Permanent diabetes insipidus in a patient with mesothelioma treated with immunotherapy

Endocrine side effects of immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs) have increasingly been the mainstay of treatment for numerous malignancies. However, due to their association with autoimmunity, ICIs have resulted in a variety of side effects that involve multiple organs including the endocrine system. In this review article, we describe our current understanding of the autoimmune endocrinopathies as a result of the use of ICIs. We will review the epidemiology, pathophysiology, clinical presentation, diagnosis, and management of the most commonly encountered endocrinopathies, including thyroiditis, hypophysitis, Type 1 diabetes, adrenalitis, and central diabetes insipidus.

Diabetes insipidus: A rare endocrine complication of immune check point inhibitors: A case report and literature review

Immune checkpoint inhibitors (ICIs), including anti-programmed cell death protein 1 (PD-1), anti-programmed cell death protein ligand 1 (PD-L1) and anti-cytotoxic T-lymphocyte antigen 4 (CTLA-4) monoclonal antibodies, are novel therapeutic agents widely used in numerous malignancies. They are known to cause multiple immune-related endocrine adverse events (irAEs); however, anterior pituitary hypophysitis with secondary hypopituitarism is the most frequently reported irAE, especially in patients receiving anti-CTLA-4 treatment. By contrast, posterior pituitary involvement, such as central diabetes insipidus (CDI), is relatively rare and only few case reports have been published. The present report describes the case of a 53-year-old woman with metastatic melanoma treated with nivolumab an anti-PD-L1 monoclonal antibody. At 6 months after the initiation of nivolumab treatment, the patient was diagnosed with deficiency of the corticotrope and thyreotrope axes and in the following 2 months the patient was diagnosed with progressive development of polyuria-polydipsia syndrome. The diagnosis of partial CDI was retained based on plasma and urinary osmolalities, the water deprivation test and baseline copeptin levels as well as on the absence of the bright spot in the posterior pituitary in magnetic resonance imaging. Systematic research of the literature revealed a total of 13 cases reports (including 14 patients) presenting with CDI treated with monotherapy with CTLA-4 (n=5) or PD-1/PD-L1 Abs (n=6) or combined treatments (n=3). The improved understanding of the mechanisms of ICI action along with their extensive use should contribute to the early recognition of irAE symptoms. We hypothesized that clinicians should be aware of this clinical entity and its symptoms and treat it appropriately.

Immune Checkpoint Inhibitor-Induced Central Diabetes Insipidus: Looking for the Needle in the Haystack or a Very Rare Side-Effect to Promptly Diagnose?

Immune checkpoint inhibitors have improved the survival in patients affected by an increasing number of malignancies, but they may also trigger various autoimmune side-effects, including endocrinopathies. Very rarely, immune checkpoint inhibitors have been reported to cause central diabetes insipidus. However, with their expanding use, the likelihood that oncologists will face this endocrine adverse event is expected to increase. By reviewing the limited literature on central diabetes insipidus induced by immune checkpoint inhibitors, some inconsistencies emerge in the diagnosis and the management of patients presenting with this toxicity, together with difficulties related to classifying its severity. Until now, specific guidelines on the management of central diabetes insipidus induced by immune checkpoint inhibitors are lacking. In clinical practice, endocrinological consultation may relieve medical oncologists from difficulties in treating this side-effect; oncologists, however, remain responsible for its early diagnose and the management of the causative drugs. To this aim, some practical suggestions are advised for the multidisciplinary management of cancer patients presenting with central diabetes insipidus induced by immune checkpoint inhibitors.

Immune Checkpoint Inhibitors as a Threat to the Hypothalamus-Pituitary Axis: A Completed Puzzle

