Paraneoplastic isolated adrenocorticotropic hormone deficiency revealed after immune checkpoint inhibitors therapy: new insights into anti-corticotroph antibody.

Introduction: A recently discovered facet of paraneoplastic adrenocorticotropic hormone (ACTH) deficiency exists in two forms: a paraneoplastic spontaneous isolated ACTH deficiency (IAD) and an immune checkpoint inhibitor (ICI)-related hypophysitis. Autoantibodies against corticotrophs, such as circulating anti-proopiomelanocortin (POMC) antibodies are considered disease markers. However, the number of identified cases was limited, implying that the characteristics of these autoantibodies are not fully understood. Methods: We investigate circulating autoimmune autoantibodies in detail through a novel case of IAD that developed as a paraneoplastic autoimmune ACTH deficiency. Results: The patient developed IAD after 25 weeks of ICI therapy for metastasis of large-cell neuroendocrine carcinoma at 69 years of age. Ectopic ACTH expression and infiltration of CD3+, CD4+, CD8+, and CD20+ lymphocytes were observed in the tumor tissues and circulating anti-POMC antibodies were detected specifically in the patient's serum. Moreover, detailed analyses of immunofluorescence staining using patient serum revealed that the recognition site of the autoantibody was ACTH25-39, which had not been identified in previous cases of paraneoplastic autoimmune ACTH deficiency. Conclusion: This case involved a combination of paraneoplastic spontaneously acquired IAD and ICI-related hypophysitis occupying the middle ground. Moreover, our study reveals new aspects of anti-POMC antibodies in patients with paraneoplastic ACTH deficiency. This report expands our understanding of the immunological landscape and provides new insights for the identification of antibodies associated with paraneoplastic autoimmune ACTH deficiency.

IgG4-related hypophysitis in patients with autoimmune pancreatitis.

PURPOSE: IgG4-related disease involves various organs including the pituitary and pancreas. The prevalence of IgG4-related hypophysitis is relatively rare compared with IgG4-related pancreatitis (autoimmune pancreatitis). Although several cases demonstrating both autoimmune pancreatitis and hypophysitis have been reported, the prevalence of IgG4-related hypophysitis in patients with autoimmune pancreatitis remains unknown. This study aimed at screening for IgG4-related hypophysitis to accurately determine its prevalence in patients with autoimmune pancreatitis. METHODS: In this cohort study, we screened IgG4-related hypophysitis via pituitary magnetic resonance imaging (MRI) and endocrinological examination in 27 patients who were undergoing follow-up for autoimmune pancreatitis at Kobe University Hospital between 2014 and 2018. RESULTS: Among 27 patients with autoimmune pancreatitis, 5 patients exhibited morphological abnormalities in the pituitary (18.5%). Among them, one patient (3.7%) met the criteria for hypophysitis with an enlarged pituitary and stalk concomitant with hypopituitarism. After glucocorticoid treatment, the enlarged pituitary shrank and became empty sella during the clinical course. Four patients (14.8%) revealed empty sella without obvious pituitary dysfunction. Four of 5 patients with morphological pituitary abnormalities showed multiple organ involvement in addition to pancreatic and pituitary involvement. Accordingly, multiple organ involvement was more prevalent in patients with morphological pituitary abnormalities (80%) compared to those without (48%). CONCLUSIONS: Although a large-scale study is necessary to validate these results, these data suggest that the prevalence of hypophysitis in patients with autoimmune pancreatitis may be underestimated. Based on our findings, we recommend screening for hypophysitis, especially in patients with multiple organ involvement.

Primary hypophysitis and other autoimmune disorders of the sellar and suprasellar regions.

