Single-cell and spatial transcriptomics in endocrine research.

Accumulating evidence suggests that cellular heterogeneity in organs and cell-cell and tissue-tissue interactions are crucial for maintaining physical homeostasis and disease progression. Endocrine organs also exhibit cellular heterogeneity and comprise multiple cell types. For instance, the pituitary gland comprises five types of pituitary hormone-producing cells as well as non-hormone-producing supporting cells, such as fibroblasts, endothelial cells, and folliculostellate cells. However, the functional roles of the interactions between hormone-producing and non-producing cells in the pituitary gland remain incompletely understood. Over the past decade, emerging technologies such as single-cell and spatial transcriptomics have provided excellent tools for studying cellular heterogeneity and their interactions; however, the application of these technologies in endocrine research remains limited. This review provides an overview of these technologies and discusses their strengths and limitations. Additionally, we also summarize the potential future applications of single-cell and spatial transcriptomics in the study of endocrine organs and their disorders.

Responsiveness to DDAVP in Cushing's disease is associated with USP8 mutations through enhancing AVPR1B promoter activity.

PURPOSE: To clarify the characteristics of Cushing's disease (CD) patients who respond to the desmopressin (DDAVP) test and its underlying mechanisms. METHODS: Forty-seven patients with CD who underwent DDAVP testing were included. Patients were divided into two groups: DDAVP test (+) (adrenocorticotropic hormone [ACTH] levels increased by ≥ 1.5-fold during the DDAVP test) and DDAVP test (-) (ACTH levels increased by < 1.5-fold). AVP receptor expression levels in these tumors were quantified using quantitative RT-PCR and immunohistochemistry. AVP receptor promoter activity was analyzed using a dual-luciferase reporter assay system. RESULTS: Females (96.9%) and USP8 mutants (85.7%) were more prevalent in the DDAVP test (+) than in the DDAVP test (-). Indeed, the ACTH and cortisol responsiveness to DDAVP was greater in USP8 mutation positive tumors than that in USP8 wild type tumors (3.0-fold vs. 1.3-fold, 1.6-fold vs. 1.1-fold, respectively). Responsiveness to DDAVP was correlated with the expression levels of AVPR1B, but not with those of AVPR2. Comparably, Avpr1b promoter activity was enhanced by the overexpression of mutant USP8 compared to the wild type. CONCLUSIONS: We found that the responsiveness of ACTH to DDAVP in CD was greater in tumors with USP8 mutations. The present data suggest that USP8 mutations upregulate the AVPR1B promoter activity. Additionally, we showed that the DDAVP test can predict the presence of USP8 mutations.

Human pituitary development and application of iPSCs for pituitary disease.

The pituitary plays a pivotal role in maintaining systemic homeostasis by secreting several hormones. During fetal development, the pituitary develops from the oral ectoderm in contact with the adjacent hypothalamus. This process is regulated by the fine-tuned expression of transcription and growth factors. Impairments of this process result in congenital pituitary hypoplasia leading to dysfunction of the pituitary. Although animal models such as knockout mice have helped to clarify these underlying mechanisms, the developmental processes of the human pituitary gland and the mechanisms of human pituitary disorders have not been fully understood. This is because, at least in part, of the lack of a human pituitary developmental model. Recently, methods for in vitro induction of the pituitary gland from human pluripotent stem cells were developed. These models can be utilized not only for regenerative medicine but also for human pituitary studies on developmental biology and for modeling of pituitary disorders, such as hypopituitarism and pituitary tumors. In this review, we provide an overview of recent progress in the applications of pluripotent stem cells for pituitary research and discuss further perspectives for pituitary studies.

Mechanistic insights into immune checkpoint inhibitor-related hypophysitis: a form of paraneoplastic syndrome.

