrinopathies that affect around 10% of all treated patients. Endocrine dysfunctions can manifest as hypophysitis, thyroid dysfunction, hypoparathyroidism, insulin-deficient diabetes mellitus, and primary adrenal insufficiency. Currently, there are multiple ongoing clinical trials that aim to identify possible predictive biomarkers for immune-related adverse effects. The design of those clinical trials relies on collecting a variety of biological specimens (tissue biopsy, blood, plasma, saliva, and stool) at baseline and regular intervals during treatment. In this review, we present the predictive biomarkers (such as antibodies, hormones, cytokines, human leukocyte antigens, and eosinophils) that could potentially be utilized in clinical practice in order to predict adverse effects and manage them appropriately.

Combined Hypophysitis and Type 1 Diabetes Mellitus Related to Immune Checkpoint Inhibitors

Context

The occurrence of multiple endocrinopathies due to immune checkpoint inhibitors (ICIs) is a relatively common adverse event. However, the occurrence of a combination of hypophysitis and type 1 diabetes mellitus (T1DM) is extremely rare, and its clinical features are unclear.

Objective

We comparatively analyzed the clinical features of this combination and each individual ICI-induced endocrinopathy.

Methods

We reported 3 cases that we encountered and reviewed previously reported cases of patients with combined hypophysitis and T1DM due to ICIs.

Results

Anti-programmed cell death-1 (anti-PD-1) antibodies were prescribed to all 3 cases. The duration from ICI initiation to the onset of endocrine disease was 12 to 48 weeks. Several human leukocyte antigen (HLA) haplotypes that have disease susceptibility to hypophysitis were detected in all 3 patients. With the 17 previously reported cases, combined endocrinopathies were more common in men (85%). The onset age was in the 60s for both combined and single endocrinopathies. Anti-PD-1 antibodies were used in most of the cases (90%). The time from ICI initiation to the onset of endocrinopathies was 24 (8-76) weeks for hypophysitis and 32 (8-76) weeks for T1DM in patients with combined endocrinopathies, which was not significantly different from that for each single endocrinopathy.

Conclusion

We presented 3 cases of patients with combined endocrinopathies of hypophysitis and T1DM that may have been caused by anti-PD-1 antibodies. There was no difference in the time from ICI initiation to the onset of endocrinopathies between combined and single endocrinopathies. Further case accumulation and pathogenic investigations are required.

Cutaneous manifestations associated with immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs) are monoclonal antibodies that block key mediators of tumor-mediated immune evasion. The frequency of its use has increased rapidly and has extended to numerous cancers. ICIs target immune checkpoint molecules, such as programmed cell death protein 1 (PD-1), PD ligand 1 (PD-L1), and T cell activation, including cytotoxic T-lymphocyte-associated protein-4 (CTLA-4). However, ICI-driven alterations in the immune system can induce various immune-related adverse events (irAEs) that affect multiple organs. Among these, cutaneous irAEs are the most common and often the first to develop. Skin manifestations are characterized by a wide range of phenotypes, including maculopapular rash, psoriasiform eruption, lichen planus-like eruption, pruritus, vitiligo-like depigmentation, bullous diseases, alopecia, and Stevens-Johnson syndrome/toxic epidermal necrolysis. In terms of pathogenesis, the mechanism of cutaneous irAEs remains unclear. Still, several hypotheses have been proposed, including activation of T cells against common antigens in normal tissues and tumor cells, increased release of proinflammatory cytokines associated with immune-related effects in specific tissues/organs, association with specific human leukocyte antigen variants and organ-specific irAEs, and acceleration of concurrent medication-induced drug eruptions. Based on recent literature, this review provides an overview of each ICI-induced skin manifestation and epidemiology and focuses on the mechanisms underlying cutaneous irAEs.

Clinical characteristics of adrenal insufficiency induced by pembrolizumab in non-small-cell lung cancer

BACKGROUND AND AIM

Immune checkpoint inhibitors have significantly improved the clinical outcomes of many cancer types, but they induce a range of immune-related adverse events (irAEs). Although adrenal insufficiency (AI) is a rare irAE, it can lead to serious consequences. This study aimed to determine the clinical features of patients with advanced non-small-cell lung cancer (NSCLC) who developed AI following pembrolizumab treatment.

METHODS

We retrospectively reviewed and analyzed the clinical data of all patients with NSCLC treated with pembrolizumab at Juntendo University Hospital from February 2017 to December 2020. The diagnosis of AI was established based on the Endocrine Emergency Guidance for the acute management of endocrine complications of checkpoint inhibitor therapy in the UK and the clinical practice guidelines of the Japan Endocrine Society.

