title: Accuracy of cystatin C in prediction of acute kidney injury in children; serum or urine levels: which one works better? A systematic review and meta-analysis.
abstract: There is still an ongoing discussion on the prognostic value of cystatin C in assessment of kidney function. Accordingly, the present study aimed to conduct a meta-analysis to provide evidence for the prognostic value of this biomarker for acute kidney injury (AKI) in children.
  
  
  
  An extensive search was performed in electronic databases of Medline, Embase, ISI Web of Science, Cochrane library and Scopus until the end of 2015. Standardized mean difference (SMD) with a 95% of confidence interval (95% CI) and the prognostic performance characteristics of cystatin C in prediction of AKI were assessed. Analyses were stratified based on the sample in which the level of cystatin C was measured (serum vs. urine).
  
  
  
  A total of 24 articles were included in the meta-analysis [1948 children (1302 non-AKI children and 645 AKI cases)]. Serum (SMD = 0.96; 95% CI: 0.68-1.24; p < 0.0001) and urine (SMD = 0.54; 95% CI:0.34-0.75; p < 0.0001) levels of cystatin C were significantly higher in children with AKI. Overall area under the curve of serum cystatin C and urine cystatin C in prediction of AKI were 0.83 (95% CI: 0.80-0.86) and 0.85 (95% CI: 0.81-0.88), respectively. The best sensitivity (value = 0.85; 95% CI: 0.78-0.90) and specificity (value = 0.61; 95% CI: 0.48-0.73), were observed for the serum concentration of this protein and in the cut-off points between 0.4-1.0 mg/L.
  
  
  
  The findings of the present study showed that cystatin C has an acceptable prognostic value for prediction of AKI in children. Since the serum level of cystatin C rises within the first 24 h of admission in patients with AKI, this biomarker can be a suitable alternative for traditional diagnostic measures.
authors.affiliation: Pediatric Chronic Kidney Disease Research Center, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Babak
authors.initials: B
authors.lastname: Nakhjavan-Shahraki
authors.affiliation: Physiology Research Center and Department of Physiology, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Yousefifard
authors.affiliation: Pediatric Chronic Kidney Disease Research Center, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran.|Department of Pediatric Nephrology, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Neamatollah
authors.initials: N
authors.lastname: Ataei
authors.affiliation: Department of Neurology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Masoud
authors.initials: M
authors.lastname: Baikpour
authors.affiliation: Department of Nuclear Medicine, Taleghani Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Ataei
authors.affiliation: Pediatric Chronic Kidney Disease Research Center, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran.|Department of Pediatric Nephrology, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Behnaz
authors.initials: B
authors.lastname: Bazargani
authors.affiliation: Pediatric Chronic Kidney Disease Research Center, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran.|Department of Pediatric Nephrology, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Arash
authors.initials: A
authors.lastname: Abbasi
authors.affiliation: Department of Intensive Care Nursing, School of Nursing and Midwifery, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Parisa
authors.initials: P
authors.lastname: Ghelichkhani
authors.affiliation: Department of Pediatric Nephrology, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran.|Department of Pediatric Nephrology, Atieh Hospital, Tehran, Iran.
authors.forename: Faezeh
authors.initials: F
authors.lastname: Javidilarijani
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Poursina Ave, Tehran, Iran. mhossein110@yahoo.com.
authors.forename: Mostafa
authors.initials: M
authors.lastname: Hosseini
mesh_terms: D058186:Acute Kidney Injury / Q000097:blood* / Q000175:diagnosis / Q000652:urine; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D055316:Cystatin C / Q000097:blood* / Q000652:urine; D006801:Humans; D007223:Infant; D012680:Sensitivity and Specificity
chemical_list: D055316:Cystatin C
keywords: Acute kidney injury; Cystatin C; Prognostic value