超声剪切波弹性成像技术无创性评价肾组织病理的探索性研究

Exploratory study on noninvasive evaluation of renal histopathology by ultrasonic shear wave elastography

目的确立慢性肾脏病(chronic kidney disease,CKD)儿童超声剪切波弹性成像(shear wave elastography,SWE)与肾组织病理改变的相关性。方法该研究为单中心横断面观察性研究,纳入2021年1—12月于华中科技大学同济医学院附属同济医院儿科住院经肾活检明确病理诊断的儿童。采用肾脏SWE技术获取肾脏上极、中部和下极的皮质、髓质区杨氏模量(YM_(皮质)、YM_(髓质))。对肾组织病理进行分级或分类,采用统计学方法分析右肾下极YM_(皮质)、YM_(髓质)与肾组织病理之间的关系。结果该研究纳入经肾活检明确病理诊断的儿童110例,年龄(10.1±3.4)岁(2~17岁),男性55例(50.0%),体重指数(20.6±2.4)kg/m^(2),平均动脉压(95±24)mmHg。CKD 1期94例(85.4%),2期和3期各有8例(7.3%)。不同分期CKD患者右肾上极和中部YM_(皮质)、YM_(髓质)以及右肾下级YM_(髓质)组间差异均无统计学意义(均P>0.05)。CKD 3期患者右肾下级YM_(皮质)[(15.75±3.36)kPa]和YM_(髓质)[(13.50±2.43)kPa]均显著高于CKD 1期患者[(12.94±2.45)kPa、(11.88±2.23)kPa](均P<0.05)。CKD 1期和2期患者右肾下极YM_(皮质)和YM_(髓质)差异均无统计学意义(均P>0.05)。新月体性肾小球肾炎患者YM_(皮质)[(17.93±3.23)kPa]、YM_(髓质)[(15.50±1.48)kPa]均高于局灶节段性肾小球硬化症[(12.71±2.42)kPa、(11.57±2.63)kPa]和系膜增生性肾小球肾炎[(12.73±2.04)kPa、(11.48±2.10)kPa]患者(均P<0.05)。局灶节段性肾小球硬化症和系膜增生性肾小球肾炎之间YM_(皮质)和YM_(髓质)差异均无统计学意义(均P>0.05)。IgA肾病Lee氏分级Ⅳ级患者YM_(皮质)[(16.30±2.63)kPa]、YM_(髓质)[(15.54±1.59)kPa]均高于Ⅲ级患者[(13.32±2.70)kPa、(12.57±2.50)kPa](均P<0.05),而紫癜性肾炎国际小儿肾脏病研究组分级与YM_(皮质)和YM_(髓质)均无明显相关性(均P>0.05)。IgA肾病和紫癜性肾炎肾小管萎缩或肾间质纤维化(T1/T2)组YM_(皮质)[(15.41±2.37)kPa]、YM_(髓质)[(13.82±2.59)kPa]均高于T0组[(12.99±2.40)kPa、(11.79±2.05)kPa](均P<0.05),伴新月体形成(C1)组YM_(皮质)[(14.21±2.77)kPa]、YM_(髓质)[(12.80±2.47)kPa]均高于C0组[(12.73±2.15)kPa、(11.59±1.97)kPa](均P<0.05),而系膜细胞增生(M)、毛细血管内增生(E)、节段性硬化或粘连(S)与YM_(皮质)、YM_(髓质)均无相关性(均P>0.05)。狼疮肾炎患者YM_(皮质)(r=0.744,P=0.035)、YM_(髓质)(r=0.728,P=0.009)与慢性指数均呈正相关,而与活动性指数均无相关性(均P>0.05)。结论右肾下极部位YM_(皮质)、YM_(髓质)与肾组织肾小管萎缩或肾间质纤维化和新月体形成相关。SWE可用于评价儿童CKD早中期的肾组织慢性化病变,有望成为无创性评价肾组织病理的新方法。