BACKGROUND: Immune checkpoint inhibitors (ICIs) as a cancer immunotherapy have emerged as a treatment for multiple advanced cancer types. Because of enhanced immune responses, immune-related adverse events (irAEs), including endocrinopathies such as hypophysitis, have been associated with the use of ICIs. Most underlying mechanisms of ICI-related hypophysitis remain unclear, especially for programmed cell death-1 (PD-1)/PD-1 ligand 1 (PD-L1) inhibitors. We hypothesized that ICI-related hypophysitis is associated with paraneoplastic syndrome caused by ectopic expression of pituitary-specific antigens. METHODS: Twenty consecutive patients with ICI-related hypophysitis between 2017 and 2019 at Kobe University Hospital were retrospectively analyzed. Circulating anti-pituitary antibodies were detected using immunofluorescence staining and immunoblotting. Ectopic expression of pituitary autoantigens in tumor specimens was also examined. RESULTS: Eighteen patients were treated with PD-1/PD-L1 inhibitors, and two were treated with a combination of cytotoxic T-lymphocyte antigen-4 (CTLA-4) and PD-1 inhibitors. All patients showed adrenocorticotropic hormone (ACTH) deficiency and additionally, three showed thyroid-stimulating hormone (TSH) deficiency, and one showed gonadotropin-releasing hormone (GnRH) deficiency. Among these patients, three exhibited anti-pituitary antibodies, two with anti-corticotroph antibody and one with anti-somatotroph antibody. Interestingly, the anti-corticotroph antibody recognized proopiomelanocortin (POMC) and those two patients exhibited ectopic ACTH expression in the tumor, while the patients without anti-corticotroph antibody did not. CONCLUSIONS: We demonstrated 10% of PD-1/PD-L1 inhibitors-related hypophysitis were associated with the autoimmunity against corticotrophs and maybe caused as a form of paraneoplastic syndrome, in which ectopic expression of ACTH in the tumor was observed. It is also suggested that the pathophysiology is heterogenous in ICI-related hypophysitis.

Complex Organ Construction from Human Pluripotent Stem Cells for Biological Research and Disease Modeling with New Emerging Techniques.

Human pluripotent stem cells (hPSCs) are grouped into two cell types; embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs). hESCs have provided multiple powerful platforms to study human biology, including human development and diseases; however, there were difficulties in the establishment of hESCs from human embryo and concerns over its ethical issues. The discovery of hiPSCs has expanded to various applications in no time because hiPSCs had already overcome these problems. Many hPSC-based studies have been performed using two-dimensional monocellular culture methods at the cellular level. However, in many physiological and pathophysiological conditions, intra- and inter-organ interactions play an essential role, which has hampered the establishment of an appropriate study model. Therefore, the application of recently developed technologies, such as three-dimensional organoids, bioengineering, and organ-on-a-chip technology, has great potential for constructing multicellular tissues, generating the functional organs from hPSCs, and recapitulating complex tissue functions for better biological research and disease modeling. Moreover, emerging techniques, such as single-cell transcriptomics, spatial transcriptomics, and artificial intelligence (AI) allowed for a denser and more precise analysis of such heterogeneous and complex tissues. Here, we review the applications of hPSCs to construct complex organs and discuss further prospects of disease modeling and drug discovery based on these PSC-derived organs.

Patients with pheochromocytoma exhibit low aldosterone renin ratio-preliminary reports.

BACKGROUND: Plasma renin activity (PRA) is generally increased in patients with pheochromocytoma (PCC) due to low circulating plasma volume and activation of ß-1 adrenergic receptor signaling. However, there has been no study on the aldosterone renin ratio (ARR) in patients with PCC. To elucidate the issue, this study aimed to determine the PRA, plasma aldosterone concentration (PAC), and ARR in patients with PCC and compare them with those in patients with subclinical Cushing's syndrome (SCS) and non-functioning adrenal adenoma (NFA). METHODS: In this retrospective single-center, cross-sectional study, 67 consecutive patients with adrenal tumors (PCC (n = 18), SCS (n = 18), and NFA (n = 31)) diagnosed at Kobe University Hospital between 2008 and 2014 were enrolled. RESULTS: PRA was significantly higher in patients with PCC than in those with SCS and NFA (2.1 (1.3 ~ 2.8) vs. 0.7 (0.5 ~ 1.8) and 0.9 (0.6 ~ 1.4) ng/mL/h; p = 0.018 and p = 0.025). Although PACs were comparable among the three groups, ARR was significantly lower in patients with PCC than in those with SCS and NFA (70.5 (45.5 ~ 79.5) vs. 156.0 (92.9 ~ 194.5) and 114.9 (90.1 ~ 153.4); p = 0.001 and p < 0.001). Receiver operating characteristic curve analysis demonstrated that, in differentiating PCC from NFA, PRA > 1.55 ng/mL/h showed a sensitivity of 70.0% and specificity of 80.6%. Interestingly, ARR < 95.4 showed a sensitivity of 83.3% and specificity of 86.7%, which were higher than those in PRA. CONCLUSIONS: ARR decreased in patients with PCC, which was a more sensitive marker than PRA. Further study is necessary to understand the usefulness of this convenient marker in the detection of PCC. TRIAL REGISTRATION: This study was not registered because of the retrospective analysis.

