Generation and purification of ACTH-secreting hPSC-derived pituitary cells for effective transplantation.

Pituitary organoids are promising graft sources for transplantation in treatment of hypopituitarism. Building on development of self-organizing culture to generate pituitary-hypothalamic organoids (PHOs) using human pluripotent stem cells (hPSCs), we established techniques to generate PHOs using feeder-free hPSCs and to purify pituitary cells. The PHOs were uniformly and reliably generated through preconditioning of undifferentiated hPSCs and modulation of Wnt and TGF-ß signaling after differentiation. Cell sorting using EpCAM, a pituitary cell-surface marker, successfully purified pituitary cells, reducing off-target cell numbers. EpCAM-expressing purified pituitary cells reaggregated to form three-dimensional pituitary spheres (3D-pituitaries). These exhibited high adrenocorticotropic hormone (ACTH) secretory capacity and responded to both positive and negative regulators. When transplanted into hypopituitary mice, the 3D-pituitaries engrafted, improved ACTH levels, and responded to in vivo stimuli. This method of generating purified pituitary tissue opens new avenues of research for pituitary regenerative medicine.

Anti-tumor effects of anti-programmed cell death-1 antibody treatment are attenuated in streptozotocin-induced diabetic mice.

Hyperglycemia impairs immune response; however, it remains unknown whether the anti-tumor effects of anti-programmed cell death-1 antibody (PD-1-Ab) treatment are changed in hyperglycemic conditions. We analyzed the effect of PD-1-Ab on tumor growth in streptozotocin-induced diabetic mice (STZ-mice) subcutaneously inoculated with MC38 (a colon carcinoma cell line). Furthermore, we assessed the expression of chemokines by polymerase chain reaction (PCR) array in tumor-draining lymph nodes (dLNs) of these mice and MC38 cells cultured in different glucose concentrations. The suppressive effect of PD-1-Ab on tumor growth was attenuated. This was accompanied by fewer tumor-infiltrating CD8+ T cells, and STZ-mice had fewer tumor-infiltrating CD11c+ dendritic cells (DCs) than normoglycemic mice. mRNA expression levels of CXCL9, a chemokine recruiting CD8+ T cells, were lower in dLNs of STZ-mice than in normoglycemic mice after PD-1-Ab treatment, and its protein was expressed in DCs. In MC38 cells cultured with 25 mM glucose, mRNA expression of CCL7, a chemokine recruiting DCs, was decreased compared to cells cultured with 5 mM glucose. These results suggest that the STZ-induced hyperglycemia impairs the effect of PD-1-Ab treatment on MC38 tumor growth, and is accompanied by reduced infiltration of DCs and CD8+ T cells and decreased expression of CCL7 and CXCL9.

Resting energy expenditure depends on energy intake during weight loss in people with obesity: a retrospective cohort study

Abstract Objective: Resting energy expenditure (REE) decreases if there is reduced energy intake and body weight (BW). The decrease in REE could make it difficult for patients with obesity to maintain decreased BW. This study aimed to investigate the correlation among changes in REE, energy intake, and BW during the weight loss process in patients with obesity. Materials and methods: We conducted a retrospective cohort study of patients hospitalized for the treatment of obesity in Japan. Patients received fully controlled diet during hospitalization and performed exercises if able. REE was measured once a week using a hand-held indirect calorimetry. Energy intake was determined by actual dietary intake. Results: Of 44 inpatients with obesity, 17 were included in the analysis. Their BW decreased significantly after 1 week (−4.7 ± 2.0 kg, P < 0.001) and 2 weeks (−5.7 ± 2.2 kg, P < 0.001). The change in REE after 1 and 2 weeks was positively correlated with the energy intake/energy expenditure ratio (r = 0.66, P = 0.004 at 1 week, r = 0.71, P = 0.002 at 2 weeks). Using a regression equation (y = 0.5257x - 43.579), if the energy intake/energy expenditure ratio within the second week was 82.9%, the REE after 2 weeks was similar to the baseline level. There was no significant correlation between the change in REE and BW. Conclusions: Our data suggest that changes in REE depend on energy intake/energy expenditure ratio and that the decrease in REE can be minimized by matching energy intake to energy expenditure, even during the weight loss process.