RESULT

AI was clinically suspected in 59 out of 186 patients treated with pembrolizumab, and 10 (5.4%) cases were confirmed. The symptoms included hyponatremia (n = 9), fatigue (n = 8), and loss of appetite (n = 6). All patients had low adrenocorticotropic hormone (ACTH) levels, and five patients were diagnosed with isolated ACTH deficiency. All patients completely recovered with corticosteroid replacement. The median time to onset of AI was 8.0 (range 3.8-15.2) months. The median progression-free survival in these patients was 22.4 (95% confidence interval 11.2-not reached) months.

CONCLUSION

The incidence of AI among patients treated with pembrolizumab is more frequent than previously reported. In addition, secondary AI, especially isolated ACTH deficiency, is a major form of AI induced by pembrolizumab.

HLA analysis of immune checkpoint inhibitor-induced and idiopathic isolated ACTH deficiency

PURPOSE

Isolated adrenocorticotropic hormone deficiency is a rare disease; however, since immune check point inhibitors (ICIs) have become widely used, many more cases have been reported. In this study, we compared the human leukocyte antigen (HLA) signatures between ICI-induced isolated adrenocorticotropic hormone deficiency (IAD) and idiopathic IAD (IIAD).

DESIGN AND METHODS

Clinical features and HLA frequencies were compared among 13 patients with ICI-induced IAD, 8 patients with IIAD, and healthy controls. HLA frequencies of healthy controls were adopted from a HLA database of Japanese population.

RESULTS

Age and body mass index were higher, while the rate of weight loss was lower, in patients with ICI-induced IAD than in those with IIAD. No HLA alleles had a significantly higher frequency in patients with ICI-induced IAD than in healthy controls, whereas the frequencies of HLA-DRB1*09:01, HLA-DQA1*03:02, and DQB1*03:03 were significantly higher in patients with IIAD than in healthy controls.

CONCLUSIONS

ICI-induced IAD and IIAD were different in terms of HLA frequencies. There were no specific HLAs related to ICI-induced IAD, whereas several HLAs in strong linkage disequilibrium were associated with IIAD. This might suggest that the two diseases have different pathological mechanisms. HLAs unique to IIAD may be helpful in predicting its pathophysiology.

Immune checkpoint inhibitor-related hypophysitis

Immune checkpoint inhibitors (ICIs) have been recently proposed as a strategy for treating anti-malignant neoplasms. However, this treatment leads to immune-related adverse events (irAEs) such as autoimmune endocrinopathy. Early diagnosis and appropriate treatment of ICI-related hypophysitis are essential as it can manifest as a life-threatening condition due to an adrenal crisis. In this review, we summarize the pathogenesis, risk factors, diagnostic processes, clinical characteristics, and its current management. In particular, we discuss the different aspects of anti-CTLA-4 antibody-related and anti-PD-1/anti-PD-L1 antibody-related hypophysitis. We also propose key points for early detection and diagnosis by identifying the target group that should be monitored more carefully. Specific methods of hormone replacement therapy have also been described. We hope that this review will lead to a better understanding and management of this rare but serious condition during cancer treatment and further elucidate the pathophysiology of pituitary autoimmunity.

Human Leukocyte Antigens and Biomarkers in Type 1 Diabetes Mellitus Induced by Immune-Checkpoint Inhibitors

BACKGROUND

Type 1 diabetes mellitus induced by immune-checkpoint inhibitors (ICI-T1DM) is a rare critical entity. However, the etiology of ICI-T1DM remains unclear.

METHODS

In order to elucidate risk factors for ICI-T1DM, we evaluated the clinical course and immunological status of patients with ICI-T1DM who had been diagnosed during 2016 to 2021.

RESULTS

Seven of 871 (0.8%, six men and one woman) patients developed ICI-T1DM. We revealed that the allele frequencies of human leukocyte antigen (HLA)-DPA1*02:02 and DPB1*05:01 were significantly higher in the patients with ICI-T1DM In comparison to the controls who received ICI (11/14 vs. 10/26, P=0.022; 11/14 vs. 7/26, P=0.0027, respectively). HLA-DRB1*04:05, which has been found to be a T1DM susceptibility allele in Asians, was also observed as a high-risk allele for ICI-T1DM. The significance of the HLA-DPB1*05:01 and DRB1*04:05 alleles was confirmed by an analysis of four additional patients. The absolute/relative neutrophil count, neutrophils-lymphocyte ratio, and neutrophil-eosinophil ratio increased, and the absolute lymphocyte count and absolute/relative eosinophil count decreased at the onset as compared with 6 weeks before. In two patients, alterations in cytokines and chemokines were found at the onset.

