Changes in serum levels of autotaxin with direct-acting antiviral therapy in patients with chronic hepatitis C

Rising Lysophosphatidylcholine Levels Post-Hepatitis C Clearance

Hepatitis C virus (HCV) infection alters lysophosphatidylcholine (LPC) metabolism, enhancing viral infectivity and replication. Direct-acting antivirals (DAAs) effectively treat HCV and rapidly normalize serum cholesterol. In serum, LPC species are primarily albumin-bound but are also present in lipoprotein particles. This study aims to assess the impact of HCV eradication on serum LPC species levels in patients infected with HCV. Therefore, 12 different LPC species were measured by electrospray ionization tandem mass spectrometry (ESI-MS/MS) in the sera of 178 patients with chronic HCV infections at baseline, and in 176 of these patients after therapy with DAAs. All LPC species increased at 4 and 12 weeks post-initiation of DAA therapy. The serum profiles of the LPC species were similar before and after the viral cure. Patients with HCV and liver cirrhosis exhibited lower serum levels of all LPC species, except LPC 16:1, both before and after DAA treatment. Percentages of LPC 18:1 (relative to the total LPC level) were higher, and % LPC 22:5 and 22:6 were lower in cirrhotic compared to non-cirrhotic patients at baseline and at the end of therapy. LPC species levels inversely correlated with the model of end-stage liver disease score and directly with baseline and post-therapy albumin levels. Receiver operating characteristic curve analysis indicated an area under the curve of 0.773 and 0.720 for % LPC 18:1 (relative to total LPC levels) for classifying fibrosis at baseline and post-therapy, respectively. In summary, HCV elimination was found to increase all LPC species and elevated LPC 18:1 relative to total LPC levels may have pathological significance in HCV-related liver cirrhosis.

A Diagnostic Impact of Serum Autotaxin Levels in Patients with Bone Marrow Fibrosis

BACKGROUND

Bone marrow (BM) fibrosis is a condition characterized by deposition of reticulin and collagen fibers in BM. It may confer a poor prognosis in some of hematological malignancies. However, the relationship between fibrosis and the disease pathology is not fully understood and no biomarkers for BM fibrosis are available in clinical practice. Autotaxin (ATX) is a secreted enzyme that is associated with various pathophysiological responses, including fibrosis. We conducted a pilot study to investigate the serum ATX levels in various hematological disorders in patients with or without BM fibrosis.

PATIENTS AND METHODS

The serum levels of ATX in a total of 198 patients with hematological disorders and 160 healthy subjects were analyzed. Because of sexual difference in ATX level, the ATX ratio-determined by dividing the ATX level by the mean value of ATX of control subjects of the same sex-was calculated for further comparative analysis. A trephine biopsy samples from 53 patients were also evaluated to determine the Reticulin Fibrosis Index and Collagen Fibrosis Index of each sample.

RESULTS

In comparison to the control group, the ATX ratio was significantly higher in patients, especially those with malignant lymphoma. The ATX ratio in lymphoma patients with BM fibrosis was significantly higher than that in patients without BM fibrosis. The Collagen Fibrosis Index showed statistically significant negative correlation with the ATX ratio.

CONCLUSION

Our results suggest that the ATX ratio may be a candidate diagnostic biomarker for BM fibrosis in selected patients, including those with malignant lymphoma.

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.

Enhanced liver fibrosis score as a predictive marker for hepatocellular carcinoma development after hepatitis C virus eradication