Preconditioning of the immune system modulates the response of papillary thyroid cancer to immune checkpoint inhibitors.

BACKGROUND: The response of solid tumors such as papillary thyroid cancer (PTC) to immune checkpoint inhibitors (ICIs) is highly variable. The biological basis of this variability remains unknown. METHODS: To test the hypothesis that preconditioning of the immune system modulates the therapeutic effect of ICIs, we used a murine model where PTC and iodine exacerbated thyroiditis (IET) can be induced in a temporally predictable fashion. A total of 122 mice were divided into 3 experimental groups. In the first one, named concomitant IET and PTC (No.=40), IET, and PTC were induced at the same time; in the second one, named pre-existing IET (No.=44), IET was induced prior to the induction of PTC; in the third one, named no IET (No.=38), only PTC was induced. Following disease induction, mice of each group were treated with anti-PD-1 antibody, anti-lymphocyte activation gene 3 antibody (anti-Lag3), anti-T-cell immunoglobulin and mucin domain 3 antibody (anti-Tim3), or IgG control. Ten weeks after the initial ICI injection, mice were sacrificed to collect the thyroid gland for histological analysis, to quantify the incidence and burden of PTC, and to perform high-throughput single-cell RNA sequencing of infiltrating CD45+ cells. RESULTS: In the concomitant IET and PTC group, ICI treatment reduced PTC incidence (p=0.002 comparing treatment with any ICI vs control), while it had no effect in the pre-existing IET and no IET groups. Single-cell sequencing of thyroidal CD45+ cells showed that the different ICIs tested had both specific and shared effects on all the components of the thyroidal immune cell infiltrate. The shared effect of the tested ICIs was dependent on the presence of pre-existing versus concomitant IET. In the context of concomitant IET, ICI treatment resulted in the modulation of a greater number of pathways related to both innate and adaptive immunity. CONCLUSIONS: Response to ICIs depends on the status of the immune system of the treated individual. Modulation of the immune system should be explored as a tool to improve response to ICIs in patients with PTC or other forms of cancer.

The Immune Landscape of Papillary Thyroid Cancer in the Context of Autoimmune Thyroiditis.

Papillary thyroid cancer (PTC) often co-occurs with Hashimoto's thyroiditis, an association that has long been reported in clinical studies, remaining controversial. Experimental evidence has recently shown that pre-existing thyroiditis has a beneficial effect on PTC growth and progression by a distinctive expansion of effector memory CD8 T cells. Although the link between inflammation and PTC might involve different components of the immune system, a deep characterization of them which includes T cells, B cells and tertiary lymphoid structures, Mye-loid cells, Neutrophils, NK cells and dendritic cells will be desirable. The present review article considers the role of the adaptive and innate immune response surrounding PTC in the context of Hashimoto's thyroiditis. This review will focus on the current knowledge by in vivo and in vitro studies specifically performed on animals' models; thyroid cancer cells and human samples including (i) the dual role of tumor-infiltrating lymphocytes; (ii) the emerging role of B cells and tertiary lymphoid structures; (iii) the role of myeloid cells, dendritic cells, and natural killer cells; (iv) the current knowledge of the molecular biomarkers implicated in the complex link between thyroiditis and PTC and the potential implication of cancer immunotherapy in PTC patients in the context of thyroiditis.

Inflammation in VTA Caused by HFD Induces Activation of Dopaminergic Neurons Accompanied by Binge-like Eating.

