Insulin-dependent Diabetes Mellitus Type Research Articles

Immunotherapy in Autoimmune Type 1 Diabetes

Type 1 diabetes (T1D) is a chronic autoimmune disease affecting millions of people worldwide. The disease is characterized by the loss of self-tolerance to the insulin-producing β-cells in the pancreas, the destruction of β-cells, and finally the development of chronic hyperglycemia at diagnosis of T1D. Its incidence and prevalence are rising dramatically, highlighting the need for immunotherapeutic strategies able to prevent or treat the disease in a safe and specific manner. Immunotherapeutic strategies are being developed, and aim to restore immunological self-tolerance, thereby limiting unwanted immunity and β-cell destruction. Foxp3+ regulatory T (Treg) cells exert essential functions to maintain and restore immunological self-tolerance. The identification of the transcription factor Foxp3 as the specification factor for the Treg cell lineage facilitated our understanding in the biology of Treg generation and function. This review highlights the current understanding of immunotherapeutic approaches as preventative and curative measures for autoimmune T1D. It includes an overview on early immunointervention studies, which made use of general immunosuppressive agents such as cyclosporin A, followed by a discussion on newly emerging clinical trials. Besides non-antigen-specific therapies, particular attention is given to antigen-specific generation of Foxp3+ Treg cells and their potential use to limit autoimmunity such as T1D.

Ten Years of Simultaneous Pancreas-Kidney Transplantation: A Retrospective Single-Center Analysis of Prospectively Obtained Data

Introduction Simultaneous pancreas-kidney transplantation (SPK) is a standardized and life-saving procedure for a patient suffering from both insulin-dependent diabetes mellitus type 1 (IDDM 1) and end-stage diabetic nephropathy. To expand the donor pool and to determine the influence of the preprocurement pancreas suitability scoring system (P-PASS) on pancreas graft survival we retrospectively analyzed our data on SPK. Patients and Methods From 1999 to 2010 we performed 55 SPKs, using systemic-enteric drainage as surgical approach. The immunosuppressive therapy was induced with basiliximab; maintenance therapy was based on tacrolimus, mycophenolate mofetil, and steroids. Data were prospectively obtained, analyzed, and correlated to the P-PASS. Results The overall 10-year patient survival rate was 78% with a 10-year pancreas survival rate of 53%. Three patients needed retransplantation of SPK and 6 patients needed singular pancreas retransplantation. Seventeen patients showed acute rejection episodes and 14 patients suffered from cytomegalovirus (CMV) infections. We compared 43 patients receiving organs from an “ideal” donor (P-PASS <17) with 12 patients receiving grafts from “marginal” donors (P-PASS ≥17). Neither P-PASS nor donor age demonstrated significant influence on pancreas graft survival. However, the body mass index (BMI) of the donor showed a negative tendency ( P = .059). Conclusion The P-PASS showed no significant prediction of pancreas graft survival. In view of our data, expansion of the German donor pool is possible. A multicenter study of SPK using “marginal” pancreas grafts is mandatory to define a realistic “cut-off” value for P-PASS.

Immunomodulation and Regeneration of Islet Beta Cells by Cytokines in Autoimmune Type 1 Diabetes

Juvenile or type 1 diabetes (T1D) involves autoimmune-mediated destruction of insulin-producing β cells in the islets of Langerhans in the pancreas. Lack of insulin prevents the absorption and metabolism of glucose throughout the body by interfering with cell signaling. Cytokines have been shown to play a key role in β cell destruction and regulation of autoimmunity in T1D. The multiple roles of cytokines in T1D pathogenesis, regulation, and regeneration of β cells presents both promise and challenge for their use in immunotherapy. We found that mycobacterial adjuvants induce various regulatory T cells in the non-obese diabetic (NOD) mouse model of T1D. Cytokines produced by these cells not only regulate innate and adaptive immunity but also prevent the development of diabetes and partially restored normoglycemia in diabetic NOD mice. We discovered that adjuvant immunotherapy upregulated Regenerating (Reg) genes in the islets and induced interleukin 22 (IL-22)-producing Th17 cells. IL-22 is known to upregulate Reg gene expression in islets and could potentially induce regeneration of β cells and prevent their apoptosis. Therefore, cytokines both induce and regulate T1D and have the potential to regenerate and preserve insulin-producing β cells in the islets.