CONCLUSION

Novel high-risk HLA alleles and haplotypes were identified in ICI-T1DM, and peripheral blood factors may be utilized as biomarkers.

Eosinophil counts can be a predictive marker of immune checkpoint inhibitor-induced secondary adrenal insufficiency: a retrospective cohort study

Immune checkpoint inhibitors (ICIs) treatment can result in endocrine immune-related adverse events (irAEs), including pituitary dysfunction. Quick diagnosis of secondary adrenal insufficiency (AI) is challenging because no universal definition of ICI-induced secondary AI has been agreed. The aim of this study was to clarify the clinical features of ICI-induced secondary AI that can be used for screening in standard clinical practice. This retrospective study was performed using the medical records of patients who received ICIs at Hirosaki University Hospital between 1 September 2014 and 31 January 2021. Longitudinal clinical data of patients who developed AI were analyzed and compared with the data of thyroid irAEs. Regression analysis showed a significant correlation between ICI-induced secondary AI and absolute or relative eosinophil counts at pre-onset of AI, as well as differences or rate of increase in eosinophil counts at baseline and at pre-onset. Absolute eosinophil counts > 198.36/µL or relative eosinophil counts > 5.6% at pre-onset, and a difference of 65.25/µL or a rate of eosinophil count increase of 1.97 between the baseline and at pre-onset showed the best sensitivity and specificity. This is the first report to demonstrate that eosinophil counts can be a predictor of ICI-induced secondary AI.

Management of Immune-Related Adverse Events in Patients With Non-Small Cell Lung Cancer

With proven efficacy of the use of immunotherapy in almost all stages of NSCLC, immunotherapy toxicity has become a very important topic that requires immediate recognition and management. The diagnosis of toxicities associated with immunotherapy in lung cancer can be very challenging and often requires multidisciplinary effort. This mini review gives an overview of the diagnosis and management of immune-related adverse events that arise from using immunotherapy in NSCLC, as well as the potential biomarkers for its early identification and future directions.

Isolated ACTH deficiency induced by cancer immunotherapy: a systematic review

Immunotherapy with immune checkpoint inhibitor (ICI) monoclonal antibodies has shown to be an effective therapeutic alternative in several malignant tumors. However, adverse effects related to an activation of the immune system may accompany ICI therapy. Among the immune-related adverse events (irAEs) are autoimmune endocrine adverse effects, such as thyroiditis, and hypophysitis. Secondary adrenal insufficiency due to isolated ACTH deficiency (IAD) has also been recently reported to be associated with ICI antibodies. We carried out a systematic review of IAD cases induced by cancer immunotherapy published to date using PubMed's database. We selected 35 articles that reported 60 cancer patients diagnosed with IAD induced by ICI therapy. The prevalence was higher in men (ratio 1.6/1). Mean age at diagnosis was 63.2 ± 11.6 (range,30-87). Melanoma was the tumor most commonly reported (35%) followed by lung (28.3%) and kidney cancer (18.3%). The ICI monoclonal antibody most frequently associated was nivolumab in monotherapy (60%), followed by pembrolizumab (18.3%). Median (IQR) time to develop IAD after starting ICI therapy was 6 (4-8) months. The main symptoms at IAD diagnosis were fatigue (82.8%) and anorexia (67.2%). Hyponatremia (68%) and eosinophilia (31.8%) were the laboratory abnormalities most frequently associated with IAD. Pituitary magnetic resonance imaging (MRI) was normal in most patients (93%). Thyroiditis was the most prevalent (35%) endocrine irAE associated with IAD. In conclusion, ICI-induced IAD is a rare and potentially life-threatening condition that must be taken into account whenever treatment with immunotherapy in cancer patients is started due to their potential serious prognostic implications.

Immune checkpoint inhibitor combination therapies very frequently induce secondary adrenal insufficiency

Immune checkpoint inhibitors (ICIs) are potent therapeutic options for many types of advanced cancer. The expansion of ICIs use however has led to an increase in immune-related adverse events (irAEs). Secondary adrenal insufficiency (AI) can be life-threatening especially in patients with delayed diagnosis. We retrospectively investigated secondary AI in ICI-treated patients. A total of 373 cancer patients treated with ICIs were included and evaluated. An adrenocorticotropic hormone (ACTH) deficiency was described in 13 patients. Among 24 patients with a combination of nivolumab and ipilimumab therapy, 7 patients (29%) developed secondary AI in a median time of 8 weeks during the combination therapy and 2 of 15 patients (13%) developed isolated ACTH deficiency during maintenance nivolumab monotherapy following the combination therapy. More than half of the patients (4/7) with a combination therapy-induced multiple anterior hormone deficiencies was diagnosed as secondary AI based on regular ACTH and cortisol tests with slight subjective symptoms. Secondary AI can arise frequently and rapidly in cancer patients receiving a combination ICI therapy, and thus we speculate active surveillance of AI using regular ACTH and cortisol tests during the combination therapy might be useful for avoiding life-threatening conditions due to secondary AI.

