Clinical Applying of Urinary IL-18 Level in Preterm Neonates with acute Kidney Injury
|Keywords||Preterm neonates AKI urinary IL-18|
Objective The purpose of the study is to investigate wether urinary IL-18 could serve as an acute kidney injury biomarker in preterm neonates.Methods We studied 30 preterm neonates admitted in the neonatal department of Soochow University affiliated children’s hospital from August to September,2010. Among all the neonates,23 were male (77%). The mean gestational age was 33.18 weeks, ranged from 26+1 to 36+6 weeks. The mean birth weight was 1953 g, ranged from 1070-2950g. These neonates were divided into 3 groups by gestational age:group A (n=8) was neonates whose gestational ages were less than 32 weeks, group B (n=14) was those whose gestational ages were more than 32 weeks but less than 35 weeks, the other 8 cases were group C. We further divided all the neonates into 2 groups according to their APGAR score: one group (n= 11) was neonates with APGAR score<7 at birth, the other group was the rest. All the asphyxia neonates were mild asphyxia. Urine samples were collected in the first 24 hours of life. The concentration of urinary IL-18 was detected by Enzyme-linked Immunosorbent Assay(ELISA).Results (1) The morbidity of AKI in our study is 20%. For predicting AKI, the specificity of urinary IL-18 was 0.88, the sensitivity was 0.67, and the likehood ratio positive is 5.3, which indicating the risk of AKI is 5.3 times than those with urinary IL-18 concentration lower than 57.9 pg/ml. (2) The median level of Scr, CrCl, and urinary IL-18 which from asphyxia neonates was 65 (52.1～74.7) umol/L,18.8 (15.1-23.5) ml/min/1.73m2,42.0 (17.3～102.6) pg/ml respectively. The median level of Scr, CrCl, and urinary IL-18 which from no-asphyxia neonates was 58.9 (43.2-99.5) umol/L,23.5 (12.5-28.0) ml/min/1.73m2,27.6 (11.6-93.7) pg/ml respectively. Between the two groups, no significant difference were found (P>0.05). (3) The level of urinary IL-18 was not associated with gestational age or birth weight. (4) There was a decreased tendency of urinary IL-18 as the gestational ages raised among the 3 groups, but with no significant difference. The median level of urinary IL-18 which from group A and group C was 42.0 (17.3-102.6) pg/ml,27.6 (11.6-93.7) pg/ml respectively. The level of urinary IL-18 of Group A was significantly higher than that of group C (P<0.05), which indicating that preterm neonate whose gestational age smaller than 32 weeks was more likely to suffer from AKI for it might with server diseases such as respiratory distress syndrome, et al.Conclusions 1. Our study suggest urinary IL-18 might be an ideal biomarker for AKI, especially when neonates with clinical indicators for AKI.2. Asphyxia might have no/or little effect on the concentration of urinary IL-18.3. The concentration of urinary IL-18 is not associated with gestational age or birth weight (NRDS was excluded).4. Preterm neonate whose gestational age smaller than 32 weeks was more likely to suffer from AKI for it might with server diseases such as NRDS, et al.