Interleukin-6 and epidermal growth factor as noninvasive biomarkers of progression in chronic glomerulonephritis

Several cytokines and chemokines are involved in the pathogenesis and progressive injury of renal tissues in patients with primary chronic glomerulonephritis (CGN). The objective of this study was to determine whether the urinary excretion of interleukin-6 (IL-6), transforming growth factor β1 (TGFβ1), monocytes chemoattractant protein (MCP-1), soluble tumor necrosis factor receptor 1 (sTNFR1), and epidermal growth factor (EGF) in patients with newly recognized CGN can serve as prognostic biomarkers in patients with newly recognized CGN and whether they can be effective in predicting a progressive reduction of renal function in prospective observation. The study included 150 Caucasian patients. UIL-6, UTGFβ1, UMCP-1, UsTNFR1, and UEGF were measured using enzyme-linked immunosorbent assay (ELISA) methods (Quantikine R&D System). UIL-6, UTGFβ1, UMCP-1, and UsTNFR1 were significantly higher, yet UEGF excretion was significantly lower in nephrotic patients, in patients with estimated glomerular filtration rate (eGFR) < 60/min/1.73 m² at presentation, as well as in the progressor (PG) subgroup. In a multivariate regression analysis basal eGFR correlated with UsTNFR1, UIL-6, and UEGF excretion, although in the follow-up, ΔeGFR (delta estimated glomerular filtration rate) significantly correlated only with UEGF excretion. A logistic regression analysis showed that the most significant independent risk factors for the deterioration of renal function with time are initial high (>11.8 pg/mgCr) UIL-6 excretion, initial low (<15.5 ng/mgCr) urinary UEGF excretion, and male gender. In patients with newly diagnosed CGN, UIL-6, and UEGF can serve as prognostic biomarkers for the progression of the disease.NEW & NOTEWORTHY Baseline high urinary interleukin-6 (IL-6) excretion and low urinary epidermal growth factor (EGF) excretion and particularly high IL-6/EGF ratio were stronger predictive factors of the progression of the deterioration of the kidney function than initial estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m² or proteinuria. In patients with newly diagnosed chronic glomerulonephritis, UIL-6 and UEGF can serve as prognostic biomarkers for the progression of the disease.