Binge eating is a characteristic symptom observed in obese individuals that is related to dysfunction of dopaminergic neurons (DNs). Intermittent administration of a high-fat diet (HFD) is reported to induce binge-like eating, but the underlying mechanisms remain unclear. We generated dopaminergic neuron specific IKKß deficient mice (KO) to examine the effects of inflammation in DNs on binge-like eating under inflammatory conditions associated with HFD. After administration of HFD for 4 weeks, mice were fasted for 24 h, and then the consumption of HFD was measured for 2 h. We also evaluated that the mRNA expressions of inflammatory cytokines, glial markers, and dopamine signaling-related genes in the ventral tegmental area (VTA) and striatum. Moreover, insulin was administered intraventricularly to assess downstream signaling. The consumption of HFD was significantly reduced, and the phosphorylation of AKT in the VTA was significantly increased in female KO compared to wild-type (WT) mice. Analyses of mRNA expressions revealed that DNs activity and inflammation in the VTA were significantly decreased in female KO mice. Thus, our data suggest that HFD-induced inflammation with glial cell activation in the VTA affects DNs function and causes abnormal eating behaviors accompanied by insulin resistance in the VTA of female mice.

Elevated TSH Level, TgAb, and Prior Use of Ramucirumab or TKIs as Risk Factors for Thyroid Dysfunction in PD-L1 Blockade.

BACKGROUND: Thyroid dysfunction is frequently caused by treatment with antiprogrammed cell death-1 ligand 1 antibodies (PD-L1-Abs) and anticancer drugs, including ramucirumab (RAM) and multitargeted tyrosine kinase inhibitors (multi-TKIs), which are often used prior to PD-L1-Ab treatment in cancer patients. METHODS: A total of 148 patients treated with PD-L1-Abs were evaluated for antithyroid antibodies at baseline and for thyroid function every 6 weeks for 24 weeks after treatment initiation and then were observed until the visits stopped. RESULTS: Of the 148 patients, 15 (10.1%) developed thyroid dysfunction after PD-L1-Ab treatment (destructive thyroiditis in 8 and hypothyroidism without preceding thyrotoxicosis in 7). The prevalence of an elevated thyroid-stimulating hormone (TSH) level at baseline (3/15 [20.0%] vs 4/133 [3.0%], P < .05), positive antithyroglobulin antibodies (TgAbs) at baseline (4/15 [26.7%] vs 5/133 [3.8%], P < .05) and prior treatment with RAM or multi-TKIs (3/15 [20.0%] vs 5/133 [3.8%], P < .05) were significantly higher in patients with vs without thyroid dysfunction. In a multivariate analysis, elevated TSH level at baseline, TgAb positivity at baseline, and prior treatment with RAM or multi-TKIs were significantly associated with the development of thyroid dysfunction, with ORs of 7.098 (95% CI 1.154-43.638), 11.927 (95% CI 2.526-56.316), and 8.476 (95% CI 1.592-45.115), respectively. CONCLUSION: The results of this real-world study suggest that the risk of thyroid dysfunction induced by PD-L1-Abs can be predicted by the TSH level at baseline, TgAb positivity at baseline, and prior treatment with RAM or multi-TKIs.

Immune checkpoint inhibitor-related thyroid dysfunction.

Immune-related adverse events (irAEs) are caused by immune checkpoint inhibitors in several organs including the endocrine glands. Thyroid dysfunction (thyroid irAEs) is often observed among endocrine irAEs and is induced by blockade of programmed cell death 1 (PD-1), programmed death ligand 1, or PD-1 plus cytotoxic T-lymphocyte antigen 4. Endocrinologically, destructive thyroiditis or hypothyroidism is observed in most cases, whereas hyperthyroidism (Graves' disease) is rare. Most patients who develop destructive thyroiditis or hypothyroidism subsequently require thyroid hormone replacement therapy. Thyroid irAE development is associated with prolonged survival in patients with non-small cell lung carcinoma. The incidence of thyroid irAEs is higher in patients who are positive versus negative for anti-thyroid antibodies at baseline, suggesting that these antibodies can predict thyroid irAE development. Cytotoxic T cells, especially CD4 T cells, are reportedly involved in the development of destructive thyroiditis. In this review, we describe the clinical features, potential biomarkers, and mechanism of thyroid irAEs.

Functional Lactotrophs in Induced Adenohypophysis Differentiated From Human iPS Cells.

