title: Is serum CRP level a reliable inflammatory marker in pediatric nephrotic syndrome?
abstract: This study tested the hypothesis that during massive proteinuria, C-reactive protein (CRP) may be lost into the urine along with other proteins, making serum CRP (sCRP) level an unreliable marker of infection severity in nephrotic syndrome (NS).
  
  
  
  Children with active NS (n = 23) were compared with two matched control groups: patients with febrile non-renal infectious disease (n = 30) and healthy subjects (n = 16). Laboratory measurements included sCRP, urine protein, creatinine, IgG, and protein electrophoresis. Urinary CRP (uCRP) was measured by ELISA.
  
  
  
  Sixty-nine patients were enrolled: 23 patients with NS, 30 patients with non-renal febrile infectious diseases, and 16 healthy children. Median uCRP concentrations were 0 mcg/gCr (0-189.7) in NS, 11 mcg/gCr (0-286) in the febrile group, and 0 mcg/gCr (0-1.8) in the healthy group. The uCRP/creatinine ratio was similar in the NS and healthy groups (p > 0.1) and significantly higher in the febrile group than the other two groups (p < 0.0001). There was no association of uCRP concentration with severity of proteinuria or IgG excretion.
  
  
  
  NS in children is not characterized by significant loss of CRP into the urine. Therefore, sCRP may serve as a reliable marker of inflammation in this setting. The significant urinary excretion of CRP in children with transient non-renal infectious disease might be attributable to CRP synthesis in renal epithelial cells.
authors.affiliation: Pediatric Intensive Care Unit, Schneider Children's Medical Center of Israel, 14 Kaplan Street, PO Box 559, Petach Tikva, 49202, Israel. eran.shostak@gmail.com.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. eran.shostak@gmail.com.
authors.forename: Eran
authors.initials: E
authors.lastname: Shostak
authors.affiliation: Institute of Pediatric Nephrology, Schneider Children's Medical Center of Israel, Petach Tikva, 49202, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Irit
authors.initials: I
authors.lastname: Krause
authors.affiliation: Institute of Pediatric Nephrology, Schneider Children's Medical Center of Israel, Petach Tikva, 49202, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Amit
authors.initials: A
authors.lastname: Dagan
authors.affiliation: Multidisciplinary Laboratories, Schneider Children's Medical Center of Israel, Petach Tikva, 49202, Israel.
authors.forename: Anat
authors.initials: A
authors.lastname: Ben-Dor
authors.affiliation: Institute of Pediatric Nephrology, Schneider Children's Medical Center of Israel, Petach Tikva, 49202, Israel.
authors.forename: Meital
authors.initials: M
authors.lastname: Keidar
authors.affiliation: Institute of Pediatric Nephrology, Schneider Children's Medical Center of Israel, Petach Tikva, 49202, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Miriam
authors.initials: M
authors.lastname: Davidovits
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000032:analysis*; D002097:C-Reactive Protein / Q000032:analysis* / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000652:urine; D008297:Male; D009404:Nephrotic Syndrome / Q000097:blood* / Q000652:urine
chemical_list: D015415:Biomarkers; D002097:C-Reactive Protein
keywords: C-reactive protein; Children; Nephrotic syndrome; Urinary inflammatory markers