SAT-393 The profile of biopsy-proven renal tubulointerstitial lesions in patients with Glomerular disease

Abstract

Renal tubules and interstitium are vulnerable to injury and play a central role in the progression of various CKDs. However, high quality study on the profiles of biopsy-proven tubulointerstitial lesions (TIL) is extremely limited. We conducted a retrospective renal biopsy series including 62,521native biopsies at 1211 hospitals across China from 2015 to 2017. The TILs, including the shedding of tube epithelial, renal tubular atrophy, renal interstitial fibrosis, edema and inflammatory infiltration, were identified from the pathological report. We analyzed the severity and chronicity of TILs stratified by gender, age groups, biopsy indications, and concurrent glomerular diseases. We also examined the effect of intrarenal arterial lesion on the risk of TIL. Of the 56,701 patients with exact pathological diagnosis, 79.95% of the patients had tubulointerstitial lesions, renal interstitial inflammatory infiltration was the most common type of TIL (77.70%), followed by renal tubular atrophy (56.36%) and renal interstitial fibrosis (27.84%). Severe and chronic TIL was more common in adults than in children. The prevalence of moderate to severe TIL was 74.14%, 26.00%, and 18.84% in patients with diabetic nephropathy (DN), IgA nephropathy (IgAN) and focal segmental glomerulosclerosis (FSGS), respectively. Similarly, patients with DN, IgAN, focal segmental glomerulosclerosis (FSGS) were more likely to have chronic TIL. Moderate to severe TIL was more common in the south of China. After adjusting for age, sex, hospital level, region, biopsy indication and type of concurrent glomerular diseases, patients with renal arteriole injury had a six-fold higher risk of TIL (OR 7.22, 95% CI, 6.48 to 8.05). In this large, multicenter renal biopsy series, the type and severity of TILs varied with age, region and concurrent glomerular diseases. Renal arteriole injury was associated with a significantly increased risk of TIL.