144 research outputs found
Zinc Transporter 8 Antibodies Complement GAD and IA-2 Antibodies in the Identification and Characterization of Adult-Onset Autoimmune Diabetes: Non Insulin Requiring Autoimmune Diabetes (NIRAD) 4
OBJECTIVE: Zinc transporter 8 (ZnT8) is an islet beta-cell secretory granule
membrane protein recently identified as an autoantibody antigen in type 1
diabetes. The aim of this study was to determine the prevalence and role of
antibodies to ZnT8 (ZnT8As) in adult-onset diabetes.
RESEARCH DESIGN AND METHODS: ZnT8As were measured by a radioimmunoprecipitation
assay using recombinant ZnT8 COOH-terminal or NH(2)-terminal proteins in 193
patients with adult-onset autoimmune diabetes having antibodies to either GAD
(GADAs) or IA-2 (IA-2As) and in 1,056 antibody-negative patients with type 2
diabetes from the Non Insulin Requiring Autoimmune Diabetes (NIRAD) study.
RESULTS: ZnT8As-COOH were detected in 18.6% patients with autoimmune diabetes and
1.4% with type 2 diabetes. ZnT8As-NH(2) were rare. ZnT8As were associated with
younger age and a high GADA titer. The use of GADAs, IA-2As, and ZnT8As in
combination allowed a stratification of clinical phenotype, with younger age of
onset of diabetes and characteristics of more severe insulin deficiency (higher
fasting glucose and A1C, lower BMI, total cholesterol, and triglycerides) in
patients with all three markers, with progressive attenuation in patients with
two, one, and no antibodies (all P(trend) < 0.001). Autoantibody titers,
association with high-risk HLA genotypes, and prevalence of thyroid peroxidase
antibodies followed the same trend (all P < 0.001).
CONCLUSIONS: ZnT8As are detectable in a proportion of patients with adult-onset
autoimmune diabetes and seem to be a valuable marker to differentiate clinical
phenotypes
Directed self-assembly of a xenogeneic vascularized endocrine pancreas for type 1 diabetes.
Intrahepatic islet transplantation is the standard cell therapy for β cell replacement. However, the shortage of organ donors and an unsatisfactory engraftment limit its application to a selected patients with type 1 diabetes. There is an urgent need to identify alternative strategies based on an unlimited source of insulin producing cells and innovative scaffolds to foster cell interaction and integration to orchestrate physiological endocrine function. We previously proposed the use of decellularized lung as a scaffold for β cell replacement with the final goal of engineering a vascularized endocrine organ. Here, we prototyped this technology with the integration of neonatal porcine islet and healthy subject-derived blood outgrowth endothelial cells to engineer a xenogeneic vascularized endocrine pancreas. We validated ex vivo cell integration and function, its engraftment and performance in a preclinical model of diabetes. Results showed that this technology not only is able to foster neonatal pig islet maturation in vitro, but also to perform in vivo immediately upon transplantation and for over 18 weeks, compared to normal performance within 8 weeks in various state of the art preclinical models. Given the recent progress in donor pig genetic engineering, this technology may enable the assembly of immune-protected functional endocrine organs
Glutamic acid decarboxylase autoantibodies are dominant but insufficient to identify most Chinese with adult-onset non-insulin requiring autoimmune diabetes: LADA China study 5.