Prolactin (PRL), a hormone involved in lactation, is mainly produced and secreted by the lactotrophs of the anterior pituitary (AP) gland. We previously reported a method to generate functional adrenocorticotropic hormone-producing cells by differentiating the AP and hypothalamus simultaneously from human induced pluripotent stem cells (iPSCs). However, PRL-producing cells in the induced AP have not been investigated. Here, we confirmed the presence of PRL-producing cells and evaluated their endocrine functions. We differentiated pituitary cells from human iPSCs using serum-free floating culture of embryoid-like aggregates with quick reaggregation (SFEB-q) method and evaluated the appearance and function of PRL-producing cells. Secretion of PRL from the differentiated aggregates was confirmed, which increased with further culture. Fluorescence immunostaining and immunoelectron microscopy revealed PRL-producing cells and PRL-positive secretory granules, respectively. PRL secretion was promoted by various prolactin secretagogues such as thyrotropin-releasing hormone, vasoactive intestinal peptide, and prolactin-releasing peptide, and inhibited by bromocriptine. Moreover, the presence of tyrosine hydroxylase-positive dopaminergic nerves in the hypothalamic tissue area around the center of the aggregates connecting to PRL-producing cells indicated the possibility of recapitulating PRL regulatory mechanisms through the hypothalamus. In conclusion, we generated pituitary lactotrophs from human iPSCs; these displayed similar secretory responsiveness as human pituitary cells in vivo. In the future, this is expected to be used as a model of human PRL-producing cells for various studies, such as drug discovery, prediction of side effects, and elucidation of tumorigenic mechanisms using disease-specific iPSCs. Furthermore, it may help to develop regenerative medicine for the pituitary gland.

Increased Risk of Thyroid Dysfunction by PD-1 and CTLA-4 Blockade in Patients Without Thyroid Autoantibodies at Baseline.

BACKGROUND: Previous studies showed that although the risk of thyroid dysfunction [thyroid immune-related adverse events (irAEs)] induced by anti-programmed cell death-1 antibodies (PD-1-Ab) was as low as 2% to 7% in patients negative for anti-thyroid antibodies (ATAs) at baseline, it was much higher (30%-50%) in patients positive for ATAs. However, whether a similar increase occurs with combination therapy using PD-1-Ab plus anti-cytotoxic T-lymphocyte antigen-4 antibody (CTLA-4-Ab) is unknown. METHODS: A total of 451 patients with malignancies treated with PD-1-Ab, CTLA-4-Ab, or a combination of PD-1-Ab and CTLA-4-Ab (PD-1/CTLA-4-Abs) were evaluated for ATAs at baseline and for thyroid function every 6 weeks for 24 weeks after treatment initiation and then observed until the last clinical visit. RESULTS: Of the 451 patients, 51 developed thyroid irAEs after immunotherapy [41 of 416 (9.9%) treated with PD-1-Ab, 0 of 8 (0%) treated with CTLA-4-Ab, and 10 of 27 (37.0%) treated with PD-1/CTLA-4-Abs]. The cumulative incidence of thyroid irAEs was significantly higher in patients who were positive vs negative for ATAs at baseline after both PD-1-Ab [28/87 (32.2%) vs 13/329 (4.0%), P < 0.001] and PD-1/CTLA-4-Abs [6/10 (60.0%) vs 4/17 (23.5%), P < 0.05] treatments. The risk of thyroid irAEs induced by PD-1/CTLA-4Abs, which was significantly higher than that induced by PD-1-Ab, in patients negative for ATAs at baseline was not statistically different from that induced by PD-1-Ab in patients positive for ATAs at baseline. CONCLUSIONS: This study showed that the incidence of thyroid irAEs was high and not negligible after PD-1/CTLA-4-Abs treatment even in patients negative for ATAs at baseline.

Pre-existing Thyroiditis Ameliorates Papillary Thyroid Cancer: Insights From a New Mouse Model.