Anti-pituitary antibodies and susceptible human leukocyte antigen alleles as predictive biomarkers for pituitary dysfunction induced by immune checkpoint inhibitors

BACKGROUND

Pituitary dysfunction is a life-threatening immune-related adverse event (irAE) induced by immune checkpoint inhibitors (ICIs). To date, it is not possible to identify patients who may develop pituitary irAEs prior to ICI treatment. The aim of this study was to characterize the predisposition for ICI-induced pituitary irAEs by analyzing anti-pituitary antibodies (APAs) and human leukocyte antigens (HLAs).

METHODS

In this case-control study, APAs and HLA alleles were analyzed in 62 patients (17 who developed ICI-induced isolated adrenocorticotropic hormone deficiency (ICI-IAD), 5 who developed ICI-induced hypophysitis (ICI-H) and 40 who did not develop pituitary irAEs) treated with ICIs between November 2, 2015, and March 31, 2020, at Nagoya University Hospital. The main outcome measures in this study were the association between the development of pituitary irAEs with APAs at baseline and after treatment and HLA alleles.

RESULTS

Eleven of 17 (64.7%) patients who developed ICI-IAD had APAs at baseline, whereas APAs were positive only in 1 of 40 (2.5%) control patients. Although APAs were negative at baseline in all patients who developed ICI-H, they had become positive before the onset of ICI-H in 3 of 4 patients several weeks after ipilimumab administration. At the onset of ICI-IAD and ICI-H, APAs were positive in 15 of 17 (88.2%) and 4 of 5 (80%) patients, respectively. The prevalence of HLA-Cw12, HLA-DR15, HLA-DQ7, and HLA-DPw9 was significantly higher in patients with ICI-IAD, whereas that of HLA-Cw12 and HLA-DR15 was significantly higher in patients with ICI-H than in controls.

CONCLUSIONS

This study showed distinct and overlapped patterns of APAs and HLA alleles between ICI-IAD and ICI-H. Our findings also showed that positive APAs at baseline and after treatment, together with susceptible HLA alleles, could become predictive biomarkers for ICI-IAD and ICI-H, respectively.

TRIAL REGISTRATION NUMBER

UMIN000019024.

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.

Distinct clinical features and prognosis between persistent and temporary thyroid dysfunctions by immune-checkpoint inhibitors

Immune-related adverse events in the thyroid glands (thyroid irAEs) during treatment with immune-checkpoint inhibitors (ICIs) are most frequent endocrine irAE. Thyroid irAE can be divided into that requiring continuous therapy for thyroid dysfunction (P-THY), and that requiring only temporal treatment (T-THY). However, predictive factors for those differential outcomes are unknown, and susceptibility of human leukocyte antigen (HLA) to thyroid irAE has never been investigated. This study aimed to elucidate clinical courses and prognosis of P-THY in comparison with T-THY in the aspect of thyroid immunity and HLA. Patients with P-THY (n = 15) that required L-T4 supplemental therapy for hypothyroidism for more than 3 months, and patients with T-THY who required no therapy or therapy within 1 month were enrolled in the study. Lower-value of TSH, higher-value of FT4, and lower value of TSH/FT4 were thought to be predictive markers to estimate P-THY. In addition, anti-thyroglobulin antibody (TgAb) levels were significantly higher in patients with P-THY than those in patients with T-THY. HLA-DPA1*01:03 and HLA-DPB1*02:01 allele, and their haplotype frequencies were significantly higher in patients with P-THY than those in controls. P-THY had better survival rate than T-THY. Pre-existing thyroid autoimmunity, the extent of thyroid dysfunction, and predisposing HLA were associated with the differential course of thyroid irAEs. It was suggested that thyroid function tests, TgAb, and HLA typing tests are useful for prediction of clinical course in thyroid irAEs.

Clinical features and thyroid dysfunction in adverse events involving the pituitary gland during PD-1 blockade therapy

OBJECTIVE

Programmed cell death-1 (PD-1) blockade therapy, an immune checkpoint treatment, can induce hypophysitis or hypopituitarism as an immune-related adverse event (pituitary irAE). We aimed to clarify the clinical features of pituitary irAEs during PD-1 blockade therapy.

