Decreased islet amyloid polypeptide staining in the islets of insulinoma patients.

Islet amyloid polypeptide (IAPP) is a factor that regulates food intake and is secreted from both pancreatic islets and insulinoma cells. Here, we aimed to evaluate IAPP immunohistochemically in islets or insulinoma cells in association with clinical characteristics. We recruited six insulinoma patients and six body mass index-matched control patients with pancreatic diseases other than insulinoma whose glucose tolerance was confirmed to be normal preoperatively. IAPP and IAPP-insulin double staining were performed on pancreatic surgical specimens. We observed that the IAPP staining level and percentage of IAPP-positive beta cells tended to be lower (p = 0.1699) in the islets of insulinoma patients than in those of control patients, which might represent a novel IAPP expression pattern under persistent hyperinsulinemia and hypoglycemia.

Preoperative hemoglobin A1c is associated with postoperative bleeding after vitrectomy for vitreous hemorrhage in patients with diabetic retinopathy.

We previously reported that a high HbA1c level 3 months before vitrectomy for vitreous hemorrhage or a large preoperative decrease in the HbA1c level over 3 months tended to increase the risk of rebleeding in diabetic retinopathy patients evaluated between 2010 and 2014. Here, we aimed to confirm these results with an extended study period and an increased number of operated eyes. This study included 121 diabetic patients who were admitted to Osaka University Hospital between 2010 and 2019 and who underwent vitrectomy for vitreous hemorrhage. Binomial logistic regression analysis was performed with the presence of postoperative bleeding as the outcome. The present study showed that the duration of the operation was associated with rebleeding (odds ratio = 1.02, p = 0.0016). A high HbA1c level just before vitrectomy tended to be associated with the bleeding (odds ratio = 1.27, p = 0.05), while preoperative HbA1c changes were not associated with rebleeding. The results of this study suggest that a high preoperative HbA1c level just before vitrectomy, not a decrease in HbA1c levels, in addition to the duration of the operation may increase the risk of postoperative bleeding after vitrectomy in diabetic retinopathy patients.

Single-housing-induced islet epigenomic changes are related to polymorphisms in diabetic KK mice.

A lack of social relationships is increasingly recognized as a type 2 diabetes (T2D) risk. To investigate the underlying mechanism, we used male KK mice, an inbred strain with spontaneous diabetes. Given the association between living alone and T2D risk in humans, we divided the non-diabetic mice into singly housed (KK-SH) and group-housed control mice. Around the onset of diabetes in KK-SH mice, we compared H3K27ac ChIP-Seq with RNA-Seq using pancreatic islets derived from each experimental group, revealing a positive correlation between single-housing-induced changes in H3K27ac and gene expression levels. In particular, single-housing-induced H3K27ac decreases revealed a significant association with islet cell functions and GWAS loci for T2D and related diseases, with significant enrichment of binding motifs for transcription factors representative of human diabetes. Although these H3K27ac regions were preferentially localized to a polymorphic genomic background, SNVs and indels did not cause sequence disruption of enriched transcription factor motifs in most of these elements. These results suggest alternative roles of genetic variants in environment-dependent epigenomic changes and provide insights into the complex mode of disease inheritance.

Interrelationships Among Accumulations of Intra- and Periorgan Fats, Visceral Fat, and Subcutaneous Fat.

We aimed to clarify the relationship between intra- and periorgan fats, visceral fat, and subcutaneous fat. We used abdominal computed tomography to evaluate intra- and periorgan fat accumulations in the pancreas, liver, spleen, renal parenchyma, renal sinus, and skeletal muscle. The relationships between these fats, visceral fat, and subcutaneous fat were examined by using partial correlation and covariance analysis, adjusting for BMI. We found that visceral fat and all intra- and periorgan fat accumulations were positively correlated, whereas subcutaneous fat and accumulations of all intra- and periorgan fats and visceral fat were negatively correlated. Individuals with excessive visceral fat accumulation had significantly greater accumulations of fat in the pancreas, liver, renal sinus, and skeletal muscle than those without excessive visceral fat accumulation (P = 0.01, 0.006, 0.008, and 0.02, respectively). In conclusion, all intra- and periorgan fat accumulations show a positive correlation with visceral fat and a negative correlation with subcutaneous fat, independent of BMI.

