Clinical analysis of pre-existing diabetes mellitus and dipeptidyl peptidase-4 inhibitors in patients with remitting seronegative symmetrical synovitis and pitting edema syndrome.

Objectives: To analyze the association among remitting seronegative symmetrical synovitis with pitting edema (RS3PE) syndrome, diabetes mellitus (DM), and antidiabetic drugs.Methods: We retrospectively analyzed the clinical and serologic manifestations of patients who had RS3PE syndrome with and without pre-existing DM. Then we performed a subanalysis in which patients with pre-existing DM were classified into two groups according to whether they were or were not taking a dipeptidyl peptidase 4 inhibitor (DPP4i), an antidiabetic drug that was suggested to have an association with the pathogenesis of RS3PE syndrome.Results: Pre-existing DM was found in 13 (35.1%) of 37 patients with RS3PE syndrome. No significant differences in age, gender, physical manifestations, and laboratory findings were observed between the patients with DM and those without DM. DPP4i had been administered to 6 of 13 patients with RS3PE and pre-existing DM. We observed no significant differences in manifestations of RS3PE syndrome before treatment; however, one relapse occurred in a patient with poorly controlled DM who had been continuing DPP4i therapy.Conclusion: This study revealed no evidence suggesting an association among RS3PE syndrome, DM, and antidiabetic drugs. DPP4i would be safe for use by most of patients with RS3PE syndrome. However, elderly patients and patients with poorly controlled DM might require careful observation.

Type 1 Diabetes Mellitus Diagnosed during Follow-up of Gestational Diabetes Mellitus in the Early Postpartum Period.

A 27-year-old woman with a history of gestational diabetes mellitus (GDM) developed type 1 diabetes mellitus (T1D) in the early postpartum period. Women with a history of GDM are at an increased risk of developing T1D, which is rarer than type 2 diabetes mellitus. A postpartum follow-up 75-g oral glucose tolerance test and the measurement of glutamic acid decarboxylase autoantibodies aided in the early detection of T1D in this patient. Careful attention should be paid to women with a history of GDM who exhibit clinical features suggestive of future development of T1D.

Haploinsufficiency of interferon regulatory factor 4 strongly protects against autoimmune diabetes in NOD mice.

AIMS/HYPOTHESIS: Interferon regulatory factor (IRF)4 plays a critical role in lymphoid development and the regulation of immune responses. Genetic deletion of IRF4 has been shown to suppress autoimmune disease in several mouse models, but its role in autoimmune diabetes in NOD mice remains unknown. METHODS: To address the role of IRF4 in the pathogenesis of autoimmune diabetes in NOD mice, we generated IRF4-knockout NOD mice and investigated the impact of the genetic deletion of IRF4 on diabetes, insulitis and insulin autoantibody; the effector function of T cells in vivo and in vitro; and the proportion of dendritic cell subsets. RESULTS: Heterozygous IRF4-deficient NOD mice maintained the number and phenotype of T cells at levels similar to NOD mice. However, diabetes and autoantibody production were completely suppressed in both heterozygous and homozygous IRF4-deficient NOD mice. The level of insulitis was strongly suppressed in both heterozygous and homozygous IRF4-deficient mice, with minimal insulitis observed in heterozygous mice. An adoptive transfer study revealed that IRF4 deficiency conferred disease resistance in a gene-dose-dependent manner in recipient NOD/severe combined immunodeficiency mice. Furthermore, the proportion of migratory dendritic cells in lymph nodes was reduced in heterozygous and homozygous IRF4-deficient NOD mice in an IRF4 dose-dependent manner. These results suggest that the levels of IRF4 in T cells and dendritic cells are important for the pathogenesis of diabetes in NOD mice. CONCLUSIONS/INTERPRETATION: Haploinsufficiency of IRF4 halted disease development in NOD mice. Our findings suggest that an IRF4-targeted strategy might be useful for modulating autoimmunity in type 1 diabetes.

Zinc transporter 8 autoantibodies in fulminant, acute-onset, and slow-onset patients with type 1 diabetes.

