Serum levels of the high-mobility group box 1 protein (HMGB1) in children with type 1 diabetes mellitus: case-control study

INTRODUCTION: The involvement of the high-mobility group box 1 protein (HMGB1) in various autoimmune and inflammatory diseases has been documented; however, the role of this proinflammatory molecule in children with diabetes type 1 (T1DM) has not been addressed. The aim of this case-control study is to compare the serum level of HMGB1 in children with newly diagnosed T1DM (group 1) and a control group composed of healthy children. MATERIAL AND METHODS: This case-control study included 136 children: group 1 (n = 96) and a control group (n = 40). Measurements were taken from serum for the following: HMGB1, white blood cell count, C-reactive protein, glucose, haemoglobin A(1C), and β-cell autoantibodies (GADA-65, IA-2, ICA). HMGB1 was determined using enzyme-linked immunosorbent assay on a Labsystems iEMS Reader MF analyser (Labsystems Diagnostics Oy, Helsinki, Finland). RESULTS: The level (median and interquartile range) of HMGB1 was statistically higher (p < 0.001) in children with T1DM: 8.7 (5.0-9.8) µg/l, in comparison with the control group: 1.0 (0.6-1.4) µg/l. No correlation was found between HMGB1 and HbA1c in group 1, or between HMGB1 and BMI. A statistically higher percentage of positive children for autoantibodies were present in group 1 compared to the control group (p ≤ 0.001). HMGB1 serum levels were also tested and the presence of autoantibodies, and none of those antibodies correlated with the level of HMGB1. CONCLUSIONS: The higher level of HMGB1 in children with T1DM, compared to the control group, indicates that this proinflammatory molecule is a good candidate marker of inflammation in children with T1DM.