Advanced liver fibrosis is the most important risk factor for hepatocellular carcinoma (HCC) development after achieving sustained virological response (SVR) by direct-acting antiviral (DAA) treatment in patients with chronic hepatitis C. Wisteria floribunda agglutinin-positive Mac-2-binding protein (M2BPGi), enhanced liver fibrosis (ELF) score, type IV collagen and fibrosis-4 (FIB-4) index have been reported as non-invasive biomarkers for liver fibrosis. In the present study, the possibility of using fibrosis biomarkers and other parameters to predict the development of HCC was evaluated. A total of 743 patients infected with hepatitis C virus who achieved SVR by using DAA were retrospectively enrolled. Of these, 122 patients whose blood samples were stored were selected. The aforementioned four fibrosis biomarkers were analyzed at baseline, at the end of treatment (EOT) and at post-treatment week 24 (PTW24). Tumor markers and laboratory tests were also analyzed. The baseline/EOT/PTW24 values for each fibrosis biomarker were as follows: ELF score: 11.5±1.2/10.8±1.1/10.4±1.0; type IV collagen: 213±85/190±67/174±55 ng/ml; M2BPGi: 4.8±3.5/2.7±2.0/2.2±1.8; and FIB-4 index: 5.31±3.82/4.36± 2.79/4.24±3.09. Of the 122 patients, 23 developed HCC. A high baseline ELF score (P=0.0264), PTW24 ELF score (P=0.0003), PTW24 α-fetoprotein level (P=0.0133), baseline FIB-4 index (P=0.0451) and low baseline prothrombin time (P=0.0455) were risk factors for HCC development based on univariate analyses. Based on the multivariate analysis, a high PTW24 ELF score was the only risk factor for HCC development (P=0.0035). The ELF score after DAA therapy was strongly associated with HCC development; therefore, it may be a useful marker for predicting HCC.

Hepatitis C Virus (HCV) Direct-Acting Antiviral Therapy in Persons With Human Immunodeficiency Virus-HCV Genotype 1 Coinfection Resulting in High Rate of Sustained Virologic Response and Variable in Normalization of Soluble Markers of Immune Activation

BACKGROUND

Hepatitis C virus (HCV) direct-acting antivirals are highly effective. Less is known about changes in markers of immune activation in persons with human immunodeficiency virus (HIV) in whom a sustained virologic response (SVR) is achieved.

METHODS

We conducted a nonrandomized clinical trial of 12 or 24 weeks of paritaprevir-ritonavir-ombitasvir plus dasabuvir (PrOD) with or without ribavirin in persons with HCV-1/HIV coinfection suppressed with antiretroviral therapy. Plasma HCV, soluble CD14 (sCD14), interferon-inducible protein 10, soluble CD163 (sCD163), interleukin 6 (IL-6), interleukin 18, monocyte chemoattractant protein (MCP-1), autotaxin (ATX), and Mac2-binding protein (Mac2BP) were measured over 48 weeks.

RESULTS

Participants were treated with PrOD for 12 (n = 9) or 24 (n = 36) weeks; the SVR rate at 12 weeks was 93%. At baseline, cirrhosis was associated with higher ATX and MCP-1, female sex with higher ATX and IL-6, older age with higher Mac2BP, higher body mass index with higher ATX, and HIV-1 protease inhibitor use with higher sCD14 levels. In those with SVR, interferon-inducible protein 10, ATX, and Mac2BP levels declined by week 2, interleukin 18 levels declined by the end of treatment, sCD14 levels did not change, and sCD163, MCP-1, and IL-6 levels changed at a single time point.

CONCLUSIONS

During HIV/HCV coinfection, plasma immune activation marker heterogeneity is in part attributable to age, sex, cirrhosis, body mass index, and/or type of antiretroviral therapy. HCV treatment with paritaprevir-ritonavir-ombitasvir plus dasabuvir is highly effective and is associated with variable rate and magnitude of decline in markers of immune activation.

CLINICAL TRIALS REGISTRATION

NCT02194998.

Association of serum autotaxin levels with liver fibrosis in patients pretreatment and posttreatment with chronic hepatitis C

BACKGROUND AND AIM

The evaluation of liver fibrosis in patients with chronic hepatitis C virus (HCV) infection is important as it is a risk factor for hepatocellular carcinoma. In the recent years, autotaxin (ATX) has been established as a new noninvasive biomarker to predict liver fibrosis. However, antiviral treatment has been reported to decrease serum ATX, but it is unclear whether posttreatment ATX levels reflect liver fibrosis. In the present study, the correlation between ATX and liver fibrosis in pretreatment and posttreatment patients with HCV infection was analyzed.

METHODS

A total of 199 samples from 136 patients with HCV infection who had undergone hepatic biopsy before and/or after antiviral treatment at Osaka City University Hospital were used. Posttreatment patients included 38 interferon-treated patients and 80 interferon-free direct-acting antiviral-treated patients; all patients achieved a sustained virological response (SVR). Serum ATX levels were determined by enzyme immunoassay with an AIA-2000 analyzer.

