| 1. |
- Kanatsuna, N, et al.
(författare)
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Doubly reactive INS-IGF2 autoantibodies in children with newly diagnosed autoimmune (type 1) diabetes
- 2015
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Ingår i: Scandinavian Journal of Immunology. - : Wiley-Blackwell. - 0300-9475 .- 1365-3083. ; 82:4, s. 361-369
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Tidskriftsartikel (refereegranskat)abstract
- The splice variant INS-IGF2 entails the preproinsulin signal peptide, the insulin B-chain, eight amino acids of the C-peptide and 138 unique amino acids from an ORF in the IGF2 gene. The aim of this study was to determine whether levels of specific INS-IGF2 autoantibodies (INS-IGF2A) were related to age at diagnosis, islet autoantibodies, HLA-DQ or both, in patients and controls with newly diagnosed type 1 diabetes. Patients (n = 676), 0-18 years of age, diagnosed with type 1 diabetes in 1996-2005 and controls (n = 363) were analysed for specific INS-IGF2A after displacement with both cold insulin and INS-IGF2 to correct for non-specific binding and identify double reactive sera. GADA, IA-2A, IAA, ICA, ZnT8RA, ZnT8WA, ZnT8QA and HLA-DQ genotypes were also determined. The median level of specific INS-IGF2A was higher in patients than in controls (P < 0.001). Irrespective of age at diagnosis, 19% (126/676) of the patients had INS-IGF2A when the cut-off was the 95th percentile of the controls (P < 0.001). The risk of INS-IGF2A was increased among HLA-DQ2/8 (OR = 1.509; 95th CI 1.011, 2.252; P = 0.045) but not in 2/2, 2/X, 8/8, 8/X or X/X (X is neither 2 nor 8) patients. The association with HLA-DQ2/8 suggests that this autoantigen may be presented on HLA-DQ trans-heterodimers, rather than cis-heterodimers. Autoantibodies reactive with both insulin and INS-IGF2A at diagnosis support the notion that INS-IGF2 autoimmunity contributes to type 1 diabetes.
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| 2. |
- Andersen, Marie Louise M., et al.
(författare)
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Association between autoantibodies to the Arginine variant of the Zinc transporter 8 (ZnT8) and stimulated C-peptide levels in Danish children and adolescents with newly diagnosed type 1 diabetes
- 2012
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Ingår i: Pediatric Diabetes. - : Hindawi Limited. - 1399-543X .- 1399-5448. ; 13:6, s. 454-462
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Tidskriftsartikel (refereegranskat)abstract
- Background The zinc transporter 8 (ZnT8) was recently identified as a common autoantigen in type 1 diabetes (T1D) and inclusion of ZnT8 autoantibodies (ZnT8Ab) was found to increase the diagnostic specificity of T1D. Objectives The main aims were to determine whether ZnT8Ab vary during follow-up 1 year after diagnosis, and to relate the reactivity of three types of ZnT8Ab to the residual stimulated C-peptide levels during the first year after diagnosis. Subjects A total of 129 newly diagnosed T1D patients <15 years was followed prospectively 1, 3, 6, and 12 months after diagnosis. Methods Hemoglobin A1c, meal-stimulated C-peptide, ZnT8Ab, and other pancreatic autoantibodies were measured at each visit. Patients were genotyped for the rs13266634 variant at the SLC30A8 gene and HLA-DQ alleles. Results The levels of all ZnT8Ab [ZnT8Arg (arginine), ZnT8Trp (tryptophan), ZnT8Gln (glutamine)] tended to decrease during disease progression. A twofold higher level of ZnT8Arg and ZnT8Gln was associated with 4.6%/5.2% (p = 0.02), 5.3%/8.2% (p = 0.02) and 8.9%/9.7% (p = 0.004) higher concentrations of stimulated C-peptide 3, 6, and 12 months after diagnosis. The TT genotype carriers of the SLC30A8 gene had 45.8% (p = 0.01) and 60.1% (p = 0.002) lower stimulated C-peptide 6 and 12 months after diagnosis compared to the CC and the CT genotype carriers in a recessive model. Conclusions The levels of the Arg variant of the ZnT8 autoantibodies are associated with higher levels of stimulated C-peptide after diagnosis of T1D and during follow-up. Carriers of the TT genotype of the SLC30A8 gene predict lower stimulated C-peptide levels 12 months after diagnosis.
