TY - JOUR
T1 - Doubly reactive INS-IGF2 autoantibodies in children with newly diagnosed autoimmune (type 1) diabetes.
AU - Kanatsuna, Norio
AU - Delli, Ahmed
AU - Andersson, Cecilia K
AU - Nilsson, Anna-Lena
AU - Vaziri Sani, Fariba
AU - Larsson, Karin
AU - Carlsson, Annelie
AU - Cedervall, Elisabeth
AU - Jönsson, Björn
AU - Neiderud, Jan
AU - Larsson, Helena
AU - Ivarsson, Sten
AU - Törn, Carina
AU - Fex, Malin
AU - Lernmark, Åke
PY - 2015
Y1 - 2015
N2 - 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 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 newly diagnosed type 1 diabetes patients and controls. Patients (n=676), 0-18 years of age, diagnosed with type 1 diabetes in 1996-2005 and controls (n=363) were analyzed 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, and ZnT8QA, and HLA-DQ genotypes were also determined. The median level of specific INS-IGF2A was higher in patients than 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, 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. This article is protected by copyright. All rights reserved.
AB - 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 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 newly diagnosed type 1 diabetes patients and controls. Patients (n=676), 0-18 years of age, diagnosed with type 1 diabetes in 1996-2005 and controls (n=363) were analyzed 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, and ZnT8QA, and HLA-DQ genotypes were also determined. The median level of specific INS-IGF2A was higher in patients than 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, 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. This article is protected by copyright. All rights reserved.
U2 - 10.1111/sji.12325
DO - 10.1111/sji.12325
M3 - Article
C2 - 26073034
SN - 1365-3083
VL - 82
SP - 361
EP - 369
JO - Scandinavian Journal of Immunology
JF - Scandinavian Journal of Immunology
IS - 4
ER -