RESULTS

Serum ATX levels were largely correlated with liver fibrosis stage in patients with HCV infection before and after antiviral treatment. The measured values decreased even in similar liver fibrosis stages after treatment. The area under the receiver operating characteristic curve for the ability of ATX to diagnose above F2 stage before treatment was 0.81 (both male and female) and that after achieving SVR, it was 0.71 (male) and 0.72 (female).

CONCLUSIONS

Serum ATX levels were correlated with histological liver fibrosis stage after achieving SVR. However, separate cutoff values before and after antiviral therapy should be established.

The impact of achieving a sustained virological response with direct-acting antivirals on serum autotaxin levels in chronic hepatitis C patients

Background

Autotaxin (ATX) is an emerging biomarker for liver fibrosis. Achievement of sustained virological response (SVR) by direct-acting antivirals (DAAs) results in hepatic fibrosis regression in chronic hepatitis C (CHC) patients. In this context, the clinical implications of ATX have not yet been well-defined. In this study, we aimed to assess the impact of achieving SVR with DAA therapy on serum ATX levels and whether these levels can reflect the regression of hepatic fibrosis in CHC patients. We evaluated serum ATX levels at baseline and 12 weeks post-DAA therapy in 48 CHC patients. We compared ATX with FIB4 score and AST-to-Platelet Ratio Index (APRI) as regards the detection of grade F3–4 fibrosis.

Results

Serum ATX levels were significantly declined in 47 patients after the achievement of SVR12 (p < 0.001). The diagnostic ability of ATX for the detection of grade F3–4 fibrosis was inferior to FIB4 and APRI scores at baseline and SVR12.

Conclusion

Achievement of SVR with DAA therapy causes a significant decline in serum autotaxin concentrations, suggesting early regression of hepatic fibrosis in CHC patients. However, its diagnostic capability for routine patient monitoring and follow-up is still under debate.

Post-Treatment M2BPGi Level and the Rate of Autotaxin Reduction are Predictive of Hepatocellular Carcinoma Development after Antiviral Therapy in Patients with Chronic Hepatitis C

Patients with chronic hepatitis C virus (HCV) develop hepatocellular carcinoma (HCC) regardless of achieving a sustained viral response (SVR). Because advanced liver fibrosis is a powerful risk factor for HCC, we analyzed the association between autotaxin (ATX), a liver fibrosis marker, and post-SVR HCC development within 3 years after antiviral treatment. We included 670 patients with HCV who received direct-acting antivirals, achieved SVR and were followed up for at least 6 months (270 of them were followed up for 3 years or more). We measured serum ATX levels before treatment and 12/24 weeks after treatment. The diagnosis of HCC was based on imaging modalities, such as dynamic computed tomography and dynamic magnetic resonance imaging and/or liver biopsy. The present study revealed that high levels of serum ATX predicted post-SVR HCC development (area under the receiver operating characteristic: 0.70-0.76). However, Wisteria floribunda agglutinin positive Mac-2 binding protein (M2BPGi), another liver fibrosis marker, was a more useful predictive marker especially post-treatment according to a multivariate analysis. Patients with a high rate of ATX reduction before and after antiviral treatment did not develop HCC regardless of high pretreatment ATX levels. In conclusion, post-treatment M2BPGi level and the combination of pretreatment ATX levels and rate of ATX reduction were useful predictive markers for post-SVR HCC development in patients with chronic HCV infection.

Elevated Autotaxin and LPA Levels During Chronic Viral Hepatitis and Hepatocellular Carcinoma Associate with Systemic Immune Activation

Circulating autotaxin (ATX) is elevated in persons with liver disease, particularly in the setting of chronic hepatitis C virus (HCV) and HCV/HIV infection. It is thought that plasma ATX levels are, in part, attributable to impaired liver clearance that is secondary to fibrotic liver disease. In a discovery data set, we identified plasma ATX to be associated with parameters of systemic immune activation during chronic HCV and HCV/HIV infection. We and others have observed a partial normalization of ATX levels within months of starting interferon-free direct-acting antiviral (DAA) HCV therapy, consistent with a non-fibrotic liver disease contribution to elevated ATX levels, or HCV-mediated hepatocyte activation. Relationships between ATX, lysophosphatidic acid (LPA) and parameters of systemic immune activation will be discussed in the context of HCV infection, age, immune health, liver health, and hepatocellular carcinoma (HCC).

