Hypereosinophilia is a predictive biomarker of immune checkpoint inhibitor-induced hypopituitarism in patients with renal cell carcinoma.

BACKGROUND: This study aimed to evaluate whether hypereosinophilia is a clinical biomarker of immune checkpoint inhibitor-induced hypopituitarism in patients with renal cell carcinoma treated with nivolumab plus ipilimumab. METHODS: This was a retrospective cohort study conducted at Jichi Medical University Saitama Medical Center between January 2018 and December 2020. In total, 12 patients with renal cell carcinoma who presented with immune checkpoint inhibitor-induced hypopituitarism were enrolled in this study. The clinical parameters and symptoms at baseline, last visit, and onset of hypopituitarism were analyzed. RESULTS: The median period from the initial treatment with immune checkpoint inhibitors to the onset of hypopituitarism was 82.5 (range: 56-196) days. Most patients developed hypopituitarism within 6 months. One patient presented with hypophysitis and 11 patients presented with isolated adrenocorticotropic hormone deficiency. The major symptoms noted at onset were fatigue (66.7%) and loss of appetite (41.7%). None of the patients had symptoms during the last visit. However, four developed hypereosinophilia. Eosinophil fraction (%) and eosinophil count (/µL) increased during the last visit and at the onset of hypopituitarism, respectively. The serum sodium and plasma glucose levels were similar. CONCLUSIONS: The eosinophil count increased before the onset of hypopituitarism. Thus, hypereosinophilia can be an early predictor of hypopituitarism.

Effects of tubastatin A on adrenocorticotropic hormone synthesis and proliferation of AtT-20 corticotroph tumor cells.

Cushing's disease is an endocrine disorder characterized by hypercortisolism, mainly caused by autonomous production of ACTH from pituitary adenomas. Autonomous ACTH secretion results in excess cortisol production from the adrenal glands, and corticotroph adenoma cells disrupt the normal cortisol feedback mechanism. Pan-histone deacetylase (HDAC) inhibitors inhibit cell proliferation and ACTH production in AtT-20 corticotroph tumor cells. A selective HDAC6 inhibitor has been known to exert antitumor effects and reduce adverse effects related to the inhibition of other HDACs. The current study demonstrated that the potent and selective HDAC6 inhibitor tubastatin A has inhibitory effects on proopiomelanocortin (Pomc) and pituitary tumor-transforming gene 1 (Pttg1) mRNA expression, involved in cell proliferation. The phosphorylated Akt/Akt protein levels were increased after treatment with tubastatin A. Therefore, the proliferation of corticotroph cells may be regulated through the Akt-Pttg1 pathway. Dexamethasone treatment also decreased the Pomc mRNA level. Combined tubastatin A and dexamethasone treatment showed additive effects on the Pomc mRNA level. Thus, tubastatin A may have applications in the treatment of Cushing's disease.

Differential effects of ß-arrestin1 and ß-arrestin2 on somatostatin receptors in murine AtT-20 corticotroph tumor cells.

Autonomous production of adrenocorticotropic hormone (ACTH) from pituitary corticotroph adenomas is the primary cause of Cushing's disease. Somatostatin receptor, a G protein-coupled receptor (GPCR), types 2 (SSTR2) and 5 (SSTR5) mRNA expression is greater than that of other SSTR subtypes in human corticotroph adenomas. Further, the multiligand SOM230 shows potent effects in decreasing ACTH plasma levels and urinary free cortisol levels in patients with Cushing's disease. We previously showed that both Sstr2 and Sstr5 mRNA levels were unaffected by SOM230 treatment, suggesting that both receptors might not be downregulated by the agonist. Intracellular molecules, such as ß-arrestins, modulate ligand activated-receptor responses. In the present study, we determined regulation of ß-arrestin1 and ß-arrestin2 by SOM230 and dexamethasone in murine AtT-20 corticotroph tumor cells. In addition, we examined the effects of ß-arrestin1 and ß-arrestin2 on Sstr mRNA and their protein levels. SOM230 treatment increased ß-arrestin1 mRNA levels and did not alter ß-arrestin2 mRNA levels. SOM230 treatment could induce ß-arrestin1 production in corticotroph tumor cells. Dexamethasone treatment decreased ß-arrestin2 mRNA levels. ß-arrestin2 knockdown increased proopiomelanocortin, and both Sstr2 and Sstr5 mRNA and their protein levels. The ß-arrestin2 knockdown-increased proopiomelanocortin mRNA levels were canceled by SOM230 treatment.

Integrated treatment for autonomic paraneoplastic syndrome improves performance status in a patient with small lung cell carcinoma: a case report.

