关键词: 纤维化, 肾间质纤维化, 肾疾病, 诊断

Abstract: Background　Renal interstitial fibrosis（RIF） is a common pathway and the main pathological basis for the development of chronic kidney disease to end-stage renal disease.It is an important factor affecting the prognosis of patients with kidney disease.Early diagnosis and timely treatment are helpful to improve the prognosis.In recent years，many studies have found that RIF can be evaluated by cytokine and other biochemical indices，and ultrasound elastography and other non-invasive tests.However，due to cumbersome operation and high cost，such detections are difficult to be used widely in clinical practice.At present，RIF is manly diagnosed by pathological examination of percutaneous renal biopsy specimens using Masson's trichrome staining or other special staining techniques.But routine pathological diagnosis is made based on the pathologist's electronic microscopic observation of renal interstitial change，which may has subjective error，while diagnosis made using computer aided technology may be an automatic and objective analysis.So we performed a semi-quantitative analysis of microscopic images of the Masson's Trichrome-stained histological sections of RIF.Objective　To assess the diagnostic value of Image-Pro Plus 6.0 in RIF based on this software measured integrated optical density as well as calculated mean optical density （MOD） of Masson's Trichrome-stained histological sections of RIF.Methods　During January to September 2016，from Department of Nephrology，First Affiliated Hospital of Xi'an Jiaotong University，149 cases diagnosed with chronic interstitial nephritis （CIN） and chronic glomerular diseases（RIF group） were enrolled，and by the results of pathological examination of renal biopsy specimens，they were divided into CIN subgroup（including those with a diagnosis of tubulointerstitial nephritis with or without mesangial proliferative glomerulonephritis，n=26） and chronic glomerular disease （CGD） subgroup〔n=123，consisting of IgA nephropathy（n=79）（IgAN Ⅱ-Ⅴby LEE's glomerular grading with 3，35，25，16，respectively）；including IgAN with different degrees of chronic glomerulonephritis hardening（n=44），that is，focal or proliferative sclerosing glomerulonephritis（n=31），or sclerosing glomerulonephritis（n=10），and chronic glomerulonephritis（n=3）〕．They were compared with 27 cases of stageⅠ-Ⅱmembranous nephropathy without RIF confirmed by the same pathological examination in our hospital.Correlations of MOD with clinical indicators 〔serum urea nitrogen （BUN），serum creatinine （Scr），cystatin C，hemoglobin （Hb），and serum and urine β2 microglobulin（β2-MG）〕 were analyzed.ROC analysis of MOD in the diagnosis of RIF was performed，with the optimal cutoff value，sensitivity and specificity were determined.Results　In RIF group，MOD was positively correlated with Scr，serum and urine β2-MG，and was negatively correlated with Hb （P<0.05）.In CGD subgroup，MOD was positively correlated with cystatin C，serum and urine β2-MG，and negatively correlated with Hb （P<0.05）.In the diagnosis of RIF，the AUC of MOD was 0.982〔95%CI（0.961，1.000）〕 when the optimal cutoff value was determined as 0.012 3，with 0.886 sensitivity and 0.963 specificity in RIF group.In CIN subgroup，its AUC was 0.991〔95%CI（0.975，1.000）〕when the optimal cutoff value was determined as 0.011 8，with 1.000 sensitivity and 0.926 specificity.And in CGD subgroup，its AUC was 0.980〔95%CI（0.958，1.000）〕when the optimal cutoff value was determined as 0.008 0，with 0.992 sensitivity and 0.852 specificity.Conclusion　MOD may reflect the degree of RIF，and the estimated optimal cut-off value of diagnosis may be to be 0.012 3.Moreover，it showed high sensitivity and specificity in diagnosing different types of RIF.

Key words: Fibrosis, Renal interstitial fibrosis, Kidney diseases, Diagnosis