Serum paraoxonase-1 as biomarker for improved diagnosis of fatty liver in dairy cows

Abstract

BackgroundFatty liver is a major metabolic disorder in dairy cows and is believed to result in major economic losses in dairy farming due to decreased health status, reproductive performance and fertility. Currently, the definitive means for diagnosing fatty liver is determining the fat content of hepatic tissue by liver biopsy, which is an invasive and costly procedure, making it poorly suited to dairy farms. Therefore, the key aim of this study was to investigate the measurement of serum paraoxonase-1 (PON1), an enzyme exclusively synthesized by the liver, as a sensitive noninvasive biomarker for diagnosis of fatty liver in dairy cows.ResultsA comparative cohort study using serum specimens from Holstein–Friesian dairy cows (46 healthy and 46 fatty liver cases) was conducted. Serum PON1 (paraoxonase, lactonase and arylesterase) activity and other biochemical and hematological parameters were measured. We found that serum PON1 activity was lower (P<0.001) in cows suffering from fatty liver. The area under the receiver operating characteristic curve (AUC-ROC) of PON1 activity for diagnosis of fatty liver was 0.973–0.989 [95% confidence interval (CI) 0.941, 1.000] which was higher than the AUC-ROC of aspartate aminotransferase (AST), lecithin-cholesterol acyltransferase (LCAT), alkaline phosphatase (ALP), non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA), total cholesterol, high-density lipoprotein (HDL) and low-density lipoprotein (LDL). We found that adding serum PON1 measurement to different batteries of serum diagnostic panels showed a combination of high sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (+LR), negative likelihood ratio (−LR), diagnostic odd ratio (DOR) and overall diagnostic accuracy in diagnosing fatty liver.ConclusionsThe present results indicate that addition of serum PON1 activity measurement to the biochemical profile could improve the diagnosis of fatty liver in dairy cows, which would have a considerable clinical impact and lead to greater profitability in the dairy industry.

Serum paraoxonase 1 (PON1) measurement: an update

“…This could explain the high correlation when using phenyl acetate and TBBL observed in human studies [50], bovine [51] and dog [48]. In this later study in dogs, TBBL, phenyl acetate and 4-nitrophenyl acetate showed significant correlations with r higher than 0.85 in all cases.…”

Relationship of vaginal discharge characteristics evaluated by Metricheck device to metabolic status in postpartum dairy cows

“…Furthermore, cows with endometritis exhibited higher AST activity and lower Alb concentration, possibly indicating hepatic dysfunction (Bertoni, Trevisi, Han, & Bionaz, ; Swarup et al, ). Cows with fatty liver show higher AST activity and lower Alb concentration as well as higher blood NEFA and BHBA concentrations in blood compared with healthy cows (Farid, Honkawa, Fath, Nonaka, & Horii, ). Hepatic dysfunction in cows with endometritis of the present study may be a result of greater fat mobilization.…”

A review of paraoxonase 1 properties and diagnostic applications

“…This conversion via LCAT leads to HDL core formation (Gan et al 1991). Serum PON1 activity significantly decreases shortly after parturition in comparison to non-pregnant cows (Turk et al 2004) and its depletion is seen in dairy cow fatty liver syndrome (Farid et al 2013).…”