Elevated Urinary Fibronectin Excretion Predicts Poor Outcome in Patients with Primary Chronic Glomerulonephritis

Abstract

Background/Aims: Fibronectin (FN) is one of the major matrix proteins in the kidney. The accumulation of FN fragments in inflamed glomeruli could contribute to the progression of renal injury. In the present study, the urinary FN excretion (UFN) was measured for evaluation of its possible role as a prognostic marker in patients with newly diagnosed chronic glomerulonephritis (GN). Methods: In 55 patients with newly diagnosed biopsy-proven chronic GN, UFN was measured using an enzyme-immunossay kit. The progression of kidney disease was defined as a reduction of the estimated glomerular filtration rate (eGFR) ≧5 ml/min/year during the 4-year follow-up. Results: The mean UFN in patients with GN (245.0 ± 229.2 ng/mmol creatinine) was higher than in the 19 healthy subjects (100.7 ± 87.3 ng/mmol creatinine; p < 0.002). No correlations between the initial UFN and eGFR and proteinuria were found. We did not find any association between UFN and the severity of glomerular sclerosis or the intensity of interstitial fibrosis. The progressive fall of eGFR was recorded in 13 patients (progressors). The mean initial UFN was significantly higher in progressors than in nonprogressors (p < 0.01). In logistic regression analysis, the initial high UFN was identified as independent factor predicting kidney function deterioration. Conclusion: These results indicate that UFN measured before treatment could serve as an additional prognostic marker of a poor outcome in patients with newly diagnosed primary GN.