Analysis of early diagnostic markers for chronic kidney disease

Abstract

Chronic kidney disease (CKD) is a common disorder that cause of death in cats. In the classification proposed by the International Renal Interest Society (IRIS), stage I and II CKD is difficult to diagnose accurately using markers (creatinine and blood urea nitrrogen). The urinary albumin levels in normal control and stage I CKD cats were 6.0±4.5 and 11.2±8.4 mg/dL, respectively, and the urinary transferrin levels were 0.09±0.42 and 0.52±0.79 mg/dL, respectively. Based on ROC curve analysis, the sensitivity and specificity of urinary albumin and urinary transferrin were higher than the plasma creatinine level. Among several candidates, we focused on carboxylesterase 5A fragment which is a 39.2 kDa protein as the most promising biomarker for CKD. To move carboxylesterase 5A fragment toward potential diagnostic use, we developed an enzyme immunoassay that enables the measurement urine carboxylesterase 5A fragment levels. The performance of the ELISA was satisfactory in terms of recovery (96.1–106.4%) and within-run (3.5–5.1%) and between-day (4.8–8.2%) reproducibility.