Objective To determine a relationship between ultrasound shear wave elastography(SWE)and pathological lessions of renal tissues in children with chronic kidney disease(CKD).Methods It was a cross-sectional observational study,involving children admitted to the Department of Pediatrics of Tongji Hospital,Tongji Medical College,Huazhong University of Science and Technology from January to December 2021 with definite pathological diagnosis through kidney biopsy.The SWE was used to determine the Young's modulus(elastic modulus)of the cortex and medulla of the upper,middle,and lower poles of the kidney.The renal histopathology was classified or graded.The statistical method was used to analyze the relationship between Young's modulus of the inferior polar cortex(YM_(cor))and medulla(YM_(med))of the right kidney and renal pathology.Results The study included 110 children with definite pathological diagnosis through renal biopsy,aged(10.1±3.4)years old(2-17 years old),with 55 males(50.0%).The body mass index was(20.6±2.4)kg/m^(2),and mean arterial pressure was(95±24)mmHg.There were 94 patients(85.4%)with CKD stage 1,8 patients(7.3%)with CKD stage 2,and 8 patients(7.3%)with CKD stage 3.There was no significant difference of YM_(cor)and YM_(med)in the upper and middle poles of the right kidneys,and YM_(med)in the lower poles of right kidneys in CKD patients with different stages(all P>0.05).Both YM_(cor)[(15.75±3.36)kPa]and YM_(med)[(13.50±2.43)kPa]of CKD stage 3 patients were significantly higher than those of CKD stage 1 patients[(12.94±2.45)kPa,(11.88±2.23)kPa](both P<0.05).There was no significant difference of YM_(cor)and YM_(med)in the lower poles of right kidneys between stage 1 and stage 2 CKD patients(both P>0.05).YM_(cor)[(17.93±3.23)kPa]and YM_(med)[(15.50±1.48)kPa]in patients with crescentic glomerulonephritis were higher than those in patients with focal segmental glomerulosclerosis[(12.71±2.42)kPa,(11.57±2.63)kPa]and mesangial proliferative glomerulonephritis[(12.73±2.04)kPa,(11.48±2.10)kPa](all P<0.05).There was no significant difference of YM_(cor)and YM_(med)between focal segmental glomerulosclerosis and mesangial proliferative glomerulonephritis(both P>0.05).YM_(cor)[(16.30±2.63)kPa]and YM_(med)[(15.54±1.59)kPa]of Lee'sⅣgrade of IgA nephropathy were higher than those of Lee'sⅢgrade[(13.32±2.70)kPa,(12.57±2.50)kPa](both P<0.05),while the International Study of Kidney Disease in Children grade of purpura nephritis had no significant correlation with YM_(cor)and YM_(med)(both P>0.05).YM_(cor)[(15.41±2.37)kPa]and YM_(med)[(13.82±2.59)kPa]of interstitial fibrosis/tubular atrophy(T1/T2)group of IgA nephropathy mixed with purpura nephritis were significantly higher than those of T0 group's[(12.99±2.40)kPa,(11.79±2.05)kPa](both P<0.05).Moreover,crescent formation(C1)group had a higher YM_(cor)[(14.21±2.77)kPa]and YM_(med)[(12.80±2.47)kPa]than those in C0 group[(12.73±2.15)kPa,(11.59±1.97)kPa](both P<0.05),while YM_(cor)and YM_(med)were unrelated to the mesangial hypercellularity(M),endocapillary cellularity(E),segmental sclerosis or adhesion(S)indicators(all P>0.05).In lupus nephritis patients,YM_(cor)(r=0.744,P=0.035)and YM_(med)(r=0.728,P=0.009)were favorably linked with the chronic index,but not with the activity index(both P>0.05).Conclusions Renal interstitial fibrosis/tubular atrophy and crescentic development are connected with YM_(cor)and YM_(med)at the lower pole of the kidney as measured by SWE.SWE can be used to assess the chronic renal lesions in children with CKD in the early and middle stages.It may develop into a new noninvasive way to assess renal pathology.