Prediction of future insulin-deficiency in glutamic acid decarboxylase autoantibody enzyme-linked immunosorbent assay-positive patients with slowly-progressive type 1 diabetes.

AIMS/INTRODUCTION: This study aimed to identify risk factors that contribute to the progression of slowly-progressive type 1 diabetes by evaluating the positive predictive value (PPV) of factors associated with the progression to an insulin-dependent state. MATERIALS AND METHODS: We selected 60 slowly-progressive type 1 diabetes patients who tested positive for glutamic acid decarboxylase autoantibodies (GADA) at diagnosis from the Japanese Type 1 Diabetes Database Study. GADA levels in these patients were concurrently measured using both radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA) techniques. RESULTS: Compared with the non-progressor group (fasting C-peptide [F-CPR] levels maintained ≥0.6 ng/mL), the progressor group showed a younger age at diagnosis, lower body mass index (BMI), lower F-CPR levels and a higher prevalence of insulinoma-associated antigen-2 autoantibodies (IA-2A). The PPV of RIA-GADA increased from 56.3 to 70.0% in the high titer group (≥10 U/mL), and further increased to 76.9, 84.2, 81.0 and 75.0% when combined with specific thresholds for age at diagnosis <47 years, BMI <22.6 kg/m2, F-CPR <1.41 ng/mL and IA-2A positivity, respectively. In contrast, the PPV of ELISA-GADA (71.8%) remained the same at 73.1% in the high titer group (≥180 U/mL), but increased to 81.8, 82.4 and 79.0% when evaluated in conjunction with age at diagnosis, BMI and F-CPR level, respectively. CONCLUSIONS: Our findings show that, unlike RIA-GADA, ELISA-GADA shows no association between GADA titers and the risk of progression to an insulin-dependent state. The PPV improves when age at diagnosis, BMI and F-CPR levels are considered in combination.

New diagnostic criteria (2023) for slowly progressive type 1 diabetes (SPIDDM): Report from Committee on Type 1 Diabetes of the Japan Diabetes Society (English version).

The diagnostic criteria for slowly progressive type 1 diabetes (slowly progressive insulin-dependent diabetes mellitus; SPIDDM) have been revised by the Committee on Type 1 Diabetes of the Japan Diabetes Society. All of the following three criteria must be met for 'a definitive diagnosis of SPIDDM': (1) presence of anti-islet autoantibodies at some point in time during the disease course; (2) absence of ketosis or ketoacidosis at the diagnosis of diabetes with no requirement for insulin treatment to correct hyperglycemia immediately after diagnosis in principle; and (3) gradual decrease of insulin secretion over time, with insulin treatment required at more than 3 months after diagnosis, and the presence of severe endogenous insulin deficiency (fasting serum C-peptide immunoreactivity <0.6 ng/mL) at the last observed point in time. When a patient fulfills only (1) and (2), but not (3), he/she is diagnosed with 'SPIDDM (probable)' because the diabetes is non-insulin-dependent type.

Effects of liraglutide on intrapancreatic fat deposition in patients with type 2 diabetes.

BACKGROUND & AIMS: Ectopic fat deposition is associated with worsening of glycemic control. This study was conducted to determine whether liraglutide reduces ectopic fat deposition, especially in pancreas, in patients with type 2 diabetes (T2D). METHODS: We retrospectively recruited T2D patients who underwent abdominal unenhanced CT scans both before and after administration of liraglutide (N = 13) or glimepiride (N = 29). Using CT values of pancreas (P), liver (L) and spleen (S), we defined the indices of intrapancreatic and liver fat as P-S value and L-S value, respectively. Increase of each value suggests the reduction of each fat deposition. RESULTS: The values of HbA1c (p = 0.0017) and body weight (p = 0.0081) decreased, and L-S (p = 0.0024) increased significantly after administration of liraglutide compared with those at baseline. Similarly, P-S tended to increase in the liraglutide group (p = 0.0547) and increased significantly in the liraglutide subgroup with fatty pancreas (p = 0.0303), defined as having baseline P-S less than -5. In the glimepiride group, P-S did not increase regardless of baseline P-S. Among patients with fatty pancreas, administration of liraglutide tended to be a significant factor for the change in P-S after adjustment for the change in HbA1c (p = 0.1090) and the change in visceral fat area (p = 0.1030). CONCLUSIONS: Intrapancreatic fat deposition was decreased after treatment with liraglutide, but not glimepiride, in T2D patients with fatty pancreas. Liraglutide might reduce intrapancreatic fat deposition independently of decreases in HbA1c and visceral fat volume.

