Yingjin Shi1, Tao Su, Lei Qu, Caili Wang, Xiaomei Li, Li Yang. 1. Renal Division (YS, TS, LQ, XL, LY), Department of Medicine, First Hospital, Institute of Nephrology, Peking University, Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; and Renal Division (YS, CW), the First Affiliated Hospital of Baotou Medical College, Baotou, China.
Abstract
BACKGROUND: The efficacy of urinary biomarkers for predicting adverse clinical outcomes in drug-induced chronic tubulointerstitial nephritis (D-CTIN) has not been well described. METHODS: A total of 54 patients with D-CTIN were prospectively followed-up in this study. The urinary excretion of α1-microglobulin and transforming growth factor-β1 and the activity of urinary N-acetyl-β-D-glucosaminidase (NAG) and matrix metalloproteinases (MMPs) 2 and 9 at baseline were measured. Changes in the estimated glomerular filtration rate (GFR) over a period of 11 to 54 months (median, 38 months) of follow-up were recorded. The efficacy of urinary biomarkers for differentiating patients with various outcomes was tested. Ten patients with IgA nephropathy and 20 healthy volunteers were enrolled as controls. RESULTS: The areas under the receiver operating characteristic curve for urinary NAG, MMP-9, MMP-2 and α1-microglobulin for predicting deterioration of the estimated GFR were 0.879, 0.867, 0.735 and 0.709, respectively (P < 0.05 for all). Partial regression coefficient results demonstrated that urinary NAG (P = 0.02), MMP-2 (P = 0.046) and MMP-9 (P = 0.041) were inversely correlated with the rate of GFR decline. CONCLUSIONS: Urinary NAG, MMP-2 and MMP-9 may be considered as possible candidates for forecasting the progression rate of D-CTIN.
BACKGROUND: The efficacy of urinary biomarkers for predicting adverse clinical outcomes in drug-induced chronic tubulointerstitial nephritis (D-CTIN) has not been well described. METHODS: A total of 54 patients with D-CTIN were prospectively followed-up in this study. The urinary excretion of α1-microglobulin and transforming growth factor-β1 and the activity of urinary N-acetyl-β-D-glucosaminidase (NAG) and matrix metalloproteinases (MMPs) 2 and 9 at baseline were measured. Changes in the estimated glomerular filtration rate (GFR) over a period of 11 to 54 months (median, 38 months) of follow-up were recorded. The efficacy of urinary biomarkers for differentiating patients with various outcomes was tested. Ten patients with IgA nephropathy and 20 healthy volunteers were enrolled as controls. RESULTS: The areas under the receiver operating characteristic curve for urinary NAG, MMP-9, MMP-2 and α1-microglobulin for predicting deterioration of the estimated GFR were 0.879, 0.867, 0.735 and 0.709, respectively (P < 0.05 for all). Partial regression coefficient results demonstrated that urinary NAG (P = 0.02), MMP-2 (P = 0.046) and MMP-9 (P = 0.041) were inversely correlated with the rate of GFR decline. CONCLUSIONS: Urinary NAG, MMP-2 and MMP-9 may be considered as possible candidates for forecasting the progression rate of D-CTIN.