The balance of several cytokines likely influences the resolution of glomerulonephritis. Monocyte chemoattractant protein-1(MCP-1) is a chemokine that promotes renal inflammation whereas epidermal growth factor (EGF) stimulates protective responses. Previously, high urine MCP-1(MCP-1) and low urine EGF (EGF) levels were found to be associated with tubulointerstitial fibrosis, but there is limited information on the value of these mediators as predictors of therapeutic responses or long term outcome in primary glomerulonephritis.Objectives:
To determine the performance of urine EGF, MCP-1 or their ratio at baseline as biomarkers to predict complete remission, and the relationship of these mediators with subsequent renal function 24months later in primary glomerulonephritis.Methods:
This is a prospective study of patients with biopsy-proven primary glomerulonephritis. Baseline urine samples were collected at biopsy before therapy. MCP-1 and EGF were analyzed by enzyme-linked immunosorbent assays and expressed as a ratio to urine creatinine (ng/mgCr) or as EGF/MCP-1 ratio (ng/ng). Proteinuria and estimated glomerular filtration rate (eGRF) were monitored after therapy. Complete remission (CR) was defined as proteinuria≤0.3g/gCr.Results:
Median follow-up was 20months. Of all patients (n=74), 38 patients (51.4%) subsequently achieved CR. Baseline urine EGF and EGF/MCP-1 levels were significantly higher in CR compared to Not CR. By contrast, MCP-1 was not different. High EGF (EGF>75ng/mgCr) was a significant predictor (OR 2.28) for CR by multivariate analysis after adjusting for proteinuria, blood pressure, baseline eGFR. In patients who completed 24months follow-up (n=43), baseline EGF correlated inversely with proteinuria and positively with eGFR at 24months.Conclusion:
High urine EGF level is a promising biomarker of CR. Baseline EGF levels correlated with kidney function at 2years. EGF/MCP-1 was not superior to EGF alone. Further studies are necessary to determine the role of urine EGF as a guide to therapy in primary GN.