Frequency and clinical characteristics of hypophysitis and hypopituitarism in patients undergoing immunotherapy - A systematic review

The Utility of Magnetic Resonance Imaging for Hypophysitis Secondary to Immune Checkpoint Inhibitor Use

OBJECTIVE

Immune checkpoint inhibitor (ICI) therapy is an efficacious cancer treatment, often resulting in autoimmune off-target effects. Magnetic resonance imaging (MRI) has been a recommended investigation for ICI-related hypophysitis. We sought to identify the frequency of identifiable MRI changes.

DESIGN

A retrospective case-control audit was performed of individuals who received one or more ICI between January 2018 and December 2023 at a single tertiary referral centre in Melbourne, Australia.

PATIENTS

Individuals requiring hormone supplementation were screened for hypophysitis. A randomly selected control group receiving ICI demonstrated normal pituitary function at the time of MRI.

MEASUREMENTS AND RESULTS

Fifty-four (6.9%) of 778 individuals who received ICI therapy were diagnosed with ICI-related hypophysitis. 43 had an MRI examining the pituitary gland within 2 months. Four (9.3%) had initial reporting consistent with hypophysitis. Upon re-examination by an MRI-Fellowship trained radiologist, a further 6 (total 10, 23%) had acute hypophysitis changes. Among the control group, 45 of 46 individuals had an MRI within 2 months of normal pituitary biochemistry. All initial MRI reports were normal, but upon review 1 (2.2%) had acute hypophysitis abnormalities, with a significant difference between groups (10/43 vs 1/45, p = 0.003). Within the control group, a further 10 (22%) individuals had an atrophic pituitary and/or empty sella. No other significant pituitary pathology, including pituitary metastasis, was identified.

CONCLUSIONS

Although changes were observed in a minority of patients with hypophysitis, MRI provides minimal additional clinically meaningful information, so it could be reserved for atypical cases or those with persisting symptoms despite adequate supplementation.

Central Hypothyroidism: Advances in Etiology, Diagnostic Challenges, Therapeutic Targets, and Associated Risks

OBJECTIVE

Central hypothyroidism is a rare disorder resulting from impaired thyroid hormone production due to deficiencies in TSH secretion from the pituitary or TRH secretion from the hypothalamus. This review aims to summarize recent advances in the etiology, diagnosis, and treatment of central hypothyroidism, with an emphasis on diagnostic and therapeutic challenges.

METHODS

A comprehensive review of the literature was conducted, focusing on genetic and acquired causes, particularly those related to hypothalamic-pituitary tumors and the effects of surgical and radiotherapeutic interventions. Diagnostic approaches and treatment strategies, including levothyroxine therapy and monitoring, are analyzed.

RESULTS

Early diagnosis requires simultaneous measurement of free T4 and TSH to prevent neurological sequelae, especially in congenital cases. Central hypothyroidism is associated with risks such as growth and developmental impairment, as well as metabolic and cardiovascular disturbances. Levothyroxine therapy is crucial for correcting hormonal deficits and improving patient outcomes; however, careful dosing is necessary to avoid potential complications, particularly in vulnerable populations.

CONCLUSIONS

Personalized treatment and continuous monitoring are essential to optimize clinical outcomes and enhance the quality of life in affected individuals. A thorough understanding of central hypothyroidism's etiology and management is necessary to improve early detection and therapeutic strategies.

Frequency and Consequences of Immune Checkpoint Inhibitor-Associated Inflammatory Changes in Different Organs: An Autopsy Study Over 13 -Years

Although immune checkpoint inhibitors (ICIs) have revolutionized modern oncology, they are also associated with immune-related adverse events (irAEs). Previous histopathologic descriptions of organ-related inflammatory changes do not consider systemic effects of ICIs, because of the absence of comprehensive autopsy studies. We performed a retrospective study on 42 whole-body autopsies of patients treated with ICIs from January 2011 to March 2024 to determine the frequency, organ distribution, and morphology of ICI-associated inflammatory changes as well as their clinical relevance. Twenty-three of 42 (54.8%) patients presented irAEs with inflammatory changes in at least one organ. Most frequent irAEs were ICI-related hypophysitis (N = 12; 28.6%), myocarditis (N = 8; 19.0%), pneumonitis (N = 5; 11.9%), hepatitis (N = 6; 14.3%), and adrenalitis (N = 5; 11.9%). ICI-related inflammation was mainly characterized by lymphohistiocytic and macrophage-rich tissue infiltrates, whereas a granulomatous "sarcoid-like" reaction was observed in 1 patient. Cause of death was attributable to ICI therapy in 7 (16.7%) patients, with ICI-associated myocarditis as the most common cause of death (N = 5; 71.4%). Clinically, irAEs were unsuspected in 5 of 7 ICI-related deaths (71.4%). Among irAEs, myocarditis has been clinically undiagnosed in 5 out of 8 cases (62.5%). Encephalitis was identified only at autopsy in all cases (N = 2). Hypophysitis was clinically unsuspected in 8 of 12 (66.7%) cases. Patients who died from irAEs developed more frequently a complete tumor regression than patients who died from other causes (P = .018). Of note, ICI-related myocarditis and pneumonitis were both associated with a systemic occurrence irAEs. Our study demonstrates that some irAEs, especially myocarditis, hypophysitis, and encephalitis, are clinically underdiagnosed. Autopsy remains a valuable tool to monitor diagnostic accuracy and therapeutic side effects in patients who died under ICI therapy.

