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- Delli, Ahmed, et al.
(author)
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Autoimmune (type 1) diabetes
- 2013
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In: The Autoimmune Diseases. - 0123849292 ; , s. 575-585
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Book chapter (peer-reviewed)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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2. |
- Jonsdottir, Berglind, et al.
(author)
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Thyroid autoimmunity in relation to islet autoantibodies and HLA-DQ genotype in newly diagnosed type 1 diabetes in children and adolescents
- 2013
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In: Diabetologia. - : Springer Verlag (Germany). - 0012-186X .- 1432-0428. ; 56:8, s. 1735-1742
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Journal article (peer-reviewed)abstract
- The aim of this work was to investigate, in children newly diagnosed with type 1 diabetes: (1) the prevalence of autoantibodies against thyroid peroxidase (TPOAb) and thyroglobulin (TGAb); and (2) the association between TPOAb, TGAb or both, with either islet autoantibodies or HLA-DQ genes. less thanbrgreater than less thanbrgreater thanBlood samples from 2,433 children newly diagnosed with type 1 diabetes were analysed for TPOAb and TGAb in addition to autoantibodies against arginine zinc transporter 8 (ZnT8RA), tryptophan zinc transporter 8 (ZnT8WA), glutamine zinc transporter 8 (ZnT8QA), glutamic acid decarboxylase (GADA), insulin (IAA), insulinoma-associated protein-2 (IA-2A), HLA-DQA-B1 genotypes, thyroid-stimulating hormone (TSH) and free thyroxine (T4). less thanbrgreater than less thanbrgreater thanAt type 1 diabetes diagnosis, 12% of the children had thyroid autoantibodies (60% were girls; p andlt; 0.0001). GADA was positively associated with TPOAb (p andlt; 0.001) and with TGAb (p andlt; 0.001). In addition, ZnT8A was associated with both TPOAb (p = 0.039) and TGAb (p = 0.015). DQB1*05:01 in any genotype was negatively associated with TPOAb (OR 0.55, 95% CI 0.37, 0.83, p value corrected for multiple comparisons (p (c)) = 0.012) and possibly with TGAb (OR 0.55, 95% CI 0.35, 0.87, p (c) = 0.07). Thyroid autoimmunity in children newly diagnosed with type 1 diabetes was rarely (0.45%) associated with onset of clinical thyroid disease based on TSH and free T4. less thanbrgreater than less thanbrgreater thanGADA and ZnT8A increased the risk for thyroid autoimmunity at the time of clinical diagnosis of type 1 diabetes, while HLA-DQB1*05:01 reduced the risk. However, the associations between thyroid autoimmunity and HLA-DQ genotype were weak and did not fully explain the co-occurrence of islet and thyroid autoimmunity.
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3. |
- Kanatsuna, Norio, et al.
(author)
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Autoimmunity against INS-IGF2 expressed in human pancreatic islets.
- 2013
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In: Journal of Biological Chemistry. - 1083-351X. ; 288:40, s. 29013-29023
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Journal article (peer-reviewed)abstract
- Insulin is a major autoantigen in islet autoimmunity and progression to type 1 diabetes. It has been suggested that the insulin B-chain may be critical to insulin autoimmunity in type 1 diabetes. INS-IGF2 consists of the preproinsulin signal peptide, the insulin B-chain and eight amino acids of the C-peptide in addition to 138 amino acids from the IGF2 gene. We aimed to determine 1) expression of INS-IGF2 in human pancreatic islets and 2) autoantibodies in newly diagnosed type 1 diabetes children and controls. INS-IGF2, expressed primarily in beta cells, showed higher levels of expression in islets from normal compared to donors with either type 2 diabetes (p=0.006) or high HbA1c levels (p<0.001). INS-IGF2 autoantibody levels were increased in newly diagnosed type 1 diabetes patients (n=304) compared to healthy controls (n=355; p<0.001). Displacement with cold insulin and INS-IGF2 revealed that more patients than controls had doubly reactive insulin-INS-IGF2 autoantibodies. These data suggest that INS-IGF2, which contains the preproinsulin signal peptide, the B-chain and eight amino acids of the C-peptide may be an autoantigen in type 1 diabetes. INS-IGF2 and insulin may share autoantibody binding sites, thus complicating the notion that insulin is the primary autoantigen in type 1 diabetes.
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4. |
- Kanatsuna, Norio, et al.
(author)
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Autoimmunity against INS-IGF2 Protein Expressed in Human Pancreatic Islets
- 2013
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In: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 288:40, s. 29013-29023
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Journal article (peer-reviewed)abstract
- Insulin is a major autoantigen in islet autoimmunity and progression to type 1 diabetes. It has been suggested that the insulin B-chain may be critical to insulin autoimmunity in type 1 diabetes. INS-IGF2 consists of the preproinsulin signal peptide, the insulin B-chain, and eight amino acids of the C-peptide in addition to 138 amino acids from the IGF2 gene. We aimed to determine the expression of INS-IGF2 in human pancreatic islets and autoantibodies in newly diagnosed children with type 1 diabetes and controls. INS-IGF2, expressed primarily in beta cells, showed higher levels of expression in islets from normal compared with donors with either type 2 diabetes (p = 0.006) or high HbA1c levels (p < 0.001). INS-IGF2 autoantibody levels were increased in newly diagnosed patients with type 1 diabetes (n = 304) compared with healthy controls (n = 355; p < 0.001). Displacement with cold insulin and INS-IGF2 revealed that more patients than controls had doubly reactive insulin-INS-IGF2 autoantibodies. These data suggest that INS-IGF2, which contains the preproinsulin signal peptide, the B-chain, and eight amino acids of the C-peptide may be an autoantigen in type 1 diabetes. INS-IGF2 and insulin may share autoantibody-binding sites, thus complicating the notion that insulin is the primary autoantigen in type 1 diabetes.
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