| ObjectiveThe study was to investigate the expression of urinary podocyte and its marker protein podocalyxin(PCX)in patients with type 2 diabetic nephropathy.In order to investigate the value of combined detection of podocyte and PCX in diagnosis of type 2 diabetic nephropathy.Methods300 cases of patients with type 2 diabetes mellitus were selected.They were divided into three groups which were normal albuminuria group(NA),microalbuminuria group(MA)and macroalbuminuria group(LA)by urinary albumin-creatinine ratio(UACR).Healthy people were selected as control group.The level of creatinine was detected by alkaline picric acid method,the level of serum glucose was detected by hexokinase method,the level of urinary microalbumin level was detected by immune transmission turbidimetry,the level of urinary podocyte was detected by flow cytometry,and the level of urinary PCX was measured by enzyme linked immunosorbent assay(ELISA).The correlation between urinary podocyte or PCX and estimated glomerular filtration rate(eGFR)were analyzed by Pearson.The diagnostic efficiency of urinary podocyte and PCX were analyzed.The diagnostic value of urinary podocyte and alone and combined detection in DN were also evaluated.The positive rates in diagnosis of early DN were compared between them.Furthermore,regression analysis of risk factors of DN were carried out.Flow cytometry(FCM)was used to detect podocyte and enzyme-linked immunosorbent assay(ELISA)was used to detect PCX.The correlation between two methods were compared.Results1.NA group,MA group,LA group and control group test results of urinary podocytes were 1.05±0.39 units/?L,3.22±0.85 units/?L,5.17±1.29 units/?L and 0.71±0.32 units/?L,urinary PCX detection results were 1.85±0.45 ng/mL,3.92±1.07 ng/mL,5.75±1.35 ng/mL and 1.19±0.25 ng/mL.The levels of urinary podocyte and urinary PCX in T2DM were higher than control group.And the difference was statistically significant increased with the progression of DN(P<0.05).2.The podocyte and PCX of urine were negatively correlated with eGFR respectively(r=-0.32,r=-0.41,P<0.05).3.ROC curve analysis showed that the optimal cut-off point for podocyte diagnosis of DN was 1.16 units/?L,the sensitivity was 79.1%,specificity was 87.3%,and AUC~ROCOC was 0.827.Urinary PCX in the diagnosis of the optimal cut-off point was 1.83 ng/mL,the sensitivity was83.0%,specificity was 90.9%,and AUC~ROCOC was 0.867.The sensitivity of combined detection was 90.2%,specificity was 86.1%,and AUC~ROCOC was 0.924.4.The positive rates of urinary podocyte and urinary PCX in NA were 41.8%and 50.9%respectively.The positive rate of combined detection was significantly higher than that of a single index.The positive rate of combined diagnosis was about 61.8%.The difference was statistically significant(?~2=8.832,P=0.012).5.Logistic regression analysis showed that three indicators of UACR,urinary podocyte and urinary PCX were the risk factors for progression of type 2 diabetes to DN.6.There was a positive correlation between FCM and ELISA(r=0.82,P<0.05).The two methods had detection consistency(P=0.498).ConclusionUrinary podocyte and PCX were significantly increased in T2DM patients with renal injury,and its closely related with the progression of DN.The diagnostic efficacy of combined detection was significantly higher than that of single index.The sensitivity,positive predictive value and accuracy of combined detection for the diagnosis of DN were higher than the detection of albumin which reported in the literature.Therefore,the combined detection of urinary podocyte and urinary PCX had important clinical value for early diagnosis of DN and its progression.ELISA was suitable as a routine method for detection of podocyte and suitable for application of clinical laboratory. |
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