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.

A novel mechanism of imeglimin-mediated insulin secretion via the cADPR-TRP channel pathway.

AIMS/INTRODUCTION: Imeglimin is a novel oral hypoglycemic agent that improves blood glucose levels through multiple mechanisms of action including the enhancement of glucose-stimulated insulin secretion (GSIS), however, the details of this mechanism have not been clarified. In the process of GSIS, activation of the transient receptor potential melastatin 2 (TRPM2) channel, a type of non-selective cation channel (NSCCs) in ß-cells, promotes plasma membrane depolarization. The present study aimed to examine whether imeglimin potentiates GSIS via the TRPM2 channel in ß-cells. MATERIALS AND METHODS: Pancreatic islets were isolated by collagenase digestion from male wild-type and TRPM2-knockout (KO) mice. Insulin release and nicotinamide adenine dinucleotide (NAD+ ) production in islets were measured under static incubation. NSCC currents in mouse single ß-cells were measured by patch-clamp experiments. RESULTS: Batch-incubation studies showed that imeglimin enhanced GSIS at stimulatory 16.6 mM glucose, whereas it did not affect basal insulin levels at 2.8 mM glucose. Imeglimin increased the glucose-induced production of NAD+ , a precursor of cADPR, in islets and the insulinotropic effects of imeglimin were attenuated by a cADPR inhibitor 8-Br-cADPR. Furthermore, imeglimin increased NSCC current in ß-cells, and abolished this current in TRPM2-KO mice. Imeglimin did not potentiate GSIS in the TRPM2-KO islets, suggesting that imeglimin's increase of NSCC currents through the TRPM2 channel is causally implicated in its insulin releasing effects. CONCLUSIONS: Imeglimin may activate TRPM2 channels in ß-cells via the production of NAD+ /cADPR, leading to the potentiation of GSIS. Developing approaches to stimulate cADPR-TRPM2 signaling provides a potential therapeutic tool to treat type 2 diabetes.

Daily variability in serum levels of calciprotein particles and their association with mineral metabolism parameters: A cross-sectional pilot study.

AIM: Calciprotein particles (CPPs), colloidal protein-mineral nanoparticles composed of solid-phase calcium phosphate and serum protein fetuin-A found in blood, are emerging as a novel component of chronic kidney disease-mineral and bone disorder (CKD-MBD). The relationship of CPPs with factors known to underlie the CKD-MBD pathophysiology is not well known.The aim of this study is to examine daily variations in CPPs as well as their association with mineral metabolism parameters in normal individuals and early-stage CKD patients. METHODS: Twenty subjects (10 healthy adults, 10 diabetic patients) were enrolled. Serum CPP Fetuin-A was measured and analyzed in relation to clinical parameters. RESULTS: Estimated glomerular filtration rates (eGFR) were 103 ± 11 and 75 ± 24 mL/min per 1.73 m2 in healthy adults and diabetic patients, respectively. Serum CPP Fetuin-A (g/L) were elevated at postprandial 2 h in diabetic patients. Furthermore, serum CPP Fetuin-A were inversely correlated with eGFR and serum 1,25-dihydroxyvitamin D3 and magnesium levels and were positively correlated with serum fibroblast growth factor-23. CONCLUSIONS: These findings indicated that serum CPP Fetuin-A were affected by food intake and may contribute to the pathophysiology of mineral metabolism in subjects with normal and moderately impaired renal function.