Comparison of positive rates between glutamic acid decarboxylase antibodies and ElisaRSR™ 3 Screen ICA™ in recently obtained sera from patients who had been previously diagnosed with slowly progressive type 1 diabetes.

AIMS/INTRODUCTION: This study aimed to compare the positivity rates of glutamic acid decarboxylase autoantibodies (GADA) and ElisaRSR™ 3 Screen ICA™ (3 Screen ICA), a newly developed assay for the simultaneous measurement of GADA, insulinoma-associated antigen-2 autoantibodies (IA-2A), and zinc transporter 8 autoantibodies (ZnT8A), in recently obtained sera from patients who had been previously diagnosed with slowly progressive type 1 diabetes (SPIDDM). MATERIALS AND METHODS: We enrolled 53 patients with SPIDDM who were positive for GADA at the diagnosis and 98 non-diabetic individuals, and investigated the diagnostic accuracy of the 3 Screen ICA (cutoff index ≥30 units) compared with that of GADA. In addition, we compared the clinical characteristics of patients with SPIDDM who were negative or positive on 3 Screen ICA. RESULTS: The positivity rates of 3 Screen ICA, GADA, IA-2A, and ZnT8A were 88.7, 86.8, 24.5, and 13.2%, respectively. The respective sensitivity, specificity, and positive and negative predictive values for SPIDDM were 88.7, 100, 100, and 94.2% by 3 Screen ICA and 86.8, 100, 100.0, and 93.3% by GADA. There were no significant differences in age at onset, duration of diabetes, body mass index, glycated hemoglobin and C-peptide levels, and the prevalence of autoimmune thyroiditis between patients with SPIDDM who were positive or negative on 3 Screen ICA. However, the prevalence of insulin users was significantly higher in those who were positive than in those who were negative on 3 Screen ICA. CONCLUSIONS: Similar to GADA, 3 Screen ICA may be a useful diagnostic tool for detecting patients with SPIDDM.

Efficacy of a new enzyme-linked immunosorbent assay system for three islet cell autoantibodies in Japanese patients with acute-onset type 1 diabetes.

To evaluate the clinical efficacy of a new enzyme-linked immunosorbent assay (ELISA) system for simultaneously detecting three islet cell autoantibodies against glutamic acid decarboxylase (GADA), insulinoma-associated antigen-2 (IA-2A), and zinc transporter 8 (ZnT8A) (3 Screen ICA ELISA) in Japanese patients with acute-onset type 1 diabetes (T1D). In addition, clinical factors affecting the 3 Screen ICA ELISA index were investigated. We compared the positivity values of 3 Screen ICA ELISA with that of each autoantibody alone in 97 patients with acute-onset T1D (mean age 48.7 years, 49% male) and 100 non-diabetic subjects (mean age 47.0 years, 50% male). Serum thyroid stimulating hormone receptor antibody, thyroid peroxidase antibody (TPOAb) and thyroglobulin autoantibody levels were also evaluated. The cut-off value of the 3 Screen ICA ELISA was determined based on the 97th percentile of 100 non-diabetic controls (threshold for positivity, ≥14 index). The mean age of disease onset and duration of diabetes were 34.2 years and 14.5 years, respectively. Among all T1D patients, the positivity of 3 Screen ICA ELISA was 71.1%, while that of GADA, IA-2A, and ZnT8A were 59.8%, 25.8%, and 25.8%, respectively. The median 3 Screen ICA index was 121.9 (8.7-468.2) and was associated with titers of each autoantibody, most so with GADA, and was significantly higher in TPOAb-positive patients than in TPOAb-negative patients. Our findings suggests that the 3 Screen ICA ELISA may be a time-saving diagnostic tool for evaluating islet autoantibodies in acute-onset T1D patients.

Antiatherogenic effects of liraglutide in hyperglycemic apolipoprotein E-null mice via AMP-activated protein kinase-independent mechanisms.

