Clinical immunology
Serum levels of MMP-9 in children and young adults with chronic kidney disease treated conservatively and undergoing hemodialysis

End-stage renal disease is characterized by chronic inflammatory state resulting in initiate reaction of interstitial fibrosis. The matrix metalloproteinase-9 (MMP-9) is the zinc–dependent proteolytic enzyme which has the ability to degrade the components of the extracellular matrix and plays an important role in the physiological and pathological tissue remodeling. The data suggest that MMP-9 may take part in various pathologic disorders in uremic and hemodialyzed (HD) patients. The aim of the study was to determine the level of MMP-9 (type IV collagenases/gelatinases), in peripheral blood samples taken from children and young adults with end-stage renal disease and undergo renal replacement therapy.
We investigated 21 patients (9 female, 12 male) suffering from chronic kidney disease (CKD) on maintenance hemodialysis (HD) (group A) aged from 12 to 48 years, and 13 (6 female, 7 male) with CKD treated conservatively, aged from 4 to 17.5 years (group B). In group A the analysis was performed before (A1) and after (A2) a single of the HD session. Also 20 healthy subjects (C) served as a control group was tested. Concentration of MMP-9 in serum was determined by the ELISA method.
Non significant differences between levels of MMP-9 in group A1 (median: 189.69 ng/mL, range: 31.13--673.3 ng/mL), A2 (median: 142.63 ng/mL, range: 35.42-313 ng/mL) and B (median:173.6 ng/mL, range: 30.4 -325.8 ng/mL) in comparison with group C (median: 194.6 ng/mL, range: 73-322 ng/mL) were found. Although MMP-9 levels in patients at the end of HD were not significantly lower than those in the beginning of HD but in 11/21 (52%) individual cases concentrations of MMP-9 were smaller after HD than before HD. There were no significant differences in serum MMP-9 concentrations between group A1, A2 and B.
These results indicate that serum concentration of MMP-9 in patients after HD showed a tendency to a decrease compared to the levels before HD. The increased serum concentrations of MMP-9 in some individual cases both in hemodialyzed patients and those who were treated conservatively may contribute to the high risk for complication e.g. cardiovascular diseases.
A better understanding of the inflammatory reactions in chronic kidney disease may lead to new treatment strategies.