Value of Two-Dimensional Shear Wave Elastography for Assessing Acute Liver Congestion in a Bama Mini-Pig Model

A thioacetamide-induced liver fibrosis model for pre-clinical studies in microminipig

Drug-induced liver fibrosis models are used in normal and immunosuppressed small animals for transplantation and regenerative medicine to improve liver fibrosis. Although large animal models are needed for pre-clinical studies, they are yet to be established owing to drug sensitivity in animal species and difficulty in setting doses. In this study, we evaluated liver fibrosis by administering thioacetamide (TA) to normal microminipig and thymectomized microminipig; 3 times for 1 week (total duration: 8 weeks). The pigs treated with TA showed elevated blood cytokine levels and a continuous liver injury at 8 weeks. RNA-seq of the liver showed increased expression of fibrosis-related genes after TA treatment. Histopathological examination showed degenerative necrosis of hepatocytes around the central vein, and revealed fibrogenesis and hepatocyte proliferation. TA treatment caused CD3-positive T cells and macrophages scattered within the hepatic lobule to congregate near the center of the lobule and increased αSMA-positive cells. Thymectomized pigs showed liver fibrosis similar to that of normal pigs, although the clinical signs tended to be milder. This model is similar to pathogenesis of liver fibrosis reported in other animal models. Therefore, it is expected to contribute to research as a drug discovery and pre-clinical transplantation models.

Pre-operative Detection of Liver Fibrosis in Hepatocellular Carcinoma Patients Using 2D Shear Wave Elastography: Where to Measure?

The aim of this study was to pre-operatively investigate the diagnostic performance of 2D shear wave elastography (2D-SWE) for staging liver fibrosis and inflammation in patients with hepatocellular carcinoma (HCC) who then undergo surgery and to determine the optimal locations for measurement. In total, 106 patients were enrolled in this prospective study from March 2017 to May 2018. Two-dimensional SWE was used to measure liver stiffness (LS) in each patient 0-1, 1-2 and 2-5 cm from the tumor border (groups 1, 2 and 3, respectively). Spearman's correlation was used to evaluate the relationships between LS and hepatic fibrosis and between LS and inflammation. Receiver operating characteristic curve (ROC) analysis was used to evaluate the diagnostic accuracy of 2D-SWE. The technical success rate of SWE in tissue distant from the tumor (group 3) was significantly higher than that in peri-tumoral tissue (groups 1 and 2) (p < 0.001). Moreover, the area under the ROC for diagnosing cirrhosis (F4) and severe inflammation (A3) was higher for group 3 than for groups 1 and 2. Our results suggest that 2D-SWE is a helpful approach to assessment of hepatic fibrosis in HCC patients before hepatic resection. We found that to achieve a superior success rate and preferable diagnosis accuracy for patients with HCC, LS measurement should be performed 2-5 cm from the tumor margin.

The Importance of Transaminases Flare in Liver Elastography: Characterization of the Probability of Liver Fibrosis Overestimation by Hepatitis C Virus-Induced Cytolysis

BACKGROUND

Liver stiffness measurement (LSM) is crucial for appropriate fibrosis staging in patients with ongoing hepatitis C virus (HCV) infection. However, there is still an ongoing debate on the impact of serum transaminases (aspartate-aminotransferase, AST; alanine-aminotransferase, ALT) on LSM.

METHODS

We selected 110 patients undergoing HCV eradication therapy with LSM compatible with significant liver fibrosis. LSM was evaluated prior to therapy and one year after HCV eradication.

RESULTS

LSM showed a median decrease of 35% from baseline values, and 67 (61%) patients showed posttreatment values compatible with lower fibrosis stages. We developed two logistic regression models to determine the probability of liver fibrosis overestimation according to serum transaminase. The probability of overestimation of two or more fibrosis grade is equal to (1) 50% for AST of 99 IU/L (2.2 ULN) and ALT of 90.5 IU/L (2 ULN), (2) 80% for AST of 123.5 IU/L (2.74 ULN) and ALT of 101.5 IU/L (2.25 ULN), and (3) reaches 100% for AST of 211 IU/L (4.7 ULN) and ALT of 140 IU/L (3.1 ULN).

CONCLUSIONS

This study highlights the impact of serum transaminases on LSM. We believe that our findings may serve as a reference point for appropriate fibrosis stratification by liver elastography in patients with HCV infection.