AIMS: Adult-onset autoimmune diabetes is prevalent in China, in contrast to childhood-onset type 1 diabetes mellitus. Islet autoantibodies are the most important immune biomarkers to diagnose autoimmune diabetes. We assayed four different islet autoantibodies in recently diagnosed adult non-insulin-requiring diabetes Chinese subjects to investigate the best antibody assay strategy for the correct diagnosis of these subjects. METHODS: LADA China study is a nation-wide multicenter study conducted in diabetes patients from 46 university-affiliated hospitals in China. Non-insulin-treated newly diagnosed adult diabetes patients (n = 2388) were centrally assayed for glutamic acid decarboxylase autoantibody (GADA), protein tyrosine phosphatase-2 autoantibody (IA-2A), and zinc transporter 8 autoantibody (ZnT8A) by radioligand assay and insulin autoantibody (IAA) by microtiter plate radioimmunoassay. Clinical data were determined locally. RESULTS: Two hundred and six (8.63 %) subjects were autoantibody positive, of which GADA identified 5.78 % (138/2388) of the total, but only 67 % (138/206) of the autoimmune cases. IA-2A, ZnT8A, and IAA were found in 1.51, 1.84, and 1.26 % of the total study subjects, respectively. When assaying three islet autoantibodies, the most effective strategy was the combination of GADA, ZnT8A, and IAA, which could identify 92.2 % (190/206) autoimmune diabetes patients. The clinical data showed that those subjects with positive GADA had lower random C-peptide than autoantibody negative subjects (P < 0.05). CONCLUSIONS: As with Europeans, GADA is the dominant autoantibody in this form of autoimmune diabetes in China, but in contrast to Europeans, screening should include other diabetes-associated autoantibodies
Novel enzyme-linked immunosorbent assay for bivalent ZnT8 autoantibodies
Autoantibodies to zinc transporter 8 (ZnT8A) are a powerful diagnostic or predictive marker in type 1 diabetes. However, the widely used current ZnT8A radioligand binding assay (RBA) has proved to be difficult for many laboratories to implement. The aim of this study was the development and characterization of the performance of a novel fluid-phase ZnT8A enzyme-linked immunosorbent assay (ELISA) in relation to standard RBA in type 1 diabetes. Sera from 114 patients with type 1 diabetes and 140 blinded Islet Autoantibody Standardization Program (IASP2012) samples were studied. The sensitivity of ELISA-ZnT8A is equivalent to or slightly higher than that of conventional RBA with similar specificity. Furthermore, the median SD score using this ELISA was significantly higher than that obtained with RBA (P < 0.0001). Multiple logistic regression analysis revealed that ELISA-ZnT8A positivity was associated with younger age of onset (?20 years; OR 15.91, P = 0.0002), acute-onset form of type 1 diabetes (OR 3.38, P = 0.019), and the presence of IA-2 autoantibodies (OR 3.75, P = 0.014). Furthermore, the levels of ELISA-ZnT8A were associated with the reactivity to ZnT8-325Arg, but not ZnT8-325Trp. We conclude that this nonradioactive bivalent ZnT8A assay has high performance and should facilitate large-scale autoantibody screening. Moreover, these results suggest that the humoral autoimmunity against ZnT8 is related to a high risk of faster development of type 1 diabetes and the ZnT8A levels are associated with the known aa325 variants
Genetic association of zinc transporter 8 (ZnT8) autoantibodies in type 1 diabetes cases
Autoantibodies to zinc transporter 8 (ZnT8A) are associated with risk of type 1 diabetes. Apart from the SLC30A8 gene itself, little is known about the genetic basis of ZnT8A. We hypothesise that other loci in addition to SLC30A8 are associated with ZnT8A. The levels of ZnT8A were measured in 2,239 British type 1 diabetic individuals diagnosed before age 17 years, with a median duration of diabetes of 4 years. Cases were tested at over 775,000 loci genome wide (including 53 type 1 diabetes associated regions) for association with positivity for ZnT8A. ZnT8A were also measured in an independent dataset of 855 family members with type 1 diabetes. Only FCRL3 on chromosome 1q23.1 and the HLA class I region were associated with positivity for ZnT8A. rs7522061T > C was the most associated single nucleotide polymorphism (SNP) in the FCRL3 region (p = 1.13 x 10(-16)). The association was confirmed in the family dataset (p a parts per thousand currency signaEuro parts per thousand 9.20 x 10(-4)). rs9258750A > G was the most associated variant in the HLA region (p = 2.06 x 10(-9) and p = 0.0014 in family cases). The presence of ZnT8A was not associated with HLA-DRB1, HLA-DQB1, HLA-A, HLA-B or HLA-C (p > 0.05). Unexpectedly, the two loci associated with the presence of ZnT8A did not alter risk of having type 1 diabetes, and the 53 type 1 diabetes risk loci did not influence positivity for ZnT8A, despite them being disease specific. ZnT8A are not primary pathogenic factors in type 1 diabetes. Nevertheless, ZnT8A testing in combination with other autoantibodies facilitates disease prediction, despite the biomarker not being under the same genetic control as the disease