IgG4-related hypophysitis in patients with autoimmune pancreatitis.

PURPOSE: IgG4-related disease involves various organs including the pituitary and pancreas. The prevalence of IgG4-related hypophysitis is relatively rare compared with IgG4-related pancreatitis (autoimmune pancreatitis). Although several cases demonstrating both autoimmune pancreatitis and hypophysitis have been reported, the prevalence of IgG4-related hypophysitis in patients with autoimmune pancreatitis remains unknown. This study aimed at screening for IgG4-related hypophysitis to accurately determine its prevalence in patients with autoimmune pancreatitis. METHODS: In this cohort study, we screened IgG4-related hypophysitis via pituitary magnetic resonance imaging (MRI) and endocrinological examination in 27 patients who were undergoing follow-up for autoimmune pancreatitis at Kobe University Hospital between 2014 and 2018. RESULTS: Among 27 patients with autoimmune pancreatitis, 5 patients exhibited morphological abnormalities in the pituitary (18.5%). Among them, one patient (3.7%) met the criteria for hypophysitis with an enlarged pituitary and stalk concomitant with hypopituitarism. After glucocorticoid treatment, the enlarged pituitary shrank and became empty sella during the clinical course. Four patients (14.8%) revealed empty sella without obvious pituitary dysfunction. Four of 5 patients with morphological pituitary abnormalities showed multiple organ involvement in addition to pancreatic and pituitary involvement. Accordingly, multiple organ involvement was more prevalent in patients with morphological pituitary abnormalities (80%) compared to those without (48%). CONCLUSIONS: Although a large-scale study is necessary to validate these results, these data suggest that the prevalence of hypophysitis in patients with autoimmune pancreatitis may be underestimated. Based on our findings, we recommend screening for hypophysitis, especially in patients with multiple organ involvement.

Acromegaly caused by a somatotroph adenoma in patient with neurofibromatosis type 1.

Although acromegaly has been reported in patients with Neurofibromatosis type 1 (NF1), these cases have not been associated with growth hormone (GH)-producing somatotroph adenoma, but with optic pathway glioma. A 68 year-old Japanese woman, who had been clinically diagnosed with NF1, was referred to our hospital due to a thyroid tumor and hypercalcemia. Acromegaly was suspected due to her facial features, and subsequent examinations revealed the presence of GH excess with a pituitary tumor, leading to the diagnosis of acromegaly. Histological and immunohistochemical analysis demonstrated an eosinophilic pituitary adenoma with diffuse positivity for GH, indicating typical somatotroph adenoma. In addition, her thyroid tumor was diagnosed histologically as follicular thyroid carcinoma (FTC) with primary hyperparathyroidism (PHPT). To investigate the pathogenesis of this untypical multiple endocrine tumor case of NF1, genetic analysis was performed using peripheral leukocytes and tissue of resected tumors. A heterozygous novel germline nonsense mutation (p.Arg1534*) in exon 35 of the NF1 gene was detected from peripheral leukocytes, which results in a truncated protein lacking the critical domain for GTPase activity, strongly suggesting its causal role in NF1. The loss of heterozygosity (LOH) in exon 35 of the NF1 gene was not detected in the somatotroph adenoma, parathyroid adenoma, and FTC. Although any mutations of the following genes; MEN1, CDKN1B, and PAX8-PPARγ were not detected, a heterozygous GNAS R201C mutation was detected in the somatotroph adenoma. To our knowledge, this is the first rare MEN1-like case of genetically diagnosed NF1 complicated with acromegaly caused by a somatotroph adenoma.