New diagnostic criteria (2023) for slowly progressive type 1 diabetes (SPIDDM): Report from Committee on Type 1 Diabetes in Japan Diabetes Society (English version).

The diagnostic criteria for slowly progressive type 1 diabetes (slowly progressive insulin-dependent diabetes mellitus; SPIDDM) have been revised by the Committee on Type 1 Diabetes of the Japan Diabetes Society. All of the following three criteria must be met for "a definitive diagnosis of SPIDDM": (1) presence of anti-islet autoantibodies at some point in time during the disease course; (2) absence of ketosis or ketoacidosis at the diagnosis of diabetes with no requirement of insulin treatment to correct hyperglycemia immediately after diagnosis in principle; and (3) gradual decrease of insulin secretion over time, with insulin treatment required at more than 3 months after diagnosis, and presence of severe endogenous insulin deficiency (fasting serum C-peptide immunoreactivity < 0.6 ng/mL) at the last observed point in time. When a patient fulfills the only (1) and (2), but not (3), he/she is diagnosed with "SPIDDM (probable)" because the diabetes is non-insulin-dependent state.

Daily Glucose Profiles after Switching from Injectable to Oral Semaglutide in Patients with Type 2 Diabetes Mellitus.

Objective This prospective observational study explored the changes in the daily glycemic profile after switching from injectable to oral semaglutide in patients with type 2 diabetes mellitus. Methods Patients with type 2 diabetes mellitus who were treated with once-weekly 0.5 mg injectable semaglutide and wished to switch to once-daily oral semaglutide participated in this study. Oral semaglutide was initiated at 3 mg and increased to 7 mg a month later, according to the package insert. Before and two months after the switch, participants wore a sensor for continuous glucose monitoring for up to 14 days. We also evaluated the questionnaire-based treatment satisfaction and the preference between the two formulations. Patients Twenty-three patients participated. Results Mean glucose levels significantly increased by 9 mg/dL on average, from 132±20 to 141±27 mg/dL (p=0.047), which was equivalent to a change of 0.2% in the estimated hemoglobin A1c (6.5±0.5% to 6.7±0.7%). The inter-individual variability assessed with standard deviation also significantly increased (p=0.004). The change in treatment satisfaction varied considerably among patients, with no specific trend in the overall population. After trying oral semaglutide, 48% of patients responded that they preferred the oral formulation, while 35% preferred the injectable formulation, and 17% had no preference. Conclusion The mean glucose levels increased by 9 mg/dL on average after switching from once-weekly 0.5 mg injectable semaglutide to once-daily 7 mg oral semaglutide, with an increased inter-individual variability. The change in treatment satisfaction considerably varied among patients.

Feasibility pilot study of a Japanese teaching kitchen program.

Background: This pilot study examined the feasibility of a new lifestyle modification program involving a "Teaching Kitchen" in Japan. Our goal was to explore (1) feasibility of the program; (2) acceptability for class frequency (weekly vs. bi-weekly); and (3) changes in biometrics, dietary intakes, and lifestyle factors. Methods: A total of 24 employees with obesity in a Japanese company were recruited. Participants were randomly divided into two groups (weekly or bi-weekly group), each attending the program consisting of four two-hour classes (lectures on nutrition, exercise, mindfulness, and culinary instructions). Participants were observed for changes in dietary intakes, biometrics, and health related quality of life over the subsequent 3 months. We tested the between-group differences in changes using linear mixed-effect models. Results: The program completion rates were 83.3% in total (91.7% for weekly group and 75.0% for bi-weekly group). From baseline to post-intervention, significant decreases were observed in weight (p < 0.001), body mass index (p < 0.001), diastolic blood pressure (p = 0.03), body fat mass (p < 0.001), and dietary intakes in total fat (p = 0.03) and sodium (p = 0.008) among 17 participants who were available for measurements. Improvements in biometrics remained significant 1 month after the intervention (all p ≤ 0.03 in 14 participants). Participants' health related quality of life was significantly improved in bodily pain, general health, vitality, and mental component score (all p ≤ 0.047). Conclusions: The new Japanese Teaching Kitchen program is feasible with high program completion rates in Japanese office workers with obesity. While this was a small feasibility study, significant multiple improvements in dietary intakes, biometrics, and health related quality of life suggest that this line of inquiry warrants further exploration to address obesity and obesity-related diseases in Japan.

