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

Isolated Adrenocorticotropic Hormone Deficiency Mimicking Systemic Sclerosis: A Diagnostic Challenge in Patients With Rheumatoid Symptoms

Isolated adrenocorticotropic hormone (ACTH) deficiency (IAD) is characterized by selective impairment of ACTH secretion while other anterior pituitary hormones remain unaffected. It is more common in men in their fifties, with autoimmune mechanisms likely playing a major role. Symptoms include fatigue, weight loss, and appetite loss. Some IAD patients also experience rheumatoid symptoms, such as muscle pain and joint stiffness. A 74-year-old male patient with type 2 diabetes mellitus developed worsening symptoms, including impaired consciousness, fatigue, and edema. A month before hospitalization, he was diagnosed with primary hypothyroidism and started on levothyroxine. However, his symptoms worsened, with finger contractures and joint swelling, prompting referral to our hospital. On admission, he showed signs of general malaise and facial changes. His skin showed sclerosis without characteristic features of systemic sclerosis (SSc), such as Raynaud's phenomenon or digital ulcers. His lab tests showed negative autoantibodies for collagen diseases, and the patient did not meet the criteria for SSc. Further investigation revealed hyponatremia, hypoglycemia, and low ACTH and cortisol levels, indicating anterior pituitary hormone deficiency. Imaging confirmed an intact pituitary gland and hypothalamus. The patient was diagnosed with IAD and began intravenous hydrocortisone, which improved his symptoms, including hyponatremia, hypoglycemia, and hypotension. His skin sclerosis and joint swelling also improved. Thyroid function normalized, and levothyroxine was discontinued. After physical therapy, the patient was discharged. The symptoms of IAD are primarily related to cortisol deficiency. It is often managed with hydrocortisone supplementation, which leads to rapid improvement of clinical symptoms. Autoimmune mechanisms, including the presence of anti-pituitary antibodies, are thought to play a significant role in its pathogenesis. However, this case lacked anti-pituitary antibodies and other typical causes such as opioid use or immune checkpoint inhibitors. Thyroid dysfunction can occur in IAD patients, as cortisol suppresses the thyrotropin-releasing hormone (TRH)-thyroid-stimulating hormone (TSH) axis. In this case, the patient's thyroid dysfunction was resolved after hydrocortisone therapy. Rheumatoid symptoms, such as joint pain and skin changes, can also be present in IAD, leading to misdiagnosis as systemic diseases like SSc. Hydrocortisone therapy successfully improved these symptoms, highlighting the need for adrenal function testing in patients with unexplained rheumatoid symptoms. Some cases of IAD can mimic autoimmune diseases like SSc, complicating diagnosis and delaying treatment. It is important to consider IAD in patients with unexplained joint and skin symptoms. Additionally, thyroid hormone therapy may unmask adrenal insufficiency, underscoring the importance of evaluating adrenal function before initiating treatment.

Acquired thyroid-stimulating hormone, luteinizing hormone, and follicle-stimulating hormone deficiencies with circulating anti-glycoprotein hormones alpha chain-positive cell antibodies

BACKGROUND

A patient with systemic lupus erythematosus (SLE) suffered from acquired thyroid-stimulating hormone (TSH), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) deficiencies. MRI findings revealed a slight atrophy of the pituitary gland. Further, the serum concentration of the covalent alpha subunit (glycoprotein hormones alpha chain [CGA]) in TSH-, LH-, and FSH-positive cells was below the detectable range. Because SLE is an autoimmune disorder, autoimmunity against the pituitary gland was suspected as the cause of pituitary deficiency.

METHODS AND RESULTS

Immunofluorescence analysis showed that the patient's immunoglobulin G recognized CGA-positive cells in the pituitary gland; therefore, autoimmunity against CGA-positive cells may have caused TSH, LH, and FSH deficiencies in this patient. Moreover, cell-specific autoimmunity impairs pituitary hormone levels. Further research is required to clarify whether acquired TSH, LH, and FSH deficiencies are common in patients with SLE or other autoimmune diseases.