Isolated adrenocorticotropic hormone deficiency as a form of paraneoplastic syndrome.

PURPOSE: In isolated adrenocorticoropic hormone (ACTH) deficiency (IAD), autoimmunity against corticotrophs has been suggested; however, the pathogenesis remains largely unknown. Large cell neuroendocrine carcinoma (LCNEC) of the lung is a pulmonary tumor of high-grade malignant neuroendocrine tumor and it reportedly caused paraneoplastic syndrome by autoimmunity in several cases. METHODS: A 42-year-old woman with isolated adrenocorticotropic (ACTH) hormone deficiency (IAD) was diagnosed with large cell neuroendocrine carcinoma (LCNEC) 3 years after being diagnosed with IAD. We hypothesized that the LCNEC played a causal role in the development of IAD as a paraneoplastic syndrome and analyzed the autoimmunity. We also analyzed another case of ectopic ACTH syndrome to prove this hypothesis. RESULTS: The LCNEC tissue revealed an ectopic ACTH expression and lymphocyte infiltration. Interestingly, autoantibody against the proopiomelanocortin (POMC) protein was detected in the peripheral blood. Although, patient's serum did not show any effects on cell viability, proliferation, nor pomc expression in a corticotroph cell line, AtT20 cells, patient's lymphocytes in the peripheral blood specifically reacted toward POMC protein, indicating a presence of cytotoxic T lymphocytes (CTLs). In addition, the analysis of another case of ectopic ACTH syndrome showed lymphocyte infiltration not only in the metastatic liver tumors but also in the pituitary. Moreover, most CD8-positive cells resided adjacent to corticotrophs. CONCLUSIONS: These data indicate that the ectopic ACTH expression in the tumor evoked the autoimmunity to corticotrophs and caused IAD as a form of paraneoplastic syndrome.

Cross-sectional prevalence of pancreatic cystic lesions in patients with acromegaly, a single-center experience.

PURPOSE: Acromegaly is a disease associated with an increased risk for several kinds of neoplasms including colon and thyroid cancer. Although the association between acromegaly and pancreatic neoplasms has not been elucidated, it has recently been reported that GNAS gene mutations were found in 58% of intraductal papillary mucinous neoplasms (IPMNs), which are representative pancreatic cystic lesions, suggesting a link between IPMNs and acromegaly. To assess the prevalence of pancreatic cystic lesions in patients with acromegaly, we performed a retrospective cross-sectional single institute study. METHODS: Thirty consecutive acromegalic patients (20 females and 10 males; mean age, 60.9 ± 11.9 years) who underwent abdominal contrast-enhanced computed tomography or magnetic resonance imaging between 2007 and 2015 at Kobe University Hospital were recruited. We also analyzed the relationship between presence of pancreatic cystic lesions and somatic GNAS mutations in pituitary tumors. RESULTS: Seventeen of 30 (56.7%) patients studied had pancreatic cystic lesions. Nine of 17 patients (52.9%) were diagnosed with IPMNs based on imaging findings. These results suggest that the prevalence of IPMNs may be higher in acromegalic patients in acromegalic patients than historically observed in control patients (up to 13.5%). In patients with pancreatic cystic lesions, the mean patient age was higher and the duration of disease was longer than in those without pancreatic cystic lesions (67.0 ± 2.3 vs. 53.0 ± 2.7 years, p < 0.001, 15.5 ± 2.4 vs. 7.3 ± 2.8 years, p = 0.04). There were no differences in serum growth hormone levels or insulin-like growth factor standard deviation scores between these two groups (21.3 ± 6.4 vs. 23.0 ± 7.4 ng/ml, p = 0.86, 6.6 ± 0.5 vs. 8.0 ± 0.6, p = 0.70). Neither the presence of somatic GNAS mutation in a pituitary tumor nor low signal intensity of the tumor in T2 weighted magnetic resonance imaging was associated with the presence of pancreatic cystic lesions. CONCLUSIONS: These data demonstrate that old or long-suffering patients with acromegaly have a higher prevalence of pancreatic cystic lesions. Moreover, the prevalence of pancreatic cystic lesions may be increased in acromegalic patients.

