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ContextImmune checkpoint inhibitors, including anti–programmed cell death-1 (PD-1) antibodies, have become promising treatments for a variety of advanced malignancies. However, these medicines can cause immune-related adverse events (irAEs), including endocrinopathies.ObjectiveThis study examined the incidence of endocrine irAEs induced by nivolumab.Patients and Main Outcome MeasuredSixty-six patients treated with nivolumab at Nagoya University Hospital were prospectively evaluated for pituitary hormones, thyroid function, antithyroid antibodies (Abs), and glucose levels every 6 weeks after the initiation of nivolumab for 24 weeks.ResultsFour out of 66 patients developed destructive thyroiditis, and three patients developed hypothyroidism requiring levothyroxine replacement. The prevalence of positive anti-thyroglobulin Abs (TgAbs) and/or anti–thyroid peroxidase Abs (TPOAbs) at baseline was significantly higher in the group that developed destructive thyroiditis (3/4) compared with the group that did not develop thyroiditis (3/62; P = 0.002). There were no significant differences in other clinical variables between the groups. There were no endocrine irAEs other than destructive thyroiditis during the 24 weeks. The prevalence of TgAbs and/or TPOAbs at baseline was not associated with the development of other irAEs, including pneumonitis, colitis, or skin reactions.ConclusionsOur real-world data showed that destructive thyroiditis was an endocrine irAE that was frequently induced by nivolumab and was significantly associated with positive TgAbs and/or TPOAbs before treatment. Our findings indicate that evaluating these Abs before treatment may help identify patients with a high risk of thyroidal irAEs and may have important clinical benefit.

The presence of high-molecular intestinal alkaline phosphatase (HIALP) different from bone ALP detected in the alpha(2)beta region was recently clarified. In this study we used a novel method in which HIALP was detected after conversion to ALP(5) by protease to investigate the clinical significance of the appearance of HIALP in patients with chronic liver disease. The subjects were 241 patients with chronic liver disease. When a decrease in ALP(3) in the alpha(2)beta region and an increase in ALP(5) in the beta region were noted, the patient was judged HIALP-positive. In the patients with chronic liver disease, the total ALP activity (T-ALP) increased with progression of the pathology in the order of chronic hepatitis (CH), liver cirrhosis (LC), and hepatocellular carcinoma (HCC). HIALP appeared in 22.4% and 49.3% of patients with CH and LC, respectively, but the positivity rate decreased to 30.4% in HCC. As autoimmune liver diseases, primary biliary cirrhosis (PBC) and autoimmune hepatitis (AIH) were investigated. T-ALP was lower in PBC+AIH than in LC and HCC, but the HIALP-positive rate was high (44.4%). The HIALP-positive rate was dependent on ABO blood groups, and was high in blood groups B and O. In conclusion, the HIALP-positive rate was particularly high in patients with chronic liver disease, and was related to the pathological progression, which suggests that the method is clinically useful.

Familial neurohypophysial diabetes insipidus (FNDI), an autosomal dominant disorder, is mostly caused by mutations in the gene of neurophysin II (NPII), the carrier protein of arginine vasopressin (AVP). Previous studies suggest that loss of AVP neurons might be the cause of polyuria in FNDI. Here we analyzed knockin mice expressing mutant NPII that causes FNDI in humans. The heterozygous mice manifested progressive polyuria as do patients with FNDI. Immunohistochemical analyses revealed that inclusion bodies that were not immunostained with antibodies for mutant NPII, normal NPII, or AVP were present in the AVP cells in the supraoptic nucleus (SON), and that the size of inclusion bodies gradually increased in parallel with the increases in urine volume. Electron microscopic analyses showed that aggregates existed in the endoplasmic reticulum (ER) as well as in the nucleus of AVP neurons in 1-mo-old heterozygous mice. At 12 mo, dilated ER filled with aggregates occupied the cytoplasm of AVP cells, while few aggregates were found in the nucleus. Analyses with in situ hybridization revealed that expression of AVP mRNA was significantly decreased in the SON in the heterozygous mice compared with that in wild-type mice. Counting cells expressing AVP mRNA in the SON indicated that polyuria had progressed substantially in the absence of neuronal loss. These data suggest that cell death is not the primary cause of polyuria in FNDI, and that the aggregates accumulated in the ER might be involved in the dysfunction of AVP neurons that lead to the progressive polyuria.