Papillary thyroid cancer (PTC) often co-occurs with Hashimoto's thyroiditis, an association that has long been reported in clinical studies yet remains controversial. Some studies, in fact, have suggested a protective effect of thyroiditis while others have not. We generated a mouse model where PTC and thyroiditis develop in a predictable manner, combining the oncogenic drive of the BRAFv600E mutation (inducible by tamoxifen) to the thyroiditis susceptibility of the NOD.H2h4 strain (inducible by iodine). A total of 113 NOD.H2h4_TPO-CRE-ER_BRAFV600E mice (50 followed throughout lifetime and 63 sacrificed at 16 weeks post tamoxifen) were used to determine whether the PTC phenotype differs when thyroiditis precedes or coincides with the onset of PTC. Mice with pre-existing thyroiditis lived longer (median survival of 28.2 weeks post tamoxifen) than those with concomitant (25.6 weeks) or no (24.5 weeks) thyroiditis (P < 0.01 by Laplace regression). PTC developed less frequently (33%) in the pre-existing thyroiditis group than the concomitant (100%) or no (100%) thyroiditis groups (P < 0.001 by chi-squared) and showed less aggressive histopathological features. The intratumoral mononuclear cell infiltration was more prominent in mice with pre-existing thyroiditis (P = 0.002 vs the other groups) and sustained by a significant expansion of effector memory CD8 + T cells and CD19 + B cells. These findings shed light on the controversial PTC-thyroiditis association and emphasize the contribution of intratumoral T and B lymphocytes to the evolution of PTC.

CD4+ T cells are essential for the development of destructive thyroiditis induced by anti-PD-1 antibody in thyroglobulin-immunized mice.

Immune-related adverse events induced by anti-programmed cell death-1 antibodies (PD-1-Ab), including destructive thyroiditis (thyroid-irAE), are thought to be caused by activated T cells. However, the T cell subsets that are directly responsible for damaging self-organs remain unclear. To clarify which T cell subsets are involved in the development of thyroid-irAE, a mouse model of thyroid-irAE was analyzed. PD-1-Ab administration 2.5 months after immunization with thyroglobulin caused destructive thyroiditis. Thyroiditis was completely prevented by previous depletion of CD4+ T cells and partially prevented by depleting CD8+ T cells. The frequencies of central and effector memory CD4+ T cell subsets and the secretion of interferon-γ after stimulation with thyroglobulin were increased in the cervical lymph nodes of mice with thyroid-irAE compared with controls. Histopathological analysis revealed infiltration of CD4+ T cells expressing granzyme B in thyroid glands and major histocompatibility complex class II expression on thyrocytes in mice with thyroid-irAE. Adoptive transfer of CD4+ T cells from cervical lymph nodes in mice with thyroid-irAE caused destruction of thyroid follicular architecture in the irradiated recipient mice. Flow cytometric analyses showed that the frequencies of central and effector memory CD4+ T cells expressing the cytotoxic marker CD27 were higher in peripheral blood mononuclear cells collected from patients with thyroid-irAE induced by PD-1-Ab versus those without. These data suggest a critical role for cytotoxic memory CD4+ T cells activated by PD-1-Ab in the pathogenesis of thyroid-irAE.

Anti-pituitary antibodies and susceptible human leukocyte antigen alleles as predictive biomarkers for pituitary dysfunction induced by immune checkpoint inhibitors.

BACKGROUND: Pituitary dysfunction is a life-threatening immune-related adverse event (irAE) induced by immune checkpoint inhibitors (ICIs). To date, it is not possible to identify patients who may develop pituitary irAEs prior to ICI treatment. The aim of this study was to characterize the predisposition for ICI-induced pituitary irAEs by analyzing anti-pituitary antibodies (APAs) and human leukocyte antigens (HLAs). METHODS: In this case-control study, APAs and HLA alleles were analyzed in 62 patients (17 who developed ICI-induced isolated adrenocorticotropic hormone deficiency (ICI-IAD), 5 who developed ICI-induced hypophysitis (ICI-H) and 40 who did not develop pituitary irAEs) treated with ICIs between November 2, 2015, and March 31, 2020, at Nagoya University Hospital. The main outcome measures in this study were the association between the development of pituitary irAEs with APAs at baseline and after treatment and HLA alleles. RESULTS: Eleven of 17 (64.7%) patients who developed ICI-IAD had APAs at baseline, whereas APAs were positive only in 1 of 40 (2.5%) control patients. Although APAs were negative at baseline in all patients who developed ICI-H, they had become positive before the onset of ICI-H in 3 of 4 patients several weeks after ipilimumab administration. At the onset of ICI-IAD and ICI-H, APAs were positive in 15 of 17 (88.2%) and 4 of 5 (80%) patients, respectively. The prevalence of HLA-Cw12, HLA-DR15, HLA-DQ7, and HLA-DPw9 was significantly higher in patients with ICI-IAD, whereas that of HLA-Cw12 and HLA-DR15 was significantly higher in patients with ICI-H than in controls. CONCLUSIONS: This study showed distinct and overlapped patterns of APAs and HLA alleles between ICI-IAD and ICI-H. Our findings also showed that positive APAs at baseline and after treatment, together with susceptible HLA alleles, could become predictive biomarkers for ICI-IAD and ICI-H, respectively. TRIAL REGISTRATION NUMBER: UMIN000019024.

