Autotaxin and vascular endothelial growth factor receptor-2 and -3 are related to vascular development during the progression of chronic viral hepatitis C

Serum Autotaxin Levels Predict Liver-Related Events in Patients With Primary Biliary Cholangitis: A Long-Term Multicenter Observational Study

INTRODUCTION

A straightforward, reliable, and noninvasive method for predicting the development of liver-related events (LRE) in primary biliary cholangitis (PBC) has not been attained thus far. This study investigated whether serum autotaxin (ATX) could predict LRE in patients with PBC.

METHODS

This retrospective multicenter investigation included 190 biopsy-proven untreated patients with PBC. All subjects were followed for at least 1 year, during which time the prevalence of LRE, including newly developing hepatocellular carcinoma, esophagogastric varices, ascites, and hepatic encephalopathy, was investigated in relation with ATX levels at the time of liver biopsy.

RESULTS

During the median follow-up period of 9.7 years, LRE were observed in 22 patients (11.6%). The area under the receiver operating characteristic curve and cutoff value of serum ATX for predicting LRE were 0.80 and 1.086 mg/L, respectively. Patients with serum ATX ≥1.086 had a significantly higher cumulative incidence of LRE compared with patients with ATX < 1.086 (33.3% vs 3.6%, P < 0.00001). Notably, the predictive capability of ATX for LRE in patients with PBC surpassed that of FIB-4, ALBI, APRI, and Mac-2-binding protein glycan isomer. A multivariate Cox proportional hazards model revealed ATX as an independent associated factor for LRE (hazard ratio 6.24, 95% confidence interval 1.87-20.80, P = 0.003) along with Nakanuma stage (hazard ratio 2.75, 95% confidence interval 1.52-4.99, P < 0.001). These results were closely replicated in a serologically diagnosed PBC validation cohort (n = 32).

DISCUSSION

Serum ATX levels may serve as a predictive marker for LRE in patients with PBC.

Serum autotaxin is a prognostic indicator of liver-related events in patients with non-alcoholic fatty liver disease

BACKGROUND

Circulating autotaxin (ATX) levels have been reported to correlate with liver inflammation activity and liver fibrosis severity in patients with non-alcoholic fatty liver disease (NAFLD). The objective of this study is to investigate whether serum ATX could predict liver-related events (LRE) in NAFLD patients.

METHODS

This retrospective investigation includes 309 biopsy-proven NAFLD patients registered at Shinshu University Hospital. All patients are followed for at least 1 year, during which time the prevalence of LRE, including newly developing hepatocellular carcinoma, hepatic encephalopathy, ascites, and esophagogastric varices, is investigated in relation to ATX levels at the time of liver biopsy.

RESULTS

During the median follow-up period of 7.0 years, LRE are observed in 20 patients (6.5%). The area under the receiver operating characteristic curve and cut-off value of serum ATX for predicting LRE are 0.81 and 1.227 mg/l, respectively. Multivariate Cox proportional hazards models for LRE determine ATX and advanced fibrosis as independently associated factors. Furthermore, in a competing risk analysis that considered non-liver-related death as a competing event, ATX (HR 2.29, 95% CI 1.22-4.30, p = 0.010) is identified as an independent factor associated with LRE, along with advanced fibrosis (HR 8.01, 95% CI 2.10-30.60, p = 0.002). The predictive utility of ATX for LRE is validated in an independent cohort.

CONCLUSIONS

Serum ATX may serve as a predictive marker for LRE in patients with NAFLD.

Long-term prediction of hepatocellular carcinoma using serum autotaxin levels after antiviral therapy for hepatitis C

INTRODUCTION AND OBJECTIVES

Continuous monitoring for hepatocellular carcinoma is necessary following treatment with direct-acting antivirals in patients with hepatitis C virus infection. We investigated whether the long-term follow-up of serum autotaxin levels could predict the development of hepatocellular carcinoma.

PATIENTS AND METHODS

This prospective observational study enrolled adult patients with chronic hepatitis C virus infection who presented to the study center from January 2016 to March 2021. Among the patients who achieved a sustained viral response, the relationship between the development of hepatocellular carcinoma and serum autotaxin levels was assessed before treatment with direct-acting antivirals; at the end of therapy; at 12 and 24 weeks; and at 12, 24, 36, and 48 months after treatment.

RESULTS

Data were analyzed for 139 patients. Thirteen patients developed hepatocellular carcinoma 48 months after treatment. The cut-off serum autotaxin values that predicted hepatocellular carcinoma after 24 weeks were 1.22 (men) and 1.92 (women) mg/L. The area under the curve for serum autotaxin was 0.83 (95% confidence interval [CI]:0.71-0.95) in men and 0.90 (95% CI: 0.82-0.99) in women. The positive predictive value of serum autotaxin was 0.208 (95% CI: 0.139-0.248), and the negative predictive value was 0.971 (95% CI: 0.939-0.990). The cumulative incidence of hepatocellular carcinoma was significantly higher when serum autotaxin levels were above the cut-off value after 24 weeks (p < 0.0001).

CONCLUSIONS

Serum autotaxin is a candidate biomarker for predicting hepatocellular carcinoma during the long-term follow-up of patients with a sustained viral response following treatment with direct-acting antivirals.

Plasmalemmal Vesicle-Associated Protein Is Associated with Endothelial Cells Sprouting from the Peribiliary Capillary Plexus in Human Cirrhotic Liver

INTRODUCTION

Plasmalemmal vesicle-associated protein (PLVAP) is an endothelial-specific integral membrane glycoprotein that localizes to caveolae and fenestrae in animal models; however, little is known about PLVAP in endothelial cells (ECs) in hepatic sinusoids during liver cirrhosis (LC). Here, we aimed to elucidate PLVAP localization and expression in the human liver during LC progression.

METHODS

PLVAP protein expression was detected in specimens from normal control livers and hepatitis C-related cirrhotic livers using immunohistochemistry, Western blotting, and immunoelectron microscopy.

RESULTS

PLVAP mainly localized to the peribiliary capillary plexus (PCP) and was rarely observed in hepatic artery branches and portal venules in control tissue, but was aberrantly expressed in capillarized sinusoids and proliferated capillaries in fibrotic septa within cirrhotic liver tissue. Ultrastructural analysis indicated that PLVAP localized to thin ECs in some caveolae, whereas PLVAP localized primarily to caveolae-like structures and proliferative sinusoid capillary EC vesicles in cirrhotic liver tissue. Western blot analysis confirmed that PLVAP was overexpressed at the protein level in advanced cirrhotic liver tissue.

CONCLUSION

PLVAP was strongly expressed in the caveolae of proliferated capillaries directly connected with sinusoids linked with the PCP, suggesting that it plays a role in angiogenesis and sinusoidal remodeling in LC.