Noninvasive markers of fibrosis: key concepts for improving accuracy in daily clinical practice

Towards clinical translation of urinary vitronectin for non-invasive detection and monitoring of renal fibrosis in kidney transplant patients

BACKGROUND

Interstitial fibrosis and tubular atrophy (IFTA) is a critical factor in the prognosis of kidney health. Currently, IFTA quantitation in kidney biopsy samples is crucial for diagnosis and assessing disease severity, but the available non-invasive biomarkers are not satisfactory. Proteomic studies identified urinary vitronectin (VTN) as a potential biomarker for kidney fibrosis. As mass spectrometry techniques are not practical for use in clinical settings, we tested whether evaluation of urinary VTN levels through enzyme-linked immunosorbent assay (ELISA) can help monitor fibrotic changes in kidney transplant recipients and prove the clinical viability of the assay.

METHODS

A total of 58 kidney transplant (KTx) patients who underwent renal biopsy were included in the study. Patients were categorized into two groups referred as no fibrosis (0%) or with fibrosis (≥ 5%) based on their histological findings. In a subsequent/follow-up analysis, the time elapsed from transplantation was also considered. The urinary levels of VTN were measured using ELISA.

RESULTS

VTN (p = 0.0180) and VTN normalized by urinary creatinine levels (p = 0.0037), were significantly increased in patients with fibrotic grafts. When focusing on patients with long-term grafts (> 3 years from transplantation, n = 36), VTN exhibited superior potential in identifying fibrotic grafts compared to albuminuria (VTN p = 0.0040 vs. albuminuria p = 0.0132). Importantly, in this group, while albuminuria correctly identified 71% of fibrotic patients, the combination of VTN plus albuminuria correctly classified 89% of fibrotic grafts detected by renal biopsy.

CONCLUSIONS

VTN has emerged as a valid indicator of renal fibrosis. Of interest, urinary levels of VTN in combination with conventional clinical parameters (such as albuminuria) significantly improved the non-invasive detection of renal fibrosis in kidney transplant patients.

The Link between NAFLD and Metabolic Syndrome

Metabolic syndrome (MetS) is characterized by an association of cardiovascular and diabetes mellitus type 2 risk factors. Although the definition of MetS slightly differs depending on the society that described it, its central diagnostic criteria include impaired fasting glucose, low HDL-cholesterol, elevated triglycerides levels and high blood pressure. Insulin resistance (IR) is believed to be the main cause of MetS and is connected to the level of visceral or intra-abdominal adipose tissue, which could be assessed either by calculating body mass index or by measuring waist circumference. Most recent studies revealed that IR may also be present in non-obese patients, and considered visceral adiposity to be the main effector of MetS' pathology. Visceral adiposity is strongly linked with hepatic fatty infiltration also known as non-alcoholic fatty liver disease (NAFLD), therefore, the level of fatty acids in the hepatic parenchyma is indirectly linked with MetS, being both a cause and a consequence of this syndrome. Taking into consideration the present pandemic of obesity and its tendency to drift towards a progressively earlier onset due to the Western lifestyle, it leads to an increased NAFLD incidence. Novel therapeutic resources are lifestyle intervention with physical activity, Mediterranean diet, or therapeutic surgical respective metabolic and bariatric surgery or drugs such as SGLT-2i, GLP-1 Ra or vitamin E. NAFLD early diagnosis is important due to its easily available diagnostic tools such as non-invasive tools: clinical and laboratory variables (serum biomarkers): AST to platelet ratio index, fibrosis-4, NAFLD Fibrosis Score, BARD Score, fibro test, enhanced liver fibrosis; imaging-based biomarkers: Controlled attenuation parameter, magnetic resonance imaging proton-density fat fraction, transient elastography (TE) or vibration controlled TE, acoustic radiation force impulse imaging, shear wave elastography, magnetic resonance elastography; and the possibility to prevent its complications, respectively, fibrosis, hepato-cellular carcinoma or liver cirrhosis which can develop into end-stage liver disease.

External validation and comparison of simple tools to screen for nonalcoholic fatty liver disease in Chinese community population

BACKGROUND

Various noninvasive tools based on anthropometric indicators, blood lipids, and liver enzymes, etc. have been developed to screen for nonalcoholic fatty liver disease (NAFLD), with different diagnostic performance and cutoff values among studies. We aimed to validate and compare eight NAFLD-related models developed by simple indicators and to define their cutoff values in Chinese community population.