Immune checkpoint inhibitors (ICI) prolong the survival in an increasing number of patients affected by several malignancies, but at the cost of new toxicities related to their mechanisms of action, autoimmunity. Endocrine toxicity frequently occurs in patients on ICI, but endocrine dysfunctions differ based on the ICI-subclass, as follows: agents targeting the CTLA4-receptor often induce hypophysitis and rarely thyroid dysfunction, which is the opposite for agents targeting the PD-1/PD-L1 axis. Recently, few cases of central diabetes insipidus have been reported as an adverse event induced by both ICI-subclasses, either in the context of anterior hypophysitis or as selective damage to the posterior pituitary or in the context of hypothalamitis. These new occurrences demonstrate, for the first time, that ICI-induced autoimmunity may involve any tract of the hypothalamic-pituitary axis. However, the related pathogenic mechanisms remain to be fully elucidated. Similarly, the data explaining the endocrine system susceptibility to primary and ICI-induced autoimmunity are still scarce. Since ICI clinical indications are expected to expand in the near future, ICI-induced autoimmunity to the hypothalamic-pituitary axis presents as a unique in vivo model that could help to clarify the pathogenic mechanisms underlying both the dysfunction induced by ICI to the hypothalamus-pituitary axis and primary autoimmune diseases affecting the same axis.

Grading Central Diabetes Insipidus Induced by Immune Checkpoint Inhibitors: A Challenging Task

Central diabetes insipidus (CDI) is a rare endocrine disease deriving from an insufficient production or secretion of anti-diuretic hormone. Recently, CDI has been reported as a rare side effect triggered by immune checkpoint inhibitors (ICI) in cancer patients. Despite its current rarity, CDI triggered by ICI is expected to affect an increasing number of patients because of the expanding use of these effective drugs in a growing number of solid and hematologic malignancies. An appropriate assessment of the severity of adverse events induced by anticancer agents is crucial in their management, including dosing adjustment and temporary withdrawal or discontinuation treatment. However, assessment of the severity of CDI induced by ICI may be challenging, as its main signs and symptoms (polyuria, dehydration, weight loss, and hypernatremia) can be incompletely graded. Indeed, the current grading system of toxicity induced by anticancer treatments does not include polyuria. Additionally, dehydration in patients affected by diabetes insipidus, including ICI-induced CDI, is different in certain aspects from that due to other conditions seen in cancer patients, such as vomiting and diarrhea. This prompted us to reflect on the need to grade polyuria, and how to grade it, and to consider a specific grading system for dehydration associated with CDI induced by ICI. Here we propose a new grading system for polyuria and dehydration, as critical symptoms of the CDI syndrome occurring in patients on ICI treatment, to obtain better management of both the adverse event and the triggering drugs.

Case Report: Ipilimumab-Induced Panhypophysitis: An Infrequent Occurrence and Literature Review

Background

Immune checkpoint inhibitors (ICIs), by unleashing the anticancer response of the immune system, can improve survival of patients affected by several malignancies, but may trigger a broad spectrum of adverse events, including autoimmune hypophysitis. ICI-related hypophysitis mainly manifests with anterior hypopituitarism, while the simultaneous involvement of both anterior and posterior pituitary (i.e., panhypophysitis) has rarely been described.

Case Presentation

In June 2015, a 64-year-old man affected by liver metastases of a uveal melanoma was referred to us due to polyuria and polydipsia. Two months prior, he had started ipilimumab therapy (3 mg/kg iv every 21 days). The treatment was well-tolerated (only mild asthenia and diarrhea were reported). A few days before the fourth cycle, the patient complained of intense headaches, profound fatigue, nocturia, polyuria (up to 10 L urine/daily), and polydipsia. Laboratory tests were consistent with adrenal insufficiency, hypothyroidism, and transient central diabetes insipidus. The pituitary MRI showed an enlarged gland with microinfarcts, while the hypophyseal stalk was normal, and the neurohypophyseal 'bright signal' in T1 sequences was not detected. The treatment included dexamethasone (then cortisone acetate at replacement dose), desmopressin, and levothyroxine. Within the next five days, the symptoms resolved, and blood pressure, electrolytes, glucose, and urinalysis were stable within the normal ranges; desmopressin was discontinued while cortisone acetate and levothyroxine were maintained. The fourth ipilimumab dose was entirely administered in the absence of further side effects.

Conclusion

As ICIs are increasingly used as anticancer agents, the damage to anterior and/or posterior pituitary can be progressively encountered by oncologists and endocrinologists in their clinical practice. Patients on ICIs and their caregivers should be informed about that risk and be empowered to alert the referring specialists early, at the onset of panhypopituitarism symptoms, including polyuria/polydipsia.