DESIGN, PATIENTS AND MEASUREMENTS

This retrospective study investigated consecutive patients treated with nivolumab, an anti-PD-1 antibody, at Kyoto University Hospital between 1 September 2014 and 31 August 2019. We examined patients' baseline characteristics and analysed the clinical data of those who developed pituitary irAEs.

RESULTS

Of the 374 recruited patients, 7 (1.9%) developed pituitary irAEs, and each presented with isolated secondary adrenal insufficiency. In 4 patients, changes in ACTH were delayed relative to those in cortisol: when serum cortisol levels fell below the reference range, plasma ACTH levels were still normal. Pituitary irAEs were accompanied by elevated serum-free T3 (fT3) levels, which resolved with glucocorticoid replacement. Serum TSH levels were not suppressed despite elevated serum fT3 levels and 1 patient even presented with high fT3 level above the reference range (fT3, 7.1 pmol/L; free T4 (fT4), 13.9 pmol/L; and TSH, 5.1 mIU/L).

CONCLUSIONS

Isolated secondary adrenal insufficiency was a common pituitary irAE during PD-1 blockade therapy. This condition was accompanied by thyroid dysfunction, including elevation of fT3 without TSH suppression.

Anti-PD1 and Anti-PDL1-Induced Hypophysitis: A Cohort Study of 17 Patients with Longitudinal Follow-Up

Hypophysitis, secondary to programmed cell death 1 protein (PD1) and programmed cell death 1 ligand 1 (PDL1) inhibitors, were thought to be rare, with only a few studies describing more than one case with long-term follow-up. The aim of the present study was to describe the clinical, laboratory, and morphological characteristics of PD1/PDL1 inhibitor-induced hypophysitis, and its long-term course. This cohort study was conducted at the University Hospital of Lyon, France, with longitudinal follow-up of patients. Seventeen cases of PD1/PDL1 inhibitor-induced hypophysitis were included. The median time to onset of hypophysitis was 28 weeks (range: 10–46). At diagnosis, 16 patients complained of fatigue, 12 of nausea or loss of appetite, while headache was rare. We found no imaging pituitary abnormality. All patients presented adrenocorticotropic hormone (ACTH) deficiency; other pituitary deficiencies were less common (n = 7). At last follow-up (median: 13 months), ACTH deficiency persisted in all but one patient and one patient recovered from gonadotropic deficiency. PD1/PDL1 inhibitor-induced hypophysitis is a clinical entity different from those associated to cytotoxic T-lymphocyte antigen-4 (CTLA4) inhibitors, with less obvious clinical and radiological signs, and probably a different mechanism. The paucity of symptoms demonstrates the need for systematic hormonal follow-up for patients receiving PD1/PDL1 inhibitors.

Predictive and sensitive biomarkers for thyroid dysfunctions during treatment with immune-checkpoint inhibitors

Immune‐related adverse events (irAEs) are often seen during immune‐checkpoint inhibitor (ICI) treatment of various malignancies. Endocrine irAEs including thyroid dysfunctions are the most common irAEs, but their biomarkers remain unclear. In order to identify individuals who are susceptible to thyroid irAE for earlier diagnosis and appropriate follow‐up, the current study is aimed to investigate biomarkers of thyroid irAE. Herein, patients with advanced malignant diseases who received ICIs treatment were prospectively studied. Clinical and laboratory examination, thyroid function, and autoantibodies were evaluated at baseline, and every 4 wk after first treatment with ICIs. Cytokines/chemokines were measured at baseline and at 4 wk. In vivo effects of ICIs on experimental autoimmune thyroiditis were evaluated. Twenty‐six patients with malignant diseases who received ICIs treatment were enrolled in the study. Patients were divided into two groups: those who developed thyroid irAE, and those without irAEs. Comparing the two groups, early increase (≤4 wk) in serum thyroglobulin (Tg) levels and thyroid autoantibodies was seen in thyroid irAE (P < .05). Notably, higher levels of serum IL‐1β, IL‐2, and GM‐CSF at baseline, and early decrease of IL‐8, G‐CSF, and MCP‐1 were significantly associated in the development of thyroid irAE (P < .05). In vivo effects of anti‐PD‐1 antibody on deterioration of mice experimental thyroiditis were seen. In conclusion, early change in Tg, thyroid autoimmunity, and cytokine levels might indicate development of thyroid irAE. Pre‐existing thyroid autoimmunity might be involved with the development of thyroid irAE. Potential application of these factors as surrogate biomarkers for tumor therapy was indicated.