[Significance of urinary biomarkers in differential diagnosis of acute tubulointerstitial nephritis].
OBJECTIVE
To find some urinary biomarkers with significance in the differentiation of drug-induced tubulointerstitial nephritis (DTIN).


METHODS
Forty patients with biopsy-proven DTIN were enrolled. The urine samples of DTIN patients were collected on the day of biopsy and all urine samples were measured for the following different biomarkers as indicated, respectively: urinary TGF-beta by ELISA; urinary IL-6 by radio-immunoassay; NAG by an enzyme-substrate colorimetric assay; alpha1-MG by immune transmission turbidity method. Receiver operating characteristic curves (ROC curve) were constructed to calculate the sensitivity and specificity of those biomarkers in distinguishing acute (A-DTIN) and chronic DTIN (C-DTIN).


RESULTS
Urinary NAG and alpha1-MG levels in patients with A-DTIN were as 2.5 and 2.1 times as those in C-DTIN (P<0.05), while urinary TGF-beta levels in the two groups had no statistical difference. The areas under ROC curve (AUC) of urinary NAG and alpha1-MG for differentiating A-DTIN were 0.720 (P=0.029) and 0.714 (P=0.034) respectively, while the AUCs for TGF-beta and IL-6 were 0.536 (P=0.767) and 0.150 (P=0.004) respectively. Combined measurement of NAG and alpha1-MG could make sensitivity and specificity reach 78.6% and 75.0 % respectively.


CONCLUSIONS
Urinary alpha1-MG and NAG levels can reflect the acute lesions of DTIN, and combined measurement of both could enhance efficiency in differentiating A-DTIN.
Wu
Yu
Y
Renal Division, Peking University First Hospital, Department of Medicine and Institute of Nephrology, Peking University, Key Laboratory of the Ministry of Health, Beijing 100034, China.
Su
Tao
T
Yang
Li
L
Wang
Chen
C
Liu
Gang
G
Li
Xiao-mei
XM
D000208:Acute Disease; D000328:Adult; D000900:Anti-Bacterial Agents / Q000009:adverse effects; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects; D015415:Biomarkers / Q000652:urine; D004365:Drugs, Chinese Herbal / Q000009:adverse effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017351:N-Acetylglucosaminyltransferases / Q000652:urine*; D009395:Nephritis, Interstitial / Q000139:chemically induced* / Q000175:diagnosis / Q000652:urine*; D000511:alpha-Macroglobulins / Q000652:urine*
D000900:Anti-Bacterial Agents; D000894:Anti-Inflammatory Agents, Non-Steroidal; D015415:Biomarkers; D004365:Drugs, Chinese Herbal; D000511:alpha-Macroglobulins; D017351:N-Acetylglucosaminyltransferases