Study of Urinary Angiotensinogen as a Marker to Warn the Deterioration of Renal Function in CKD Patients Early.

Chronic kidney disease (CKD) that results in end-stage renal disease (ESRD) is a major international health problem. Many clinical markers such as urine protein or eGFR(evaluated glomerular filtration rate),can estimate the renal function, but not sensitive. As well-known, the crucial role of angiotensin II (AngII), the major effector of the renin-angiotensin system (RAS), in the development of renal fibrosis that results in ESRD is widely recognized.Abundant researches find that intrarenal RAS takes an important role on the progression of CKD. At present, no clinical marker is available to evaluate intrarenal AngII activity because it is difficult to measure it directly in patients. So find and establish a bio-marker of local renal RAS activation maybe a breakthrough in early detection and treatment of CKD. Angiotensinogen(AGT) is the only known substrate for renin and the level of AGT in humans is close to Km value for renin. Thus , changes in AGT levels can control the activity of the RAS, and its up-regulation may lead to activity of Ang levels. Then we hypothesis that the AGT is a early bio-marker of local renal RAS activation as well as CKD.