The thyroid gland secretes primarily tetraiodothyronine (T), and some triiodothyronine (T). Under normal physiological circumstances, only one-fifth of circulating T is directly released by the thyroid, but in states of hyperactivation of thyroid-stimulating hormone receptors (TSHRs), patients develop a syndrome of relative T toxicosis. Thyroidal T production results from iodination of thyroglobulin (TG) at residues Tyr and Tyr, whereas thyroidal T production may originate in several different ways. In this study, the data demonstrate that within the carboxyl-terminal portion of mouse TG, T is formed independently of deiodination from T We found that upon iodination , T formation in TG was decreased in mice lacking TSHRs. Conversely, T that can be formed upon iodination of TG secreted from PCCL3 (rat thyrocyte) cells was augmented from cells previously exposed to increased TSH, a TSHR agonist, a cAMP analog, or a TSHR-stimulating antibody. We present data suggesting that TSH-stimulated TG phosphorylation contributes to enhanced T formation. These effects were reversed within a few days after removal of the hyperstimulating conditions. Indeed, direct exposure of PCCL3 cells to human serum from two patients with Graves' disease, but not control sera, led to secretion of TG with an increased intrinsic ability to form T upon iodination. Furthermore, TG secreted from human thyrocyte cultures hyperstimulated with TSH also showed an increased intrinsic ability to form T Our data support the hypothesis that TG processing in the secretory pathway of TSHR-hyperstimulated thyrocytes alters the structure of the iodination substrate in a way that enhances T formation, contributing to the relative T toxicosis of Graves' disease.

Familial neurohypophysial diabetes insipidus (FNDI) characterized by progressive polyuria is mostly caused by mutations in the gene encoding neurophysin II (NPII), which is the carrier protein of the antidiuretic hormone, arginine vasopressin (AVP). Although accumulation of mutant NPII in the endoplasmic reticulum (ER) could be toxic for AVP neurons, the precise mechanisms of cell death of AVP neurons, reported in autopsy studies, remain unclear. Here, we subjected FNDI model mice to intermittent water deprivation (WD) in order to promote the phenotypes. Electron microscopic analyses demonstrated that, while aggregates are confined to a certain compartment of the ER in the AVP neurons of FNDI mice with water access ad libitum, they were scattered throughout the dilated ER lumen in the FNDI mice subjected to WD for 4 weeks. It is also demonstrated that phagophores, the autophagosome precursors, emerged in the vicinity of aggregates and engulfed the ER containing scattered aggregates. Immunohistochemical analyses revealed that expression of p62, an adapter protein between ubiquitin and autophagosome, was elicited on autophagosomal membranes in the AVP neurons, suggesting selective autophagy induction at this time point. Treatment of hypothalamic explants of green fluorescent protein (GFP)-microtubule-associated protein 1 light chain 3 (LC3) transgenic mice with an ER stressor thapsigargin increased the number of GFP-LC3 puncta, suggesting that ER stress could induce autophagosome formation in the hypothalamus of wild-type mice as well. The cytoplasm of AVP neurons in FNDI mice was occupied with vacuoles in the mice subjected to WD for 12 weeks, when 30–40% of AVP neurons are lost. Our data thus demonstrated that autophagy was induced in the AVP neurons subjected to ER stress in FNDI mice. Although autophagy should primarily be protective for neurons, it is suggested that the organelles including ER were lost over time through autophagy, leading to autophagy-associated cell death of AVP neurons.

Thyroid hormones modulate not only multiple functions in vertebrates (energy metabolism, central nervous system function, seasonal changes in physiology, and behavior) but also in some non-vertebrates where they control critical post-embryonic developmental transitions such as metamorphosis. Despite their obvious biological importance, the thyroid hormone precursor protein, thyroglobulin (Tg), has been experimentally investigated only in mammals. This may bias our view of how thyroid hormones are produced in other organisms. In this study we searched genomic databases and found Tg orthologs in all vertebrates including the sea lamprey (Petromyzon marinus). We cloned a full-size Tg coding sequence from western clawed frog (Xenopus tropicalis) and zebrafish (Danio rerio). Comparisons between the representative mammal, amphibian, teleost fish, and basal vertebrate indicate that all of the different domains of Tg, as well as Tg regional structure, are conserved throughout the vertebrates. Indeed, in Xenopus, zebrafish, and lamprey Tgs, key residues, including the hormonogenic tyrosines and the disulfide bond-forming cysteines critical for Tg function, are well conserved despite overall divergence of amino acid sequences. We uncovered upstream sequences that include start codons of zebrafish and Xenopus Tgs and experimentally proved that these are full-length secreted proteins, which are specifically recognized by antibodies against rat Tg. By contrast, we have not been able to find any orthologs of Tg among non-vertebrate species. Thus, Tg appears to be a novel protein elaborated as a single event at the base of vertebrates and virtually unchanged thereafter.

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