The Level and Clinical Significance of Secrum and Urine MMP-9 in the Children with Purpura Nephritis

Objective To investigate the role of MMP-9 in the children with Henoch-Schoenlein purpura nephritis(HSPN),and provide a basis for the prevention and treatment of HSPN.Methods The serum and urine samples were collected from 54 patients with HSPN,54 patients with Henoch-Schonlein purpura(HSP),and 30 healthy children as control.The content of MMP-9 in the serum and urine was tested by enzyme-linked immunosorbent assay(ELISA);the levels of β2-MG in the serum were tested by automatic biochemical analysis,while the total 24 hours-urinary protein from HSP group and HSPN group were tested by biuret colorimetry method.Results(1) The level of serum MMP-9 in the children with HSPN was(259.32±78.38)ng/ml,which was remarkably higher than that of HSP group(134.09±49.93) ng/ml,(P0.05) and control group(46.25±12.87)ng/ml,(P0.01).The level of urine MMP-9 in the children with HSPN was(54.11±15.74)ng/ml,which was significantly higher than that of HSP group(30.83±8.73) ng/ml,(P0.05) and control group(23.60±4.59)ng/ml,(P0.01).(2) According to content of 24-hour urine protein,the patients with HSPN were divided into 3 subgroups:group A,urinary protein 0.15 g/24 h;group B,0.15-1.0 g/24 h;group C,1.0 g/24 h.The content of MMP-9 in serum and urine of group C was remarkably higher than group A(P0.01) and group B(P0.05);but there was no significant difference between group A and group B(P0.05).(3) There was significantly positive correlation between the level of serum MMP-9 and the serumβ2-MG,the total 24-hours urine protein in HSPN group(r=0.564,P=0.031;r=0.676,P=0.026),there was remarkably positive correlation between the levels of urinary MMP-9 and the serumβ2-MG,the total 24 hours-urine protein in HSPN group,too(r=0.787,P=0.023;r=0.536,P=0.159).Conclusion The levels of serum and urine MMP-9 from HSPN group raise significantly,which probably play a role in the pathogenesis of HSPN.