METHODS

A cross-sectional study was conducted in a health examination cohort of 3259 people. NAFLD was diagnosed by ultrasonography. General, anthropometric and biochemical data were collected. Fatty liver index (FLI), fatty liver disease index (FLD), Zhejiang University index (ZJU), lipid accumulation product (LAP), regression formula of controlled attenuation parameter (CAP), waist-to-height ratio (WHtR), triglyceride and glucose index (TyG), and visceral adiposity index (VAI) were calculated. The accuracy and cutoff points to detect NAFLD were evaluated by area under the receiver operator characteristic curve and the maximum Youden index analysis, respectively. A head-to-head comparison between these models and Decision Curve Analysis (DCA) was conducted.

RESULTS

In eight noninvasive diagnostic models of NAFLD, AUCs of FLI and FLD for NAFLD were higher than those of other models in the whole (0.852 and 0.852), male (0.826 and 0.824), and female (0.897 and 0.888) population, respectively. DCA showed that FLI, FLD, and ZJU have higher net benefit to screen for NAFLD compared to other models.

CONCLUSIONS

FLI and FLD could be the most accurate and applicable of eight models for the noninvasive diagnosis of NAFLD in both male and female groups.

Reproducibility and diagnostic accuracy of pocket-sized ultrasound devices in ruling out compensated cirrhosis of mixed etiology

Objective

Fibrosis is the key prognostic factor in chronic liver disease patients. Liver surface nodularity (LSN) is the ultrasonographic sign with the highest accuracy to detect advanced liver fibrosis. The use of pocket-sized ultrasound devices (PUDs) has been assessed in several clinical settings but never as regards chronic liver disease (CLD) severity. Our study aimed at evaluating the feasibility, reproducibility, and diagnostic accuracy of PUD in LSN identification.

Methods

We enrolled all the consecutive adults referred for percutaneous liver biopsy. Two independent operators evaluated LSN by PUD; one sonographer used standard ultrasound (US). Transient elastography (TE) and liver biopsy were performed on all the patients. PUD reproducibility was evaluated by Cohen’s k statistic. PUD, standard US, and TE results were compared with histology staging.

Results

A total of 104 consecutive patients (aged 54 ± 14 years) with mixed-etiology CLD were studied. Assessment by PUD was feasible in all the patients and showed very good inter-observer agreement with Cohen’s k = 0.87 (95% CI 0.72–0.95). The diagnostic accuracy estimates for PUD in diagnosing compensated cirrhosis (F = 4) were 87.5% sensitivity, 76.8% specificity, positive likelihood ratio (LR) 3.78, and negative likelihood ratio (LR-) 0.16, while those for standard US and TE (> 12.5 kPa) were, respectively, 87.5% sensitivity, 72.6% specificity, LR+ 3.2, and LR- 0.17, and 87.5% sensitivity, 90.5% specificity, LR + 9.2, and LR- 0.13.

Conclusions

PUD reproducibility in assessing LSN was excellent even with operators of different experience. PUD performed very well in excluding advanced CLD. PUD can be used as a first-line tool for screening patients to undergo more invasive techniques, thus shortening the time for clinical decision-making.

Key Points

• PUD is highly reproducible in assessing the sign of liver surface nodularity.

• PUD showed high diagnostic accuracy in excluding the presence of advanced chronic liver disease.

• PUD can be used as a first-line tool for screening patients with CLD who should undergo more invasive techniques.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-022-08572-2.

Artificial Intelligence in Imaging of Chronic Liver Diseases: Current Update and Future Perspectives

Here we review artificial intelligence (AI) models which aim to assess various aspects of chronic liver disease. Despite the clinical importance of hepatocellular carcinoma in the setting of chronic liver disease, we focus this review on AI models which are not lesion-specific and instead review models developed for liver parenchyma segmentation, evaluation of portal circulation, assessment of hepatic fibrosis, and identification of hepatic steatosis. Optimization of these models offers the opportunity to potentially reduce the need for invasive procedures such as catheterization to measure hepatic venous pressure gradient or biopsy to assess fibrosis and steatosis. We compare the performance of these AI models amongst themselves as well as to radiomics approaches and alternate modality assessments. We conclude that these models show promising performance and merit larger-scale evaluation. We review artificial intelligence models that aim to assess various aspects of chronic liver disease aside from hepatocellular carcinoma. We focus this review on models for liver parenchyma segmentation, evaluation of portal circulation, assessment of hepatic fibrosis, and identification of hepatic steatosis. We conclude that these models show promising performance and merit a larger scale evaluation.

