LAUSR

Purpose To investigate the relationships between hematuria, clinicopathological features and renal outcomes in patients with biopsy-proven diabetic nephropathy (DN). Methods This cohort study included 261 patients with DN. Participants were divided into two groups according to number of red blood cells per high-power field (RBC/hpf) in urine sediment: the hematuria (−) group (≤ 3 RBC/hpf) and the hematuria (+) group (> 3 RBC/hpf). Basic clinical parameters were measured at the time of renal biopsy; relationships between hematuria and clinicopathological features and renal outcomes were analyzed. Results Patients in the hematuria (+) group often had overt proteinuria. Interstitial inflammation was more severe in the hematuria (+) group than in the hematuria (−) group. Glomerular arteriolar hyalinosis, interstitial fibrosis and tubular atrophy were comparable between groups. For patients with early DN (eGFR ≥ 60 ml/min/1.73 m 2 ), urinary RBC/hpf at baseline was positively correlated with glomerular classification, interstitial fibrosis/tubular atrophy scores and interstitial inflammation scores. In prognostic analysis, hematuria was associated with a higher risk of progression to end-stage renal disease. Hematuria remained an independent predictor after adjustment for confounding factors such as sex, age, duration of diabetes, serum glucose level, hypertension, cholesterol, eGFR and urine protein excretion, especially in patients with early DN and in male patients. Conclusion In this study, hematuria was associated with more severe renal pathologic lesions in patients with DN. The presence of hematuria could be an independent predictor of renal outcome in patients with early DN.