title: Routine determination of GFR in renal transplant recipients by HPLC quantification of plasma iohexol concentrations and comparison with estimated GFR.
abstract: Estimated glomerular filtration rate (eGFR) methods are not sufficiently reliable in renal transplant recipients (RTR) and should be replaced by iohexol plasma clearance measurement. However, this method has poor availability in health centers. The aim of our study was to develop a high-performance liquid chromatography (HPLC) method for plasma iohexol measurement in routine practice and to evaluate its plasma clearance as a reference of GFR. We developed an HPLC method using UV detection. We evaluated sample storage conditions to provide recommendations for routine practice. Then, we compared GFRbased on plasma iohexol clearance (GFR-iohexol) to eGFR using modification of diet in renal disease, Cockcroft and Gault, and CDK-EPIequations in 40 RTR. The method was validated over a concentration range of 15-300 μg/l. Excellent linearity (r > 0.998), inter- and intraday precision (CV < 3.3%), and accuracy (>96.8%) were complied with ICH guidelines. We also demonstrated excellent samples stability (9 days). Although eGFR methods are not references in RTR, we found a correct concordance between eGFR and GFR-iohexol in our population. To conclude, our method is simple, rapid, accurate, and reliable for routine clinical and research use especially in RTR.
authors.affiliation: CHRU de Tours, Laboratoire de Biochimie et Biologie Moléculaire, Tours, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Castagnet
authors.forename: Hélène
authors.initials: H
authors.lastname: Blasco
authors.forename: Patrick
authors.initials: P
authors.lastname: Vourc'h
authors.forename: Isabelle
authors.initials: I
authors.lastname: Benz-De-Bretagne
authors.forename: Charlotte
authors.initials: C
authors.lastname: Veyrat-Durebex
authors.forename: Christelle
authors.initials: C
authors.lastname: Barbet
authors.forename: Azmi
authors.initials: A
authors.lastname: Alnajjar
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Ribourtout
authors.forename: Matthias
authors.initials: M
authors.lastname: Buchler
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Halimi
authors.forename: Christian R
authors.initials: CR
authors.lastname: Andres
mesh_terms: D000328:Adult; D000368:Aged; D001774:Blood Chemical Analysis / Q000379:methods*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004355:Drug Stability; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006801:Humans; D007472:Iohexol / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D016030:Kidney Transplantation; D016014:Linear Models; D008297:Male; D008657:Metabolic Clearance Rate / Q000502:physiology; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D007472:Iohexol