Islet Cell Autoantibodies Research Articles

Anti-zinc transporter protein 8 autoantibodies significantly improve the diagnostic approach to type 1 diabetes: an Italian multicentre study on paediatric patients.

Background and aim Anti-ZnT8 antibodies (ZnT8A) were recently proposed as a new independent serological marker in Type 1 diabetes (T1D), leading to a significant improvement of the positive predictive value of autoantibody measurement in this setting. The aim of this retrospective multicentre study was to investigate ZnT8A as a complement to the current T1D autoantibody assays in a large cohort of paediatric Italian patients.MethodsZnT8A were assessed by ELISA in 213 T1DM paediatric patients referred to six different centres in North-East Italy. Fifty-four were analysed at disease onset, 79 within 4 years from diagnosis and 80 after 5 or more years from diagnosis. Retrospective data about islet cell autoantibodies (ICA), anti-insulin (IAA), anti-glutamate decarboxylase (GADA) and anti-protein tyrosine phosphatase IA-2 (IA-2A) antibodies were collected and compared.ResultsOverall, ZnT8A showed positive results in 106/213 (49.8 %) T1D patients and were found in 10 (4.7 %) subjects previously classified as autoantibody negative based on the existing markers (GADA, IA-2A, IAA and ICA), increasing the overall diagnostic sensitivity from 85.9 to 90.6 %. ZnT8A disclosed the same sensitivity (61.1 %) at disease onset as GADA (61.1 %) and higher than IA-2A (53.7 %), with only GADA showing much persistence in the long-term follow-up. Focusing on patients at disease onset, all the ICA positive were associated with at least one positive autoantibody among GADA, IA-2A and ZnT8A, 16.7 % of whom presenting only anti-ZnT8-positive antibodies.ConclusionThis study confirms ZnT8A as an important additional and independent diagnostic marker of T1D and supports its introduction in the routine diagnostic process to replace less sensitive methods and improve the overall autoantibody sensitivity.Electronic supplementary materialThe online version of this article (doi:10.1007/s13317-015-0068-4) contains supplementary material, which is available to authorized users.

Prediction of type 1 diabetes in Sardinian schoolchildren using islet cell autoantibodies: 10-year follow-up of the Sardinian schoolchildren type 1 diabetes prediction study.

Stable genetic background makes individuals from the Mediterranean island of Sardinia ideal to define the predictive power of islet-related autoantibodies (IRAs): glutamic acid decarboxylase antibodies (GADA), tyrosine phosphatase-like antibodies (IA-2A), islet cell antibodies (ICA) to identify T1DM progressors. The aims of the present study were: (1) determination of IRAs reference limits in healthy non-diabetic Sardinian schoolchildren (SSc). (2) Predictive power evaluation of IRAs as single or combined determination to identify islet to identify T1DM progressors. Between 1986 and 1994, 8448 SSc were tested for IRAs. All were followed up for 10years. The predictive power of single or combination of IRAs was determined as hazard ratio (HR), sensitivity, specificity, area under the ROC curve, negative and positive predictive value (NPV, PPV). All 43 progressors to T1DM, but three showed at least one autoantibody positivity. HR for any single-autoantibody positivity was 55.3 times greater when compared to SSc negative for all IRAs. Any single autoantibody performed at least 64.9% sensitivity with PPV always lower than 16%. The best performing combination was ICA, plus IA-2A (showing 52.6% sensitivity, 99.8% specificity, 0.76 area under the ROC curve, 51.3% PPV and 99.8% NPV. Determination of IRAs reference limits in healthy SSc by standard statistical methods is crucial to establish the power of IRAs as progression markers to T1DM. Our data offer a solid rationale for future testing of ICA and IA-2A as routine laboratory markers to identify individuals at high risk of T1DM in the general population.

