目的:足细胞损伤在糖尿病肾病(DN)的进展中起着至关重要的作用。在2型糖尿病肾病(T2DN)患者中,足细胞的超微结构变化与蛋白尿与肾脏病理学学会(RPS)提出的DN病理分类之间的关系尚未阐明。
方法:收集2017-2022年北京大学第一医院肾活检确诊T2DN患者110例。对足细胞足突宽度(FPW)和足细胞脱离(PD)作为足细胞损伤的标志进行形态计量学分析,分析足细胞超微结构改变与蛋白尿严重程度及DNRPS病理分型的相关性。
结果:有肾病性蛋白尿(565.1nm)的T2DN患者组的平均FPW明显大于有微量白蛋白尿(437.4nm)或明显蛋白尿(494.6nm)的患者。FPW的临界值(>506nm)可以区分肾病性蛋白尿和非肾病性蛋白尿,敏感性为75.3%,特异性为75.8%。肾病性蛋白尿组的PD百分比(3.2%)明显高于微量白蛋白尿(0%)或明显蛋白尿(0.2%)。FPW和PD与T2DN蛋白尿呈显著正相关(r=0.473,p<0.001,r=0.656,P<0.001)。FPW和PD与T2DN的RPS病理分级相关(r=0.179,P=0.014,r=0.250,P=0.001)。随着DN分类更严重,FPW值显着增加(趋势P=0.007)。PD的百分比随着DN分类更严重而增加(趋势P=0.017)。
结论:足细胞损伤,以FPW展宽和PD为特征,与蛋白尿的严重程度和DN的病理分级有关。
OBJECTIVE: Podocyte injury plays an essential role in the progression of diabetic nephropathy (DN). The associations between the ultrastructural changes of podocyte with proteinuria and the pathological classification of DN proposed by Renal Pathology Society (RPS) have not been clarified in patients with type 2 diabetic nephropathy (T2DN).
METHODS: We collected 110 patients with kidney biopsy-confirmed T2DN at Peking University First Hospital from 2017 to 2022. The morphometric analysis on the podocyte foot process width (FPW) and podocyte detachment (PD) as markers of podocyte injury was performed, and the correlations between the ultrastructural changes of podocytes with severity of proteinuria and the RPS pathological classification of DN were analyzed.
RESULTS: Mean FPW was significantly broader in the group of T2DN patients with nephrotic proteinuria (565.1 nm) than those with microalbuminuria (437.4 nm) or overt proteinuria (494.6 nm). The cut-off value of FPW (> 506 nm) could differentiate nephrotic proteinuria from non-nephrotic proteinuria with a sensitivity of 75.3% and a specificity of 75.8%. Percentage of PD was significantly higher in group of nephrotic proteinuria (3.2%) than that in microalbuminuria (0%) or overt proteinuria (0.2%). FPW and PD significantly correlated with proteinuria in T2DN (r = 0.473, p < 0.001 and r = 0.656, P < 0.001). FPW and PD correlated with RPS pathological classification of T2DN (r = 0.179, P = 0.014 and r = 0.250, P = 0.001). FPW value was increased significantly with more severe DN classification (P for trend =0.007). The percentage of PD tended to increase with more severe DN classification (P for trend = 0.017).
CONCLUSIONS: Podocyte injury, characterized by FPW broadening and PD, was associated with the severity of proteinuria and the pathological classification of DN.