Clinical significance of high mobility group protein B1 and Toll-like receptor 4 in children with systemic lupus erythematosus / 中华风湿病学杂志

ABSTRACT

Objective To investigate the expression levels of peripheral blood and clinical signifi-cance of High mobility group protein B1 (HMGB1) and toll-like receptor 4 (TLR-4) in children with systemic lupus erythematosus (SLE). Methods Enzyme-linked immuno sorbent assay (ELISA) was used to deter-mine the HMGB1 levels in the serum of peripheral venous blood samples from 33 SLE patients and 10 healthy children. RT-polymerase chain reaction (PCR) technique was used to detect the HMGB1-mRNA expression in the mononuclear cells of peripheral blood. Flow cytometry was adopted to detect the CD14/TLR-4 on the surface of mononuclear cell membrane in the peripheral blood of active SLE patients. One-way analysis of variance (ANOVA) was used to compare HMGB1 levels between the two groups. Pearson correlation and Logistic regression were used for correlation analysis. Results ① The levels of HMGB1 and HMGB1 mRNA in the peripheral blood of SLE active patients [(25.8 ±3.9) ng/ml and (0.80 ±0.16) respectively] were signifi-cantly higher than the stable group [(9.3 ±2.7) ng/ml and (0.46 ±0.18) respectively, F=7.0, 2.8, P<0.05] and healthy children [(9.1 ±0.9) ng/ml and (0.34 ±0.10) respectively, F=50.2, 7.5, P<0.05]. ② The CD14/TLR-4 expressions on the surface of mononuclear cell membrane in the peripheral blood of SLE active patients (91.2±1.3) were significantly higher than the stable group [(87.6±2.8), F=0.8, P<0.05] and the healthy children [(87.0±2.2), F=0.9, P<0.05].③There was significant positive correlation (r=0.48, P<0.05) between the levels of HMGB1 and CD14/TLR-4 in different SLE patients. In addition, the levels of HMGB1 were also positively correlated (r=0.48, P<0.01) with the detected concentrations of urinary protein in SLE patients. However, in the stable and healthy groups, there was no correlation between HMGB1 and CD14/TLR-4 and urinary protein. These indicate that HMGB1 outside the cell membrane were involved in SLE morbidity in children through TLR-4. Conclusion The mononuclear cells in peripheral blood of children with SLE can secrete HMGB1, which could lead to the increase of HMGB1 level in the serum of peripheral blood, and possibly participate in kidney damage of SLE through CD14/TLR-4.