Urinary angiotensinogen as a predictive marker in patients with immunoglobulin A nephropathy

Abstract

The intrarenal renin-angiotensinogen system (RAS) plays a major role in the progression of chronic kidney disease. Urinary angiotensinogen (UAGT) provides a specific index of the intrarenal RAS status. This study was conducted to find the role of UAGT as a predictive marker in patients with immunoglobulin A nephropathy (IgAN). Thirty-six patients with IgAN, 14 non-IgAN and 15 healthy controls were included. The UAGT concentration was measured using human ELISA kits and adjusted by urinary creatinine. UAGT levels were significantly higher in patients with IgAN and non-IgAN than in healthy subjects (104.96 vs. 6.71ng/mgCr, p<0.01). Using univariate regression analysis, UAGT was found to correlate with the urine protein-to-creatinine ratio (UPCR), serum creatinine, and systolic and diastolic blood pressure in patients with IgAN. Multivariate regression analysis revealed that UAGT correlated positively with UPCR. Patients with levels of UAGT >100ng/mgCr showed higher serum creatinine after treatment than patients with UAGT levels <100ng/mgCr. This study showed that UAGT levels are increased and correlate positively with the UPCR in IgAN. Patients with high levels of UAGT may have poor renal function following treatment.