Contrast media as markers of GFR

Abstract

Determination of the glomerular filtration rate (GFR) is generally considered as the most important parameter of quantifying renal function. The GFR is determined as renal or plasma clearance of an ideal filtration marker which is freely filtered by the kidney, does not undergo metabolism, tubular secretion or absorption. Markers that fulfil these demands are inulin, 51Cr-EDTA, 99mTc-DTPA, labelled or unlabelled contrast media. The renal clearance of inulin is the classic reference method for estimation of the GFR. This method is however not practical for routine clinical purposes. Radionucleids have therefore been used as alternative filtration markers since the 60s. Drawbacks related to radiation exposure especially in children and pregnant women and the safety in handling radiolabelled markers have led to an increasing interest in using non-radioactive markers. The development of simple and reliable methods to determine the concentration of contrast media in plasma and urine, such as high-performance liquid chromatography (HPLC) and X-ray fluorescence analysis have made this possible. The non-ionic low osmolar contrast medium iohexol has become the most commonly used contrast medium for GFR measurements in Europe. However, other contrast media with similar pharmacokinetics may be equally suitable as GFR markers.

Accurate measurement of individual glomerular filtration rate in cancer patients: an ongoing challenge

“…There are some disadvantages related to the use of this agent such as the risks of iodine allergies and anaphylaxis which limit the use of iohexol. Finally, iohexol levels in blood and urine have to be determined by high-performance liquid chromatography (HPLC; Frennby and Sterner 2002).…”

Performance of iohexol determination in serum and urine by HPLC: Validation, risk and uncertainty assessment

“…Contrast agents like iothalamate or iohexol (N, N'-bis (2,3-dihydroxypropyl)-5-(N-2,3-dihydroxypropyl)acetamido)-2,4,6-triiodoisophtalamide) are also available and have the features of the ideal marker together with being easily available and safe. Thus iohexol clearance is replacing inulin clearance as a marker of choice for GFR [2,[8][9][10].…”

Phenotypic and Genetic Relationships between Kidney Function and Carotid Intima-Media Thickness in Koreans: The Healthy Twin Study

“…There were some potential limitations in the current study. Although radiolabeled markers such as chromium-51-labeled ethylenediaminetetraacetic acid or nonradioactive contrast media such as iothalamate are ideal methods for determining GFR [25], eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation, which might have limited precision, even though it is considered to be more accurate than the Modification of Diet in Renal Disease Study equation [18]. We were unable to fully consider the possibility that ACR might be influenced by conditions such as systemic inflammation and microvascular damage [26].…”