Selective IgA deficiency in autoimmune diseases.

Selective immunoglobulin A deficiency (IgAD) is the most common primary immunodeficiency in Caucasians. It has previously been suggested to be associated with a variety of concomitant autoimmune diseases. In this review, we present data on the prevalence of IgAD in patients with Graves disease (GD), systemic lupus erythematosus (SLE), type 1 diabetes (T1D), celiac disease (CD), myasthenia gravis (MG) and rheumatoid arthritis (RA) on the basis of both our own recent large-scale screening results and literature data. Genetic factors are important for the development of both IgAD and various autoimmune disorders, including GD, SLE, T1D, CD, MG and RA, and a strong association with the major histocompatibility complex (MHC) region has been reported. In addition, non-MHC genes, such as interferon-induced helicase 1 (IFIH1) and c-type lectin domain family 16, member A (CLEC16A), are also associated with the development of IgAD and some of the above diseases. This indicates a possible common genetic background. In this review, we present suggestive evidence for a shared genetic predisposition between these disorders.

Evidence of association with type 1 diabetes in the SLC11A1 gene region

BackgroundLinkage and congenic strain analyses using the nonobese diabetic (NOD) mouse as a model for human type 1 autoimmune diabetes (T1D) have identified several NOD mouse Idd (insulin dependent diabetes) loci, including Slc11a1 (formerly known as Nramp1). Genetic variants in the orthologous region encompassing SLC11A1 in human chromosome 2q35 have been reported to be associated with various immune-related diseases including T1D. Here, we have conducted association analysis of this candidate gene region, and then investigated potential correlations between the most T1D-associated variant and RNA expression of the SLC11A1 gene and its splice isoform.MethodsNine SNPs (rs2276631, rs2279015, rs1809231, rs1059823, rs17235409 (D543N), rs17235416 (3'UTR), rs3731865 (INT4), rs7573065 (-237 C→T) and rs4674297) were genotyped using TaqMan genotyping assays and the polymorphic promoter microsatellite (GT)n was genotyped using PCR and fragment length analysis. A maximum of 8,863 T1D British cases and 10,841 British controls, all of white European descent, were used to test association using logistic regression. A maximum of 5,696 T1D families were also tested for association using the transmission/disequilibrium test (TDT). We considered P ≤ 0.005 as evidence of association given that we tested nine variants in total. Upon identification of the most T1D-associated variant, we investigated the correlation between its genotype and SLC11A1 expression overall or with splice isoform ratio using 42 PAXgene whole blood samples from healthy donors by quantitative PCR (qPCR).ResultsUsing the case-control collection, rs3731865 (INT4) was identified to be the variant most associated with T1D (P = 1.55 × 10-6). There was also some evidence of association at rs4674297 (P = 1.57 × 10-4). No evidence of disease association was obtained at any of the loci using the family collections (PTDT ≥ 0.13). We also did not observe a correlation between rs3731865 genotypes and SLC11A1 expression overall or with splice isoform expression.ConclusionWe conclude that rs3731685 (INT4) in the SLC11A1 gene may be associated with T1D susceptibility in the European ancestry population studied. We did not observe a difference in SLC11A1 expression at the RNA level based on the genotypes of rs3731865 in whole blood samples. However, a potential correlation cannot be ruled out in purified cell subsets especially monocytes or macrophages.

