Soluble Prorenin Receptor: A Novel Biomarker for the Prediction of Renal Interstitial Fibrosis and Chronic Kidney Disease

Objective Renal interstitial fibrosis (RIF) is the common pathological feature of Chronic kidney disease (CKD). The diagnosis of RIF requires kidney biopsy, while non-invasive methods are still lacking. Given the association between (Pro)renin receptor (PRR) and organ fibrosis, and the secrete nature of soluble (pro)renin receptor (soluble PRR), we postulate that serum soluble PRR may serve as a potential biomarker of renal fibrosis in CKD patients.Methods 90 CKD patients received kidney biopsy were included, 75 of them were followed up for 1 year. Serum soluble PRR concentration was determined by ELISA kits. Masson staining and PRR immunohistochemical staining were performed on their renal biopsy specimens.Results (1) Serum soluble PRR was statistically significant in patients with different degrees of RIF (P = 0.002). Multivariate analysis showed that serum soluble PRR could independently predict the risk of RIF (P = 0.046). (2) Serum soluble PRR was positively correlated with serum creatinine (r = 0.282, P = 0.007) and negatively correlated with eGFR (r=-0.321, P = 0.002). With the progression of CKD, the serum soluble PRR level was increased significantly (P = 0.010). (3) PRR expression in renal tissues was positively correlated with the area of RIF (r = 0.836, P < 0.001). (4) Patients in the high soluble PRR group had a 4 months shorter mean retention time of renal function than that in the low soluble PRR group (P = 0.048).Conclusions Serum soluble PRR and renal PRR expression in CKD patients were positively correlated with the degree of RIF. Serum soluble PRR can independently predict the risk of RIF and the progression of CKD.