Abstract
Background
Measurement of glomerular filtration rate by iohexol disappearance (iGFR) has become a gold standard in the pediatric chronic kidney disease (CKD) population. The need for serial phlebotomy can be difficult and minimizing venipunctures would be beneficial. Furthermore, finger stick collection for dried blood spot (DBS) may be more tolerable in the pediatric population, and equivalence between these two methods may further simplify the process.
Methods
This was a cross-sectional study in children and adolescents 1 to 21 years with stages I–IV CKD. Iohexol was infused and blood drawn 10, 30, 120, and 300 min later. Blood spots on filter paper were collected by finger stick after each of the latter two blood draws. The rate of iohexol plasma disappearance was used to calculate GFR. Pearson’s correlation coefficient and bias, Students t test, and Bland-Altman graphical representations were used to compare methods.
Results
Forty-one patients were recruited. The mean creatinine was 1.13 mg/dL (SD 0.45), the mean 4-point iGFR was 73.2 ml/min/1.73m2 (SD 27.5) and the mean 2-point iGFR was 75.6 ml/min/1.73m2 (SD 27.3). Correlation between 2-point and 4-point venous GFR was r = 0.97; p < 0.001. The correlation between the DBS and the 2-point venous GFR was r = 0.95; p < 0.001, with no significant bias. Ninety-four percent of the 2-point GFR’s were within 10% of the 4-point GFR’s and 80% of DBS-GFRs were within 10% of the 2-point GFR’s.
Conclusions
The 2-point iGFR was highly correlated and agreed well with the 4-point iGFR. The same was true for the DBS method and the 2-point venous method. DBS sampling by finger stick sampling at 2 time points after iohexol infusion gave an acceptably accurate measurement of GFR.
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References
Schwartz GJ, Furth S, Cole SR, Warady B, Munoz A (2006) Glomerular filtration rate via plasma iohexol disappearance: pilot study for chronic kidney disease in children. Kidney Int 69(11):2070–2077. https://doi.org/10.1038/sj.ki.5000385
Back SE, Krutzen E, Nilsson-Ehle P (1988) Contrast media as markers for glomerular filtration: a pharmacokinetic comparison of four agents. Scand J Clin Lab Invest 48(3):247–253
Olsson B, Aulie A, Sveen K, Andrew E (1983) Human pharmacokinetics of iohexol. A new nonionic contrast medium. Investig Radiol 18(2):177–182
Ng DK, Schwartz GJ, Jacobson LP, Palella FJ, Margolick JB, Warady BA, Furth SL, Munoz A (2011) Universal GFR determination based on two time points during plasma iohexol disappearance. Kidney Int 80(4):423–430. https://doi.org/10.1038/ki.2011.155
Niculescu-Duvaz I, D'Mello L, Maan Z, Barron JL, Newman DJ, Dockrell ME, Kwan JT (2006) Development of an outpatient finger-prick glomerular filtration rate procedure suitable for epidemiological studies. Kidney Int 69(7):1272–1275. https://doi.org/10.1038/sj.ki.5000240
Krutzen E, Back SE, Nilsson-Ehle P (1990) Determination of glomerular filtration rate using iohexol clearance and capillary sampling. Scand J Clin Lab Invest 50(3):279–283
Silkalns GI, Jeck D, Earon J, Edelmann CM Jr, Chervu LR, Blaufox MD, Spitzer A (1973) Simultaneous measurement of glomerular filtration rate and renal plasma flow using plasma disappearance curves. J Pediatr 83(5):749–757
Haycock GB, Schwartz GJ, Wisotsky DH (1978) Geometric method for measuring body surface area: a height-weight formula validated in infants, children, and adults. J Pediatr 93(1):62–66
Schwartz GJ, Munoz A, Schneider MF, Mak RH, Kaskel F, Warady BA, Furth SL (2009) New equations to estimate GFR in children with CKD. J Am Soc Nephrol 20(3):629–637. https://doi.org/10.1681/ASN.2008030287
Salvador CL, Tondel C, Morkrid L, Bjerre A, Brun A, Bolann B, Brackman D, Bergan S (2015) Glomerular filtration rate measured by iohexol clearance: a comparison of venous samples and capillary blood spots. Scand J Clin Lab Invest 75(8):710–716. https://doi.org/10.3109/00365513.2015.1091091
Delanaye P, Flamant M, Dubourg L, Vidal-Petiot E, Lemoine S, Cavalier E, Schaeffner E, Ebert N, Pottel H (2018) Single- versus multiple-sample method to measure glomerular filtration rate. Nephrol Dial Transplant. https://doi.org/10.1093/ndt/gfx345
Luis-Lima S, Gaspari F, Negrin-Mena N, Carrara F, Diaz-Martin L, Jimenez-Sosa A, Gonzalez-Rinne F, Torres A, Porrini E (2017) Iohexol plasma clearance simplified by dried blood spot testing. Nephrol Dial Transplant. https://doi.org/10.1093/ndt/gfx323
Acknowledgments
We would like to acknowledge Ms. Paula Maier for her invaluable assistance with data management.
Funding
There were three sites that contributed subjects to the study. The University of New Mexico site was supported by an intramural grant awarded to AS by the UNM Department of Pediatrics and a CTSC grant (UL1TR001449). The University of Rochester site and all the biochemical assays were supported by funds for the Central Biochemistry Laboratory of the CKiD consortium (U01-DK82194). CW receives additional funding from the CKiD consortium (U01-DK066143).
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The study was approved by the Institutional Review Boards of each of the participating centers. Informed consent was obtained from all participants in the study.
Conflicts of interest
The authors declare that they have no conflicts of interest. Preliminary results were presented in abstract form at the 16th Congress of the International Pediatric Nephrology Association, September 2013, in Shanghai, China.
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Staples, A., Wong, C. & Schwartz, G.J. Iohexol-measured glomerular filtration rate in children and adolescents with chronic kidney disease: a pilot study comparing venous and finger stick methods. Pediatr Nephrol 34, 459–464 (2019). https://doi.org/10.1007/s00467-018-4110-4
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DOI: https://doi.org/10.1007/s00467-018-4110-4