BACKGROUND: The aim of this study was to determine the prevalence and role of autoantibodies to zinc transporter 8 (ZnT8A) in three forms (fulminant, acute-onset, and slow-onset) of Japanese patients with type 1 diabetes. METHODS: One-hundred and ninety-six new-onset patients with type 1 diabetes were studied: 85 were fulminant, 81 acute-onset, and 30 slow-onset type 1 diabetes. ZnT8A were determined by radioimmunoassay using a hybrid ZnT8 carboxy-terminal construct (aa268-369) carrying 325Trp and 325Arg. Furthermore, ZnT8A epitopes were analysed using ZnT8 constructs incorporating the known aa325 variants (Trp, Arg, and Gln). RESULTS: ZnT8A were detected in 58% patients with acute-onset and 20% with slow-onset type 1 diabetes (p<0.0005). In contrast, none of sera from fulminant type 1 diabetes were reactive to ZnT8 construct. Conversion of Arg or Trp to Gln at aa325 abolished reactivity in 59% of patients with an age of onset>10 years, which was significantly higher than that in patients≤10 years of age (33%, p<0.05). CONCLUSIONS: These results suggest that ZnT8A are an additional useful marker for acute-onset type 1 diabetes, but not a diagnostic marker for fulminant type 1 diabetes, and ZnT8A epitope recognition is different according to the onset age.

Differences in the humoral autoreactivity to zinc transporter 8 between childhood- and adult-onset type 1 diabetes in Japanese patients.

The aim of this study was to evaluate the humoral autoreactivity to zinc transporter 8 (ZnT8) depending on the clinical phenotype of type 1 diabetes (T1D). ZnT8 autoantibodies (ZnT8A) were determined by radioimmunoassay using carboxy-terminal ZnT8 constructs in 57 childhood-onset, 97 adult-onset, and 85 fulminant T1D. The ZnT8A frequency was higher in childhood-onset patients and decreased with increasing age of onset from 70% to 24% (P(trend)<0.005). None of the patients with fulminant T1D was positive for ZnT8A. There were at least two distinct ZnT8A epitope patterns associated with the aa325-restriction, childhood-onset patients have aa325-nonrestricted response more frequently compared to the adult-onset group (P<0.05). The level of ZnT8A was inversely associated with the copy number of HLA-DR4 allele (P<0.05). These results suggest differences in the humoral autoreactivity to ZnT8 depending on the clinical phenotype, which should provide strategy for autoantibody measurement in subjects to allow early diagnosis of autoimmune T1D.

Trajectories of anti-islet autoantibodies before development of type 1 diabetes in interferon-treated hepatitis C patients. Case reports and a literature review.

Interferon-alpha (IFN-α) is widely used in the treatment of viral hepatitis, however, it is known that IFN-α therapy may induce type 1 diabetes. We report here on two cases of chronic viral hepatitis C who developed autoimmune type 1 diabetes during Peg-IFN-α plus ribavirin (RBV) therapy. Case 1: a 48-year-old male with chronic hepatitis C with chronic thyroiditis. The patient's plasma glucose level was normal and anti-islet autoantibody tests were negative before Peg-IFN-α+RBV therapy. The emergence of glutamic acid decarboxylase 65 autoantibody (GAD65Ab) was observed after five months of treatment. Autoantibodies to insulin and insulinoma-associated antigen-2 (IA-2) also became positive. Eleven months later, thirst and polydipsia occurred with increased fasting plasma glucose level and the patient was diagnosed with type 1A diabetes. Zinc transporter-8 autoantibody (ZnT8Ab) was not detectable at any point. The patient has type 1 diabetes-susceptible HLA-DRB1-DQB1 haplotypes *0405-*0401 and *0901-*0303. Case 2: a 65-year-old male with chronic hepatitis C with type 2 diabetes on insulin treatment. GAD65Ab and IA-2Ab were negative before Peg-IFN-α+RBV therapy, however, nine months later, a single appearance of GAD65Ab was observed. After twelve months, his plasma glucose control worsened rapidly, and he was diagnosed with type 1A diabetes. IA-2Ab and ZnT8Ab were negative throughout the clinical course. His HLA-DRB1-DQB1 haplotypes were *0410-*0402 and *1407-*0503. Both cases showed a unique GAD65Ab epitope (amino acids 360-442). These clinical courses suggest that IFN-α therapy provoked acute islet autoimmunity and onset of type 1 diabetes. Therefore, during IFN-α therapy, patients should be closely monitored for the occurrence of type 1 diabetes.

Autoantibodies to insulin, insulinoma-associated antigen-2, and zinc transporter 8 improve the prediction of early insulin requirement in adult-onset autoimmune diabetes.