Pituitary enlargement and hypopituitarism in patient with lung cancer treated with immune checkpoint inhibitors: Metastasis or hypophysitis? Role of imaging

Pituitary gland metastasis is an unusual event, and pituitary metastasis from lung adenocarcinoma is extremely rare and associated with poor prognosis. To date, approximately 16 cases have been reported. Symptoms of these lesions can mimic hypophysitis, that is a possible immune-related adverse event of ICIs (Immune Checkpoint Inhibitors). Pituitary metastases and hypophisitis are life-threatening diseases and making differential diagnosis is important, because therapy of these conditions is quite different. Differentiating a condition from the other one is difficult, because many imaging features are not specific. In this presented case, cross-sectional imaging, in particular Magnetic Resonance Imaging (MRI), has revealed itself helpful to suggest the diagnosis of pituitary metastasis rather than hypophysitis.

Immune checkpoint inhibitor induced hypophysitis: a specific disease of corticotrophs?

Introduction

The aim of this study was to define functional and anatomical pituitary disease at the time of presentation following immune checkpoint inhibitor (ICI) therapy and to describe any changes in pituitary function over time.

Methods

We conducted a retrospective observational audit of patients on ICI therapy at our centre between January 2013 and September 2023. We reviewed all patients on ICI therapy under the care of the oncology department at University Hospital Plymouth, a 1000-bedded hospital serving a population of 500,000 people. From this group, we identified all individuals referred to the endocrinology department with a suspected diagnosis of adrenal insufficiency. Patients were established on adrenal steroid replacement and subsequently underwent formal pituitary testing. People were included if they had pituitary disease, as evidenced by low ACTH, other pituitary dysfunction and/or abnormalities on pituitary imaging.

Results

Nine hundred and fifty-four patients received ICI therapy during the study period, and 37 (a prevalence of 3.9%) developed hypothalamic-pituitary-adrenal axis dysfunction. Their mean age was 65 years, and 70% were male. About 86.5% of the total patients affected were treated for metastatic malignancies. Ten of the 37 patients died during follow-up as a direct consequence or complication of their primary cancer diagnosis. The median interval for the onset of symptoms was 4 months. Following repeated testing, there was no recovery in cortisol or ACTH levels for any individual. Other permanent anterior pituitary hormone defects were unusual. Hypophysitis associated with immunotherapy appears to specifically target the corticotrophs, with no evidence of recovery over time. There was a specific abnormality seen in MRI scans of 7 of 27 patients who had scans, which appeared to be a particular feature of immune-mediated hypophysitis. These were confined to the anterior aspect of the pituitary gland, appearing as striations, and were not visible on any of the scans performed more than 3 months after the likely onset of the disease.

Conclusion

These data show that immune-related hypophysitis is a common complication of immune checkpoint inhibitor therapy. This may result in an imaging abnormality within the areas of the pituitary that are richest in corticotrophs. The endocrine consequence of this is a permanent defect in ACTH and, therefore, cortisol production.

Endocrine-metabolic assessment checklist for cancer patients treated with immunotherapy: A proposal by the Italian Association of Medical Oncology (AIOM), Italian Association of Medical Diabetologists (AMD), Italian Society of Diabetology (SID), Italian Society of Endocrinology (SIE) and Italian Society of Pharmacology (SIF) multidisciplinary group

Immunotherapy with immune checkpoint inhibitors (ICI) is increasingly employed in oncology. National and international endocrine and oncologic scientific societies have provided guidelines for the management of endocrine immune-related adverse events. However, guidelines recommendations differ according to the specific filed, particularly pertaining to recommendations for the timing of endocrine testing. In this position paper, a panel of experts of the Italian Association of Medical Oncology (AIOM), Italian Association of Medical Diabetologists (AMD), Italian Society of Diabetology (SID), Italian Society of Endocrinology (SIE), and Italian Society of Pharmacology (SIF) offers a critical multidisciplinary consensus for a clear, simple, useful, and easily applicable endocrine-metabolic assessment checklist for cancer patients on immunotherapy.