Low Frequencies of Autoimmunity-Associated PTPN22 Polymorphisms in MODY Patients, Including Those Transiently Expressing Islet Cell Autoantibodies

Background: The protein tyrosine phosphatase nonreceptor type 22 (PTPN22) gene encodes lymphoid tyrosine phosphatase (LYP), which is expressed primarily in lymphoid tissues. The functional but geographically highly variable PTPN22 single-nucleotide polymorphisms (SNPs), particularly c.1858C>T, contribute to the onset and progression of autoimmunity-associated diseases and facilitate the expression of disease-associated autoantibodies. In Central Europe, 17-25% of patients with monogenic diabetes (maturity-onset diabetes of the young, MODY) transiently express islet cell autoantibodies. Methods: We addressed the links between the functional and geographically variable PTPN22 SNPs with MODY manifestation and the expression of islet cell autoantibodies in 276 MODY patients who originated from four regions (the Czech Republic, Israel, Japan and Brazil). Results: The frequency of PTPN22 polymorphisms in the MODY patients was similar to those in geographically matched healthy populations, with the exception of c.788G>A, the minor allele frequency of which was significantly elevated in the Czech hepatocyte nuclear factor 1-α (HNF1A) MODY patients [odds ratio (OR) 4.8, 95% confidence interval (CI) 2.2-10.7] and the Brazilian MODY patients (OR 8.4, 95% CI 1.8-39.1). A barely significant increase in the c.788G>A minor allele was also detected in the islet cell autoantibody-positive Czech MODY patients. However, c.788A behaves as a loss-of-function mutant in T cells, and thus protects against autoimmunity. Conclusions: MODY patients (including islet cell autoantibody-positive cases) do not display any increase in autoimmunity-associated PTPN22 alleles. The absence of autoimmunity-associated PTPN22 alleles was also demonstrated in latent autoimmune diabetes in adults, which suggests that the slow kinetics of the onset of autoantibodies is subject to a regulation that is different from that experienced in type 1 diabetes and other autoimmune disorders.

Prevalence of Latent Autoimmune Diabetes of Adult (LADA) among Type2 Diabetes Mellitus (D.M.2) in Karbala

Objective: the aim of the study is to determine the prevalence of LADA among group of clinically diagnosed type 2 diabetes mellitus. Methodology: sample size equal to 280 patients with type 2 D.M. were subjected in this study, participating patients were consecutively recruited of Diabetes outpatient clinic in AL-Hussein Teaching Hospital in Karbala of June, 2013 through January, 2014. A clinical questioner containing personal data, family history, type of diabetes, type of treatment, FBS, HA1C, BMI, diabetes duration & complications of diabetes. For analysis of data Prevalence of LADA among D.M.2 cases was calculated as the proportion of LADA cases in the D.M.2 cases. The Chi square test (X2) was used to assess the significance (P-value) of differences in frequencies of categorical variables. Results: prevalence of LADA among D.M.2 patients was 12.1%. A significant difference in family history, BMI, FBS, HA1C and duration of D.M was found between the studied groups. Conclusion: The prevalence of LADA is clinically underestimated among D.M2 patients and age of onset of diabetes should no longer be considered as a valid way to differentiate diabetes. Recommendation: the study recommends screening for islet cell autoantibodies as GAD65 for all patients with diabetes at onset or beginning of disease.

The influence of maternal islet beta-cell autoantibodies in conjunction with gestational hyperglycemia on neonatal outcomes.