OBJECTIVE: The aim of this study was to identify the predictive marker for early insulin requirement in adult-onset autoimmune diabetes in the Japanese populations. DESIGN/PATIENTS: We analyzed insulin autoantibodies (IAA), insulinoma-associated antigen-2 (IA-2) autoantibodies (IA-2icA), and zinc transporter 8 (ZnT8) autoantibodies (ZnT8A) by radioimmunoassay in 47 Japanese patients with adult-onset autoimmune diabetes who were identified by native GAD autoantibody (nGADA) screening of approximately 3000 non-insulin-requiring diabetes patients and 302 nGADA-negative type 2 diabetes patients. Furthermore, GAD65 autoantibody-specific epitopes were also analyzed using GAD65/GAD67 chimeric constructs. RESULTS: The prevalence of IAA, IA-2icA, and ZnT8A in nGADA-positive patients was 26, 15, and 19%, respectively, which was significantly higher than that in nGADA-negative type 2 diabetes (2, 2, and 2%; P < 0.0001). Among nGADA-positive patients, 38% had one or more of IAA, IA-2icA, or ZnT8A, and 15% had two or more of these autoantibodies, compared with none of the nGADA-negative patients (P < 0.0001). Thirty-six percent of nGADA-positive patients subsequently required insulin therapy; and high nGADA titer (log-rank P = 0.003), middle epitope recognition of GAD65A (P = 0.002), and the presence of one or more of IAA, IA-2icA, or ZnT8A (P = 0.002) at diagnosis marked the risk for early requirement of insulin therapy. Multivariate logistic regression analysis showed the multiple islet autoantibodies to be independently associated with the risk for insulin requirement (odds ratio = 13.77; 95% confidence interval, 2.77-68.45; P = 0.001). CONCLUSIONS: These results indicate that the determination of IAA, IA-2icA, and ZnT8A improves the prediction of a future insulin insufficiency in adult-onset autoimmune diabetes, which appears to be superior to GADA titer and GAD65A-specific epitopes.

T helper type 17 immune response plays an indispensable role for development of iodine-induced autoimmune thyroiditis in nonobese diabetic-H2h4 mice.

T helper type 1(Th1)/Th2 paradigm has been expanded by discovery of a novel effector T cell (T(eff)) subset, Th17 cells, which produce a proinflammatory cytokine IL-17. Th17 cells have recently been shown to play a major role in numerous autoimmune diseases that had previously been thought to be Th1-dominant diseases. We here studied the significance of Th17 cells in iodine-induced autoimmune thyroiditis in nonobese diabetic-H2(h4) mice, a mouse model of Hashimoto's thyroiditis in humans, which spontaneously develop antithyroglobulin autoantibodies and intrathyroidal lymphocyte infiltration when supplied with iodine in the drinking water. We observed increased numbers of Th1 and Th17 cells in spleen and accumulation of both types of T(eff) in the thyroid glands of iodine-fed wild-type mice, indicating that Th17 cells as well as Th1 cells constitute thyroid lesions. Furthermore, the incidence and severity of intrathyroidal lymphocyte infiltration, and the titers of antithyroglobulin autoantibodies were markedly reduced in iodine-treated IL-17(-/-) mice as compared with wild-type mice. Of interest, IL-17(+/-) mice showed an intermediate phenotype. Therefore, the present study, together with a previous report demonstrating the importance of Th1, not Th2, immune response for developing thyroiditis using mice deficient for interferon-gamma or IL-4, clearly indicates that both Th1 and Th17 cells are critical T(eff) subsets for the pathogenesis of spontaneous autoimmune thyroiditis in nonobese diabetic-H2(h4) mice.

Humoral immune response to islet autoantigens in Japanese patients with type 1 diabetes.

In this study, we evaluated autoantibodies to IA-2 (IA-2As), glutamic acid decarboxylase 65 (GADAs), and islet cell antibodies (ICAs) in 233 patients with type 1 diabetes (M:F = 90:143, mean duration 4.0 +/- 6.7 yr) as a cross-sectional study. Of 233 patients with type 1 diabetes, IA-2A was detected in 58% of patients with duration within 2 weeks, 61% of patients with duration <1 yr, 41% of patients with diabetes for 1-3 yr, 29% for 4-9 yr, and 21% for >or=10 yr. These prevalences were similar to those of ICA, while the prevalence of GADA was not influenced by duration of diabetes with positivity of 63-74%. Thus, as the duration of diabetes became longer, the frequency of GADA(+)/IA-2A(-) patients increased and the frequency of GADA(+)/IA-2A(+) patients decreased. However, the frequency of GADA(-)/IA-2A(+) patients was not influenced by duration of diabetes. The prevalence of IA-2A was significantly higher in abrupt-onset group (68%, n= 79) compared to the slowly progressive group (23%, n= 22) in new-onset patients (P= 0.0001). However, there was no difference in the IA-2A frequency between these two groups (abrupt-onset 26%, n= 53 vs. slowly progressive 24%, n= 21) in patients with long-standing disease, suggesting that IA-2A positivity might persist in patients with slowly progressive type 1 diabetes. These results emphasize the heterogeneity of humoral autoimmunity to protein tyrosine phosphatase-like molecules, but not to GAD, in patients with type 1 diabetes.