Acceleration of autoimmune diabetes in Rheb-congenic NOD mice with β-cell-specific mTORC1 activation

The protein Ras homolog enriched in brain (Rheb) is a Ras-like small GTPase that activates the mechanistic target of rapamycin complex 1 (mTORC1), which promotes cell growth. We previously generated transgenic C57BL/6 mice overexpressing Rheb in β-cells (B6 Rheb), which exhibited increased β-cell size and improved glucose tolerance with higher insulin secretion than wild type C57BL/6 mice. The mice also showed resistance to obesity-induced hyperglycemia, a model of type 2 diabetes, and to multiple low-dose-streptozotocin (MLDS)-induced hyperglycemia, a model of type 1 diabetes (T1D). To investigate whether the effects of mTORC1 activation by Rheb in B6 Rheb mice would also be evident in NOD mice, a spontaneous autoimmune T1D model, we created two NOD mouse lines overexpressing Rheb in their β-cells (NOD Rheb; R3 and R20). We verified Rheb overexpression in β-cells, the relative activation of mTORC1 and β-cell enlargement. By 35 weeks of age, diabetes incidence was significantly greater in the R3 line and tended to be greater in the R20 line than in NOD mice. Histological analysis demonstrated that insulitis was significantly accelerated in 12-week-old R3 NOD Rheb mice compared with NOD mice. Furthermore, serum insulin autoantibody (IAA) expression was significantly higher than that of NOD mice. We also examined whether complete Freund’s adjuvant (CFA) treatment alone or with glucagon-like peptide-1 (GLP-1) analog would reverse the hyperglycemia of NOD Rheb mice; unexpectedly, almost none achieved normoglycemia. In summary, diabetes progression was significantly accelerated rather than prevented in NOD Rheb mice. Our results suggest that the β-cell enlargement might merely enhance the autoimmunity of pathogenic T-cells against islets, leading to acceleration of autoimmune diabetes. We conclude that not only enlargement but also regeneration of β-cells in addition to the prevention of β-cell destruction will be required for the ideal therapy of autoimmune T1D.

Islet Surface Modification with Urokinase through DNA Hybridization

Transplantation of islets of Langerhans (islets) has been proposed as a safe, effective approach to treating patients with insulin-dependent diabetes mellitus (type I diabetes). It has been reported, however, that many islets are lost in the early phase after intraportal transplantation by instant blood coagulation-mediated inflammatory reactions. In this study, DNA hybridization was applied to conjugate the fibrinolytic enzyme urokinase on the islet surface. We synthesized amphiphilic polymers, PEG-lipids carrying oligo(dT)(20) (oligo(dT)(20)-PEG-lipid; PEG MW = 5000) and urokinase (UK) carrying oligo(dA)(20). The oligo(dT)(20)-PEG-lipid was spontaneously incorporated into the cell membrane through interactions between the hydrophobic parts of the PEG-lipids and the lipid bilayer, and UK was conjugated on the cell surface through DNA hybridization between oligo(dT)(20) on the cell and complementary oligo(dA)(20) on the UK. The activity of UK was maintained on the islet surface. The surface modification with UK did not influence islet morphology or islet ability to secrete insulin in response to changes in glucose concentration. No practical volume increase was observed with our method, indicating that islet graft loss could be suppressed at the early stage of intraportal islet transplantation.

Drug-induced lymphadenopathy with eosinophilia and renal failure mimicking lymphoma disease: dramatic onset of DRESS syndrome associated with antibiotic treatment