ObjectiveTo determine the predictive value of the presence of maternal islet beta-cell autoantibodies with respect to neonatal outcomes.MethodsA total of 311 pregnant women with abnormal 75 g oral glucose tolerance test (OGTT) results were enrolled in this study. Maternal glutamic acid decarboxylase autoantibodies (GADA), islet cell autoantibodies (ICA) and insulin autoantibodies (IAA) were tested in fasting blood both on the day following the routine OGTT and before delivery. The birth weight, Apgar score, blood glucose and outcomes of each neonate were later evaluated and recorded.Results1. In this study, 33.9% of the pregnant women with gestational hyperglycemia had detectable levels of one or more types of anti-islet cell antibodies in the third trimester. The proportion of women who produced GADA and/or ICA was significantly higher in the group of women with gestational hyperglycemia than in the control group (P<0.05). The groups similarly differed in the proportion of women who tested positive for any anti-islet cell antibody (P<0.05). 2. Of the patients in our study, those who produced GADA exhibited an increase in uterine and umbilical arterial pulsatility indexes (PIs) during the third trimesters compared with the control group (P˂0.05). Additionally, an increased frequency of fetal growth restriction (FGR) was observed in the infants of women who produced IAA during pregnancy compared with those without autoantibodies (P˂0.05). 3. The rate of newborn admission to the neonatal intensive care unit (NICU) was significantly associated with the presence of maternal ICA during the third trimester (OR, 6.36; 95% CI, 1.22–33.26). 4. The incidence of neonatal asphyxia was associated with the presence of maternal GADA in both the second (OR, 10.44; 95% CI, 1.46–74.92) and the third (OR, 8.33; 95% CI, 1.45–47.82) trimesters.ConclusionApproximately one-third of the women with gestational hyperglycemia produced anti-islet cell antibodies. The incidence of FGR was higher in women with gestational hyperglycemia who produced IAA than in those without autoantibodies. Maternal ICA production in the third trimester was a risk factor for the subsequent admission of newborns to the NICU. Furthermore, the presence of maternal GADA placed the neonate at increased risk for asphyxia.

Type 1 diabetes pathogenesis - Prevention???

Pathogenesis of type 1 diabetes is multi-faceted, including, autoimmunity, genetics and environment. Autoimmunity directed against pancreatic islet cells results in slowly progressive selective beta-cell destruction (“Primary autoimmune insulitis”), culminating over years in clinically manifested insulin-dependent diabetes mellitus (IDDM). Circulating serum autoantibodies directed against the endocrine cells of the islets of Langerhans (Islet cell autoantibodies - ICAb) are an important hallmark of this disease. Assays for islet cell autoantibodies have facilitated the investigation and understanding of several facets in the pathogenesis of autoimmune diabetes. Their applications have extended into clinical practice and have opened new avenues for early preclinical prediction and preventive prophylaxis in IDDM/type 1 DM. Recently, surprisingly, differences in insulin content between T1DM islets, as well as, ‘patchy’ or ‘lobular’ destruction of islets have been described. These unique pathobiological phenomena, suggest that beta cell destruction may not always be inexorable and inevitably complete/total, and thus raise hopes for possible therapeutic interruption of beta cell autoimmunity – destruction and cure of type 1 diabetes. “Recurrent or secondary autoimmune insulitis” refers to the rapid reappearance of islet cell autoantibodies post pancreas transplant, and selective islet beta cell destruction in the grafted pancreas [never forgetting or “anamnestic” beta cell destructive memory], in the absence of any graft pancreas rejection [monozygotic twin to twin transplantation]. The one definite environmental factor is congenital rubella, because of which a subset of children subsequently develop type 1 diabetes. The putative predisposing factors are viruses, gluten and cow's milk. The putative protective factors include gut flora, helminths, viral infections, and Vitamin D. Prevention of T1DM can include: Primary prevention strategies before the development of autoantibodies and Secondary prevention regimens after autoantibody development. Once islet cell autoantibodies have developed, the goal is to establish a therapeutic regimen to preserve at least 90% of the beta cells, and prevent the development of hyperglycaemia. The targets for T1DM reversal should include autoimmunity, beta cell regeneration and protection of beta cell mass. Anti-CD3 teplizumab and anti-CD3 otelixizumab have been shown to provide C-peptide preservation. The unanswered questions in diabetes research include elimination of autoimmune memory responses, reestablishment of immune self-tolerance, and mechanisms of disease initiation.

Obesity, islet cell autoimmunity, and cardiovascular risk factors in youth at onset of type 1 autoimmune diabetes.

