Author/Editor		Hojs, Radovan; Antolinc, Barbara; Gorenjak, Maksimiljan; Puklavec, Ludvik
Title		Serum cystatin C - new marker of glomerular filtration rate
Translated title		Serumski cistatin C - nov označevalec glomerulne filtracije
Type		članek
Source		Zdrav Vestn
Vol. and No.		Letnik 73, št. 4
Publication year		2004
Volume		str. 171-5
Language		eng
Abstract		Background. Estimation of the glomerular filtration rate is an essential part of the evaluation of patients with renal disease. A standard for glomerular filtration rate assessment is CrEDTA clearance. Serum creatinine is the most commonly used marker to estimate the glomerular filtration rate, but it is often not enough accurate. Recently serum cystatin C has been proposed as a new endogenous marker of glomerular filtration rate. Patients and methods. A total of 231 patients (100 woman and 131 men), who performed CrEDTA clearance in previous 17 months, were enrolled in our study. In each patient seru.m creatinine and serum cystatin C were also determined. Average age of our patients was 55 years (from 7 to 85 years). Results. Average CrEDTA clearance was 54.4 ml/min/1.73 m2 (from 2 to 186 ml/min/1.73 m2). Average serum creatinine concentration was 270.2 micromol/L (from 64 to 915 micromol/l) and average serum cystatin C concentration was 2.53 mg/l (from 0.59 to 6.99 mg/l). The correlations between CrEDTA clearance, serum creatinine and serum cystatin C were statistically significant. The correlation between CrEDTA clearance and serum cystatin C was better than correlation between CrEDTA clearance and serum creatinine. Conclusions. CrEDTA clearance, serum creatinine and serum cystatin C are comparable markers of renal function. Based on our study, serum cystatin C is a more reliable measure of glomerular filtration rate than serum creatinine.
Summary		Izhodišča. Ocena glomerulne filtracije (GF) je pomemben del obravnave bolnika z ledvično boleznijo. GF ali njena sprememba je lahko prvi znak ledvične bolezni, lahko kaže na resnost ledvične bolezni, omogoča spremljanje poteka ledvične bolezni in pomaga pri določanju pravilnega odmerka zdravil, ki se izločajo preko ledvic. Temeljna metoda za oceno GF je očistek snovi. To je prostornina plazme, ki se v določeni časovni enoti očisti te snovi z izločanjem v seč. GF bi lahko natančno določili s pomočjo snovi, ki v telesu nastaja stalno, ki se izloča iz telesa izključno s prosto filtracijo, ki se v ledvicah ne presnavlja in ne sintetizira in ki se v ledvičnih tubulih ne secernina in ne reabsorbira. Zaenkrat ni poznana endogena snov, ki bi zadostila. vsem tem pogojem. V vsakdanji klinični praksi se za oceno GF najpogosteje uporablja serumska koncentracija kreatinina, ki pa pogosto ni dovolj natančna. Očistek kreatinina je boljši pokazatelj GF kot serumska koncentracija kreatinina, vendar zahteva 24-urno zbiranje urina, ki pogosto ni zanesljivo. Standardna referenčna metoda za določanje GF je očistek CrEDTA, vendar je to radioizotopni označevalec, zato ga ni možno zelo pogosto uporabiti pri, istem bolniku. V zadnjem času se kot eden novih označevalcev glomerulne filtracije pojav ja serumska koncentracija cistatina C. Cistatin C je inhibitor proteaz, v telesu nastaja stalno v vseh jedrnih celicah in se prosto filtrira čez glomerulno membrano. Velik del se ga katabolizira v proksimalnem tubulu, vendar se ne secernira niti se ne vrača v krvni obtok. Zaradi razgradnje v proksimalnem tubulu se njegov očistek ne da meriti, njegova serumska koncentracija pa je dober pokazatelj GF. Pomen cista.tina C za oceno GF je sicer poznan že mnogo let, se pa v preteklosti ni uporabljal, saj je bilo njegovo določanje tehnično zelo težavno. Bolniki in metode. (Izvleček skrajšan pri 2000 znakih).
Descriptors		KIDNEY DISEASES GLOMERULAR FILTRATION RATE CYSTATINS CREATININE METABOLIC CLEARANCE RATE CHROMIUM RADIOISOTOPES EDETIC ACID