Pituitary dysfunction induced by immune checkpoint inhibitors is associated with better overall survival in both malignant melanoma and non-small cell lung carcinoma: a prospective study.

BACKGROUND: Several immune-related adverse events (irAEs) are reported to be associated with therapeutic efficacy of immune checkpoint inhibitors, yet whether pituitary dysfunction, a life-threatening irAE, affects overall survival (OS) in patients with malignancies is unclear. This prospective study examined the association of pituitary dysfunction (pituitary-irAE) with OS of patients with non-small cell lung carcinoma (NSCLC) or malignant melanoma (MM). METHODS: A total of 174 patients (NSCLC, 108; MM, 66) treated with ipilimumab, nivolumab, pembrolizumab, or atezolizumab at Nagoya University Hospital were evaluated for OS and the development of pituitary-irAE. Kaplan-Meier curves of OS as a function of the development of pituitary-irAE were produced with the log-rank test as a primary endpoint. RESULTS: Pituitary-irAE was observed in 16 patients (4 (3.7%) with NSCLC, 12 (18.2%) with MM) having two different disease types: hypophysitis with deficiency of multiple anterior pituitary hormones accompanied by pituitary enlargement, and isolated adrenocorticotropic hormone (ACTH) deficiency without pituitary enlargement. Among these patients, 6 developed pituitary-irAE while being treated with ipilimumab (6/25 patients (24.0%) treated with ipilimumab) and 10 developed pituitary-irAE during treatment with nivolumab or pembrolizumab (10/167 (6.0%)). All 16 patients had ACTH deficiency and were treated with physiological doses of hydrocortisone. The development of pituitary-irAE was associated with better OS in patients with NSCLC (not reached vs 441 (95% CI not calculated) days, p<0.05) and MM (885 (95% CI 434 to 1336) vs 298 (95% CI 84 to 512) days, p<0.05). CONCLUSIONS: In our study cohort, the incidence of pituitary-irAE was higher than previously reported and the development of pituitary-irAE predicted better prognosis for both NSCLC and MM when patients were treated with physiological doses of hydrocortisone. CLINICAL TRIALS REGISTRATION: UMIN000019024.

Anti-thyroid antibodies and thyroid echo pattern at baseline as risk factors for thyroid dysfunction induced by anti-programmed cell death-1 antibodies: a prospective study.

BACKGROUND: Anti-programmed cell death-1 (PD-1) antibodies can cause thyroid dysfunction. However, no predictive biomarkers enabling stratification of thyroid dysfunction risk have been identified. METHODS: A total of 209 patients treated with an anti-PD-1 antibody were evaluated for anti-thyroid antibodies at baseline and prospectively for thyroid function every 6 weeks for 24 weeks after treatment initiation, and then observed until the visits stopped. Thyroid ultrasonography was performed if the patient was positive for anti-thyroid antibodies at baseline. RESULTS: Of the 209 patients, 19 (9.1%) developed thyroid dysfunction (destructive thyroiditis or hypothyroidism). The cumulative incidence of thyroid dysfunction was significantly higher in patients who were positive vs. negative for anti-thyroid antibodies (15/44 [34.1%] vs. 4/165 [2.4%], p < 0.001). Forty-two patients positive for anti-thyroid antibodies at baseline were divided into two groups according to the presence of an irregular echo pattern. The cumulative incidence of thyroid dysfunction was significantly higher in those with an irregular vs. a regular echo pattern (13/23 [56.5%] vs. 1/19 [5.3%], p = 0.001). None of the patients developed thyroid dysfunction after the initial 24-week period. CONCLUSIONS: The risk of thyroid dysfunction induced by anti-PD-1 antibodies can be predicted by evaluation of anti-thyroid antibodies and the thyroid echo pattern at baseline. TRIAL REGISTRATION: UMIN000019024.

