title: Relationship between serum and urine interleukin-6 elevations and renal scarring in children with acute pyelonephritis.
abstract: OBJECTIVE
  Acute pyelonephritis is a common infectious disease in children and can result in permanent renal damage. Interleukin-6 (IL-6) is an important mediator of inflammation in response to bacterial infection. This study investigated the potential relationship between acute-phase IL-6 and subsequent renal scarring in children with a first time febrile acute pyelonephritis.
  
  
  METHODS
  In total, 79 children (age range 1-120 months) with a first time febrile urinary tract infection (UTI) were included. The diagnosis of acute pyelonephritis was confirmed by (99m)Tc-dimercaptosuccinic acid (DMSA) renal scan. Serum and urine samples were collected for IL-6 measurement by enzyme-linked immunosorbent assay before antibiotic treatment for the infection.
  
  
  RESULTS
  The 79 children were divided into acute pyelonephritis (n=45) and lower UTI (n=34) groups according to the findings of DMSA scans. The initial serum and urine IL-6 levels of children with acute pyelonephritis were significantly higher compared with lower UTI (p < 0.001). Renal scarring was detected at the follow-up DMSA scans in 15 (34.1%) of the 44 children with acute pyelonephritis. Both serum and urine IL-6 levels during the acute phase of pyelonephritis were significantly higher in children with renal scarring than in those without (p=0.005 and p = 0.002). The median age of children with renal scarring was significantly lower than those without (p=0.034). Multiple regression analysis showed that higher initial serum and urine IL-6 levels and a younger age were associated with renal scarring.
  
  
  CONCLUSIONS
  These results demonstrate that in younger children with a first time febrile acute pyelonephritis, elevations of the acute-phase serum and urine IL-6 levels were correlated with an increased risk of subsequent renal scarring.
authors.affiliation: Departments of Pediatrics, Chung Shan Medical University Hospital, Taichung, Taiwan. cshy098@csh.org.tw
authors.forename: Ji-Nan
authors.initials: JN
authors.lastname: Sheu
authors.forename: Meng-Chi
authors.initials: MC
authors.lastname: Chen
authors.forename: Shan-Ming
authors.initials: SM
authors.lastname: Chen
authors.forename: Sun-Long
authors.initials: SL
authors.lastname: Chen
authors.forename: Shyh-Ying
authors.initials: SY
authors.lastname: Chiou
authors.forename: Ko-Huang
authors.initials: KH
authors.lastname: Lue
mesh_terms: D000208:Acute Disease; D002614:Chelating Agents; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D015850:Interleukin-6 / Q000097:blood* / Q000652:urine*; D007668:Kidney / Q000473:pathology*; D008297:Male; D011704:Pyelonephritis / Q000097:blood* / Q000652:urine*; D004113:Succimer; D014718:Vesico-Ureteral Reflux / Q000097:blood / Q000652:urine
chemical_list: D002614:Chelating Agents; D015850:Interleukin-6; D004113:Succimer