title: Clinical relevance of urinary angiotensinogen and renin as potential biomarkers in patients with overt proteinuria.
abstract: Urinary angiotensinogen (AGT) and renin have been reported to reflect the intrarenal renin-angiotensin system (RAS) activity. However, the adequacy and clinical significance of these markers have not been evaluated in overtly proteinuric patients. In patients with biopsy-proven glomerulonephritis, plasma and urinary AGT and renin were analyzed. A cohort of 75 patients treated with RAS inhibitors was followed for 1 year. Among the 207 patients, 105 had subnephrotic and 102 had nephrotic-range proteinuria. Mean age, estimated glomerular filtration rate (eGFR), and urinary protein-to-creatinine ratio (P/Cr) of all patients were 48 years, 79.7 mL/min/1.73 m(2), and 5.66 mg/mg, respectively. Both natural logarithm of urinary AGT/creatinine (ln [urinary AGT/Cr]) and ln (urinary renin/Cr) showed positive correlations with urinary P/Cr. There was a positive correlation between ln (urinary AGT/Cr) and ln (urinary renin/Cr). Ln (urinary renin/Cr) was not affected by ln (plasma renin) regardless of the degree of proteinuria. The treatment response to RAS inhibitors was greatest in patients with high urinary AGT and renin. However, the predictive value of those parameters was no longer present when the values were adjusted by the degree of proteinuria. Ln (urinary renin/Cr) and initial eGFR were independently associated with the changes in renal function for 1 year. Ln (urinary AGT/Cr) was associated with persistent overt proteinuria after 1 year. Our study suggests that urinary renin may be a better marker in heavy proteinuria, and the treatment response to RAS inhibitors may be enhanced in patients with high urinary renin and AGT. Further studies will be necessary to explore the value of urinary AGT and renin.
authors.affiliation: Nephrology Division, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Hye Ryoun
authors.initials: HR
authors.lastname: Jang
authors.affiliation: Nephrology Division, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Junseok
authors.initials: J
authors.lastname: Jeon
authors.affiliation: Nephrology Division, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Ji Hyeon
authors.initials: JH
authors.lastname: Park
authors.affiliation: Nephrology Division, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Jung Eun
authors.initials: JE
authors.lastname: Lee
authors.affiliation: Nephrology Division, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Wooseong
authors.initials: W
authors.lastname: Huh
authors.affiliation: Nephrology Division, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Ha Young
authors.initials: HY
authors.lastname: Oh
authors.affiliation: Nephrology Division, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. Electronic address: ygkim26@skku.edu.
authors.forename: Yoon-Goo
authors.initials: YG
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000808:Angiotensinogen / Q000652:urine*; D015415:Biomarkers; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011507:Proteinuria / Q000378:metabolism / Q000652:urine*; D051436:Renal Insufficiency, Chronic / Q000378:metabolism / Q000652:urine*; D012083:Renin / Q000652:urine*; D012084:Renin-Angiotensin System / Q000502:physiology
chemical_list: D015415:Biomarkers; D000808:Angiotensinogen; D012083:Renin