Increased urinary Angiotensinogen/Creatinine (AGT/Cr) ratio may be associated with reduced renal function in autosomal dominant polycystic kidney disease patients
Hayne Cho Park, Ah-Young Kang, Joon Young Jang, Hyunsuk Kim, Miyeun Han, Kook-Hwan Oh, Seung Hyup Kim, Jung Woo Noh, Hae Il Cheong, Young-Hwan Hwang, Curie Ahn
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common hereditary kidney diseases that frequently result in renal failure. In this cross-sectional observational cohort study, we evaluated urinary angiotensinogen (AGT) as a potential biomarker to assess renal function in ADPKD.
Urinary AGT was measured in 233 ADPKD patients and its association with estimated glomerular filtration rate (eGFR) and height-adjusted total kidney volume (htTKV) were evaluated. The localization of AGT and other renin-angiotensin system (RAS)-related molecules were identified using immunohistochemistry in human ADPKD tissues.
Baseline urinary AGT/Cr was negatively correlated with CKD-EPI eGFR (r (2) = 0.162, P < 0.001) and positively correlated with htTKV (r (2) = 0.107, P < 0.001). Both urinary AGT/Cr and plasma renin activity levels were significantly elevated in hypertensive ADPKD patients. Among hypertensive subjects, urinary AGT/Cr was significantly increased in the advanced CKD stages (III-V) compared to early CKD stages (I-II) (28.6 ± 60.3 vs. 93.2 ± 139.3 μg/g, P < 0.001). Immunohistochemical study showed strong expression of AGT along the cyst-lining epithelial cells as well as the nearby compressed tubular epithelial cells.
Our results suggested that urinary AGT/Cr may be a valuable biomarker for renal damage in ADPKD since intrarenal ischemic insults induced by cyst growth and subsequent intrarenal RAS activation may play a potential role in the development of hypertension and renal dysfunction in ADPKD.