Dear Editor,Here, we report a rare complication of antibiotic treatmentleading to lymphoma-mimicking lymphadenopathy withconcomitant eosinophilia, dermatitis, and acute renalfailure.A 30-year-old man was admitted for aortic valvereplacement because of endocarditis. The medical historyrevealed insulin-dependent diabetes mellitus (type 1),diabetic retinopathy, vascular disease, hypertension, andstage 2 chronic renal failure. Five weeks prior to admission,transesophageal echocardiography had revealed acuteinfectious endocarditis of the aortic valve and moderateaortic valve insufficiency. Blood cultures were positive forStreptococcus dysgalactiae and antibiotic therapy withpenicillin G and gentamycin was initiated. Penicillin Gwas replaced by vancomycin due to exanthema; gentamy-cin was stopped. Control echocardiography showed severevalve insufficiency, which prompted surgical valve replace-ment. Antibiotic treatment with vancomycin was continuouslyadministered.Ten days after successful surgery, the patient developedacute renal failure (creatinine, 637 μmol/l; reference range(rr), 74–110 μmol/l) requiring single-time hemodialysis.Concomitantly, the patient developed fever with a dailyintermittent pattern (max., 39.7°C) and an elevated whiteblood cell count (35.1/nl; rr, 4.4–11.3/nl) showing a leftshift in the differential count. C-reactive protein wassignificantly elevated (189 mg/ml). Antibiotic therapy withvancomycin, gentamycin, and ceftriaxone did not result inany improvement. The antibiotic therapy was changed tolinezolid/tigecycline; later, to rifampicin, cefuroxime, andfluconazole, without improving symptoms. Echocardiogra-phy showed no signs of acute infectious endocarditis. Bloodcultures were negative. Peripheral lymphadenopathy promp-ted further imaging studies, including a FDG–PET–CT scanwhich showed ubiquitous, highly metabolic, active lymph-adenopathy ranging between 7 and 25 mm in size (Fig. 1a).When the hematology consultant was called in fordiagnosis of suspected lymphoma, the leukocytes hadincreased to 40/nl, and the differential revealed 24%eosinophils. IgE levels were significantly elevated(42,684 kU/l; rr<120 kU/l). Lactate dehydrogenase waslikewise increased (8.1 μmol/l; rr<4.1 μmol/l). In addition,the patient presented with a generalized pruritic rash. Urineanalysis was evident for tubular proteinuria, indicatingtubulointerstitial renal disease. Lymph node biopsy showeda high proliferative activity (Ki-67, 60–80%), initially

Induction of Mixed Chimerism With MHC-Mismatched but Not Matched Bone Marrow Transplants Results in Thymic Deletion of Host-Type Autoreactive T-Cells in NOD Mice

OBJECTIVEInduction of mixed or complete chimerism via hematopoietic cell transplantation (HCT) from nonautoimmune donors could prevent or reverse type 1 diabetes (T1D). In clinical settings, HLA-matched HCT is preferred to facilitate engraftment and reduce the risk for graft versus host disease (GVHD). Yet autoimmune T1D susceptibility is associated with certain HLA types. Therefore, we tested whether induction of mixed chimerism with major histocompatibility complex (MHC)-matched donors could reverse autoimmunity in the NOD mouse model of T1D.RESEARCH DESIGN AND METHODSPrediabetic wild-type or transgenic BDC2.5 NOD mice were conditioned with a radiation-free GVHD preventative anti-CD3/CD8 conditioning regimen and transplanted with bone marrow (BM) from MHC-matched or mismatched donors to induce mixed or complete chimerism. T1D development and thymic deletion of host-type autoreactive T-cells in the chimeric recipients were evaluated.RESULTSInduction of mixed chimerism with MHC-matched nonautoimmune donor BM transplants did not prevent T1D in wild-type NOD mice, although induction of complete chimerism did prevent the disease. However, induction of either mixed or complete chimerism with MHC-mismatched BM transplants prevented T1D in such mice. Furthermore, induction of mixed chimerism in transgenic BDC2.5-NOD mice with MHC-matched or -mismatched MHC II−/− BM transplants failed to induce thymic deletion of de novo developed host-type autoreactive T-cells, whereas induction of mixed chimerism with mismatched BM transplants did.CONCLUSIONSInduction of mixed chimerism with MHC-mismatched, but not matched, donor BM transplants re-establishes thymic deletion of host-type autoreactive T-cells and prevents T1D, with donor antigen-presenting cell expression of mismatched MHC II molecules being required.