Relationships between intra-pancreatic fat deposition and lifestyle factors: a cross-sectional study.

Aims: The excess deposition of intra-pancreatic fat deposition (IPFD) has been reported to be associated with type 2 diabetes, chronic pancreatitis, and pancreatic ductal adenocarcinoma. In the current study, we aimed to identify a relationship between lifestyle factors and IPFD. Materials and methods: 99 patients admitted to the Osaka University Hospital who had undergone abdominal computed tomography were selected. We evaluated the mean computed tomography values of the pancreas and spleen and then calculated IPFD score. Multiple regression analyses were used to assess the associations between IPFD score and lifestyle factors. Results: Fast eating speed, late-night eating, and early morning awakening were significantly associated with a high IPFD score after adjusting for age, sex, diabetes status and Body Mass Index (p=0.04, 0.01, 0.01, respectively). Conclusion: The current study has elucidated the significant associations of fast eating speed, late-night eating, and early morning awakening with IPFD.

Myocardial fat accumulation is associated with cardiac dysfunction in patients with type 2 diabetes, especially in elderly or female patients: a retrospective observational study.

BACKGROUND: Ectopic fat is fat that accumulates in or around specific organs or compartments of the body including myocardium. The clinical features of type 2 diabetes patients with high fat accumulation in the myocardium remain unknown. Moreover, little is known about the influence of myocardial fat accumulation in type 2 diabetes on coronary artery disease and cardiac dysfunction. We aimed to clarify the clinical features, including cardiac functions, of type 2 diabetes patients with myocardial fat accumulation. METHODS: We retrospectively enrolled type 2 diabetes patients who underwent ECG-gated coronary computed tomography angiography (CCTA) and abdominal computed tomography (CT) scan examinations within 1 year of CCTA from January 2000 to March 2021. High fat accumulation in the myocardium was defined as the low mean myocardial CT value of three regions of interest, and the associations between CT values and clinical characteristics or cardiac functions were assessed. RESULTS: In total, 124 patients were enrolled (72 males and 52 females). The mean age was 66.6 years, the mean BMI was 26.2 kg/m2, the mean ejection fraction (EF) was 67.6%, and the mean myocardial CT value was 47.7 Hounsfield unit. A significant positive correlation was found between myocardial CT value and EF (r = 0.3644, p = 0.0004). The multiple regression analyses also showed that myocardial CT value was independently associated with EF (estimate, 0.304; 95% confidence interval (CI) 0.092 to 0.517; p = 0.0056). Myocardial CT value showed significant negative correlations with BMI, visceral fat area and subcutaneous fat area (r = - 0.1923, - 0.2654, and -0.3569, respectively, p < 0.05). In patients who were ≥ 65 years or female, myocardial CT value showed significant positive correlations with not only EF (r = 0.3542 and 0.4085, respectively, p < 0.01) but also early lateral annular tissue Doppler velocity (Lat e') (r = 0.5148 and 0.5361, respectively, p < 0.05). The multiple regression analyses showed that myocardial CT value was independently associated with EF and Lat e' in these subgroups (p < 0.05). CONCLUSIONS: Patients with type 2 diabetes, especially in elderly or female patients, who had more myocardial fat had more severe left ventricular systolic and diastolic dysfunctions. Reducing myocardial fat accumulation may be a therapeutic target for type 2 diabetes patients.

Bivalent GAD autoantibody ELISA improves clinical utility and risk prediction for adult autoimmune diabetes.