Genetic and clinical characteristics of Japanese patients with sporadic somatotropinoma.

Most of acromegaly is caused by a sporadic somatotropinoma and a couple of novel gene mutations responsible for somatotropinoma have recently been reported. To determine the cause of sporadic somatotropinoma in Japanese patients, we analyzed 61 consecutive Japanese patients with somatotropinoma without apparent family history. Comprehensive genetic analysis revealed that 31 patients harbored guanine nucleotide-binding protein, alpha stimulating (GNAS) mutations (50.8%) and three patients harbored aryl hydrocarbon receptor interacting protein (AIP) mutations (4.9%). No patients had G protein-coupled receptor 101 (GPR101) mutations. The patients in this cohort study were categorized into three groups of AIP, GNAS, and others and compared the clinical characteristics. The AIP group exhibited significantly younger age at diagnosis, larger tumor, and higher nadir GH during oral glucose tolerance test. In all patients with AIP mutation, macro- and invasive tumor was detected and repetitive surgery or postoperative medical therapy was needed. One case showed a refractory response to postoperative somatostatin analogue (SSA) but after the addition of cabergoline as combined therapy, serum IGF-I levels were controlled. The other case showed a modest response to SSA and the switching to cabergoline monotherapy was also effective. These data suggest that although resistance to SSA has been reported in patients with AIP mutations, the response to dopamine agonist (DA) may be retained. In conclusion, the cause of sporadic somatotropinoma in Japanese patients was comparable with the previous reports in Caucasians, patients with AIP mutations showed unique clinical characteristics, and DA may be a therapeutic option for patients with AIP mutations.

The prevalence and associated factors of colorectal neoplasms in acromegaly: a single center based study.

PURPOSE: Colorectal neoplasms are well known to be a complication in cases of acromegaly; however, data on the prevalence of colorectal neoplasms in Asian patients with acromegaly are limited. Further, the factors associated with colorectal neoplasms in cases of acromegaly are controversial. Therefore, we aimed to clarify the prevalence of and factors associated with colorectal neoplasms in Japanese patients with acromegaly in a single center. METHODS: We analyzed consecutive 57 patients who had undergone full-length colonoscopy at the time of diagnosis at Kobe University Hospital between 1986 and 2012. RESULTS: Of the 57 patients, 22 (38.6%), 18 (31.6%) and 3 (5.3%) patients were diagnosed with hyperplastic polyps, adenomas, and adenocarcinomas, respectively and the prevalence was significantly higher than in a historical control group, Chinese patients with irritable bowel syndrome (The odds ratio was 4.0, 8.7, and 17.5, respectively). The prevalence of adenocarcinomas was also significantly higher in these patients than in the general Japanese population (odds ratio 14.5). Patients with acromegaly who had colorectal neoplasms had longer disease duration than those without colorectal neoplasms. Of note, the area under the growth hormone (GH) concentration-time curve (GH AUC) during the oral glucose tolerance test was significantly higher in patients with adenocarcinomas than in those with no colonic lesion or those with hyperplastic polyps. CONCLUSION: Japanese patients with acromegaly exhibited an increased risk of colorectal neoplasms, especially colorectal adenocarcinomas. An increased GH AUC was associated with an increased risk for colon adenocarcinomas in patients with acromegaly.

The quality of life in acromegalic patients with biochemical remission by surgery alone is superior to that in those with pharmaceutical therapy without radiotherapy, using the newly developed Japanese version of the AcroQoL.

