Iohexol clearance

WB Saunders, Philadelphia, pp 93-123 Finco DR (1997) Kidney function. In Kaneko JJ, Harvey JW, Bruss ML (eds) Clinical Biochemistry of Domestic Animals, 6th edn. Academic Press, San Diego, pp 441—485 Finco DR, Braselton WE, Cooper TA (2001) Relationship between plasma iohexol clearance and urinary exogenous creatinine clearance in dogs. J Vet Intern Med 2001 Jul-Aug 15(4) 368-373... 

P2.m. The cysteine proteinases are one of four major classes of endoproteinases that possess the ability to degrade intact glomerular basement membranes [144]. All nucleated cells produce cystatin at a stable rate. More than 99% is freely filtered by the glomerulus with little secretion or reabsorption. As a result, it has many of the ideal features for use as a marker of kidney function and eshmate of GFR. Serum cystatin C concentrations demonstrate a good inverse correlation with radionuclide derived measurements of GFR and has been shown in several studies to be superior to creatinine and comparable to iohexol clearances in estimating eGFR [145,146]. 

Jonsson AS, Flodin M, Flansson LO, Larsson A. Estimated glomerular filtration rate (eGFR(CystC)) from serum cystatin C shows strong agreement with iohexol clearance in patients with low GFR. Scand J Clin Lab Invest. 2007 9 1 -9. 

Frennby B, Sterner G, Alman T, et al. The use of iohexol clearance to determine GFR in patients with severe chronic renal failure—A comparison 89. 

Most authors define CMIN by an increase of serum creatinine of more than 1 mg/ dl 2-3 days after CM exposure. Other reasons for an acute deterioration of renal function have to be excluded. Some investigators even believe that a lower increase of serum creatinine (0.5 mg/ dl 2-4 days after CM) also should be classified as CMIN. It would also be prudent to look for a fall of GFR (general >25% from basehne) with more sensitive methods (i.e. inuhn clearance, iothahnate clearance, iohexol clearance [7. Next to changes in GFR or serum creatinine levels an increase in urinary enzyme excretion seems to also be a sensitive marker of tubular damage after CM exposure [7, 8]. However, no conclusive relationship has been demonstrated between the detection of enzymes in urine and the fall in GFR [8-11]. 

Aurell M. Accurate and feasible measurements of glomerular filtration rate - is the iohexol clearance the answer. Nephrol Dial Transplant 1994 9 1222-1224. 

Jenkins et al. developed a capillary electrophoresis system for the measurement of iohexol as a marker of the glomerular filtration rate (GFR) with a run time of 5.25 min and a coefficient of variation (CV) of 4.3% at 80 mg L" [121]. The GFR, calculated from the plasma clearance, had a reproducibility of 5.47 %. A similar approach (liquid chromatography-mass spectrometry with positive electrospray ionization after enrichment by solid phase extraction) was applied by Putschew et al. for the determination of iodinated contrast agents in treatment plant effluents and surface waters [118]. 

DNA sequence The nucleotide sequence data are available from the EMBL, GenBank, and DDBJ Nucleotide Sequence Databases under accession number X52255 Half-life About 20 min (experimentally determined for human cystatin C in rat plasma. The similarity in distribution volume and renal clearance between human cystatin C and acknowledged markers of human glomerular filtration, i.e., iohexol and 51 Cr-EDTA, suggests that the substances are eliminated at the same rate in humans with a half-life of approximately 2 h in individuals with normal renal function)... 

Arvidsson A, Hedman A. Plasma and renal clearance of iohexol A study on the reproducibility of a method for the glomerular filtration rate. Scand J Clin Lab Invest 1990 50 757-6. 

Back S-E, Ljungberg B, Nilsson-Ehle I, Borga O, Nilsson-Ehle P. Age dependence of renal function Clearance of iohexol andp-amino hippurate in healthy males. Scand J Clin Lab Invest 1989 641-6. 

Effersoe H, Rosenkilde P, Groth S, et al. Measurement of renal function with iohexol A comparison of iohexol, 99mTc-DTPA and 51Cr-EDTA clearance. Invest Radiol 1990 25 778-82. 

Gaspari F, Perico N, Matalone M, Signorini O, Azzollini N, Mister M, et al. Precision of plasma clearance of iohexol for estimation of GFR in patients with renal disease. J Am Soc Nephrol 1998 9 310-13. 

Gaspari F, Perico N, Ruggenenti P, Mosconi L, Amuchastegui CS, Guerini E, et al. Plasma clearance of nonradioactive iohexol as a measure of glomerular filtration rate. J Am Soc Nephrol 1995 6 257-63. 

BCrutzen E, Back SE, Nilsson-Ehlr I, Nilsson-Ehle P. Plasma clearance of a new contrast agent, iohexol A method for the assessment of glomerular filtration rate. J Lab Clin Med 1984 104 955-61,... 

Iohexol, a nonionic, low osmolar, iodinated contrast agent, has also been nsed for the determination of GFR. It is eliminated almost entirely by glomerular filtration, and plasma and renal clearance valnes... 

ESKD (see Chap. 44), necessitating dialysis or transplantation for survival (see Chaps. 45 and 87). The rate of progression can be slowed and in some cases halted through dietary modification and blood pressure control, angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker therapy, and improved glucose control in patients with type I diabetes mellitus (see Chap. 43). The efficacy of these interventions is optimally assessed with serial measurements of accurate and sensitive indices of GFR such as iohexol, iothalamate, or radioisotope clearances. ... 

The gold standard for measuring GFR is by monitoring the renal clearance of an ideal filtration marker, such as inulin, iothalamate, or iohexol. Renal clearance is calculated as follows ... 

The GFR can be estimated by clearance measurements of endogenous or exogenous small molecules (urea, creatinine, 2-MPT, inulin, cystatin C, iohexol, or iodixanol). An ideal marker of GFR should be primarily excreted by the kidneys, freely filtered by the glomerulus, and neither secreted nor reabsorbed by the tubule. It should also be supplied to the plasma at a constant rate and exhibit no or minimal protein binding. If these criteria are met, such as for inulin, the GFR is equivalent to the renal/urinary clearance of the substance, as defined earlier in this chapter. 

An easy and rapid method with intravenous bolus administration of an iohexol/ PAH mixture in dogs has been developed for simultaneous measurement of GFR and eRPF, based on plasma clearances of both substances (Laroute et al. 1999). 

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