The current increase in childhood type 1 diabetes (T1D) and obesity has led to two conflicting hypotheses and conflicting reports regarding the effects of overweight on initiation and spreading of islet cell autoimmunity vs earlier clinical manifestation of preexisting autoimmune β-cell damage driven by excess weight. The objective of the study was to address the question of whether the degree of β-cell autoimmunity and age are related to overweight at diabetes onset in a large cohort of T1D youth. This was a prospective cross-sectional study of youth with autoimmune T1D consecutively recruited at diabetes onset. The study was conducted at a regional academic pediatric diabetes center. Two hundred sixty-three consecutive children younger than 19 years at onset of T1D participated in the study. Relationships between body mass index and central obesity (waist circumference and waist to height ratio) and antigen spreading (islet cell autoantibody number), age, and cardiovascular (CVD) risk factors examined at onset and/or 3 months after the diagnosis were measured. There were no significant associations between number of autoantibodies with measures of adiposity. Age relationships revealed that a greater proportion of those with central obesity (21%) were in the youngest age group (0-4 y) compared with those without central obesity (6%) (P = .001). PATIENTS with central obesity had increased CVD risk factors and higher onset C-peptide levels (P < .05). No evidence was found to support the concept that obesity accelerates progression of autoantibody spreading once autoimmunity, marked by standard islet cell autoantibody assays, is present. Central obesity was present in almost one-third of the subjects and was associated with early CVD risk markers already at onset.

Islet autoantibody status in a multi-ethnic UK clinic cohort of children presenting with diabetes

ObjectiveWe prospectively determined islet autoantibody status in children presenting with diabetes to a single UK region in relation to ethnicity.Design316 (68.0% non-white) children presenting with diabetes between 2006 and 2013...

Autoimmune Polyglandular Syndrome Type II: Epidemiological, Clinical and Immunological Data

Background: Autoimmune polyglandular syndrome (APS) is characterized by the coexistence of several autoimmune diseases, affecting predominantly the endocrine glands. APS type I is distinguished from type II in which autoimmune thyroiditis, Addison’s disease and diabetes type 1 predominate. This article summarizes extensive epidemiological, clinical, and immunological data of a large population of Tunisian patients with APS II. Methods: In a retrospective case finding study, we collected data from patients with APS type II who had been treated in our endocrine outpatient clinic between 1980 and 2007. One hundred and six patients fulfilled the criteria of APS II. Results: Among these patients, 73 were female and 33 were male (mean age 36 and 42 years, respectively; P = 0.04). The mean age at the onset was 38 ± 14.9 years. Of the 106 patients, 76 had hypothyroidism due to autoimmune thyroiditis while 23 had hyperthyroidism (Grave’s disease). Sixty-six patients had type I diabetes mellitus (60.6% females and 39.5% males; P = 0.01). Addison’s disease was diagnosed in 39 patients, primary hypogonadism in 12 cases (11 females and one male), and neuro-hypophysitis was less frequently noted (n = 6). The most frequent coexistence of APS component diseases was between type I diabetes and thyroid disease (56.2%). The time interval between the advent of the first and the second autoimmune endocrinopathies varied considerably with longest time intervals between diabetes type I and thyroid disease and shortest time intervals between Addison’s disease and thyroid disease. Regarding autoantibodies in patients with APS II, anti-thyroid peroxidase antibodies were detected in 67.6%, thyroid stimulating hormone-receptor antibodies in 58%, and anti-thyroglobulin were less frequently positive (43.3%). Type I diabetes-associated antibodies against islet cell (islet cell autoantibodies) and glutamic acid decarboxylase were found in 23.6% and 51.8%, respectively. Antibodies to adrenal cortex were observed in 9.7% and ovarian antibodies in 8.8%. Conclusion: The present study indicates that most patients with autoimmune thyroid disease will not develop additional endocrine disease. If they do, when a thyroid disease was as a first component disease, the time interval until the onset of a further autoimmune disease was relatively short and when thyroid disease was a second component disease a longer period of time elapsed. J Endocrinol Metab. 2014;4(4):101-109 doi: http://dx.doi.org/10.14740/jem227w