PURPOSE: To develop a Japanese version of the acromegaly quality of life (QoL) questionnaire (AcroQoL) and investigate the factors associated with impaired QoL in patients with acromegaly. METHODS: We developed a Japanese version of the AcroQoL by a forward-backward method and evaluated QoL in 38 patients with acromegaly who had been followed up at an outpatient clinic at Kobe University Hospital. Its reliability was examined with Cronbach's alpha and item-total correlations. Second examination was performed for concurrent validity by assessment of correlations with the Short Form-36 (SF-36) and longitudinal analysis of the AcroQoL in 25 patients. RESULTS: Cronbach's alpha and item-total correlations showed a range of 0.76-0.93 and 0.20-0.84, respectively, and significant correlations were found between the AcroQoL and the SF-36. Younger age and a history of radiotherapy were associated with worse total score by the multivariate linear regression analysis (p = 0.020 and p = 0.042, respectively). Intriguingly, in the biochemically-controlled group after the exclusion of patients who received radiotherapy, patients who underwent surgery alone exhibited a higher psychological (75.0 vs. 65.7 %, p = 0.036) and appearance (64.3 vs. 53.6 %, p = 0.036) score than those who are treating with pharmaceutical therapy. CONCLUSIONS: The reliability of the Japanese version of the AcroQoL was satisfactory. Younger age and a history of radiotherapy were associated with lower QoL in patients with acromegaly. In biochemically-controlled acromegaly, patients who underwent surgery alone exhibited better QoL than those under pharmaceutical therapy.

A diagnostic pitfall in IgG4-related hypophysitis: infiltration of IgG4-positive cells in the pituitary of granulomatosis with polyangiitis.

INTRODUCTION: Immunoglobulin (Ig) G4-related hypophysitis is an emerging clinical entity, which is characterized by an elevated serum IgG4 concentration and infiltration of IgG4-positive plasma cells in the pituitary. Although some criteria for its diagnosis have been proposed, they have not been fully established. In particular, differential diagnosis from secondary chronic inflammation including granulomatosis with polyangiitis (GPA) is difficult in some cases. We describe central diabetes insipidus with pituitary swelling exhibiting infiltration of IgG4-positive cells. PATIENT: A 43-year-old woman in the remission stage of GPA presented with sudden-onset polyuria and polydipsia. Pituitary magnetic resonance imaging revealed swelling of the anterior and posterior pituitary and stalk, with heterogeneous gadolinium enhancement and disappearance of the high signal intensity of the posterior pituitary. Evaluation of biochemical markers for GPA suggested that the disease activity was well-controlled. Endocrinological examination revealed the presence of central diabetes insipidus and growth hormone deficiency. Pituitary biopsy specimen showed IgG4-positive cells, with a 43% IgG4(+)/IgG(+) ratio, which met the criteria for IgG4-related hypophysitis. However, substantial infiltration of polymorphonuclear neutrophils with giant cells was also noted, resulting in a final diagnosis of pituitary involvement of GPA. CONCLUSION: These results suggest that pituitary involvement of GPA should be taken into account for the differential diagnosis of IgG4-related hypophysitis.

The prevalence of acromegaly in hospitalized patients with type 2 diabetes.

The prevalence of acromegaly is estimated to be 8-24/100,000, but several recent studies suggest it is underestimated. In particular, acromegaly is considered more prevalent in patients with type 2 diabetes mellitus (T2DM) than in the normal population. This study aimed to evaluate the prevalence of acromegaly in hospitalized patients with T2DM. A total of 327 hospitalized patients with T2DM were recruited as subjects. If serum insulin-like growth factor 1 (IGF-1) levels were found to be elevated, random GH level was measured or oral glucose tolerance test (OGTT) was performed. Five patients with elevated serum IGF-1 levels and random GH level or inadequate suppression of GH in the OGTT underwent pituitary magnetic resonance imaging. Of those patients, pituitary adenoma was detected in 2 patients. These 2 patients were diagnosed with acromegaly, as they also exhibited mild acromegalic features. Intriguingly, both these patients exhibited severe macroangiopathy and an absence of microangiopathy. The prevalence of acromegaly in the hospitalized patients with T2DM in this study was therefore 0.6%, suggesting a higher prevalence than that predicted. Although a large-scale prospective study is required to clarify the precise prevalence of acromegaly in hospitalized patients with T2DM, the present study shows that it is useful to screen hospitalized patients with T2DM for acromegaly by measuring their serum IGF-1 level.

