title: Urinary angiotensinogen levels in relation to renal involvement of Henoch-Schonlein purpura in children.
abstract: OBJECTIVE
  To investigate whether urinary angiotensinogen (UAGT) levels are correlated with renal involvement of Henoch-Schonlein purpura (HSP) in children, and to explore whether UAGT has any relation to the severity of HSP.
  
  
  METHODS
  The study sample consisted of 107 patients (50 boys and 57 girls, 6.68±2.41 years) with clinical diagnosis of HSP. A 24 h urine sample was collected before treatment. UAGT levels were measured in patients with HSP in the acute and convalescent phases by enzyme linked immunosorbent assay.
  
  
  RESULTS
  Urinary angiotensinogen/urinary concentration of creatinine levels were significantly higher in proteinuric HSP in the acute phase and the convalescent phase (32.02±3.95 and 25.31±4.11 µg/g) compared with those with HSP without renal involvement (17.26±2.60 and 15.14±3.81 µg/g) and those with hematuric HSP (19.70±2.21 and 17.28±3.62 µg/g) (P<0.0001 and P<0.01, respectively). Using matched urine samples from the same patients, UAGT/urinary concentration of creatinine (UCr) levels of proteinuric HSP patients were significantly lower in the convalescent phase (25.31 ± 4.11 µg/g, P<0.01) than in the acute phase (32.02±3.95 µg/g). UAGT/UCr levels showed positive correlation with 24 h urine protein or serum creatinine in both hematuric HSP and proteinuric HSP groups during the acute phase (P<0.05).
  
  
  CONCLUSIONS
  Urinary angiotensinogen levels were remarkably high in the acute phase in the patients with proteinuric HSP, suggesting increased UAGT may indicate a series of functional changes in the kidney and it may be used as a potential biomarker of severity of HSP to monitor the progression of HSP with renal involvement.
authors.affiliation: Pediatrics Department of The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
authors.forename: Yan Na
authors.initials: YN
authors.lastname: Mao
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Yan Ge
authors.initials: YG
authors.lastname: Li
authors.forename: Guo Cun
authors.initials: GC
authors.lastname: Jia
authors.forename: Zhang
authors.initials: Z
authors.lastname: Zhang
authors.forename: Yu Jie
authors.initials: YJ
authors.lastname: Guan
authors.forename: Xu Feng
authors.initials: XF
authors.lastname: Zhou
authors.forename: Yu Feng
authors.initials: YF
authors.lastname: Liu
mesh_terms: D000210:Acute-Phase Reaction / Q000097:blood / Q000652:urine; D000808:Angiotensinogen / Q000652:urine*; D015415:Biomarkers; D002648:Child; D002675:Child, Preschool; D003289:Convalescence; D003404:Creatinine / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006417:Hematuria / Q000097:blood / Q000209:etiology / Q000652:urine; D006801:Humans; D011695:IgA Vasculitis / Q000097:blood / Q000150:complications / Q000503:physiopathology / Q000652:urine; D007668:Kidney / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods; D017063:Outcome Assessment, Health Care; D011507:Proteinuria / Q000097:blood / Q000209:etiology / Q000652:urine; D012084:Renin-Angiotensin System; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D000808:Angiotensinogen; D003404:Creatinine