A highly sensitive microsphere-based assay for early detection of Type I diabetes

Type 1 Diabetes Mellitus (T1DM) is a T-cell mediated autoimmune disease in which deterioration of insulin producing pancreatic β-cells leads to a state of insulin deficiency. It has been shown that the clinical symptoms of T1DM are preceded by presence of islet cell autoantibodies (ICA) in serum. Radioimmunoassay (RIA) based detection of ICA are the current gold standard for diagnosis of T1DM. While the onset of hyperglycemia is an indicator of onset of T1DM, detection of ICA within the serum is important to differentiate T1DM from ketogenic Type 2 Diabetes (T2D) and Maturity Onset Diabetes of the Young (MODY). Due to their limited range of sensitivity, however, RIA cannot detect ICA at low concentrations in serum which could lead to delay in proper diagnosis and treatment. In addition, the use of radioactive species presents major disadvantages including exposure, waste removal, need for specialized licensed facilities to conduct the tests and the time required for the test (&gt; 24 hours). To overcome these limitations, we have developed a rapid, highly sensitive, fluorescent and microsphere-based assay technique using Rolling Circle Amplification (RCA), to profile T1DM marker antibodies in serum. This assay utilizes the ability of RCA to detect very small amounts of DNA coupled with microsphere-immobilization resulting in an assay which is at least 50 times more sensitive than RIA. Further, this assay method requires very low volume of sample (5 μL), and can be easily adapted to detect other autoantibodies at similar sensitivities while reducing the assay time to ~6 hours. This powerful technique could enable detection of T1DM markers much earlier than current methods and enable earlier intervention to deter the progression of disease. In addition, the modularity of this assay would have implications for enhancing the sensitivities of any standard ELISA technique.

The Occurrence of Iron-Deficiency Anemia in Children With Type 1 Diabetes

ObjectiveA higher risk for iron deficiency, which can lead to anemia, has been noticed in children with early stages of type 1 diabetes. Anemia in diabetes is not uncommon and...

Biomarker discovery study design for type 1 diabetes in The Environmental Determinants of Diabetes in the Young (TEDDY) study.

The Environmental Determinants of Diabetes in the Young planned biomarker discovery studies on longitudinal samples for persistent confirmed islet cell autoantibodies and type 1 diabetes using dietary biomarkers, metabolomics, microbiome/viral metagenomics and gene expression. This article describes the details of planning The Environmental Determinants of Diabetes in the Young biomarker discovery studies using a nested case-control design that was chosen as an alternative to the full cohort analysis. In the frame of a nested case-control design, it guides the choice of matching factors, selection of controls, preparation of external quality control samples and reduction of batch effects along with proper sample allocation. Our design is to reduce potential bias and retain study power while reducing the costs by limiting the numbers of samples requiring laboratory analyses. It also covers two primary end points (the occurrence of diabetes-related autoantibodies and the diagnosis of type 1 diabetes). The resulting list of case-control matched samples for each laboratory was augmented with external quality control samples.

Compromised Gut Microbiota Networks in Children With Anti-Islet Cell Autoimmunity

The gut microbiome is suggested to play a role in the pathogenesis of autoimmune disorders such as type 1 diabetes. Evidence of anti-islet cell autoimmunity in type 1 diabetes appears in the first years of life; however, little is known regarding the establishment of the gut microbiome in early infancy. Here, we sought to determine whether differences were present in early composition of the gut microbiome in children in whom anti-islet cell autoimmunity developed. We investigated the microbiome of 298 stool samples prospectively taken up to age 3 years from 22 case children in whom anti-islet cell autoantibodies developed, and 22 matched control children who remained islet cell autoantibody-negative in follow-up. The microbiome changed markedly during the first year of life, and was further affected by breast-feeding, food introduction, and birth delivery mode. No differences between anti-islet cell autoantibody-positive and -negative children were found in bacterial diversity, microbial composition, or single-genus abundances. However, substantial alterations in microbial interaction networks were observed at age 0.5 and 2 years in the children in whom anti-islet cell autoantibodies developed. The findings underscore a role of the microbiome in the pathogenesis of anti-islet cell autoimmunity and type 1 diabetes.