AIM/INTRODUCTION: To investigate the differences in the clinical significance and glutamic acid decarboxylase autoantibody (GADA) affinity between RIA (RIA-GADA) and ELISA (ELISA-GADA) in patients with type 1 diabetes. METHODS: A total of 415 patients with type 1 diabetes were enrolled, including 199 acute-onset type 1 diabetes, 168 slowly progressive type 1 diabetes (SPIDDM), and 48 fulminant type 1 diabetes. GADA affinity was measured by a competitive binding experiment using unlabeled recombinant human GAD65 protein, and the diagnostic performance of both assays and the relationship between GADA affinity and the decline of fasting C-peptide (F-CPR) were examined. RESULTS: While the ELISA-GADA displayed a higher sensitivity than the RIA method in diagnosing type 1 diabetes in acute-onset patients, about 40% of SPIDDM patients with low-titer RIA-GADA were determined as negative by the ELISA method. Patients with type 1 diabetes with RIA-GADA alone had an older age of onset, less diabetic ketoacidosis, a higher BMI, and a higher F-CPR compared with patients positive for both RIA-GADA and ELISA-GADA. Additionally, 36% of RIA-GADA-positive patients had low-affinity GADA (<1010 L/mol), which was significantly higher than in the ELISA-GADA-positive patients (4%, P < 0.0001). Furthermore, over a 3 year monitoring period, F-CPR levels decreased in ELISA-GADA-positive SPIDDM, whereas it was maintained in patients with RIA-GADA alone, regardless of GADA affinity. CONCLUSIONS: These results suggest that bivalent ELISA for GADA is superior to the RIA method in diagnosing type 1 diabetes. Moreover, the diagnostic superiority of the ELISA-GADA made possible the concurrent identification of SPIDDM patients at high-risk of early progression, and allowed for more accurate clinical diagnosis and management.

Inflammatory Cell Infiltration Into Islets Without PD-L1 Expression Is Associated With the Development of Immune Checkpoint Inhibitor-Related Type 1 Diabetes in Genetically Susceptible Patients.

Immune checkpoint inhibitors (ICIs) could cause type 1 diabetes (T1D). However, the underlying mechanism remains unclear. We immunohistochemically analyzed pancreatic specimens from three individuals with ICI-related T1D, and their histopathological data were compared those from three patients who had received ICI therapy but did not develop T1D (non-T1D) and seven normal glucose-tolerant subjects as control subjects. All ICI-related T1D patients had susceptible HLA haplotypes. In ICI-related T1D, the ß-cell area decreased and the α-cell area increased compared with non-T1D and control subjects. The number of CD3-positive cells around islets increased in ICI-related T1D and non-T1D compared with control subjects, while the number of CD68-positive cells around islets increased in ICI-related T1D compared with non-T1D and control subjects. The expression ratios of programmed death-ligand 1 (PD-L1) on islets decreased in non-T1D and almost completely disappeared in ICI-related T1D, while PD-L1 expression was observed in most cells of pancreatic islets in control subjects. This study, therefore, indicates that ICI therapy itself could reduce PD-L1 expression on islets in all subjects, which may be related to ß-cell vulnerability. In addition, we showed that absence of PD-L1 expression on ß-cells, genetic susceptibility, and infiltration of macrophages as well as T lymphocytes around islets might be responsible for T1D onset.

Comparing the clinical significance and antigen specificity of insulinoma-associated antigen-2 autoantibodies between radioimmunoassay and enzyme-linked immunosorbent assay in Japanese patients with type 1 diabetes.

AIMS/INTRODUCTION: This study aimed to investigate the clinical significance and antigen specificity of autoantibodies to insulinoma-associated antigen-2 (IA-2A) by radioimmunoassay (RIA; IA-2A-RIA) and enzyme-linked immunosorbent assay (ELISA; IA-2A-ELISA) in Japanese patients with type 1 diabetes. MATERIALS AND METHODS: A total of 338 type 1 diabetic patients were enrolled, including 38 fulminant type 1 diabetes, 168 acute-onset type 1 diabetes and 137 slowly-progressive type 1 diabetes (SPIDDM). The concordance, correlation of autoantibody titer, and the relationship between IA-2A and progression to the insulin-deficient state were examined. Also, competitive assay was used to examine the antigen specificity. RESULTS: The prevalence of IA-2A-ELISA was 4-5% lower than that of IA-2A-RIA in both the acute-onset type 1 diabetes and SPIDDM, but the diagnostic sensitivities of both subtypes, when measured in combination with glutamic acid decarboxylase autoantibody, were comparable. The diagnosis of type 1 diabetes using either the RIA or ELISA methods showed substantial agreement with the exponential correlation of autoantibody titers detected by RIA and ELISA. Among the SPIDDM patients, the fasting C-peptide for IA-2A-positive cases by ELISA, but not the RIA method, was significantly lower than in the negative cases (P < 0.05). Furthermore, IA-2A-ELISA proved superior to the RIA method in predicting the progression to insulin deficiency in SPIDDM. Competitive analysis showed that even sera with discrepant results by RIA and ELISA have IA-2-specific autoantibodies. CONCLUSION: These results suggest that IA-2A-ELISA is a reliable marker not only for the diagnosis of type 1 diabetes, but also for the prediction of future insulin dependency; that is, detection of IA-2A-ELISA helps identify a subtype of SPIDDM patients who would likely progress onto insulin-deficient state.