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| 3. |
- Delli, Ahmed, et al.
(författare)
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Autoimmune type 1 diabetes.
- 2010
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Ingår i: Textbook of Diabetes. - : Wiley. - 9781405191814 ; , s. 141-152
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Bokkapitel (refereegranskat)abstract
- The pathophysiologic mechanisms in type 1 diabetes (T1DM) involve loss of islet β-cell secretory function caused by selective killing of these cells primarily by aggressive autoimmune responses involving both cellular and humoral immune pathways. Inflammatory cells heavily infiltrate pancreatic islets leading to insulitis where CD8+ T lymphocytes are thought to be responsible for selective and specific killing of β-cells. The complex etiology of T1DM involves a strong genetic predisposition, mainly human leukocyte antigen class II genes, and several putative environmental factors, which are thought to trigger autoimmunity or progression to clinical T1DM. A preclinical prodrome in T1DM may vary in duration in which one or more islet autoantibodies may precede insulitis and predict the disease at the early stages of pathologic insult. In genetically susceptible individuals with islet autoantibodies, metabolic indicators such as insulin release abnormalities and insulin resistance may best predict T1DM especially near clinical onset. Based on the improving understanding of the etiopathogenesis of T1DM, several clinical trials have been launched aiming at halting the autoimmunity responses, retarding disease progression or preserving remaining β-cell function after clinical onset.
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| 4. |
- Delli, Ahmed, et al.
(författare)
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Autoimmune (type 1) diabetes
- 2013
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Ingår i: The Autoimmune Diseases. - 0123849292 ; , s. 575-585
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Bokkapitel (refereegranskat)abstract
- Autoimmune (type 1) diabetes (AI-DM) is a multistage disorder. Children are born genetically predisposed to putative environmental exposures. These trigger an aggressive, selective and chronic autoimmune response against the pancreatic islet beta cells. This stage is marked by autoantibodies against insulin, glutamic acid decarboxylase (GAD65), IA-2 and the ZnT8 transporter. Progression to clinical onset of diabetes is highly variable but the time to onset is shortened with an increased number of islet autoantibodies. Both islet autoantibodies and diabetes are associated with HLA-DQ on chromosome 6. More than 50 non-HLA genetic factors, mostly associated with the human immune response also contribute. It remains to be clarified to what extent HLA-DQ and the non-HLA genes contribute to the initiation of the chronic islet autoimmunity, progression to diabetes, or both. Insulin replacement therapy is still the only treatment as all attempts to halt the loss of beta cells by immunosuppression or immune modulation have failed so far.
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| 5. |
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| 6. |
- Delli, Ahmed
(författare)
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Immunogenetics of Childhood Type 1 Diabetes in Immigrant Patients in Sweden. Migration Studies on Type 1 Diabetes
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis examined whether the offspring of immigrants (non-Swedes) to Sweden are at increased risk of Type 1 Diabetes (T1D) when they are born or live in Sweden. It also evaluated if their T1D and T2D-related genes differed from Swedish patients and whether this genetic heritage determined the types and existence of islet autoantibodies at time of diagnosis and affected the classification of diabetes. A total of 3451 (55% males) newly diagnosed T1D patients (<18 y) were recruited from the Better Diabetes Diagnosis (BDD) study. We calculated the “patients/105/y” rate of confirmed T1D, which was 14 (95%CI: 13-15) among non-Swedes (8% of total) compared to 22 (95% CI: 21-23) for Swedes (66%). The rate for non-Swedes was at least 2 times higher than the mean incidence rates for countries of parents’ origins. Non-Swedes had predominately GAD65A (64%) in association with DQ2, which prevailed in the non-Swedes (34%, OR=1.5) compared to Swedes (15%). The Swedes had more multiple (>=2) autoantibodies and IA-2A in association with the dominant DQ8 and 2/8. The ZnT8-WA (38%) found less