The pituitary gland and the hypothalamus can be affected by autoimmune-mediated structural and functional disruption. These autoimmune-mediated diseases occur more commonly in females and are often found during pregnancy or in the post-partum period. Autoimmune diseases can either affect parts of the pituitary or hypothalamus, or can involve both sellar and suprasellar structures. Most of these cases comprise primary hypophysitis (PRH). Over the years, there has been a tremendous increase in the number of reported PRH cases and related disorders, including hypophysitis induced by immune checkpoint inhibitors. With this increasing data, more light is being shed on the spectrum of clinical presentations, biochemical and imaging abnormalities of these disorders. Regardless, these disorders are still relatively rare. The clinical presentation can vary vastly, based on the type of pituitary cell or the area of the suprasellar region affected. The severity can range from clinically silent disease to progressive and rapid deterioration and death, likely due to unrecognized central adrenal insufficiency. Although biopsy remains a gold standard for diagnosing these disorders, the current standard of practice is biochemical assessment for hormonal deficiencies and imaging studies. In several instances, these disorders spontaneously resolve, but medical or surgical intervention might be necessary to treat symptomatic disease. Due to the subtlety and a vast spectrum of clinical manifestations which could often be asymptomatic, and the rarity of the occurrence of these diseases in clinical practice, the diagnosis can be easily missed which could potentially lead to substantial morbidity or mortality. Therefore, it is crucial to have a strong clinical suspicion and pursue timely biochemical and imaging studies to initiate prompt treatment. In this article, we review the various autoimmune conditions that affect the sellar and suprasellar structures, their diagnostic approach and management of these disorders.

Clinical, Endocrine and Imaging Characteristics of Patients with Primary Hypophysitis.

Primary hypophysitis (PH) is a rare disease with a poorly-defined natural history. Our aim was to characterise patients with PH at presentation and during prolonged follow-up. Observational retrospective study of 22 patients was conducted from 3 centres. In 14 patients, PH was confirmed histologically and in the remaining 8 clinically, after excluding secondary causes of hypophysitis. All patients had hormonal and imaging investigations before any treatment. Median follow up was 48 months (25-75%: 3-60). There was a female predominance with a female/male ratio: 3.4:1. Eight out of 22 patients had another autoimmune disease. Headaches and gonadal dysfunction were the most common symptoms. Five patients presented with panhypopituitarism; 17 patients had anterior pituitary deficiency, and 7 had diabetes insipidus. At presentation, 9 patients were treated surgically, 5 received replacement hormonal treatment, and 8 high-dose glucocorticoids from whom 5 in association with other immunosuppressive agents. Six patients showed complete recovery of pituitary hormonal deficiencies while 6 showed a partial recovery during a 5-year follow-up period. No difference was found between patients treated with surgery and those treated medically. The overall relapse rate was 18%. PH can be manifested with a broad spectrum of clinical and hormonal disturbances. Long-term follow-up is required to define the natural history of the disease and response to treatment, since pituitary hormonal recovery or relapse may appear many years after initial diagnosis. We suggest that surgery and immunosuppressive therapy be reserved for exceptional cases.

[Immune checkpoint inhibitors and endocrinological side effects].

Immune checkpoint inhibitors including anti-cytotoxic T-lymphocyte-associated antigen-4 and anti-programmed cell death-1 have revolutionized cancer therapy but have also induced serious immune-related adverse events including hormonal dysfunction. The objective of this review is to characterize the incidence, clinical presentation, management and prognosis of the endocrine-related adverse events including hypophysitis, thyroid dysfunction and diabetes mellitus. Combination therapy is associated with an increased risk of adverse events. We recommend close monitoring of the hormone levels and glycaemic status during and a year after treatment.

Immunotherapy and hypophysitis: clinical presentation, treatment, and biologic insights.

INTRODUCTION: Advances in immunotherapy have transformed the management of metastatic melanoma and generated encouraging results in the treatment of other malignancies. Autoimmune side effects from these agents, termed immune-related adverse events (IRAEs), are diverse and can include multiple endocrinopathies. Ipilimumab-induced hypophysitis (IH) is a recently recognized endocrine IRAE. METHODS: This review summarizes published data and experience from our center on the incidence, presentation and management, and proposed mechanisms for immunotherapy-related hypophysitis, with a focus on patients treated with ipilimumab (Ipi). CONCLUSION: Hypophysitis occurs in a significant minority of patients treated with Ipi, in contrast to the relative rarity of idiopathic autoimmune hypophysitis or hypophysitis after treatment with other immunotherapies. Recently published cohorts have described the clinical presentation and management of IH and longitudinal outcomes in these patients. Additional studies with Ipi and other emerging agents have helped identify potential risk factors for the development of immunotherapy-related hypophysitis and possible underlying mechanisms for IH. Clarification of the mechanism(s) for IH may enhance our understanding of idiopathic autoimmune hypophysitis and could have potential therapeutic applications.