Lipid droplet accumulation in ß cells in patients with type 2 diabetes is associated with insulin resistance, hyperglycemia and ß cell dysfunction involving decreased insulin granules.

Background and objective: Pancreatic fat is a form of ectopic fat. Lipid droplets (LDs) are also observed in ß cells; however, the pathophysiological significance, especially for ß cell function, has not been elucidated. Our aim was to assess LD accumulation in ß cells in various stages of glucose intolerance and to clarify its relationship with clinical and histological parameters. Methods: We examined 42 Japanese patients who underwent pancreatectomy. The BODIPY493/503-positive (BODIPY-positive) area in ß cells was measured in pancreatic sections from 32 patients. The insulin granule numbers were counted in an additional 10 patients using electron microscopy. Results: The BODIPY-positive area in ß cells in preexisting type 2 diabetes patients was higher than that in normal glucose tolerance patients (p = 0.031). The BODIPY-positive area in ß cells was positively correlated with age (r = 0.45, p = 0.0097), HbA1c (r = 0.38, p = 0.0302), fasting plasma glucose (r = 0.37, p = 0.045), and homeostasis model assessment insulin resistance (r = 0.41, p = 0.049) and negatively correlated with an increase in the C-peptide immunoreactivity level by the glucagon test (r = -0.59, p = 0.018). The ratio of mature insulin granule number to total insulin granule number was reduced in the patients with rich LD accumulation in ß cells (p = 0.039). Conclusions: Type 2 diabetes patients had high LD accumulation in ß cells, which was associated with insulin resistance, hyperglycemia, aging and ß cell dysfunction involving decreased mature insulin granules.

Consumption of two meals per day is associated with increased intrapancreatic fat deposition in patients with type 2 diabetes: a retrospective study.

INTRODUCTION: This study aimed to identify the associations between lifestyle factors and intrapancreatic fat deposition in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: The participants were 185 patients with type 2 diabetes who were hospitalized at Osaka University Hospital between 2008 and 2020 and underwent abdominal CT during hospitalization. Information regarding lifestyle factors, including the number of meals consumed per day, snacking habits, exercise habits, exercise at work, smoking habits, alcohol intake, insomnia, sleep apnea syndrome, and night-shift working, was acquired from self-administered questionnaires or medical records. We measured the mean CT values for the pancreas (P), liver (L), and spleen (S), and the visceral fat area (VFA), and quantified intrapancreatic and liver ectopic fat accumulation as P-S and L-S, respectively. RESULTS: After adjustment for age, sex, hemoglobin A1c, and body mass index (BMI), participants who consumed two meals per day had significantly lower P-S (higher intrapancreatic fat deposition, p=0.02) than those who consumed three meals per day. There were no significant associations between the number of meals consumed and liver ectopic fat accumulation and VFA (p=0.73 and p=0.67, respectively). CONCLUSIONS: Patients with diabetes who consumed two meals per day showed greater intrapancreatic fat deposition than those who consumed three meals per day, even after adjustment for BMI. These findings support the current guideline for diabetes treatment that skipping meals should be avoided.

Human adipose-derived mesenchymal stem cells prevent type 1 diabetes induced by immune checkpoint blockade.

