Ghys Liesbeth F E, Meyer Evelyne, Paepe Dominique, Delanghe Joris, Daminet Sylvie
Department of Medicine and Clinical Biology of Small Animals, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
Vet Clin Pathol. 2014 Jun;43(2):226-34. doi: 10.1111/vcp.12144. Epub 2014 Apr 28.
In people and dogs, Cystatin C (CysC), a renal glomerular and tubular marker, seems superior to serum creatinine to estimate the glomerular filtration rate (GFR). A particle-enhanced nephelometric immunoassay is available to measure human CysC, but there are no reports in cats.
The goal of this study was the validation of the human CysC nephelometric assay with feline serum and urine, and to perform a pilot study comparing serum and urine CysC between healthy cats and cats with chronic kidney disease (CKD).
Western blot analysis was used to assess cross-reactivity between the polyclonal rabbit anti-human CysC antibody and feline CysC. Imprecision and linearity were determined for feline serum and urine CysC. Serum and urine CysC were measured in 10 healthy and 10 CKD cats.
Cross-reactivity between the polyclonal rabbit anti-human CysC antibody and feline CysC was demonstrated. Intra- and inter-assay coefficients of variation in feline serum and urine were 1.3% and 0.4%, and 12.5%, and 4.1%, respectively. Cats with CKD had a significantly higher serum CysC concentration (1.24 [0.63-2.99] vs 0.79 [0.43-1.05] mg/L; P = .02) and urine CysC/urinary Creatinine (uCr) ratio (565.6 [0-1311] vs < 0.049/uCr mg/mol; P = .005) compared with healthy cats.
The human nephelometric assay showed satisfactory validation results for feline CysC. Cats with CKD had a significantly higher sCysC concentration and uCysC/uCr ratio compared with healthy cats. Additional studies are necessary to evaluate CysC as an early marker of renal damage in cats.
在人和犬中，作为肾小球和肾小管标志物的胱抑素C（CysC）在估算肾小球滤过率（GFR）方面似乎优于血清肌酐。有一种颗粒增强散射比浊免疫分析法可用于检测人CysC，但在猫中尚无相关报道。
本研究的目的是验证人CysC散射比浊法在猫血清和尿液中的应用，并进行一项初步研究，比较健康猫和慢性肾病（CKD）猫的血清和尿液CysC。
采用蛋白质印迹分析评估兔抗人CysC多克隆抗体与猫CysC之间的交叉反应性。测定猫血清和尿液CysC的不精密度和线性。对10只健康猫和10只CKD猫进行血清和尿液CysC检测。
证实兔抗人CysC多克隆抗体与猫CysC之间存在交叉反应性。猫血清和尿液的批内和批间变异系数分别为1.3%和0.4%，以及12.5%和4.1%。与健康猫相比，CKD猫的血清CysC浓度显著更高（1.24 [0.63 - 2.99] 对 0.79 [0.43 - 1.05] mg/L；P = .02），尿液CysC/尿肌酐（uCr）比值也显著更高（565.6 [0 - 1311] 对 < 0.049/uCr mg/mol；P = .005）。
人散射比浊法对猫CysC的验证结果令人满意。与健康猫相比，CKD猫的血清CysC浓度和尿液CysC/uCr比值显著更高。需要进一步研究以评估CysC作为猫肾损伤早期标志物的价值。
