FP293
The Role of Urinary Angiotensinogen in Kidney Interstitial Inflammation and Renal Prognosis

INTRODUCTION: Urinary angiotensinogen (uAGT) has been described as a novel biomarker of acute kidney injury (AKI) and chronic kidney disease (CKD). Renal interstitial inflammatory cell infiltration is a common renal pathological feature of both AKI and CKD. However, the correlation between uAGT and renal interstitial inflammatory cell infiltration is unknown. The aim of this study was to analyze the expression of uAGT, its relationship with interstitial inflammatory cell infiltration, and prognosis in patients with renal insufficiency.

METHODS: The expression of uAGT, urinary kidney injury molecule 1 (uKIM-1), and urinary neutrophil gelatinase-associated lipocalin (uNGAL) were examined by enzyme-linked immunosorbent assay (ELISA) at baseline, and kidney pathology was evaluated at the same time.

RESULTS: 65 patients with renal insufficiency were enrolled and 12 healthy people were selected as the control group. uAGT, uKIM-1, and uNGAL levels were significantly higher compared with those measured in healthy participants. uAGT showed the strongest correlation with interstitial inflammatory cell infiltration (r = 0.366, P = 0.003) and reflected its severity(Table 1). ROC curve analysis showed that uAGT level was able to identify interstitial inflammatory cell infiltration with greater accuracy (AUC = 0.664, P = 0.023) than other urinary biomarkers and pathological lesions. After a median follow-up of 22 months, 15 patients reached the composite renal endpoint. Kaplan-Meier survival curves followed by multivariate Cox proportional hazards regression analysis showed that uAGT (>166.8 ng/mg creatinine) independently predicted higher risk of the progression endpoint.

CONCLUSIONS: Therefore, uAGT may be used as a non-invasive biomarker of interstitial inflammatory cell infiltration and is a strong predictor of renal prognosis in patients with renal insufficiency.