Masked and Overt Autoantibodies Specific to the DPD Epitope of 65-kDa Glutamate Decarboxylase (GAD65-DPD) Are Associated With Preserved β-Cell Functional Reserve in Ketosis-Prone Diabetes

Ketosis-prone diabetes (KPD), defined by presentation with diabetic ketoacidosis (DKA), comprises 4 subgroups based on the presence or absence of islet cell autoantibodies (A(-) or A(+)) and β-cell functional reserve (β(-) or β(+)). Among A(+) KPD, autoantibody epitope reactivity to 65-kDa glutamate decarboxylase (GAD65), defined by monoclonal GAD65Ab(DPD), was associated with greater β-cell functional reserve. In a majority of healthy individuals, GAD65Ab are present in the sera but are masked by anti-idiotypic antibodies; in contrast, overtly GAD65Ab-positive patients with autoimmune type 1 diabetes patients lack these anti-idiotypic antibodies. Our objective was to determine the presence of masked and overt GAD65Ab(DPD) in relation to β-cell function and genetic risk factors in KPD patients. We investigated the associations of masked and overt GAD65Ab(DPD) with β-cell functional reserve, and their relationship with human leukocyte antigen (HLA) class II haplotypes linked to autoimmune diabetes susceptibility or resistance, in a large KPD cohort. Adult KPD patients (n = 384) were followed longitudinally in a research clinic. β-Cell function, autoantibody status, GAD65Ab epitopes, and HLA class II haplotypes were evaluated. Overall, KPD patients with β-cell functional reserve (β(+) subgroups) showed significantly higher frequency of masked GAD65Ab(DPD) than patients without β-cell functional reserve (β(-) subgroups): 112 of 144 (79%) compared with 59 of 100 (59%), respectively (P = .002). Masked or overt GAD65Ab(DPD) were also more frequent among autoantibody-positive patients with preserved β-cell functional reserve (A(+)β(+) KPD) than those lacking β-cell function (A(+)β(-) KPD): 77% compared with 55% (P = .01). The susceptibility HLA haplotypes DQA1*0301/DQB1*0302 and DQA1*0301/DQB1*0201 were associated with absence of overt or masked GAD65Ab(DPD) (odds Ratios 2.3 and 2.2, respectively). Masked GAD65Ab(DPD) are strongly associated with preserved β-cell functional reserve among patients with KPD. Absence of GAD65Ab(DPD) reactivity is associated with 2 HLA class II susceptibility haplotypes for autoimmune type 1 diabetes.

The New Miracle of Habbatus Sauda: Its Major Component Thymoquinone can be Used in the Management of Autoimmune Diseases

Prophet Muhammad (SWS) once stated that habbatus sauda (black seed) can heal every disease except death. To our knowledge the effect of this seed on autoimmunity process has never been examined.This study was carried out in UiTM Malaysia to investigate the potential immunomodulatory effect of administration of the major component of Habbatus Sauda; (Thymoquinone) in the autoimmune disease process of type 1 diabetes mellitus as a common example of autoimmune diseases. We have evaluated with the help of ELISA kits the levels of anti- islet cell autoantibodies (ICA), Pan T lymphocytes marker, Pan B lymphocytes marker, and Pan innate cells marker in male Sprague-Dawley rats with Streptozocin-induced the autoimmune disease process of type 1 diabetes mellitus. The four groups (6 rats each) under study received or not different doses of Thymoquinone. The results have been compared to the ones obtained from healthy and non treated diabetic rats. The administration of Thymoquinone especially in high doses to the type1 diabetic rats leads to a significant decreases in the levels of all immunological parameters and stop the disease process (p<0.001). The data may provide new strategies about Habbatus Sauda to be recommended in the clinical management of autoimmune diseases as one of documented halal prescription.

