Case Report: A Variety of Immune-Related Adverse Events Triggered by Immune Checkpoint Inhibitors in a Subject With Malignant Melanoma: Destructive Thyroiditis, Aseptic Meningitis and Isolated ACTH Deficiency

Recently, immune checkpoint inhibitors have been drawing much attention as cancer immunotherapy, but it has been shown that various immune-related adverse events (irAEs) are induced by immune checkpoint inhibitors in various organs, which has become one of the serious issues at present. A 58-year-old Japanese male with malignant melanoma was treated with nivolumab and/or ipilimumab. During the period of treatment, he suffered from various irAEs. Firstly, about 1 month after starting nivolumab monotherapy, destructive thyroiditis was induced, and so we started replacement therapy with levothyroxine. Secondly, about 1 month after starting nivolumab and ipilimumab combination therapy, aseptic meningitis was induced. We stopped both drugs and started steroid therapy with prednisolone. Finally, about 9 months after restarting nivolumab, isolated adrenocorticotropic hormone (ACTH) deficiency was induced, and so we started replacement therapy with hydrocortisone. Taken together, we should bear in mind the possibility of a variety of irAEs when we use immune checkpoint inhibitors.

Immunotherapy-induced isolated ACTH deficiency in cancer therapy

Central adrenal insufficiency (AI) due to isolated adrenocorticotropic hormone (ACTH) deficiency (IAD) has been recently associated with immune checkpoint inhibitor (ICI) therapy. Our aim was to analyze the prevalence, clinical characteristics, and therapeutic outcomes in cancer patients with IAD induced by ICI therapy. A retrospective and multicenter study was performed. From a total of 4,447 cancer patients treated with ICI antibodies, 37 (0.8%) [23 men (62.2%), mean age 64.7 ± 8.3 years (range 46-79 yr)] were diagnosed with IAD. The tumor most frequently related to IAD was lung cancer (n=20, 54.1%), followed by melanoma (n=8, 21.6%). The most commonly ICI antibody inhibitor reported was nivolumab (n=18, 48.6%), pembrolizumab (n=16, 43.2%) and ipilimumab (n=8, 21.6%). About half of the patients (n=19, 51.4%) had other immune-related adverse events, mainly endocrine adverse effects (n=10, 27.0%). IAD was diagnosed at a median time of 7.0 months (IQR, 5-12) after starting immunotherapy. The main reported symptom at presentation was fatigue (97.3%), followed by anorexia (81.8%) and general malaise (81.1%). Mean follow-up time since IAD diagnosis was 15.2 ± 12.5 months (range 0.3-55 months). At last visit all patients continued with hormonal deficiency of ACTH. Median overall survival since IAD diagnosis was 6.0 months. In conclusion, IAD is a rare but a well-established complication associated with ICI therapy in cancer patients. It develops around 7 months after starting treatment, mainly anti-PD1 antibodies. Recovery of the corticotropic axis function should not be expected.

Missplicing due to a synonymous, T96= exonic substitution in the T-box transcription factor TBX19 resulting in isolated ACTH deficiency

Summary Congenital isolated ACTH deficiency (IAD) is a rare condition characterised by low plasma ACTH and serum cortisol with normal production of other pituitary hormones. TBX19 (also known as TPIT) is a T-box pituitary restricted transcription factor important for POMC gene transcription and terminal differentiation of POMC-expressing cells. TBX19 gene mutations have been shown to cause neonatal-onset congenital IAD. We report a neonate of Romanian origin, who presented at 15 h of life with respiratory arrest and hypoglycaemia which recurred over the following 2 weeks. Biochemical investigations revealed IAD, with undetectable serum cortisol (cortisol < 1 μg/dL; normal range (NR): 7.8–26.2) and plasma ACTH levels within the normal range (22.1 pg/mL; NR: 4.7–48.8). He responded to hydrocortisone treatment. Patient DNA was analysed by a HaloPlex next-generation sequencing array targeting genes for adrenal insufficiency. A novel homozygous synonymous mutation p.Thr96= (Chr1:168260482; c.288G>A; rs376493164; allele frequency 1 × 10−5, no homozygous) was found in exon 2 of the TBX19 gene. The effect of this was assessed by an in vitro splicing assay, which revealed aberrant splicing of exon 2 giving rise to a mutant mRNA transcript whereas the WT vector spliced exon 2 normally. This was identified as the likely cause of IAD in the patient. The predicted protein product would be non-functional in keeping with the complete loss of cortisol production and early presentation in the patient. Learning points Synonymous variants (a nucleotide change that does not alter protein sequence) usually thought to be benign may still have detrimental effects on RNA and protein function causing disease. Hence, they should not be ignored, especially if very rare in public databases. In vitro splicing assays can be employed to characterise the consequence of intronic and exonic nucleotide gene changes that may alter splicing. Establishing a diagnosis due to a TBX19 mutation is important as it defines a condition of isolated ACTH deficiency not associated with additional pituitary deficiencies.