A decrease in hepatitis C virus RNA to undetectable levels in chronic hepatitis C patients after PegIFNα + RVB or sofosbuvir + NS5A inhibitor treatment is associated with decreased insulin resistance and persistent oxidative stress

Oxidative stress (OS) and insulin resistance (IR) induced by hepatitis C virus (HCV) infection, are involved in the development of chronic hepatitis C (CHC) complications and progression to hepatocellular carcinoma. The aim of this study was to investigate the effect of pegylated interferon alpha (IFNα) + ribavirin (PegIFNα+RVB) or sofosbuvir + NS5A inhibitor (SOF+InNS5A) on IR and the components of OS. HCV was genotyped in 20 CHC patients grouped by treatment with either PegIFNα+RVB (n = 10) or SOF+InNS5A (n = 10). The treatment's effect on OS-induced damage to lipids (HNE-HDL), proteins (advanced glycation end products [AGEs]), and DNA (8-OHdG) as well as the concentrations of proinflammatory cytokines (IL-2, TNFα, IFNγ), ALT, AST, GSH and platelets was determined. Superoxide dismutase (SOD) and catalase activity as well as IR, determined by the HOMA1-IR index, was evaluated. The HCV genotypes (GT) found were GT1b (45%), GT1a (30%), GT2b (20%), and GT2a (5%). Viral RNA became undetectable by week 12 with SOF+InNS5A in 100% of the cases and with PegIFNα+RVB in 70% of the cases. After viral RNA became undetectable, regardless of treatment and GT, a significant increase in the platelet concentration and SOD activity was observed, whereas ALT, insulin, and IR decreased (p < 0.05). However, only for the SOF+InNS5A treated group was there an increase in oxidative damage to lipids (p < 0.017) and proteins (p < 0.05). None of the other parameters demonstrated any differences. These data confirm that OS persisted after treatment with either SOF+InNS5A or PegIFNα+RVB. IR could be considered a response biomarker to treatment with direct-acting antivirals.

Ultrasound shear wave elastography and liver biopsy to determine liver fibrosis in adult patients

Introduction:

Liver biopsy is considered as the gold standard for diagnosis of chronic liver disease, yet liver biopsy is an invasive method that may be associated with complications. Therefore, non-invasive methods are needed to diagnose fibrosis. This study was conducted to compare liver stiffness measured by Shear-wave Elastography (SWE) to fibrosis in liver biopsy.

Method and Materials:

In this prospective study, 176 adult patients with chronic liver disease of different etiologies were included. All patients were evaluated using SWE and a liver biopsy. The diagnostic accuracy of SWE was evaluated using receiver operating characteristics (ROC) plots based on the degree of fibrosis (METAVIR score). SPSS software version 19 was used for statistical analysis and P < 0.05 considered significant.

Results:

There was a significant correlation between liver stiffness and fibrosis stage (ρ=0.939; P < 0.0001). The ROC curve AUC were 0.871, 0.895 and 0.937 for fibrosis stages F2, F3 and F4 respectively. The cutoff values were 8.6 kPa for F2, 10.7 kPa for F3, and 13.8 kPa for F4, with sensitivity and specificity of 81.76% and 77.01%, 90.20% and 78.40%, 89.53% and 94.38% respectively.

Conclusion:

The results of this study showed that liver SWE is an effective non-invasive method for assessing liver fibrosis in patients with chronic liver disease of different etiologies.

Procollagen C-Proteinase Enhancer 1 (PCPE-1) in Liver Fibrosis

Fibrosis is characterized by excessive deposition of collagen and additional extracellular matrix (ECM) components in response to chronic injuries. Liver fibrosis often results from chronic hepatitis C virus infection and alcohol abuse that can deteriorate to cirrhosis and liver failure. Current noninvasive diagnostic methods of liver fibrosis are limited in their ability to detect and differentiate between early and intermediate stages of fibrosis. New biomarkers of fibrosis that reflect ECM turnover are therefore badly needed. Procollagen C-proteinase enhancer 1 (PCPE-1), a connective tissue glycoprotein that functions as a positive regulator of C-terminal procollagen processing and subsequent collagen fibril assembly, is a promising candidate. Its tissue distribution and expression profile overlap those of collagen, and its expression in fibrosis is upregulated in parallel to the increase in collagen expression. The potential of PCPE-1 as a biomarker of liver fibrosis was recently established using a CCl₄ mouse model of liver fibrosis by showing that the increase in collagen and PCPE-1 content in the fibrotic mouse liver was reflected by elevated plasma levels of PCPE-1. This was achieved using a newly developed highly sensitive, specific, accurate, and reproducible ELISA for mouse PCPE-1, which is based on commercially available antibodies and is offered as a new research tool in the field. A similar ELISA test was developed for human PCPE-1, and preliminary results with plasma from liver fibrosis patients revealed increased plasma concentrations of PCPE-1 in some patients. The protocols of both ELISA tests are outlined herein in great detail to permit their application by any laboratory with similar interests.