BACKGROUND: Paraneoplastic neurological syndromes (PNS) are rare disorders associated with cancer and are believed to be immune mediated. Patients with autonomic PNS suffer from variable combinations of parasympathetic and sympathetic failure. Autonomic PNS are usually associated with other PNS, such as encephalomyelitis and sensory neuropathy; however, autonomic symptoms may rarely manifest as PNS symptoms. Autonomic symptoms, therefore, may be overlooked in patients with cancer. CASE PRESENTATION: We described a 65-year-old Japanese man who was diagnosed with autonomic PNS due to small-cell lung carcinoma (SCLC) with Eastern Cooperative Oncology Group (ECOG) performance status 3, who suffered from orthostatic hypotension, and urinary retention needing a urethral balloon. Laboratory studies showed decreased levels of noradrenaline, and were positive for anti-ganglionic acetylcholine receptor antibody, type 1 antineuronal nuclear antibody, and sry-like high mobility group box 1 antibody. Nerve conduction evaluations and 123I-metaiodobenzylguanidine myocardial scintigraphy showed no abnormalities. Abdominal contrast-enhanced computed tomography revealed marked colonic distention. The patient's autonomic symptoms resolved following integrated treatment (symptomatic treatment, immunotherapy, and additional chemotherapy) enabling the patient to walk, remove the urethral balloon, and endure further chemotherapy. ECOG performance status remained at 1, 10 months after admission. CONCLUSIONS: Integrated treatment for autonomic PNS may improve autonomic symptoms and ECOG performance status of patients with cancer.

Upper Respiratory Symptoms as Long COVID: Insight from a Multicenter Cohort Study.

Objective: This study aimed to investigate the clinical features of long COVID cases presenting with upper respiratory symptoms, a topic not yet fully elucidated. Study Design: Prospective cohort study. Setting: A multicenter study involving 26 medical facilities in Japan. Methods: Inclusion criteria were patients aged ≥18 years old with a confirmed COVID-19 diagnosis via severe acute respiratory syndrome coronavirus 2 polymerase chain reaction or antigen testing, who were hospitalized at the participating medical facilities. Analyzing clinical information and patient-reported outcomes from 1009 patients were analyzed. The outcome measured the degree of initial symptoms for taste or olfactory disorders and assessed the likelihood of these symptoms persisting as long COVID, as well as the impact on quality of life if the upper respiratory symptoms persisted as long COVID. Results: Patients with high albumin, low C-reactive protein, and low lactate dehydrogenase in laboratory tests tended to experience taste or olfactory disorders as part of long COVID. Those with severe initial symptoms had a higher risk of experiencing residual symptoms at 3 months, with an odds ratio of 2.933 (95% confidence interval [CI], 1.282-6.526) for taste disorders and 3.534 (95% CI, 1.382-9.009) for olfactory disorders. Presence of upper respiratory symptoms consistently resulted in lower quality of life scores. Conclusion: The findings from this cohort study suggest that severe taste or olfactory disorders as early COVID-19 symptoms correlate with an increased likelihood of persistent symptoms in those disorders as long COVID.

Involvement of histone deacetylase 1/2 in adrenocorticotropic hormone synthesis and proliferation of corticotroph tumor AtT-20 cells.

Cushing's disease is mainly caused by autonomous production of adrenocorticotropic hormone (ACTH) from pituitary adenomas. In our previous study, a histone deacetylase (HDAC) inhibitor, trichostatin A, inhibited cell proliferation and ACTH production via decreased pituitary tumor-transforming gene 1 (PTTG1) in AtT-20 mouse corticotroph tumor cells. In the present study, we examined the effects of romidepsin, a potent and selective HDAC1/2 inhibitor, on cell proliferation and ACTH synthesis. To elucidate further potential mechanisms of romidepsin, we examined the effects of HDAC1/2 on proopiomelanocortin (Pomc) and Pttg1 mRNA levels and cell proliferation. Small interfering RNA-mediated knockdown was used to decrease HDAC1 or 2. Romidepsin treatment decreased Pomc and Pttg1 mRNA levels, and cell proliferation. The drug also increased Hdac1 and decreased Hdac2 mRNA levels. Hdac1 knockdown decreased basal Pttg1 mRNA levels and cell proliferation, but not Pomc mRNA levels. Romidepsin treatment decreases ACTH synthesis in corticotroph tumor cells. Romidepsin suppresses cell proliferation via PTTG1. HDAC1 is also involved in the proliferation of corticotroph cells via PTTG1.

Spontaneous recovery of immune checkpoint inhibitor-induced thyroiditis with high free T4 level: A case report.

We describe a case of severe hyperthyroidism with high free thyroxine and C-reactive protein levels, wherein thyroid function rapidly improved without treatment. In a similar case, conservative management with imaging follow-up can be considered.