Urinary angiotensinogen levels in relation to renal involvement of Henoch-Schonlein purpura in children.

摘要

AIM: 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 microg/g) compared with those with HSP without renal involvement (17.26+/-2.60 and 15.14+/-3.81 microg/g) and those with hematuric HSP (19.70+/-2.21 and 17.28+/-3.62 microg/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 microg/g, P<0.01) than in the acute phase (32.02+/-3.95 microg/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.