Assessment of urinary kidney injury molecule-1 and interleukin-18 in the early post-burn period to predict acute kidney injury for various degrees of burn injury.
BACKGROUND
Burn patients with AKI have a higher mortality, rapid diagnosis and early treatment of AKI are necessary. Recent studies have demonstrated that urinary KIM-1 and IL-18 are potential biomarkers of early-stage AKI, however, changes in urinary KIM-1 and IL-18 levels are unclear in patients with burns. The aim of our study was to determine whether combined KIM-1 and IL-18 are more sensitive than traditional markers in detecting kidney injury in patients with burns.


METHODS
Ninety-five burn patients hospitalized at the Burns and Plastic Surgery Center of our hospital from April 2013 to September 2013 were enrolled into this prospective study and divided into mild- (n = 37), moderate- (n = 30) and severe-burn groups (n = 28) by burn injury surface area. In the moderate- and severe-burn groups, patients were subcategorized to either the acute kidney injury (AKI) group, in which serum creatinine (Scr) increased to ≥ 26.5 μmol/L within 48 h, or the non-AKI group. Fifteen healthy subjects were selected as a control group. Blood specimens were collected to determine blood urea nitrogen (BUN), Scr, and other biochemical indicators. Urine samples collected at admission and 48 h after admission were analyzed for KIM-1 and IL-18. Correlations among urinary KIM-1 and IL-18, burn degree, and clinical biochemical indicators were investigated.


RESULTS
AKI occurred in 11.2 % of burn patients (none in the mild-burn group). AKI developed 48 h after admission in 10.0 % of the moderate- and 28.6 % of the severe-burn groups. Urinary KIM-1 concentration in the moderate- and severe-burn groups was significantly higher than that in the control group; urinary IL-18 concentrations did not differ significantly among the burn and control groups. The AKI group had significantly higher concentrations of urinary KIM-1 and IL-18 than the non-AKI group, both at admission (p = 0.001 and p < 0.001, respectively) and 48 h later (p = 0.001 and p < 0.001, respectively). Both urinary KIM-1 and IL-18 increased before Scr. Receiver operating-curve (ROC) analysis demonstrated that KIM-1 combined with IL-18 predicted AKI with 72.7 % sensitivity and 92.8 % specificity. The area under the ROC curve was 0.904.


CONCLUSIONS
Our results suggest that urinary KIM-1 and IL-18 may be used as early, sensitive indicators of AKI in patients with burns of varying degrees and provide clinical clues that can be used in early prevention of AKI.
Department of Nephrology, Jinling Hospital, Nanjing Clinical College of Second Military Medical University, 305 Zhongshan East Road, Nanjing, China. sznk2005@163.com.
Hongqi
H
Ren
Department of Nephrology, HuaiHai Hospital of Xuzhou Medicine College, 226 Tongshan Road, XuZhou, 221004, China. 2011snkzx@sina.cn.
Xuan
X
Zhou
Department of Nephrology, HuaiHai Hospital of Xuzhou Medicine College, 226 Tongshan Road, XuZhou, 221004, China. daideshu0608@126.com.
Deshu
D
Dai
Department of Nephrology, HuaiHai Hospital of Xuzhou Medicine College, 226 Tongshan Road, XuZhou, 221004, China. 995780980@qq.com.
Xiang
X
Liu
Department of Burns, HuaiHai Hospital of Xuzhou Medicine College, 226 Tongshan Road, XuZhou, 221004, China. wlx73@163.com.
Liangxi
L
Wang
Department of Burns, HuaiHai Hospital of Xuzhou Medicine College, 226 Tongshan Road, XuZhou, 221004, China. xzldxxh@sina.com.
Yifang
Y
Zhou
Department of Clinical Laboratory, HuaiHai Hospital of Xuzhou Medicine College, 226 Tongshan Road, XuZhou, 221004, China. XiaomeiLuo@163.com.
Xiaomei
X
Luo
Department of Nephrology, HuaiHai Hospital of Xuzhou Medicine College, 226 Tongshan Road, XuZhou, 221004, China. qingdan0000@163.com.
Qing
Q
Cai
D058186:Acute Kidney Injury / Q000175:diagnosis* / Q000209:etiology / Q000652:urine*; D000328:Adult; D019540:Area Under Curve; D015415:Biomarkers / Q000652:urine; D001806:Blood Urea Nitrogen; D001830:Body Surface Area; D002056:Burns / Q000145:classification / Q000150:complications / Q000652:urine*; D016022:Case-Control Studies; D003404:Creatinine / Q000097:blood; D005260:Female; D000072596:Hepatitis A Virus Cellular Receptor 1; D006801:Humans; D020382:Interleukin-18 / Q000652:urine*; D008297:Male; D008562:Membrane Glycoproteins / Q000652:urine*; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D011991:Receptors, Virus; D015599:Trauma Severity Indices; D055815:Young Adult
D015415:Biomarkers; C491143:HAVCR1 protein, human; D000072596:Hepatitis A Virus Cellular Receptor 1; D020382:Interleukin-18; D008562:Membrane Glycoproteins; D011991:Receptors, Virus; D003404:Creatinine