Concentrations of autoantibodies to neural receptors in children with diabetes mellitus

Abstract

Aim: to compare concentrations of autoantibodies (AAB) to dopamine and NMDA receptors and to the S-100 protein in children with diabetes mellitus (DM) in therapeutic remission. Methods. Blood serum from 42 children aged 4 to 17 years (20 boys and 22 girls) was tested. 21 of these children had been diagnosed with type 1 DM (insulin-dependent) and were in therapeutic remission. The group of “apparently healthy children” consisted of children without DM (21 children). AAB to dopamine and NMDA receptors and to the S-100B protein were measured by ELISA. Results. Mean AAB concentrations were higher in patients with type 1 DM compared with the “apparently healthy children”. The concentration of AAB to NMDA receptors was 31.70±6.07 U/mL in group 1 and 3.30±0.89 U/mL in group 2 (p=0.0021). The concentration of AAB to type 2 dopamine receptors (DAR2) was significantly higher (p=0.0082) in patients with DM than in “apparently healthy children”: 49.47±2.31 U/mL in the study group and 4.73±0.12 U/mL in the reference group. The concentration of AAB to the S-100B protein was significantly higher (p=0.0045) in children of group 1 (36.84±3.54 U/mL) compared with group 2 (6.39±0.15 U/mL). The difference between concentrations of AABs depended on the disease duration: AAB concentrations were significantly higher in patients with a DM history longer than 5 years. Conclusion. The increase in AAB to NMDA receptors in patients with type 1 DM may indicate the activation of the glutamatergic system while the increase in AAB to dopamine receptors indicates the activation of the dopaminergic system. The increased concentrations of AAB to the S-100B protein may indicate damage to brain tissue in children with type 1 DM due to excitotoxicity. The observed abnormalities evidence a damage to the central nervous system in children with type 1 DM with a tendency towards increases in the studied AABs with the progression of the disease.