The effect of feeding, storage and anticoagulant on feline serum cystatin C.
Serum cystatin C (sCysC) is a possible marker for early detection of chronic kidney disease (CKD) in cats. In contrast with serum creatinine (sCr), feline sCysC is not affected by age, breed or sex. However, further biological and clinical validation is required. The objectives of this study were: (1) to investigate if food intake and circadian rhythm affect feline sCysC; (2) to determine the stability of sCysC under different storage conditions, and (3) to investigate if plasma concentrations of CysC (pCysC) differed from sCysC. A crossover study with 10 healthy laboratory cats fed the same commercial dry food was performed to study the influence of feeding and diurnal variation. Storage effects and comparison of pCysC with sCysC were determined using healthy cats (n = 3 and n = 10, respectively) and cats with CKD (n= 4 and n = 17, respectively). A significant daily sCysC variation was seen. Pre- and postprandial sCysC and sCr concentrations did not change significantly. Serum CysC significantly increased during storage at room temperature. After freezing, sCysC significantly decreased after 5 and 12 months at both -20 °C and -72 °C. Plasma CysC was significantly lower than sCysC. These findings suggest that it is not mandatory to fast cats before evaluation of sCysC and sCr. Samples were stable during routinely used storage conditions. Based on these findings, freezing for more than 5 months is not recommended, although additional studies are required to evaluate the clinical relevance of decreased sCysC after prolonged storage. Plasma and serum CysC cannot be compared directly.
Department of Medicine and Clinical Biology of Small Animals, Faculty of Veterinary Medicine, Ghent University, 133 Salisburylaan, B-9820 Merelbeke, Belgium. Electronic address: Liesbeth.Ghys@Ugent.be.
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Ghys
Department of Medicine and Clinical Biology of Small Animals, Faculty of Veterinary Medicine, Ghent University, 133 Salisburylaan, B-9820 Merelbeke, Belgium.
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Paepe
Department of Clinical Sciences and UMR 181 de Physiopathologie et Toxicologie Expérimentales INRA/ENVT, École Nationale Vétérinaire de Toulouse, 23 Chemin des Capelles, BP 87614, F-31076 Toulouse Cedex 3, France.
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Lefebvre
Department of Medicine and Clinical Biology of Small Animals, Faculty of Veterinary Medicine, Ghent University, 133 Salisburylaan, B-9820 Merelbeke, Belgium.
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Taffin
Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, 19 Heidestraat, B-9820 Merelbeke, Belgium.
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Hesta
Department of Clinical Chemistry, Microbiology and Immunology, Faculty of Health Medicine and Life Sciences, Ghent University, 185 De Pintelaan, B-9000 Gent, Belgium.
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Delanghe
Department of Medicine and Clinical Biology of Small Animals, Faculty of Veterinary Medicine, Ghent University, 133 Salisburylaan, B-9820 Merelbeke, Belgium.
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Smets
Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, 19 Heidestraat, B-9820 Merelbeke, Belgium.
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Vandendriessche
Department of Medicine and Clinical Biology of Small Animals, Faculty of Veterinary Medicine, Ghent University, 133 Salisburylaan, B-9820 Merelbeke, Belgium.
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Daminet
D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D000925:Anticoagulants / Q000494:pharmacology*; D015415:Biomarkers; D001800:Blood Specimen Collection / Q000662:veterinary*; D002415:Cats; D018592:Cross-Over Studies; D055316:Cystatin C / Q000097:blood* / Q000737:chemistry; D005260:Female; D008297:Male
D000925:Anticoagulants; D015415:Biomarkers; D055316:Cystatin C
Cat; Chronic kidney disease; Meal; Plasma; Serum; Temperature