Antibodies to islet cell autoantigens, rotaviruses and/or enteroviruses in cord blood and healthy mothers in relation to the 2010–2011 winter viral seasons in Israel: a pilot study

To determine whether antivirus and/or islet cell antibodies can be detected in healthy pregnant mothers without diabetes and/or their offspring at birth in two winter viral seasons. Maternal and cord blood sera from 107 healthy pregnant women were tested for islet cell autoantibodies using radioligand binding assays and for anti-rotavirus and anti-CoxB3 antibody using an enzyme-linked immunosorbent assay. Glutamic acid decarboxylase (GAD)65 autoantibodies and rotavirus antibodies, present in both maternal and cord blood sera, correlated with an odds ratio of 6.89 (95% CI: 1.01-46.78). For five, 22 and 17 pregnancies, antibodies to GAD65, rotavirus and CoxB3, respectively, were detected in cord blood only and not in the corresponding maternal serum. In 10 pregnancies, rotavirus antibody titres in the cord blood exceeded those in the corresponding maternal serum by 2.5-5-fold. Increased antibody titres after the 20(th) week of gestation suggested CoxB3 infection in one of the 20 pregnancies and rotavirus in another. The concurrent presence of GAD65 antibodies in cord blood and their mothers may indicate autoimmune damage to islet cells during gestation, possibly caused by cross-placental transmission of viral infections and/or antivirus antibodies. Cord blood antibody titres that exceed those of the corresponding maternal sample by >2.5-fold, or antibody-positive cord blood samples with antibody-negative maternal samples, may imply an active in utero immune response by the fetus.

Expression of Innate Immunity Genes and Damage of Primary Human Pancreatic Islets by Epidemic Strains of Echovirus: Implication for Post-Virus Islet Autoimmunity

Three large-scale Echovirus (E) epidemics (E4,E16,E30), each differently associated to the acute development of diabetes related autoantibodies, have been documented in Cuba. The prevalence of islet cell autoantibodies was moderate during the E4 epidemic but high in the E16 and E30 epidemic. The aim of this study was to evaluate the effect of epidemic strains of echovirus on beta-cell lysis, beta-cell function and innate immunity gene expression in primary human pancreatic islets. Human islets from non-diabetic donors (n = 7) were infected with the virus strains E4, E16 and E30, all isolated from patients with aseptic meningitis who seroconverted to islet cell antibody positivity. Viral replication, degree of cytolysis, insulin release in response to high glucose as well as mRNA expression of innate immunity genes (IFN-b, RANTES, RIG-I, MDA5, TLR3 and OAS) were measured. The strains of E16 and E30 did replicate well in all islets examined, resulting in marked cytotoxic effects. E4 did not cause any effects on cell lysis, however it was able to replicate in 2 out of 7 islet donors. Beta-cell function was hampered in all infected islets (P<0.05); however the effect of E16 and E30 on insulin secretion appeared to be higher than the strain of E4. TLR3 and IFN-beta mRNA expression increased significantly following infection with E16 and E30 (P<0.033 and P<0.039 respectively). In contrast, the expression of none of the innate immunity genes studied was altered in E4-infected islets. These findings suggest that the extent of the epidemic-associated islet autoimmunity may depend on the ability of the viral strains to damage islet cells and induce pro-inflammatory innate immune responses within the infected islets.