Severe hypocalcemia following denosumab treatment in a patient with secondary osteoporosis associated with primary sclerosing cholangitis.

Primary sclerosing cholangitis (PSC) has been known as a cause of secondary osteoporosis, which often requires medication. Herein, we give the first report of a case of a 38-year-old man with fatigue and paralysis in both upper limbs who had been treated with denosumab for secondary osteoporosis associated with PSC. Since bisphosphonate (alendronate) was ineffective in our patient, the treatment was changed from alendronate to denosumab. Despite replacements with calcium and active vitamin D (alfacalcidol; 1-hydroxycholecalciferol), he developed severe hypocalcemia (albumin-adjusted serum calcium: 5.2 mg/dL) 2 weeks after the second administration of denosumab, which required immediate correction. After that, the corrected serum calcium levels were controlled within the normal range with 0.75 µg of eldecalcitol (1α,25-dihydroxy-2ß-(3-hydroxypropyloxy)vitamin D3) and increased doses of calcium (1,500 mg daily) and phosphate (900 mg daily) without denosumab. Even though denosumab treatment had been terminated, the T score of the lumbar spine improved from -4.4 to -2.6 by 1 year after the second administration, possibly due to the amelioration of osteomalacia through the treatment with eldecalcitol and the higher doses of calcium and phosphate. This report indicates that denosumab can cause severe hypocalcemia in patients with osteoporosis associated with chronic diseases of the hepatobiliary system including PSC, in turn suggesting that the possibility of vitamin D deficiency or osteomalacia should be considered before administering treatments and that serum calcium levels should be closely monitored to detect life-threatening hypocalcemia in patients who have high risk factors for hypocalcemia.

Patients With Antithyroid Antibodies Are Prone To Develop Destructive Thyroiditis by Nivolumab: A Prospective Study.

CONTEXT: Immune 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. OBJECTIVE: This study examined the incidence of endocrine irAEs induced by nivolumab. PATIENTS AND MAIN OUTCOME MEASURED: Sixty-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. RESULTS: Four 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. CONCLUSIONS: Our 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.

Cullin-associated NEDD8-dissociated protein 1, a novel interactor of rabphilin-3A, deubiquitylates rabphilin-3A and regulates arginine vasopressin secretion in PC12 cells.

The molecular mechanism involved in the exocytosis of arginine vasopressin (AVP) is not fully known. Rabphilin-3A has been suggested as a novel autoantigen in infundibulo-neurohypophysitis (LINH), which leads to central diabetes insipidus through insufficient secretion of AVP. However, the role of rabphilin-3A in the pathogenesis of LINH remains unclear. Thus, the aim of the present study was to identify proteins binding rabphilin-3A in the posterior pituitary. Using glutathione S-transferase (GST)-pulldown assays and proteomic analyses, cullin-associated NEDD8-dissociated protein 1 (CAND1) was identified as a rabphilin-3A-binding protein in the posterior pituitary. Co-immunoprecipitation assays indicated that CAND1 interacted endogenously with rabphilin-3A. In addition, immunohistochemistry experiments showed that CAND1 immunoreactivity was detected mainly in the posterior pituitary, intermediate lobe, and the supraoptic nucleus in the hypothalamus, and less in the anterior lobe, partially co-localizing with rabphilin-3A. Overexpression of CAND1 resulted in deubiquitylation of rabphilin-3A in PC12 cells. Moreover, overexpression of CAND1 in PC12 cells co-transfected with AVP enhanced both basal and KCl-stimulated AVP secretion. The findings indicate that CAND1 inhibits the ubiquitylation of rabphilin-3A and positively regulates AVP secretion. These data shed light on a novel potential mechanism involving rabphilin-3A in AVP secretion, and suggest a new role of CAND1 as a regulator of hormone or neurotransmitter secretion.

