title: A portable fiberoptic ratiometric fluorescence analyzer provides rapid point-of-care determination of glomerular filtration rate in large animals.
abstract: Measurement of the glomerular filtration rate (GFR) is the gold standard for precise assessment of kidney function. A rapid, point-of-care determination of the GFR may provide advantages in the clinical setting over currently available assays. Here we demonstrate a proof of principle for such an approach in a pig and dogs, two species that approximate the vascular access and GFR results expected in humans. In both animal models, a sub-millimeter optical fiber that delivered excitation light and collected fluorescent emissions was inserted into a peripheral vein (dog) or central venous access (pig) by means of commercial intravenous catheters. A mixture of fluorescent chimeras of a small freely filterable reporter and large non-filterable plasma volume marker were infused as a bolus, excited by light-emitting diodes, and the in vivo signals detected and quantified by photomultiplier tubes in both species in less than 60 min. Concurrent standardized 6-h iohexol plasma kidney clearances validated the accuracy of our results for both physiologic and a chronic kidney disease setting. Thus, our ratiometric technique allows for both measurement of plasma vascular volume and highly accurate real-time GFR determinations, enabling clinical decision making in real time.
authors: Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Indiana Center for Biological Microscopy, Indianapolis, Indiana 46202, USA.
authors: Exing
authors: E
authors: Wang
authors: Daniel J
authors: DJ
authors: Meier
authors: Ruben M
authors: RM
authors: Sandoval
authors: Vanessa E
authors: VE
authors: Von Hendy-Willson
authors: Barrak M
authors: BM
authors: Pressler
authors: Robert M
authors: RM
authors: Bunch
authors: Mouhamad
authors: M
authors: Alloosh
authors: Michael S
authors: MS
authors: Sturek
authors: George J
authors: GJ
authors: Schwartz
authors: Bruce A
authors: BA
authors: Molitoris
mesh_terms: D000818:Animals; D004285:Dogs; D004867:Equipment Design; D005456:Fluorescent Dyes; D005919:Glomerular Filtration Rate; D007472:Iohexol; D007677:Kidney Function Tests / Q000295:instrumentation / Q000662:veterinary*; D055100:Optical Fibers; D019095:Point-of-Care Systems; D011874:Radiometry / Q000295:instrumentation / Q000662:veterinary; D013552:Swine
chemical_list: D005456:Fluorescent Dyes; D007472:Iohexol