Deregulated Lysophosphatidic Acid Metabolism and Signaling in Liver Cancer

Liver cancer is one of the leading causes of death worldwide due to late diagnosis and scarcity of treatment options. The major risk factor for liver cancer is cirrhosis with the underlying causes of cirrhosis being viral infection (hepatitis B or C), metabolic deregulation (Non-alcoholic fatty liver disease (NAFLD) in the presence of obesity and diabetes), alcohol or cholestatic disorders. Lysophosphatidic acid (LPA) is a bioactive phospholipid with numerous effects, most of them compatible with the hallmarks of cancer (proliferation, migration, invasion, survival, evasion of apoptosis, deregulated metabolism, neoangiogenesis, etc.). Autotaxin (ATX) is the enzyme responsible for the bulk of extracellular LPA production, and together with LPA signaling is involved in chronic inflammatory diseases, fibrosis and cancer. This review discusses the most important findings and the mechanisms related to ATX/LPA/LPAR involvement on metabolic, viral and cholestatic liver disorders and their progression to liver cancer in the context of human patients and mouse models. It focuses on the role of ATX/LPA in NAFLD development and its progression to liver cancer as NAFLD has an increasing incidence which is associated with the increasing incidence of liver cancer. Bearing in mind that adipose tissue accounts for the largest amount of LPA production, many studies have implicated LPA in adipose tissue metabolism and inflammation, liver steatosis, insulin resistance, glucose intolerance and lipogenesis. At the same time, LPA and ATX play crucial roles in fibrotic diseases. Given that hepatocellular carcinoma (HCC) is usually developed on the background of liver fibrosis, therapies that both delay the progression of fibrosis and prevent its development to malignancy would be very promising. Therefore, ATX/LPA signaling appears as an attractive therapeutic target as evidenced by the fact that it is involved in both liver fibrosis progression and liver cancer development.

Past history of hepatocellular carcinoma is an independent risk factor of treatment failure in patients with chronic hepatitis C virus infection receiving direct-acting antivirals

Direct-acting antiviral (DAA) treatment can achieve a high sustained virological response (SVR) rate in patients with hepatitis C virus (HCV) infection regardless of a history of hepatocellular carcinoma (HCC [+]). We examined 838 patients (370 men, median age: 69 years) who were treated with DAAs for comparisons of clinical findings between 79 HCC (+) (9.4%) and 759 HCC (-) (90.6%) patients and associations with treatment outcome. Male frequency was significantly higher in the HCC (+) group (60.8% vs 42.4%, P = 0.006). There were significant differences between the HCC (+) and HCC (-) groups for platelet count (115 vs 152 ×10⁹ /L, P < 0.001), baseline alpha fetoprotein (AFP) (9.9 vs 4.5 ng/mL, P < 0.001) and the established fibrosis markers of FIB-4 index (4.7 vs 3.0, P < 0.001), AST-to-platelet ratio index (APRI) (1.1 vs 0.7, P = 0.009), M2BPGi (3.80 vs 1.78 COI, P < 0.001) and autotaxin (1.91 vs 1.50 mg/L, P < 0.001). The overall SVR rate was 94.7% and significantly lower in the HCC (+) group (87.3 vs 95.5%, P = 0.001). Multivariate analysis revealed that a history of HCC was independently associated with DAA treatment failure (odds ratio: 3.56, 95% confidence interval: 1.32-9.57, P = 0.01). In conclusion, patients with chronic HCV infection and prior HCC tended to exhibit more advanced disease progression at DAA commencement. HCC (+) status at the initiation of DAAs was significantly associated with adverse therapeutic outcomes. DAA treatment for HCV should therefore be started as early as possible, especially before complicating HCC.