Influence of HLA-DR and -DQ alleles on autoantibody recognition of distinct epitopes within the juxtamembrane domain of the IA-2 autoantigen in type 1 diabetes
Aims/hypothesis: Insulinoma-associated protein 2 (IA-2) is a major target of autoimmunity in type 1 diabetes. When first detected, IA-2-autoantibodies commonly bind epitopes in the juxtamembrane (JM) domain of IA-2 and antibody responses subsequently spread to the tyrosine phosphatase domain. Definition of structures of epitopes in the JM domain, and genetic requirements for autoimmunity to these epitopes, is important for our understanding of initiation and progression of autoimmunity. The aims of this study were to investigate the contribution of individual amino acids in the IA-2 JM domain to antibody binding to these epitopes and the role of HLA genotypes in determining epitope specificity. Methods: Regions of the JM domain recognised by autoantibodies were identified by peptide competition and inhibitory effects of alanine substitutions of residues within the JM region. Antibody binding was determined by radioligand binding assays using sera from patients genotyped for HLA-DRB1 and -DQB1 alleles. Results: Patients were categorised into two distinct groups of JM antibody reactivity according to peptide inhibition. Inhibition by substitutions of individual amino acids within the JM domain differed between patients, indicating heterogeneity in epitope recognition. Cluster analysis defined six groups of residues having similar inhibitory effects on antibody binding, with three clusters showing differences in patients affected or unaffected by peptide. One cluster demonstrated significant differences in antibody binding between HLA-DRB1*04 and HLA-DRB1*07 patients and within DRB1*04 individuals; antibody recognition of a second cluster depended on expression of HLA-DQB1*0302. Conclusions/interpretation: The results identify amino acids contributing to distinct epitopes on IA-2, with both HLA-DR and HLA-DQ alleles influencing epitope specificity
Autoantibodies against type I IFNs in patients with life-threatening COVID-19
Interindividual clinical variability in the course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is vast. We report that at least 101 of 987 patients with life-threatening coronavirus disease 2019 (COVID-19) pneumonia had neutralizing immunoglobulin G (IgG) autoantibodies (auto-Abs) against interferon-w (IFN-w) (13 patients), against the 13 types of IFN-a (36), or against both (52) at the onset of critical disease; a few also had auto-Abs against the other three type I IFNs. The auto-Abs neutralize the ability of the corresponding type I IFNs to block SARS-CoV-2 infection in vitro. These auto-Abs were not found in 663 individuals with asymptomatic or mild SARS-CoV-2 infection and were present in only 4 of 1227 healthy individuals. Patients with auto-Abs were aged 25 to 87 years and 95 of the 101 were men. A B cell autoimmune phenocopy of inborn errors of type I IFN immunity accounts for life-threatening COVID-19 pneumonia in at least 2.6% of women and 12.5% of men
A/H1N1 hemagglutinin antibodies show comparable affinity in vaccine-related Narcolepsy type 1 and control and are unlikely to contribute to pathogenesis
data used in figures and tables from paper Sci Rep . 2021 Feb 18;11(1):4063. doi: 10.1038/s41598-021-83543-z.A/H1N1 hemagglutinin antibodies show comparable affinity in vaccine-related Narcolepsy type 1 and control and are unlikely to contribute to pathogenesisAlexander Lind # 1 , Ilaria Marzinotto # 2 , Cristina Brigatti 2 , Anita Ramelius 1 , Lorenzo Piemonti 2 , Vito Lampasona 3Affiliations 1 Department of Clinical Sciences, Clinical Research Center (CRC), Skåne University Hospital SUS, Lund University, Malmö, Sweden. 2 San Raffaele Diabetes Research Institute, IRCCS Ospedale San Raffaele, Via Olgettina 60, 20132, Milan, Italy. 3 San Raffaele Diabetes Research Institute, IRCCS Ospedale San Raffaele, Via Olgettina 60, 20132, Milan, Italy. [email protected]. # Contributed equally.PMID: 33603024 PMCID: PMC7893011 DOI: 10.1038/s41598-021-83543-zTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV
Intrinsic factor autoantibodies by luminescent immuno-precipitation system in patients with corpus atrophic gastritis
J Transl Autoimmun . 2021 Nov 1;4:100131. doi: 10.1016/j.jtauto.2021.100131. eCollection 2021.Intrinsic factor autoantibodies by luminescent immuno-precipitation system in patients with corpus atrophic gastritisIlaria Marzinotto et alTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV
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