Clinical course and management of pembrolizumab-associated isolated adrenocorticotrophic hormone deficiency: a new case and literature review

Hypophysitis is rarely reported in patients receiving pembrolizumab-only immunotherapies. Since the clinical presentation is usually as isolated adrenocorticotrophic hormone (ACTH) deficiency, patients may be misjudged as having clinical symptoms due to cancer or chemotherapy. A 49-year-old male with laryngeal cancer applied to our clinic just after the tenth cycle of his pembrolizumab treatment, with weakness and nausea/vomiting. Serum morning cortisol and ACTH were 0.47 mcg/dl and 10.1 pg/ml, respectively; the remaining anterior pituitary hormone levels were normal. Pituitary MRI revealed mild glandular enlargement and loss of posterior pituitary bright-spot. All symptoms and signs improved with low-dose prednisolone. This is the second reported case of pembolizumab-associated isolated ACTH deficiency having abnormal pituitary MRI findings as we have reviewed all reported cases in the literature.

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.

Silent, isolated ACTH deficiency in malignant melanoma patients treated with immune checkpoint inhibitors

Treatment with immune checkpoint inhibitors (ICI) has drastically improved the prognosis for melanoma patients, but immune-mediated adverse events can occur in any organ, including the pituitary. In ICI-induced hypophysitis, lymphocytic infiltration and hypersensitivity reactions cause headache and pituitary deficiency. Most cases with ICI-induced hypophysitis develop central adrenal insufficiency. Here, we describe three patients treated with anticytotoxic T-lymphocyte-associated protein 4 (ipilimumab) for metastatic malignant melanoma: case 1 was asymptomatic when hypocortisolism was suspected; case 2 had symptoms of hypocortisolism and suspected severe systemic infection; case 3 had unspecific fatigue. In all cases, routine cortisol measurements and clinical suspicion (cases 2 and 3) led to the diagnosis of adrenocortical hormone (ACTH) deficiency and thereby central adrenal insufficiency. Undiagnosed and untreated, central adrenal insufficiency results in adrenal crisis. In patients treated with ICI, particularly, ipilimumab, hypophysitis and ACTH deficiency must be considered if morning cortisol is low or unspecific clinical symptoms of hypocortisolism are present.

Autoimmune hypophysitis as a cause of adrenocorticotropic hormone deficiency in pulmonary arterial hypertension: a case report

Background Severe pulmonary arterial hypertension (PAH) is generally treated with multiple PAH-specific vasodilators. If these agents are unsuccessful, additional treatment options are scarce, and the prognosis is poor due to right-sided heart failure. Some of these severe cases are also accompanied by endocrinological side effects. The most common side effect of prostacyclin is thyroid dysfunction, but in very few cases, adrenocorticotropic hormone (ACTH) deficiency may occur. Case summary A 35-year-old woman was diagnosed with hereditary PAH 2 years ago. Since her mean pulmonary arterial pressure was high, combination therapy of vasodilators, including prostacyclin, was introduced. Several months later, she was hospitalized with a persistent fever. Laboratory tests showed no findings suggestive of infection. However, hypereosinophilia and decreased secretion of ACTH and cortisol were noted, which led to the diagnosis of ACTH deficiency. A multimodal diagnostic approach, including pituitary magnetic resonance imaging and axillary lymph node biopsy, indicated that the aetiology of the ACTH deficiency was likely autoimmune hypophysitis. She was treated with hydrocortisone supplementation, which significantly relieved her condition. Discussion Endocrinological side effects in PAH patients using prostacyclin should be carefully addressed. If right-sided heart failure worsens during the administration of prostacyclin, it is essential to determine whether it is due to progression of pulmonary hypertension or endocrinological side effects. Careful diagnosis and treatment are important for managing the haemodynamics and symptoms of PAH patients given prostacyclin.