Induction of Mixed Chimerism for Reversal of Autoimmunity in Type 1 Diabetes

Type 1 diabetes (T1D) results from autoimmune attack of insulin-producing pancreatic islet β cells. T1D autoimmunity is associated with particular MHC or HLA types in mouse or humans. T1D autoimmunity arises from defects in both central negative selection and peripheral regulation of autoreactive T cells as well as intrinsic defects of B cells. Current therapies that target at improving peripheral tolerance of autoreactive T cells or depleting B cells have not yielded significant therapeutic effects in reversal of autoimmunity in T1D patients. Induction of mixed chimerism with bone marrow cells from non-autoimmune donors has been recently indicated to be a curative therapy for reversal of autoimmunity in T1D. In this review, we have summarized and discussed T1D related abnormalities in the hematopoietic compartment, regimens that induce mixed chimerism in the T1D animal model of non-obese diabetic (NOD) mice, and how mixed chimerism corrects central negative selection and peripheral tolerance of autoreactive T and B cells.

Juvenile, insulin‐dependent diabetes mellitus, type 1‐related dermatoses

Juvenile insulin-dependent diabetes mellitus type 1 (IDDM) is a well-recognized worldwide entity, the significance of which has increased because of its recent upsurging trends, warranting attention on variety of its clinical expressions, in particular, pertaining to skin, an aspect seldom taken cognizance of. Hence an endeavour to recap the related dermatoses, such as limited joint mobility syndrome including sclerodermoid (scleroderma-like) changes, xerosis, necrobiosis lipoidica diabeticorum, granuloma annulare, diabetic foot syndrome, has been made. Complexities relating to the recently explored issues of atopic dermatitis and drug hypersensitivity syndrome have also been covered adequately. In addition, the current concepts of the physiopathology of type 1 diabetes-related dermatoses are briefly recapitulated for clarity.

Genome-Wide Analysis of Copy Number Variation in Type 1 Diabetes

Type 1 diabetes (T1D) tends to cluster in families, suggesting there may be a genetic component predisposing to disease. However, a recent large-scale genome-wide association study concluded that identified genetic factors, single nucleotide polymorphisms, do not account for overall familiality. Another class of genetic variation is the amplification or deletion of >1 kilobase segments of the genome, also termed copy number variations (CNVs). We performed genome-wide CNV analysis on a cohort of 20 unrelated adults with T1D and a control (Ctrl) cohort of 20 subjects using the Affymetrix SNP Array 6.0 in combination with the Birdsuite copy number calling software. We identified 39 CNVs as enriched or depleted in T1D versus Ctrl. Additionally, we performed CNV analysis in a group of 10 monozygotic twin pairs discordant for T1D. Eleven of these 39 CNVs were also respectively enriched or depleted in the Twin cohort, suggesting that these variants may be involved in the development of islet autoimmunity, as the presently unaffected twin is at high risk for developing islet autoimmunity and T1D in his or her lifetime. These CNVs include a deletion on chromosome 6p21, near an HLA-DQ allele. CNVs were found that were both enriched or depleted in patients with or at high risk for developing T1D. These regions may represent genetic variants contributing to development of islet autoimmunity in T1D.

Myeloid-Derived Suppressor Cells Prevent Type 1 Diabetes in Murine Models

Effective immunotherapy for type 1 diabetes (T1D) relies on active induction of peripheral tolerance. Myeloid-derived suppressor cells (MDSCs) play a critical role in suppressing immune responses in various pathologic settings via multiple mechanisms, including expansion of regulatory T cells (Tregs). In this study, we investigated whether MDSCs could act as APCs to induce expansion of Ag-specific Tregs, suppress T cell proliferation, and prevent autoimmune T1D development. We found that MDSC-mediated expansion of Tregs and T cell suppression required MHC-dependent Ag presentation. A murine T1D model was established in INS-HA/RAG(-/-) mice in which animals received CD4-HA-TCR transgenic T cells via adoptive transfer. We found a significant reduction in the incidence of diabetes in recipients receiving MDSC plus HA, but not OVA peptide, leading to 75% diabetes-free mice among the treated animals. To test further whether MDSCs could prevent diabetes onset in NOD mice, nondiabetic NOD/SCID mice were injected with inflammatory T cells from diabetic NOD mice. MDSCs significantly prevented diabetes onset, and 60% of MDSC-treated mice remained diabetes free. The pancreata of treated mice showed significantly lower levels of lymphocyte infiltration in islet and less insulitis compared with that of the control groups. The protective effects of MDSCs might be mediated by inducing anergy in autoreactive T cells and the development of CD4(+)CD25(+)Foxp3(+) Tregs. Thist study demonstrates a remarkable capacity of transferred MDSCs to downregulate Ag-specific autoimmune responses and prevent diabetes onset, suggesting that MDSCs possess great potential as a novel cell-based tolerogenic therapy in the control of T1D and other autoimmune diseases.