Critical role of rabphilin-3A in the pathophysiology of experimental lymphocytic neurohypophysitis.

Autoimmune hypophysitis (AH) is thought to be an autoimmune disease characterized by lymphocytic infiltration of the pituitary gland. Among AH pathologies, lymphocytic infundibulo-neurohypophysitis (LINH) involves infiltration of the neurohypophysis and/or the hypothalamic infundibulum, causing central diabetes insipidus resulting from insufficiency of arginine vasopressin secretion. The pathophysiological and pathogenetic mechanisms underlying LINH are largely unknown. Clinically, differentiating LINH from other pituitary diseases accompanied by mass lesions, including tumours, has often been difficult, because of similar clinical manifestations. We recently reported that rabphilin-3A is an autoantigen and that anti-rabphilin-3A antibodies constitute a possible diagnostic marker for LINH. However, the involvement of rabphilin-3A in the pathogenesis of LINH remains to be elucidated. This study was undertaken to explore the role of rabphilin-3A in lymphocytic neurohypophysitis and to investigate the mechanism. We found that immunization of mice with rabphilin-3A led to neurohypophysitis. Lymphocytic infiltration was observed in the neurohypophysis and supraoptic nucleus 1 month after the first immunization. Mice immunized with rabphilin-3A showed an increase in the volume of urine that was hypotonic as compared with control mice. Administration of a cocktail of monoclonal anti-rabphilin-3A antibodies did not induce neurohypophysitis. However, abatacept, which is a chimeric protein that suppresses T-cell activation, decreased the number of T cells specific for rabphilin-3A in peripheral blood mononuclear cells (PBMCs). It ameliorated lymphocytic infiltration of CD3+ T cells in the neurohypophysis of mice that had been immunized with rabphilin-3A. Additionally, there was a linear association between the number of T cells specific for rabphilin-3A in PBMCs and the number of CD3+ T cells infiltrating the neurohypophysis. In conclusion, we suggest that rabphilin-3A is a pathogenic antigen, and that T cells specific for rabphilin-3A are involved in the pathogenesis of neurohypophysitis in mice. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Anti-pituitary antibodies against corticotrophs in IgG4-related hypophysitis.

PURPOSE: IgG4-related disease is a systemic inflammatory disease characterized by infiltration of IgG4-positive plasma cells into multiple organs, including the pituitary gland. Autoimmunity is thought to be involved in the pathogenesis of IgG4-related disease. The diagnosis of IgG4-related hypophysitis (IgG4-RH) is difficult because its clinical features, such as pituitary swelling and hypopituitarism, are similar to those of other pituitary diseases, including lymphocytic hypophysitis and sellar/suprasellar tumors. The presence and significance of anti-pituitary antibodies (APA) in IgG4-RH is unclear. METHODS: In this case-control study, we used single indirect immunofluorescence on human pituitary substrates to assess the prevalence of serum APA in 17 patients with IgG4-RH, 8 control patients with other pituitary diseases (lymphocytic infundibulo-neurohypophysitis, 3; craniopharyngioma, 2; germinoma, 3), and 9 healthy subjects. We further analyzed the endocrine cells targeted by the antibodies using double indirect immunofluorescence. RESULTS: APA were found in 5 of 17 patients with IgG4-RH (29%), and in none of the pituitary controls or healthy subjects. The endocrine cells targeted by the antibodies in the 5 IgG4-RH cases were exclusively corticotrophs. Antibodies were of the IgG1 subclass, rather than IgG4, in all 5 cases, suggesting that IgG4 is not directly involved in the pathogenesis. Finally, antibodies recognized pro-opiomelanocortin in 2 of the cases. CONCLUSIONS: Our study suggests that autoimmunity is involved in the pathogenesis of IgG4-RH and that corticotrophs are the main antigenic target, highlighting a possible new diagnostic marker for this condition.