Variation in fat content between liver lobes and comparison with histopathological scores in dairy cows with fatty liver

Abstract

BackgroundThe assessment of a liver biopsy remains the gold standard for diagnosing and staging fatty liver in dairy cows, which is often necessary for diagnostic and research purposes. Accuracy of the diagnosis relays on the quality of the biopsy, the assumed representativeness of a small tissue sample for a disease process throughout the liver and accurate human evaluation of histologic specimens. The objective of the present study was to assess the distribution of triacylglycerol (TAG) infiltration throughout the parenchyma of livers with different degrees of fatty liver in dairy cows. In addition, histopathological scores from the corresponding specimens were compared to a quantitative measurement of TAG, as well as the agreement between two observers.MethodsThirty livers with different degrees of lipid infiltration were selected and 10 different locations throughout the liver were assessed. The TAG content was measured enzymatically, calculated in % or mg/g wet weight, and assigned to a scoring system. Corresponding tissue specimens were stained with hematoxylin-eosin (H&E) and Oil red O (ORO) for histopathological evaluation, using a scoring system.ResultsThe difference in TAG content between any locations was less than 2%. Based on the scoring system the TAG concentration was even distributed in 79.3% of the livers. Based on kappa statistics the agreement between two pathologists and staining technique in scoring histological specimens was moderate to fair.ConclusionsOverall the distribution of TAG throughout the liver and the accuracy of human evaluation of liver biopsies may lead to acceptable diagnoses for clinical purposes. Within the liver lobules a common pattern of lipid distribution depending on severity could be observed. For the staging of lipid infiltration for research projects, some degree of variation needs to be considered.

Transient elastography: a novel, non-invasive method for the evaluation of liver stiffness and controlled attenuation parameter in cows

“…Hepatic lipidosis is reportedly reversible and neither inflammation nor fibrosis are usually seen in cattle [10]. The cows used in this study did not have liver fibrosis or fatty liver and there was no difference in liver stiffness.…”

“…Liver function tests for cows that are currently in general use include blood biochemical analysis [1,26,27], clearance tests for foreign substances such as bromosulfophthalein (BSP) [14] and indocyanine green (ICG) [19,24], liver biopsy [1,10,12,26], and ultrasound examination [1,26].…”

“…Liver biopsy is considered to be the most reliable method of evaluating fibrosis or fatty changes in the liver [10,12,26]; however, the procedure is highly invasive and can lead to complications [28]. A previous study had reported that the incidence of complications associated with liver biopsy in human medicine is 1-5%, and the mortality rate from complications of liver biopsy is 0-0.4% [20].…”

Anti-Inflammatory and Antioxidant Effects of Regular Consumption of Cooked Ham Enriched with Dietary Phenolics in Diet-Induced Obese Mice

“…Adipose tissue directly correlated with the presence of inflammatory biomarkers such as IL-6 and TNF-α [ 41 , 42 ]. Variation in lipid infiltration in liver also showed the effectiveness of high-fat diets inducing obesity [ 43 ]…”

Diagnostic performance of cytology for assessment of hepatic lipid content in dairy cattle

“…This can be avoided by using proper technique but may require practice in the hands of a novice. In a study aimed at evaluating the variability in severity of lipid accumulation across the liver parenchyma, a difference of less than 2% in [TG] was found between any of 10 sites sampled in the same liver (Gerspach et al, 2017). Another limitation of the study was that temperature extremes of the regional climate might have affected the BHB values: samples were collected over the winter when the average regional temperature is −4°C.…”