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.

Haptoglobin as an early serum biomarker of virus-induced autoimmune type 1 diabetes in biobreeding diabetes resistant and LEW1.WR1 rats

Proteomic profiling of serum is a powerful technique to identify differentially expressed proteins that can serve as biomarkers predictive of disease onset. In this study, we utilized two-dimensional (2D) gel analysis followed by matrix-assisted-laser desorption/ionization time-of-flight mass spectrometry analysis to identify putative serum biomarkers for autoimmune type 1 diabetes (T1D) in biobreeding diabetes resistant (BBDR) rats induced to express the disease. Treatment with toll-like receptor 3 ligand, polyinosinic:polycytidilic acid (pIC), plus infection with Kilham rat virus (KRV), a rat parvovirus, results in nearly 100% of young BBDR rats becoming diabetic within 11-21 d. Sera collected from prediabetic rats at early time points following treatment with pIC + KRV were analyzed by 2D gel electrophoresis and compared with sera from control rats treated with phosphate-buffered saline, pIC alone or pIC + H1, a non-diabetogenic parvovirus. None of the latter three control treatments precipitates T1D. 2D gel analysis revealed that haptoglobin, an acute phase and hemoglobin scavenger protein, was differentially expressed in the sera of rats treated with pIC + KRV relative to control groups. These results were confirmed by Western blot and enzyme-linked immunosorbent assay studies, which further validated haptoglobin levels as being differentially increased in the sera of pIC + KRV-treated rats relative to controls during the first week following infection. Early elevations in serum haptoglobin were also observed in LEW1.WR1 rats that became diabetic following infection with rat cytomegalovirus. The identification and validation of haptoglobin as a putative serum biomarker for autoimmune T1D in rats now affords us the opportunity to test the validity of this protein as a biomarker for human T1D, particularly in those situations where viral infection is believed to precede the onset of disease.

The diagnostic value of zinc transporter 8 autoantibody (ZnT8A) for type 1 diabetes in Chinese

Zinc transporter-8 (ZnT8) was recently identified as a novel autoantigen in human type 1 diabetes (T1D). Autoantibody to ZnT8 (ZnT8A) was detected in up to 80% of patients with new-onset T1D and 26% of patients with T1D otherwise classified as negative on the basis of existing markers. As no data of ZnT8A in Chinese have been reported, we aim to evaluate the utility of ZnT8A for diagnosis of autoimmune T1D in Chinese relative to other autoantibody markers. Radioligand binding assays were performed on 539 T1D sera using human ZnT8 carboxyterminal 325Arg construct or a dimer incorporating 325Arg and 325Trp alongside antibodies to glutamic acid decarboxylase (GADA) or insulinoma-associated protein 2 (IA-2A). The antigenic specificity was analysed in the context of clinical characteristics of the patients. ZnT8A were present in 24.1% (130 of 539) of patients with T1D versus 1.8% (10 of 555; P < 0.001) in type 2 diabetes. At diagnosis, ZnT8A and IA-2A were less prevalent in Chinese subjects with T1D than in Caucasian populations (both P < 0.001) but similar to Japanese. The diagnostic sensitivity of combined GADA, IA-2A and ZnT8A measurements reached 65.5% with ZnT8A detected in 13.5% (29 of 215) of GADA and/or IA-2A-negative subjects. ZnT8A prevalence was lower in older and fatter patients. ZnT8A+ alone patients were distinguished from Ab- ones (P < 0.05-0.001) on the basis of higher insulin requirement and lower systolic blood pressure level. ZnT8A is an independent marker for T1D in Chinese and combined with GADA and IA-2A enhances diagnostic sensitivity. ZnT8A may be associated with different clinical phenotypes than GADA or IA-2A.

