Clinical Application Study Of Shear Wave Elastography In Evaluating Clinical Staging Of Chronic Kidney Disease

Objective: To estimate the value of Shear Wave Elastography(SWE)in differentiating the clinical staging of Chronic Kidney Disease(CKD).Methods: A total of 112 renals with 56 CKD patients who were hospitalized in the Department of Nephrology or Rheumatology of Affiliated Hospital of Yangzhou University Hospital from April 2022 to December 2022 were enrolled as the study group.All patients underwent kidney SWE examination before renal puncture biopsy.Meanwhile,124 renals of 62 volunteers who came to our hospital for physical examination during the same period were enrolled as the control group for kidney SWE examination.The age,sex,height,weight and other general data of the two groups were collected.Young’s Modulus(YM)values in the middle and lower pole parenchymal area of both kidneys in the control group and the CKD group were measured and recorded by SWE.Meanwhile,clinic parameters of the CKD patients,such as 24 h urinary protein content,blood creatinine,urinary Albumin creatinine ratio(ACR),α1-microglobulin and pathological diagnosis results of renal biopsy,were recorded.The differences of YM values of kidney parenchyma between different clinical stages,Primary glomerular nephroprthy(PGN)subgroups and Secondary renal disease(SRD)subgroups in patients with CKD were compared.Additionally,the correlation between the YM value of CKD patients and clinical parameters was further analyzed.The CKD group was further divided into normal serum creatinine group(≤ 133 umol/L)and abnormal serum creatinine group(> 133 umol/L)based on their serum creatinine levels.The CKD group with Ig A nephropathy was classified into Ig A nephropathy III,IV and V according to the Lee classification.The differences of YM values between different CKD subgroups and different Ig A pathological grades were analyzed.The control group was also divided into different subgroups according to age,sex and body mass index,and the differences of YM value of renal parenchyma between the subgroups were compared.Results: 1.The pathological diagnosis results of kidney tissues in 56 CKD patients(a total of 112 kidney samples)were as follows: 60 kidney samples in the PGN subgroup,including 36 cases of Ig A nephropathy,12 cases of mesangial proliferative glomerulonephritis,6 cases of membranous nephropathy and 6 cases of podocytopathy;52 kidney samples in the SRD subgroup,including 24 cases of diabetic nephropathy,20 cases of lupus nephritis,6 cases of Sjogren’s syndrome-related nephritis and 2 cases of renal amyloidosis;2.The YM value of renal parenchyma in CKD group was significantly higher than that in control group(11.71 ± 3.89 k Pa vs.5.61 ± 0.52 k Pa,t =-16.486,P < 0.001).The AUC of YM value in differentiating CKD patients from control group was 0.99.With a cut-off value of 6.89 k Pa,the sensitivity,specificity,positive predictive value and negative predictive value of YM value in differentiating CKD patients from control group was 96 %,100 %,100 % and 97 %,respectively;3.The renal parenchyma YM value in CKD stages 4-5 was significantly higher than that in CKD stages 1-3(13.97 ± 2.89 k Pa vs.11.33 ± 3.92 k Pa,t =-2.576 P <0.05).The AUC for the YM value in diagnosing CKD stages 4-5 from CKD stages 1-3was 0.76.With a cut-off value of 12.51 k Pa,the sensitivity,specificity,positive predictive value and negative predictive value of the YM value for distinguishing between CKD stages 1-3 and CKD stages 4-5 were 75 %,76 %,95 % and 34 %,respectively;4.No significant difference was observed in the renal parenchyma YM values between the PGN group and the SRD group(11.19 ± 3.11 k Pa vs.10.78 ± 3.21 k Pa,t =0.675,P > 0.05);5.16 cases of Ig A nephropathy Grade III,14 cases of Ig A nephropathy Grade IV,and 6 cases of Ig A nephropathy Grade V,the renal parenchyma YM values were 8.86 ±1.22 k Pa,11.10 ± 2.23 k Pa,and 16.69 ± 3.29 k Pa,respectively.The differences among the three subgroups were statistically significant(F = 12.213,P < 0.001),and pairwise comparisons between subgroups also exhibited statistical significance(P < 0.05);6.The renal parenchyma YM value in the CKD group showed significant correlations with 24 h urinary protein content,serum creatinine,ACR,andα1-microglobulin(r = 0.335,r = 0.474,r = 0.328,r = 0.418,respectively).These clinical parameters had a positive and weak correlation with the YM value in the renal parenchyma of CKD patients(P < 0.001).The AUC of the YM value for differentiating CKD patients with serum creatinine ≤ 133 umol/L from those with serum creatinine >133 umol/L was 0.96.With a cut-off value of 12.35 k Pa,the sensitivity,specificity,positive predictive value and negative predictive value of the YM value for this differentiation were 92 %,91 %,97 % and 76 %,respectively;7.The renal parenchyma YM value in the control group was 5.61 ± 0.52 k Pa,with no significant differences among various age,sex,and body mass index subgroups(P >0.05).Conclusion: SWE can effectively evaluate renal fibrosis levels and holds clinical value in CKD staging assessments.Furthermore,it provides meaningful guidance for the selection of CKD treatment plans.