Dataset Information

Mechanistic insights into immune checkpoint inhibitor-related hypophysitis: a form of paraneoplastic syndrome.

ABSTRACT:

Background

Immune checkpoint inhibitors (ICIs) as a cancer immunotherapy have emerged as a treatment for multiple advanced cancer types. Because of enhanced immune responses, immune-related adverse events (irAEs), including endocrinopathies such as hypophysitis, have been associated with the use of ICIs. Most underlying mechanisms of ICI-related hypophysitis remain unclear, especially for programmed cell death-1 (PD-1)/PD-1 ligand 1 (PD-L1) inhibitors. We hypothesized that ICI-related hypophysitis is associated with paraneoplastic syndrome caused by ectopic expression of pituitary-specific antigens.

Methods

Twenty consecutive patients with ICI-related hypophysitis between 2017 and 2019 at Kobe University Hospital were retrospectively analyzed. Circulating anti-pituitary antibodies were detected using immunofluorescence staining and immunoblotting. Ectopic expression of pituitary autoantigens in tumor specimens was also examined.

Results

Eighteen patients were treated with PD-1/PD-L1 inhibitors, and two were treated with a combination of cytotoxic T-lymphocyte antigen-4 (CTLA-4) and PD-1 inhibitors. All patients showed adrenocorticotropic hormone (ACTH) deficiency and additionally, three showed thyroid-stimulating hormone (TSH) deficiency, and one showed gonadotropin-releasing hormone (GnRH) deficiency. Among these patients, three exhibited anti-pituitary antibodies, two with anti-corticotroph antibody and one with anti-somatotroph antibody. Interestingly, the anti-corticotroph antibody recognized proopiomelanocortin (POMC) and those two patients exhibited ectopic ACTH expression in the tumor, while the patients without anti-corticotroph antibody did not.

Conclusions

We demonstrated 10% of PD-1/PD-L1 inhibitors-related hypophysitis were associated with the autoimmunity against corticotrophs and maybe caused as a form of paraneoplastic syndrome, in which ectopic expression of ACTH in the tumor was observed. It is also suggested that the pathophysiology is heterogenous in ICI-related hypophysitis.

SUBMITTER: Kanie K

PROVIDER: S-EPMC8571153 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:BACKGROUND:The objective of this study was to characterize the clinicopathologic features of sicca syndrome associated with immune checkpoint inhibitor (ICI) therapy. SUBJECTS, MATERIALS, AND METHODS:Consecutive patients with new or worsening xerostomia in the setting of ICI treatment for benign or malignant neoplastic disease were evaluated, including labial salivary gland biopsy (LSGB). RESULTS:Twenty patients (14 male; median age 57 years) had metastatic melanoma (n = 10), metastatic carcinoma (n = 6), or recurrent respiratory papillomatosis (n = 4) and were being treated with avelumab (n = 8), nivolumab (n = 5), pembrolizumab (n = 4), nivolumab/ipilimumab (n = 2), and M7824, a biologic targeting programmed cell death ligand 1 (PD-L1) and transforming growth factor ß (n = 1). Four had pre-existing autoimmune disease. Nineteen had very low whole unstimulated saliva flow; six had new dry eye symptoms. The median interval between ICI initiation and dry mouth onset was 70 days. Rheumatoid factor and anti-Sjögren's Syndrome-related Antigen A (Anti-SSA) were both positive in two subjects. LSGB showed mild-to-severe sialadenitis with diffuse lymphocytic infiltration and architectural distortion. There were lymphocytic aggregates in eight patients, composed mainly of CD3+ T cells with a slight predominance of CD4+ over CD8+ T cells. ICI targets (e.g., programmed cell death 1 and PD-L1) were variably positive. In direct response to the advent of the sicca immune-related adverse event, the ICI was held in 12 patients and corticosteroids were initiated in 10. Subjective improvement in symptoms was achieved in the majority; however, salivary secretion remained very low. CONCLUSION:ICI therapy is associated with an autoimmune-induced sicca syndrome distinct from Sjögren's syndrome, often abrupt in onset, usually developing within the first 3 months of treatment, and associated with sialadenitis and glandular injury. Improvement can be achieved with a graded approach depending on severity, including withholding the ICI and initiating corticosteroids. However, profound salivary flow deficits may be long term. IMPLICATIONS FOR PRACTICE:Sicca syndrome has been reported as an immune-related adverse event (irAE) of immune checkpoint inhibitor therapy (ICI) for neoplastic diseases. Severe dry mouth (interfering with eating or sleeping) developed abruptly, typically within 90 days, after initiation of ICI therapy. Salivary gland biopsies demonstrated mild-to-severe sialadenitis distinct from Sjögren's syndrome, with diffuse T-cell lymphocytic infiltration and acinar injury. Recognition of the cardinal features of ICI-induced sicca will spur appropriate clinical evaluation and management, including withholding of the ICI and corticosteroid, initiation. This characterization should help oncologists, rheumatologists, and oral medicine specialists better identify patients that develop ICI-induced sicca to initiate appropriate clinical evaluation and therapy to reduce the likelihood of permanent salivary gland dysfunction.