40-Year-Old Man With Nausea and Vomiting “Found Down”

A 40-year-old man with a history of prior closed head injury, insulin-dependent diabetes mellitus type 2, and nicotine dependence was evaluated at Saint Marys Hospital, a Mayo Clinic–affiliated hospital in Rochester, MN, after being found unconscious at his home.

Defective FoxP3+ Treg cell differentiation in the gut of Type 1 Diabetic patients

AbstractEnvironmental factors that act at the intestinal level such as diet, drugs, and microflora have a high impact on the pathogenesis of autoimmune Type 1 Diabetes (T1D), but it is still unclear how the gut milieu affects autoimmunity outside the intestine. Here we show that peripheral FoxP3+ Treg cell differentiation, a mechanism that takes place in the gut and is crucial to maintain systemic immune tolerance, is impaired in T1D patients. These results provide the first evidence that gut mucosa alteration could predispose to autoimmune T1D by affecting systemic immune regulation.

Metabolic Syndrome and Type-1 Diabetes Mellitus: Prevalence and Associated Factors

Numerous clinical and epidemiological studies have highlighted the fact that metabolic syndrome is an important precursor of cardiovascular disease. Metabolic syndrome is generally associated with type-2 diabetes, and few data exist on its occurrence in type-1 diabetes. The aims of this study were to determine the prevalence of metabolic syndrome in patients with type-1 diabetes and to identify associated factors. This cross-sectional study included consecutive patients aged over 18 years with autoimmune type-1 diabetes of more than 6 months' duration who were treated during 2008 at the Outpatient Endocrinology Clinic of the Hospital del Mar, Barcelona, Spain. The presence of metabolic syndrome was determined using the modified criteria proposed by the National Cholesterol Education Program-Adult Treatment Panel III. Overall, 31.9% (95% confidence interval [CI], 22.3%-41.5%) of patients with type-1 diabetes had metabolic syndrome. The following factors were significantly and independently associated with the presence of metabolic syndrome in patients with type-1 diabetes: age (odds ratio [OR]=1.09; 95% CI, 1.029-1.154), body mass index (OR=1.389; 95% CI, 1.134-1.702) and glycosylated hemoglobin level (OR=1.745; 95% CI, 1.081-2.815). In addition, there was a direct relationship between the number of components of metabolic syndrome present and prevalence of microangiopathy, which reached 100% in patients who satisfied all diagnostic criteria. Metabolic syndrome was common in patients with type-1 diabetes and was associated with microvascular complications.

Early suppression of immune response pathways characterizes children with prediabetes in genome-wide gene expression profiling

Type 1 diabetes (T1D) is caused by autoimmune destruction of insulin-producing pancreatic β cells in the islets of Langerhans. Although defects in various T cell subsets have been linked to the disease pathogenesis, mechanisms initiating or enhancing the autoimmunity in prediabetes remain poorly understood. To unravel genes and molecular pathways affected by the diabetes-associated autoimmunity, we investigated transcriptomic profiles of prospective whole-blood samples from children who have developed T1D-associated autoantibodies and eventually clinical T1D. Gene-level investigation of the data showed systematic differential expression of 520 probesets. A network-based analysis revealed then a highly significant down-regulated network of genes involved in antigen presentation as well as T-cell receptor and insulin signaling. Finally, detection of dynamic changes in the affected pathways at the early or late phases of autoimmunity showed down-regulation of several novel T1D-associated pathways as well as known key components of immune response. The longitudinal genome-wide data generated in the present study allows the detection of dynamic changes relevant to the disease that may be completely missed in conventional cross-sectional studies or in genome-wide association studies. Taken together, our analysis showed systemic high-level repression of immune response pathways associated with T1D autoimmunity.