Unusual and lesser-known rare causes of adult growth hormone deficiency

Growth hormone is among the most common hormones to be deficient in pituitary insult. It can occur either in isolation or combined with other hormone deficiencies. Growth hormone deficiency in adults (AGHD) can be due to causes acquired in adulthood or have a childhood-onset etiology, but the former is about three times more common. Usual causes of AGHD include mass effects due to a pituitary tumour, and/or its treatment (surgery, medical therapy, or radiotherapy), or radiotherapy to the head and neck region for non-pituitary lesions. The unusual or lesser-known causes of AGHD, are usually due to non-tumoral etiology and range from vascular and infective to inflammatory and miscellaneous causes. These not only expand the spectrum of AGHD but may also contribute to increased morbidity, adverse metabolic consequences, and mortality due to the primary condition, if unrecognised. The review features these lesser-known and rare causes of AGHD and highlights their clinical and diagnostic implications.

Unveiling the Etiopathogenic Spectrum of Hypophysitis: A Narrative Review

Hypophysitis, a rare inflammatory disorder of the pituitary gland, has seen an uptick in reported cases in recent years. Our objective is to summarize the most recent research on the etiopathogenesis, molecular mechanisms, and genetics of both primary and secondary hypophysitis. Primary autoimmune hypophysitis (PAH): During the acute phase of the disease, the pituitary gland in enlarged due to the infiltration of T and B lymphocytes. The chronic phase is characterized by progressive and irreversible pituitary atrophy. APA may play a role in the management, diagnosis, and prognosis of PAH. Specific autoantibodies such as anti-GH, anti-PIT-1, and anti-T-PIT have been found in patients with hypophysitis and hypopituitarism. A recent study suggested that a mechanism of escaping clonal deletion and mounting an immune response against self antigens can explain the unusual nature of the immune response observed in PAH patients. A cytokine array shows the presence of gamma-interferon and interleukin-17. Patients carrying mutations in the PIT1 or PROP1 genes may present PAH. Individuals carrying the HLA DQ8 haplotype are four times more likely to develop PAH. Immune checkpoint inhibitors induce hypophysitis (IIHs): IIHs is an increasingly frequent toxicity of in patients on treatment with inhibitors targeting cytotoxic T-lymphocyte antigen 4 (CTLA-4) and programmed cell death-1 (PD-1). ICIs inhibit the CTLA-4 pathway, leading to overactivation of T lymphocytes. The binding of PD-1/PD-L1 suppresses the activity of T cells, promotes the conversion of T-helpers into T-regulatory cells, and activates pro-survival signaling pathways in cancer cells. Cytokines play a crucial role in IIHs. B-cell infiltration has been observed in IIHs, suggesting that antibody-mediated pituitary injury may contribute. Genetic polymorphisms of CTLA-4 and PD-1 genes can increase the risk of IIHs. HLA alleles may also be involved in the onset of IIHs; this HLA association presents a possible alternative mechanistic hypothesis. IIHs may also be linked to a paraneoplastic syndrome triggered by ectopic expression of pituitary specific antigens. SARS-CoV-2-related hypophysitis: Recently, the literature has reported occurrences of hypophysitis associated with the SARS-CoV-2 virus; long COVID-19 may also present as infundibulo-neuro-hypophysitis. The virus enters the central nervous system because of its distinct interaction with angiotensin-converting enzyme receptors via spike proteins binding the capillary endothelium, and it directly damages the pituitary cells. The effect of SARS-CoV-2 can occur indirectly through inflammation and the release of cytokines. The exact mechanism remains ambiguous. The available data on endocrine complications associated with the SARS-CoV-2 vaccine are scant. Nonetheless, isolated cases of hypophysitis have been documented. Treatment of hypophysitis: Glucocorticoids are the cornerstone in managing primary hypophysitis, given their targeted action on inflammation. A better understanding of the etiopathogenesis and molecular mechanism of hypophysitis can lead to more effective and personalized treatment strategies.

ACTH Stimulation Test for the Diagnosis of Secondary Adrenal Insufficiency: Light and Shadow

Secondary Adrenal Insufficiency (SAI) is a condition characterized by inappropriately low ACTH secretion due to a disease or injury to the hypothalamus or the pituitary. The evaluation when suspected is often challenging for the non-specific symptoms, the rarity of the disease, and the pitfalls associated with laboratory tests. A prompt and correct diagnosis of SAI is essential because although an adequate hormonal replacement therapy could be lifesaving, inappropriate life-long therapy with steroids can be harmful. The gold standard test for assessing the hypothalamus-pituitary-adrenal axis (HPA) is the insulin tolerance test (ITT), but due to safety issues is not widely used. Conversely, the ACTH stimulation test is a safer and well-tolerated tool for SAI diagnosis. However, data about its diagnostic accuracy show great variability due to both technical and interpretative aspects, such as dose, route of administration, the timing of the test, and assay used for cortisol measurements. Consequently, the clinical background of the patient and the pretest probability of HPA axis impairment become of paramount importance. We aimed to summarize the recent literature evidence in the conduction and interpretation of the ACTH stimulation test for the diagnosis of SAI to provide updated insights on its correct use in clinical practice.