D-dimer as a significant marker of deep vein thrombosis in patients with subclinical or overt Cushing's syndrome.

Venous thromboembolism (VTE) is frequently associated with hypercortisolemia. This retrospective single-center study aimed to clarify the significance of plasma D-dimer levels for VTE screening in patients with subclinical or overt Cushing's syndrome (soCS). A total of 72 consecutive treatment-naïve patients with soCS diagnosed at Kobe University Hospital between 2002 and 2014 were enrolled. Patients with both lower extremity ultrasound and D-dimer measurement data (n = 19) were recruited in study 1 and divided into 2 groups, a deep vein thrombosis (DVT) (-) group (n = 12) and DVT (+) group (n = 7) for a comparison of the associated factors. The age and D-dimer levels were higher in the DVT (+) group than in the DVT (-) group (p = 0.04 and 0.02, respectively). A receiver operating characteristic analysis found that D-dimer level ≥2.6 µg/mL correlated with the presence of DVT (sensitivity, 100%; specificity, 91.7%). Next, patients with D-dimer measurement data (n = 36) were recruited in study 2 and divided into 2 groups according to D-dimer level: D-dimer (-), <1 µg/mL group (n = 23) and D-dimer (+), ≥1 µg/mL group (n = 13); the groups were compared with respect to various VTE-related risk factors. A logistic regression analysis revealed that elevated cortisol level after low-dose dexamethasone suppression was a significant risk factor for D-dimer elevation (OR = 1.21, p = 0.02). In conclusion, these data demonstrate that a D-dimer level ≥2.6 µg/mL is an indicator of DVT in treatment naïve patients with soCS and suggests that relatively high autonomous cortisol secretion may be associated with thrombus formation.

A missense single-nucleotide polymorphism in the sialic acid acetylesterase (SIAE) gene is associated with anti-PIT-1 antibody syndrome.

A novel clinical entity related to autoimmune polygladular syndrome (APS) termed "anti-PIT-1 antibody syndrome" is characterized by a presence of circulating autoantibody against the pituitary-specific transcriptional factor-1 (PIT-1) with acquired specific defect in GH, PRL, and TSH. Although autoimmunity to PIT-1 has been suggested, the underlying mechanisms remain to be elucidated. Sialic acid acetylesterase (SIAE) plays a crucial role in regulating the threshold of autoantibody production of B-cells and the defective variants of SIAE are associated with an increased risk of various autoimmune diseases such as type 1 diabetes (T1DM). To explore the link between anti-PIT-1 antibody syndrome and SIAE, we analyzed SIAE gene in 3 patients with anti-PIT-1 antibody syndrome and 200 healthy control subjects, and compared the prevalence of single nucleotide polymorphisms. Intriguingly, we found A467V SIAE variants (c.1400C>T, rs7941523) in a heterozygous state in all the patients with anti-PIT-1 antibody syndrome, while we detected in 6 % of control subjects, in which the prevalence was significantly increased in the patients (P<0.0005). Considering the physiological function of SIAE and the clinical features of anti-PIT-1 antibody syndrome, present data imply a novel aspect of the pathogenesis in this disease.

Disease Modeling of Pituitary Adenoma Using Human Pluripotent Stem Cells.

Pituitary adenomas are characterized by abnormal growth in the pituitary gland. Surgical excision is the first-line treatment for functional (hormone-producing) pituitary adenomas, except for prolactin-producing adenomas; however, complete excision is technically challenging, and many patients require long-term medication after the treatment. In addition, the pathophysiology of pituitary adenomas, such as tumorigenesis, has not been fully understood. Pituitary adenoma pathophysiology has mainly been studied using animal models and animal tumor-derived cell lines. Nevertheless, experimental studies on human pituitary adenomas are difficult because of the significant differences among species and the lack of reliable cell lines. Recently, several methods have been established to differentiate pituitary cells from human pluripotent stem cells (hPSCs). The induced pituitary hormone-producing cells retain the physiological properties already lost in tumor-derived cell lines. Moreover, CRISPR/Cas9 systems have expedited the introduction of causative gene mutations in various malignant tumors into hPSCs. Therefore, hPSC-derived pituitary cells have great potential as a novel platform for studying the pathophysiology of human-specific pituitary adenomas and developing novel drugs. This review presents an overview of the recent progresses in hPSC applications for pituitary research, functional pituitary adenoma pathogenesis, and genome-editing techniques for introducing causative mutations. We also discuss future applications of hPSCs for studying pituitary adenomas.