CONCLUSION

Our findings highlight a unique case of acquired TSH, LH, and FSH deficiencies caused by circulating anti-CGA-positive cell antibodies, introducing a novel clinical concept of acquired hypopituitarism.

Acquired isolated ACTH deficiency co-occurrence with breast cancer irrespective of paraneoplastic syndrome: coincidence or inevitability

Summary

A 52-year-old female patient with breast cancer presented with a history of fatigue and malaise 1 year prior. She was diagnosed with isolated adrenocorticotropic hormone (ACTH) deficiency (IAD) on endocrinological examination. Her pituitary gland showed normal morphology. Paraneoplastic IAD associated with breast cancer was suspected; however, immunofluorescence staining revealed no ectopic ACTH or proopiomelanocortin expression in the tumor tissue. Subsequently, the patient was diagnosed with idiopathic acquired IAD concurrent with breast cancer, ruling out paraneoplastic syndrome. Although malignancy should be considered a potential cause of IAD, not all patients with concurrent IAD and malignancy necessarily develop paraneoplastic syndrome.

Learning points

Several adrenal insufficiency symptoms are similar to the nonspecific symptoms associated with malignancies, and therefore, the diagnosis of IAD remains challenging, especially in patients with cancer. When we encounter a case of IAD accompanied by a malignant tumor, it is important to suspect that paraneoplastic IAD, a novel clinical condition as secondary hypophysitis, may be the etiologic agent. Although malignant tumours should be considered a potential cause of IAD, not all patients with concurrent IAD and malignancy necessarily develop paraneoplastic autoimmune hypophysitis.

Fluctuations in plasma adrenocorticotropic hormone concentration may predict the onset of immune checkpoint inhibitor-related hypophysitis

Immune checkpoint inhibitor (ICI)-related hypophysitis (RH) is a common immune-related adverse event. The early detection of ICI-RH prevents life-threatening adrenal insufficiency. However, good predictors of secondary adrenal insufficiency in ICI-RH have not yet been reported. We hypothesized that fluctuations in plasma adrenocorticotropic hormone (ACTH) and cortisol levels occur similarly to those in thyroid-stimulating hormone and thyroid hormone (thyroxine and triiodothyronine) levels in ICI-related thyroiditis. Here, we sought to test this hypothesis. Patients who used ICI and had a history of measurement of plasma ACTH and serum cortisol concentrations were retrieved from electronic medical records, and those with a history of glucocorticoid use were excluded from the analysis. We evaluated fluctuations in plasma ACTH and serum cortisol concentrations and the development of ICI-RH. For patients with ICI-RH, data at three points (before ICI administration (pre), maximum ACTH concentration (peak), and onset of ICI-RH) were analyzed to evaluate hormone fluctuations. A total of 202 patients were retrieved from the medical record. Forty-three patients were diagnosed with ICI-RH. Twenty-six out of 43 patients had sufficient data to evaluate fluctuations in plasma ACTH and serum cortisol concentrations and no history of glucocorticoid use. ACTH concentrations changed from 37.4 (29.9–48.3) (pre) to 64.4 (46.5–106.2) (peak) pg/mL (1.72–fold increase, p=0.0026) in the patients with ICI-RH before the onset. There were no differences in cortisol concentrations between the pre and peak values in patients with ICI-RH. We also evaluated the fluctuations in plasma ACTH and serum cortisol levels in patients who did not receive ICI-RH (62 cases). However, elevation of plasma ACTH levels was not observed in patients without ICI-RH, suggesting that transient elevation of plasma ACTH levels is a unique phenomenon in patients with ICI-RH. In conclusion, plasma ACTH levels were transiently elevated in some patients with ICI-RH before the onset of secondary adrenal insufficiency. Monitoring the ACTH levels and their fluctuations may help predict the onset of ICI-RH.