in non-Swedes compared to Swedes (50%), consistent with lower frequency in the non-Swedes (37%) of the SLC30A8 CT+TT than in Swedes (54%). The ZnT8-RA (57% and 58%, respectively) did not differ despite a higher frequency of CC (RR) genotypes in non-Swedes (63%) compared to Swedes (46%). In non-Swedes only, the prevailing DQ2/X (40%) compared to Swedes (14%) was negatively associated with ZnT8-WA (p=0.008) and ZnT8-QA (p=0.03) but not ZnT8-RA (p=0.26). Molecular simulation showed non-binding of the relevant ZnT8R peptide to DQ2 explaining in part the possible lack of tolerance to ZnT8-R by DQ2. The DQ8 and DQ6.4 had stronger binding epitopes outside the polymorphic site at amino acid position 325. The INS-SNP rs689 A/A genotype contributed T1D risk in non-Swedes (65%), though less than Swedes (72%). IAA were predicted by A/A (OR=3.5) but negatively associated with increasing age at diagnosis (OR=0.1) and HLA-DQ2 regardless of ethnic background (OR=0.6) explaining, in addition to INS T/T, the lower IAA in non-Swedes. In the Swedes only, IAA were associated with DQ2/8 (40%) and 8/x (32%), which were also stronger predictors of IAA at a younger age than INS genotypes. Non-Swedes were further subdivided into non-Europeans (n=148, 63%) and European-descent (n=86, 37%). Non-European had less T1D risk genes (HLA DQ and PTPN22) and more T2D risk genes (SLC30A8 and FTO genes), therefore they were more prone to be autoantibody-negative (11% compared to 8% in Europeans and 6% in Swedes)and had less multiple autoantibodies (64%% compared to 81% in Europeans and 79% in Swedes). Our data suggest that immigrants from low incidence countries (80% were born in Sweden), especially non-Europeans, are exposed to higher T1D in Sweden, because their genetic heritage affected by the Swedish environment. Non-European immigrants develop T1D in Sweden with lesser T1D-related genes but more T2D-related genes and less islet autoantibodies when compared to Europeans and native Swedes.
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| 8. |
- Delli, Ahmed, et al.
(författare)
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Type 1 diabetes patients born to immigrants to Sweden increase their native diabetes risk and differ from Swedish patients in HLA types and islet autoantibodies
- 2010
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Ingår i: Pediatric Diabetes. - : Blackwell Publishing Ltd. - 1399-543X .- 1399-5448. ; 11:8, s. 513-520
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To determine whether type 1 diabetes mellitus (T1DM) patients, having parents who immigrated to Sweden, have increased T1DM risk before 18 yr compared with countries of origin. We also determined whether they have different human leukocyte antigen (HLA) genetic markers and islet autoantibodies at diagnosis compared with Swedish patients. Methods: A total of 1988 (53% males) newly diagnosed and confirmed T1DM patients less than 18 yr registered within the Better Diabetes Diagnosis (BDD) study (May 2005 to September 2008) were included. Participants were classified into three groups: Swedish, non-Swedish, and Mixed-origin patients according to country of origin of two generations (parents and grandparents). These groups were compared with respect to T1DM HLA markers and islet autoantibodies [glutamic acid decarboxylase autoantibodies (GAD65Ab), insulin autoantibodies (IAA), and islet antigen-2 autoantibodies (IA-2Ab)]. Results: Only 30 (1.5%) patients were born outside Sweden. Swedish patients constituted 66%, non-Swedish patients 8%, Mixed origins 17%, and 9% were of uncertain origin. Confirmed T1DM in patients within the study was 22 (95% CI: 21-23) patients/105/yr rate for Swedish patients compared with 14 (95% CI: 13-15) among non-Swedish patients. The HLA-DQ8 haplotype (p less than 0.0001) and DQ2/8 genotype (p less than 0.02) predominated among Swedish compared with non-Swedish patients. In contrast, DQ2 was the most frequent haplotype among non-Swedish patients [OR = 1.5 (95% CI: 1.0-2.0), p less than 0.04]. Multiple (greater than= 2) autoantibodies (p less than 0.04) and specifically IA-2Ab (p less than 0.001) were most prevalent among the Swedish patients. Multiple autoantibodies were associated with DQ8 among the Swedish patients only (p less than 0.001). Conclusion: Patients born to parents who had immigrated to the high T1DM incidence environment of Sweden have, compared with Swedish patients, more frequent HLA-DQ2 genetic markers and are diagnosed more often with GAD65Ab.
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