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) exert potent glucose-lowering effects without increasing risks for hypoglycemia and weight gain. Preclinical studies have demonstrated direct antiatherogenic effects of GLP-1RAs in normoglycemic animal models; however, the underlying mechanisms in hyperglycemic conditions have not been fully clarified. Here we aimed to elucidate the role of AMP-activated protein kinase (AMPK) in antiatherogenic effects of GLP-1RAs in hyperglycemic mice. Streptozotocin-induced hyperglycemic apolipoprotein E-null mice were treated with vehicle, low-dose liraglutide (17 nmol·kg-1·day-1), or high-dose liraglutide (107 nmol·kg-1·day-1) in experiment 1 and the AMPK inhibitor dorsomorphin, dorsomorphin + low-dose liraglutide, or dorsomorphin + high-dose liraglutide in experiment 2. Four weeks after treatment, aortas were collected to assess atherosclerosis. In experiment 1, metabolic parameters were similar among the groups. Assessment of atherosclerosis revealed that high-dose liraglutide treatments reduced lipid deposition on the aortic surface and plaque volume and intraplaque macrophage accumulation at the aortic sinus. In experiment 2, liraglutide-induced AMPK phosphorylation in the aorta was abolished by dorsomorphin; however, the antiatherogenic effects of high-dose liraglutide were preserved. In cultured human umbilical vein endothelial cells, liraglutide suppressed tumor necrosis factor-induced expression of proatherogenic molecules; these effects were maintained under small interfering RNA-mediated knockdown of AMPKα1 and in the presence of dorsomorphin. Conversely, in human monocytic U937 cells, the anti-inflammatory effects of liraglutide were abolished by dorsomorphin. In conclusion, liraglutide exerted AMPK-independent antiatherogenic effects in hyperlipidemic mice with streptozotocin-induced hyperglycemia, with the possible involvement of AMPK-independent suppression of proatherogenic molecules in vascular endothelial cells.

Effect of Dulaglutide Versus Liraglutide on Glucose Variability, Oxidative Stress, and Endothelial Function in Type 2 Diabetes: A Prospective Study.

INTRODUCTION: To compare the effect of dulaglutide and liraglutide on oxidative stress and endothelial function in patients with type 2 diabetes mellitus (T2DM). METHODS: Twenty-two patients with T2DM who received treatment with liraglutide for at least 12 weeks were randomized to either continue liraglutide or receive dulaglutide for 24 weeks. The primary end points were changes in the diacron-reactive oxygen metabolite (d-ROMs) test, as a marker of oxidative stress, and endothelial function, as determined by the reactive hyperemia index (RHI). The secondary end points were changes in body weight (BW), glucose variability, diabetes treatment satisfaction questionnaire (DTSQ) score, and eating behavior. RESULTS: There were no significant differences in changes in d-ROMs and logarithmic-scaled RHI (L-RHI) between the two groups after 24 weeks of treatment. Notably, the treatment with dulaglutide was superior to that with liraglutide in terms of mean glucose levels and mean amplitude of glycemic excursions following the 24-week treatment. However, in this regard, the outcome following the treatment with dulaglutide was maintained, whereas that with the treatment with liraglutide was aggravating. The DTSQ score for "convenience" improved in the dulaglutide group. No statistically significant changes in fasting plasma glucose, hemoglobin A1c, and BW were observed between the two groups. CONCLUSION: We showed that once-weekly dulaglutide was comparable to once-daily liraglutide in terms of oxidative stress and endothelial function. Switching from liraglutide to dulaglutide improved convenience by decreasing the number of injections without deteriorating glucose metabolism. TRIAL REGISTRATION: This trial was registered with the University Hospital Medical Information Network (UMIN no. 000034353) on 10 October 2018.

Proteomic profiling of thyroid papillary carcinoma.

Papillary thyroid carcinoma (PTC) is the most common endocrine malignancy. We performed shotgun liquid chromatography (LC)/tandem mass spectrometry (MS/MS) analysis on pooled protein extracts from patients with PTC and compared the results with those from normal thyroid tissue validated by real-time (RT) PCR and immunohistochemistry (IHC). We detected 524 types of protein in PTC and 432 in normal thyroid gland. Among these proteins, 145 were specific to PTC and 53 were specific to normal thyroid gland. We have also identified two important new markers, nephronectin (NPNT) and malectin (MLEC). Reproducibility was confirmed with several known markers, but the one of two new candidate markers such as MLEC did not show large variations in expression levels. Furthermore, IHC confirmed the overexpression of both those markers in PTCs compared with normal surrounding tissues. Our protein data suggest that NPNT and MLEC could be a characteristic marker for PTC.

Periostin, discovered by nano-flow liquid chromatography and mass spectrometry, is a novel marker of diabetic retinopathy.

Diabetes can lead to serious microvascular complications including proliferative diabetic retinopathy (PDR), the leading cause of blindness in adults. Recent studies using gene array technology have attempted to apply a hypothesis-generating approach to elucidate the pathogenesis of PDR, but these studies rely on mRNA differences, which may or may not be related to significant biological processes. To better understand the basic mechanisms of PDR and to identify potential new biomarkers, we performed shotgun liquid chromatography (LC)/tandem mass spectrometry (MS/MS) analysis on pooled protein extracts from neovascular membranes obtained from PDR specimens and compared the results with those from non-vascular epiretinal membrane (ERM) specimens. We detected 226 distinct proteins in neovascular membranes and 154 in ERM. Among these proteins, 102 were specific to neovascular membranes and 30 were specific to ERM. We identified a candidate marker, periostin, as well as several known PDR markers such as pigment epithelium-derived factor (PEDF). We then performed RT-PCR using these markers. The expression of periostin was significantly up-regulated in proliferative membrane specimens. Periostin induces cell attachment and spreading and plays a role in cell adhesion. Proteomic analysis by LC/MS/MS, which permits accurate quantitative comparison, was useful in identifying new candidates such as periostin potentially involved in the pathogenesis of PDR.

