The Ratio of Epidermal Growth Factor to Monocyte Chemotactic Peptide-1 in the Urine Predicts Renal Prognosis in IgA Nephropathy

The production of cytokines by resident and non-resident renal cells during immunoglobulin A nephropathy (IgAN) plays a key role in the progression of renal damage. The aim of this study was to determine if measurements of urinary epidermal growth factor (EGF) and monocyte chemotactic peptide-1 (MCP-1), at the time of renal biopsy, were a predictor of end-stage renal disease (ESRD) in a cohort of 132 patients with biopsy-proven IgAN. Outcome measures were a doubling of the baseline serum creatinine (sCr) and/or ESRD. Patients with ratios of EGF/MCP-1 in the lowest tertile had a significant decline in renal survival, while patients in the highest tertile maintained 100% renal survival at 48 and 84 months of follow-up. Multivariate Cox's regression analysis showed that the urine EGF/MCP-1 ratio was an independent prognostic factor and indirectly correlated with the combined outcome. The predictive value was also measured by the area under the receiver operating characteristic curve (ROC). The area of the EGF/MCP-1 ratio was significantly higher than that of EGF or MCP-1 alone, histologic grade, creatinine clearance, or proteinuria. Our study suggests that the urinary EGF/MCP-1 ratio may be used as a prognostic marker of ESRD for patients with IgAN.