Soluble Markers of Immune Activation Differentially Normalize and Selectively Associate with Improvement in AST, ALT, Albumin, and Transient Elastography During IFN-Free HCV Therapy

Background

During chronic hepatitis C virus (HCV) infection, Aspartate Aminotransferase (AST) and Alanine Aminotransferase (ALT) levels mark active liver inflammation and tissue damage, while albumin reflects synthetic liver function and nutritional status. Transient Elastography (TE) is a clinical measure of liver stiffness that facilitates evaluation of liver damage stage. While a portion of the TE score is attributable to liver fibrosis and relatively irreversible damage, another component of the TE score is attributable to liver inflammation or edema. Markers of inflammation during chronic HCV infection include soluble markers of immune activation, which are also associated with morbid outcome (including cardiovascular disease and liver-disease progression). Whether soluble markers of immune activation or changes in their level during HCV therapy relate to normalization of AST, ALT, Albumin, or TE score, is not clear.

Methods

We evaluated soluble markers of immune activation (plasma sCD14, IL-6, sCD163, autotaxin [ATX], and Mac2BP) and TE score, and their relationship in 20 HCV-infected patients before, during, and after HCV-directed IFN-free direct-acting antiviral (DAA) therapy. We evaluated normalization of parameters and the relationship between each over a 6-month window.

Results

Before therapy, serum AST levels positively correlated with plasma levels of sCD14, sCD163, and Mac2BP, while ALT levels positively correlated with Mac2BP. Serum albumin level negatively correlated with plasma IL-6 and ATX levels. IFN-free therapy uniformly resulted in sustained virological response at 12 and 24 weeks after therapy completion. After initiation of therapy AST and ALT normalized, while levels of ATX, Mac2BP, sCD163, and TE score partially normalized over 6 months. Additionally, change in AST level and APRI score correlated with change in sCD163, IL-6, and Mac2BP levels, and change in ALT correlated with change in IL-6 and Mac2BP levels. Improvement in TE score correlated with a decrease in the level of sCD14 at week 4, and almost statistically significant with decrease in sCD14 at weeks 20-24 after initiation of IFN-free HCV therapy.

Conclusions

Soluble markers of immune activation normalize or partially normalize at different rates after initiation of curative HCV DAA therapy, and TE scores improve, with wide variability in the degree of absolute improvement in liver stiffness from patient to patient. Decline magnitude of sCD14 was associated with improvement in TE score, while magnitude of improvement in AST correlated with reduction in sCD163 levels. These data provide support for a model where monocyte/Kupffer cell activation may account for a portion of the liver inflammation and edema, which is at least partially reversible following initiation of HCV DAA therapy.

Serum Autotaxin Is a Useful Disease Progression Marker in Patients with Primary Biliary Cholangitis

Autotaxin (ATX) is a secreted enzyme metabolized by liver sinusoidal endothelial cells that has been associated with liver fibrosis. We evaluated serum ATX values in 128 treatment-naïve, histologically assessed primary biliary cholangitis (PBC) patients and 80 healthy controls for comparisons of clinical parameters in a case-control study. The median ATX concentrations in controls and PBC patients of Nakanuma’s stage I, II, III, and IV were 0.70, 0.80, 0.87, 1.03, and 1.70 mg/L, respectively, which increased significantly with disease stage (r = 0.53, P < 0.0001) as confirmed by Scheuer’s classification (r = 0.43, P < 0.0001). ATX correlated with Wisteria floribunda agglutinin-positive Mac-2 binding protein (M2BPGi) (r = 0.51, P < 0.0001) and fibrosis index based on four factors (FIB-4) index (r = 0.51, P < 0.0001). While ALP and M2BPGi levels had decreased significantly (both P < 0.001) by 12 months of ursodeoxycholic acid treatment, ATX had not (0.95 to 0.96 mg/L) (P = 0.07). We observed in a longitudinal study that ATX increased significantly (P < 0.00001) over 18 years in an independent group of 29 patients. Patients succumbing to disease-related death showed a significantly higher ATX increase rate (0.05 mg/L/year) than did survivors (0.02 mg/L/year) (P < 0.01). ATX therefore appears useful for assessing disease stage and prognosis in PBC.