Intact glucagon-like peptide-1 levels are not decreased in Japanese patients with type 2 diabetes.

Impaired secretion of glucagon-like peptide 1 (GLP-1) has been suggested to contribute to the deficient incretin effect in patients with type 2 diabetes mellitus (T2DM). Recent studies, however, have not always supported this notion. Since Japanese patients with T2DM usually have severe impairment in the earlyphase of insulin secretion, the measurement of incretin secretions in Japanese T2DM patients would be useful for assessing the association between incretin levels and insulin secretion. We conducted an oral glucose tolerance test (75 g) (OGTT) and meal tolerance test (480 kcal) (MTT) for subjects with normal glucose tolerance (NGT, n=12), subjects with impaired glucose tolerance (IGT, n=7), and T2DM patients (n=21). The tests were carried out over 120-min study periods on separate occasions. Intact GLP-1, GIP, and dipeptidyl peptidase (DPP)-IV were measured by ELISA. T2DM exhibited an impaired early phase of insulin secretion and a reduction in glucagon suppression. There were no significant differences in GLP-1 or GIP levels at each sampling time among NGT, IGT, and T2DM after the ingestions; hence the incremental areas under the curve (IAUC) for the three groups were quite similar. The levels of DPP-IV, a limiting enzyme for the degradation of incretins, were comparable among the three groups. The GLP-1-IAUC was not correlated with IAUCs of insulin, C-peptide, or glucagon determined by the OGTT or the MTT. We concluded that intact GLP-1 levels are comparable between non-diabetics and T2DM, suggesting that impaired insulin secretion in Japanese T2DM is not attributable to defect in GLP-1 secretion.

Remnant lipoprotein cholesterol homogenous assay (RemL-C) is closely associated with very-low-density lipoprotein remnants: comparison with the immunoseparation assay.

BACKGROUND: Remnant-like particle-cholesterol (RLP-C) is recognized as a risk factor for cardiovascular disease. As an alternative to the immunoseparation assay widely used for the measurement of RLP-C, a new remnant lipoprotein-C homogenous assay (RemL-C) is available. In light of its homogeneity as an assay method, we speculated that this homogeneous assay (RemL-C) is closely associated with very-low-density lipoprotein(VLDL) remnant including intermediate-density lipoprotein(IDL). We examined the characteristics of the homogeneous assay for reacting with VLDL remnants. METHODS AND RESULTS: VLDL1, VLDL2, and IDL were separated by ultracentrifugation in the fasting serum of subjects including hypertriglyceridemia and uremic patients usually having higher levels of remnants. While RemL-C and RLP-C were mainly recovered in VLDL1 and both assays were strongly correlated with serum TG and VLDL1, the RemL-C assay was more closely correlated with VLDL2 and IDL levels than the RLP-C assay. RemL-C levels were significantly correlated with IDL-C, whereas RLP-C levels had only borderline associations with IDL-C (r= 0.56 Vs. 0.31). CONCLUSIONS: The remnant lipoprotein cholesterol homogenous assay is more closely associated with VLDL2 and IDL than the immunoseparation assay.

Significant increase of apolipoprotein B48 levels by a standard test meal in type 2 diabetic patients with nephropathy.

AIM: We investigated postprandial changes of apolipoprotein (apo) B48 in type 2 diabetics at different stages of diabetic nephropathy in order to explore non-traditional lipid abnormalities in diabetic nephropathy. METHODS: Twenty-two healthy controls and 56 type 2 diabetics with normoalbuminuria (NA), microalbuminuria (MA), and overt albuminuria (OA) were enrolled. Blood samples were taken at 0, 1, 2, 4, 6 h after the ingestion of Test meal A (460 Kcal, 18 g fat). The maximal increase of triglyceride (TG) was 40% above baseline in controls and 17% above baseline in diabetics. The incremental area under the curve (iAUC) of TG, however, was comparable among controls and diabetics with NA, MA, and OA. The maximal increase of apoB48 was 92% above baseline in controls and 56-88% above baseline in diabetics. Apo B48-iAUC was significantly higher in diabetics than in controls, and diabetics with OA exhibited the highest apoB48-iAUC among the diabetic subgroups. Small dense low-density lipoprotein-cholesterol (LDL-C) was elevated in diabetic nephropathy, and apoB48-iAUC was positively associated with the level of sd-LDL-C. CONCLUSIONS: ApoB48 is a sensitive marker for postprandial lipemia, a condition which is significantly increased in diabetic nephropathy and associated with an increase of potent atherogenic sd- LDL particles.