Urinary kallikrein excretion is related to renal function change and inflammatory status in chronic kidney disease patients receiving angiotensin II receptor blocker treatment

AIM: This study was to evaluate the correlation of urinary kallikrein to renal function, proteinuria and urinary cytokines in chronic kidney disease patients in a longitudinal follow up. METHOD: We measured urinary kallikrein and cytokines in 50 patients who were followed up for 12 months. RESULTS: Using regression model we found that the kallikrein excretion (estimated by log kallikrein/creatinine) was positively correlated to log estimated glomerular filtration rate in the beginning and the end of follow up (P = 0.049 and 0.006, respectively). No correlation existed between kallikrein excretion and proteinuria. The kallikrein excretion decreased after 12 months of follow up, which was also associated with the decrease of log estimated glomerular filtration rate. There was a significant positive correlation between the log urinary kallikrein and monocyte chemoattractant protein-1 (MCP-1) concentration (correlation coefficient = 0.277; P = 0.049). Urinary kallikrein excretion was also positively correlated with serum MCP-1 level (correlation coefficient = 0.431; P = 0.002). No correlation existed between urinary kallikrein and transforming growth factor beta-1 or tumour necrosis factor-alpha concentration. CONCLUSION: Urinary kallikrein excretion is positively correlated to renal function, serum and urinary inflammatory mediator MCP-1 in chronic kidney disease patients. These findings indicate that urinary kallikrein excretion may reflect the change of renal function and kidney inflammatory status.