Urinary podocalyxin positive-element occurs in the early stage of diabetic nephropathy and is correlated with a clinical diagnosis of diabetic nephropathy.
OBJECTIVE
We tested whether urinary podocalyxin-positive element (PCX+EL) can be a marker of early stage of diabetic nephropathy (DN).


METHODS
DN patients (n=68) and health controls (n=28) were enrolled in this study. Patients were classified into three groups: normoalbuminuria, microalbuminuria and macroalbuminuria. Urinary PCX+EL, serum cystatin C (Scys C) and serum creatinine (SCr) were quantified, and correlations between urinary PCX+EL and urinary albumin, Scys C and SCr were examined. The comparison of diagnosis efficiency among urinary PCX+EL, Scys C and SCr was made by receiver operating characteristic (ROC) analysis.


RESULTS
Urinary PCX+EL, Scys C and SCr significantly increased in DN patients compared with controls. Urinary PCX+EL increased significantly in all three patients groups compared with controls. However, the concentration of Scys C and SCr did not increase in normoalbuminuria group. Urinary albumin, Scys C and SCr correlated with urinary PCX+EL. ROC curve analysis indicated that area under the curve (AUC) of urinary PCX+EL (0.966) is higher than that of Scys C (0.857) and SCr (0.726) for discriminating nephropathy between DN patients and controls.


CONCLUSIONS
Urinary PCX+EL may be a noninvasive marker for the early stage of DN.
Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong University.
Hui
H
Ye
Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong University.
Xueli
X
Bai
Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong University.
Hua
H
Gao
Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong University.
Li
L
Li
Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong University.
Chunxiao
C
Wu
Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong University.
Xinping
X
Sun
Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong University.
Chunzhi
C
Zhang
Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong University.
Yajuan
Y
Shen
Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong University. Electronic address: slyy2008@126.com.
Jian
J
Zhang
Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong University. Electronic address: luzhiming@sdu.edu.cn.
Zhiming
Z
Lu
D000328:Adult; D000368:Aged; D000419:Albuminuria / Q000652:urine; D015415:Biomarkers / Q000652:urine; D016022:Case-Control Studies; D003404:Creatinine / Q000097:blood / Q000652:urine; D055316:Cystatin C / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications / Q000175:diagnosis / Q000652:urine; D003928:Diabetic Nephropathies / Q000175:diagnosis* / Q000652:urine*; D018450:Disease Progression; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012795:Sialoglycoproteins / Q000652:urine*
D015415:Biomarkers; D055316:Cystatin C; D012795:Sialoglycoproteins; C001643:podocalyxin; D003404:Creatinine
Diabetic nephropathy; Flow cytometry; Podocalyxin; Podocyte