AIMS/HYPOTHESIS: Immunomodulators blocking cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD-1) or programmed death-ligand 1 (PD-L1) have improved the treatment of a broad spectrum of cancers. These immune checkpoint inhibitors (ICIs) reactivate the immune system against tumour cells but can also trigger autoimmune side effects, including type 1 diabetes. Mesenchymal stem cell (MSC) therapy is the most prevalent cell therapy, with tissue-regenerating, anti-fibrosis and immunomodulatory functions provided by the secretome of the cells. Here, we examined whether systemic MSC treatment could prevent the development of type 1 diabetes in a NOD mouse model. METHODS: The purified PD-L1 monoclonal antibody was administered to induce diabetes in male NOD mice which normally do not develop diabetes. Human adipose-derived MSCs were administered by tail vein injections. T cells, macrophages and monocyte-derived macrophages expressing C-X-C motif chemokine ligand 9 (CXCL9) in pancreatic sections of NOD mice and a cancer patient who developed diabetes following the ICI treatments were analysed by immunofluorescence. Tissue localisation of the injected MSCs, plasma exosome levels and plasma cytokine profiles were also investigated. RESULTS: PD-1/PD-L1 blockade induced diabetes in 16 of 25 (64%) NOD mice which received anti-PD-L1 mAb without hMSCs [MSC(-)], whereas MSC administration decreased the incidence to four of 21 (19%) NOD mice which received anti-PD-L1 mAb and hMSCs [MSC(+)]. The PD-1/PD-L1 blockade significantly increased the area of CD3-positive T cells (6.2-fold) and macrophage-2 (Mac-2) antigen (2.5-fold)- and CXCL9 (40.3-fold)-positive macrophages in the islets. MSCs significantly reduced T cell (45%) and CXCL9-positive macrophage (67%) accumulation in the islets and the occurrence of diabetes. The insulin content (1.9-fold) and islet beta cell area (2.7-fold) were also improved by MSCs. T cells and CXCL9-positive macrophages infiltrated into the intricate gaps between the beta cells in the islets by PD-1/PD-L1 blockade. Such immune cell infiltration was largely prevented by MSCs. The most striking difference was observed in the CXCL9-positive macrophages, which normally did not reside in the beta cell region in the islets but abundantly accumulated in this area after PD-1/PD-L1 blockade and were prevented by MSCs. The CXCL9-positive macrophages were also observed in the islets of a cancer patient who developed diabetes following the administration of ICIs but few CXCL9-positive macrophages were observed in a control patient. Mechanistically, the injected MSCs accumulated in the lung but not in the pancreas and strongly increased plasma exosome levels and changed plasma cytokine profiles. CONCLUSIONS/INTERPRETATION: Our results suggest that MSCs can prevent the incidence of diabetes associated with immune checkpoint cancer therapy and may be worth further consideration for new adjuvant cell therapy.

Genetic assessment using whole-exome sequencing for a young hypertriglyceridemic patient with repeated acute pancreatitis.

Hypertriglyceridemia is caused not only by environmental factors but also by genetic factors. Severe hypertriglyceridemia is prone to complications of acute pancreatitis. Here, we report a whole-exome sequencing (WES) analysis for a young hypertriglyceridemic patient with recurrent acute pancreatitis and the patient's mother. A 28-year-old hypertriglyceridemic female was admitted to our hospital. At 23 years old, a health checkup clarified her hypertriglyceridemia. At the age of 26 and 27, she had repeated acute pancreatitis with severe hypertriglyceridemia (serum triglyceride level were 3,888 mg/dL and 12,080 mg/dL, respectively). The patient's BMI was 29.0 kg/m2, and blood samples under fibrate medication showed triglyceride 451 mg/dL and HbA1c 7.2%. Type V dyslipidemia became more apparent at postprandial state. The WES analysis showed that the patients had two heterozygous variants in Apolipoprotein A5 (APOA5) gene (p.G185C and p.V153M), a heterozygous variant in Apolipoprotein E (APOE) gene (p.R176C), three heterozygous variants in Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene (p.T1220I, p.R1453W and p.V470M). On the other hand, her mother, who had moderate hypertriglyceridemia without acute pancreatitis, had a heterozygous variant in APOA5 gene (p.G185C) and two heterozygous variants in CFTR gene (p.T1220I and p.V470M). These results suggest that the more severe pathology of the patient than her mother might be due to the possible compound heterozygous APOA5 variants, the heterozygous APOE variant, and the possible compound heterozygous CFTR variants. In this case, WES analyses were useful to evaluate not only the causative genes of hypertriglyceridemia (APOA5 and APOE) but also the genes involved in the development of acute pancreatitis (CFTR) simultaneously.