Positivity for islet cell autoantibodies in patients with monogenic diabetes is associated with later diabetes onset and higher HbA1c level

Islet cell autoantibodies are associated with autoimmune insulitis and belong to the diagnostic criteria of type 1 diabetes mellitus. However, growing evidence suggests that autoantibodies are present in other types of diabetes. Here, we focus on the autoantibody incidence in Czech patients with maturity-onset diabetes of the young and analyse their functional relevance in terms of diabetes onset and control. Autoantibodies against glutamic acid decarboxylase (GAD) 65 and protein tyrosine phosphatase islet antigen 2 (IA-2) were measured in a cohort of 28 Czech patients with maturity-onset diabetes of the young, all confirmed by genetic testing. Selected clinical data were correlated to the status and kinetics of autoantibodies. One quarter of patients with maturity-onset diabetes of the young examined (7/28; 25%) was positive for GAD or IA-2 autoantibodies. GAD autoantibodies were more prevalent (7/7) than IA-2 autoantibodies (1/7). The incidence of autoantibodies did not correlate with human leukocyte antigen status. The patients who were positive for the autoantibodies developed diabetes later than those who were autoantibody-negative, but had worse glycaemic control (increased HbA1c ). Expression of autoantibodies decreased with any improvement of diabetes compensation. Only one patient did not correspond to the above and displayed signs of combined signs of maturity-onset diabetes of the young and Type 1 diabetes. The data suggest transient but highly prevalent islet cell autoantibody expression in Czech patients with maturity-onset diabetes of the young. The autoantibodies were found in patients with delayed diabetes onset, and in times of insufficient diabetes control. As improvement of glycaemic control was associated with a decrease in levels of autoantibodies, their presence may reflect the kinetics of β-cell destruction induced by causes other than autoimmune ones.

Increased Complement Activation in Human Type 1 Diabetes Pancreata

OBJECTIVEEvidence supporting an association between complement (C) and type 1 diabetes (T1D) includes the identification of C-fixing islet cell autoantibodies in T1D sera and genetic associations with the major histocompatibility complex III C4 region on chromosome 6. Therefore, we investigated whether C activation was present in pancreata from those with or at increased risk (positive for T1D associated autoantibodies) for T1D.RESEARCH DESIGN AND METHODSImmunohistochemical techniques were used to measure the C degradation product C4d in organ donor pancreata from patients with T1D and type 2 diabetes and autoantibody-positive and autoantibody-negative subjects.RESULTSMedian C4d antigen density differed across the groups (P < 0.0001) and was highest in patients with T1D. C4d immunostaining localized to the blood vessel endothelium and extracellular matrix surrounding blood vessels and exocrine ducts. Receiver operating characteristic analysis resulted in 81.8% sensitivity and 94.4% specificity for C4d staining.CONCLUSIONSThese data suggest that C activation is occurring within pancreata from patients with T1D and C4d may be a biomarker for T1D.

Latent autoimmune diabetes in adults is perched between type 1 and type 2: evidence from adults in one region of Spain

The aim of this study was to characterize the clinical characteristics and insulin secretion in adults with latent autoimmune diabetes in adults (LADA). We also compared these characteristics in subjects with antibody-negative type 2 diabetes (T2DM) or adult-onset type 1 diabetes (T1DM) to subjects with LADA. In this cross-sectional study, 82 patients with LADA, 78 with T1DM and 485 with T2DM were studied. Clinical and metabolic data, in particular those that related to metabolic syndrome, fasting C-peptide and islet-cell autoantibodies [glutamic acid decarboxylase (GADAb) and IA2 (IA2Ab)] were measured. The frequency of metabolic syndrome in patients with LADA (37.3%) was higher than in those with T1DM (15.5%; p = 0.005) and lower than in patients with T2DM (67.2%; p < 0.001). During the first 36 months of the disease, the C-peptide concentration in LADA patients was higher than in subjects with T1DM but was lower than in T2DM patients (p < 0.01 for comparisons). Glycemic control in LADA patients (HbA1c 8.1%) was worse than in patients with T2DM (HbA1c 7.6%; p =0.007). An inverse association between GADAb titers and C-peptide concentrations was found in subjects with LADA (p < 0.001). Finally, LADA patients rapidly progressed to insulin treatment. As in other European populations, patients with LADA in Spain have a distinct metabolic profile compared with patients with T1DM or T2DM. LADA is also associated with higher impairment of beta-cell function and has worse glycemic control than in T2DM. Beta cell function is related to GADAb titers in patients with LADA.