Two Cases of anti-PIT-1 Hypophysitis Exhibited as a Form of Paraneoplastic Syndrome not Associated With Thymoma.

Anti-pituitary-specific transcription factor 1 (PIT-1) hypophysitis (anti-PIT-1 antibody syndrome) is a thymoma-associated autoimmune disease characterized by acquired growth hormone (GH), prolactin (PRL), and thyrotropin (TSH) deficiencies due to autoimmunity against PIT-1. Ectopic expression of PIT-1 in the thymoma plays a causal role in development of the disease. Here, we report 2 cases of anti-PIT-1 hypophysitis exhibiting as a form of paraneoplastic syndrome with conditions other than thymoma. A 79-year-old woman (case 1) and an 86-year-old man (case 2) were referred with a suspicion of anti-PIT-1 hypophysitis because of acquired GH, PRL, and TSH deficiencies. Case 1 was complicated by diffuse large B-cell lymphoma (DLBCL) of the bladder and case 2 was diagnosed with malignancy with multiple metastases of unknown origin. Because circulating anti-PIT-1 antibody was detected, both patients were diagnosed with anti-PIT-1 hypophysitis. Circulating PIT-1-reactive T cells were detected in case 1 via enzyme-linked immunospot (ELISPOT) assay. Interestingly, the PIT-1 protein was ectopically expressed in the DLBCL cells of case 1, whereas DLBCL tissues derived from patients without anti-PIT-1 hypophysitis were negative for PIT-1. In case 2, the materials were not available because of best supportive care was under way. These data show that anti-PIT-1 hypophysitis is associated not only with thymoma but also with other malignancies. Additionally, the ectopic expression of PIT-1 in the DLBCL tissues and presence of PIT-1-reactive T cells suggested that the underlying mechanisms were similar to those observed in thymoma. Thus, anti-PIT-1 hypophysitis is defined as a form of paraneoplastic syndrome.

Clinical Heterogeneity of Acquired Idiopathic Isolated Adrenocorticotropic Hormone Deficiency.

Objective: Heterogeneous clinical characteristics are observed in acquired isolated adrenocorticotropic hormone (ACTH) deficiency (IAD); however, its classification remains to be established because of its largely unknown pathophysiology. In IAD, anti-pituitary antibodies have been detected in some patients, although their significance remains unclear. Therefore, this study aimed to classify patients with IAD and to clarify the significance of anti-pituitary antibodies. Design and Methods: We analyzed 46 consecutive patients with IAD. Serum anti-pituitary antibodies were analyzed via immunofluorescence staining using a mouse pituitary tissue. Principal component and cluster analyses were performed to classify IAD patients based on clinical characteristics and autoantibodies. Results: Immunofluorescence analysis using the sera revealed that 58% of patients showed anti-corticotroph antibodies and 6% of patients showed anti-follicular stellate cell (FSC) antibodies. Principal component analysis demonstrated that three parameters could explain 70% of the patients. Hierarchical cluster analysis showed three clusters: Groups A and B comprised patients who were positive for anti-corticotroph antibodies, and plasma ACTH levels were extremely low. Groups A and B comprised middle-aged or elderly men and middle-aged women, respectively. Group C comprised patients who were positive for the anti-FSC antibody and elderly men; plasma ACTH levels were relatively high. Conclusions: Patients with IAD were classified into three groups based on clinical characteristics and autoantibodies. The presence of anti-corticotroph antibody suggested severe injury to corticotrophs. This new classification clearly demonstrated the heterogeneity in the pathogenesis of IAD.