Acoustic Structure Quantification Versus Point Shear Wave Speed Measurement for the Assessment of Liver Fibrosis in Viral Hepatitis B

This study was conducted to evaluate the value of acoustic structure quantification (ASQ) technology versus that of point shear wave speed measurement (PSWSM) imaging technology for the assessment of liver fibrosis stage. A total of 104 patients with chronic hepatitis B (CHB) and 30 healthy control patients underwent ASQ and PSWSM examinations. Seven quantitative parameters were obtained from ASQ, and a principal component analysis was used to establish the integrative indicators. A quantitative parameter, known as the shear wave speed (SWS, m/s), was obtained from the PSWSM. The METAVIR scores for the assessment of pathologic liver fibrosis were used as a benchmark. Liver fibrosis stages exhibited a good correlation with the integrative indicators and SWS (r = 0.682, p <0.001; r = 0.651, p <0.001). The areas under the receiver operating characteristic curves for ASQ and PSWSM were 0.705 and 0.854 for mild liver fibrosis (F ≥ 1, p = 0.045), 0.813 and 0.743 for significant liver fibrosis (F ≥ 2, p = 0.115), 0.839 and 0.857 for severe liver fibrosis (F ≥ 3, p = 0.417) and 0.874 and 0.971 for liver cirrhosis (F = 4, p = 0.016), respectively. In conclusion, both ASQ and PSWSM were promising ultrasonic methods for assessing liver fibrosis in patients with CHB; however, PSWSM was more valuable for identifying mild liver fibrosis (F ≥ 1) and cirrhosis (F = 4) than ASQ, and the combination of PSWSM and ASQ improved the accuracy of diagnosing severe liver fibrosis (F ≥ 3).

Noninvasive Liver Assessment in Adult Patients With Fontan Circulation Using Acoustic Radiation Force Impulse Elastography and Hepatic Magnetic Resonance Imaging

BACKGROUND

Patients who have undergone the Fontan procedure are at risk of developing hepatic dysfunction. However, broad recommendations regarding liver monitoring are limited. The purpose of this study was to characterize the frequency of liver disease in adult Fontan patients using multimodality imaging (hepatic magnetic resonance imaging [MRI], acoustic radiation force impulse [ARFI] elastography, or hepatic ultrasound).

METHODS

In a prospective cross-sectional analysis of adult patients palliated with a Fontan procedure, hepatic MRI, ARFI, and hepatic ultrasound were used to assess for liver disease. The protocol compared (1) varying prevalence of liver disease based on each imaging technique, (2) agreement between different techniques, and (3) association between noninvasive imaging diagnosis of liver disease and clinical variables, including specific liver disease biomarkers.

RESULTS

Thirty-seven patients were enrolled. The ARFI results showed high wave propagation velocity in 35 patients (94.6%). All patients had some abnormality in the hepatic MRI. Specifically, 8 patients (21.6%) showed signs of chronic liver disease, 10 patients (27%) had significant liver fibrosis, and 27 patients (73%) had congestion. No correlation was found between liver stiffness measured as propagation velocity and hepatic MRI findings. Only 7 patients had an abnormal hepatic ultrasound study.

CONCLUSIONS

There is an inherent liver injury in adult Fontan patients. Signs of liver disease were observed in most patients by both hepatic MRI and ARFI elastography but not by ultrasound imaging. Increased liver stiffness did not identify specific disease patterns from MRI, supporting the need for multimodality imaging to characterize liver disease in Fontan patients.

King's Variceal Prediction Score: A Novel Noninvasive Marker of Portal Hypertension in Pediatric Chronic Liver Disease

BACKGROUND AND AIMS

Variceal haemorrhage can be a life-threatening complication of chronic liver disease in children. There is limited evidence about the optimal prophylactic management and selection criteria of children who will benefit from upper gastrointestinal endoscopy.

METHODS

Children presenting in our centre with suspected portal hypertension or gastrointestinal bleeding and undergoing their first oesophagogastroduodenoscopy between 2005 and 2012 were included. Clinical, biochemical, and radiological data were collected. A separate validation cohort from May 2013 to October 2014 was obtained.

RESULTS

Data on 124 treatment-naïve patients were collected; 50% had biliary atresia. Thirty-five (28%) children presented with gastrointestinal bleeding and overall 79 (64%) had clinically significant (grade II-III) varices. Clinical prediction rule, aspartate aminotransferase-platelet ratio index, and varices prediction rule had at optimal cut-off sensitivity and specificity of 76% and 59%, 60% and 55%, and 80% and 59%, respectively. Logistic regression yielded a new prediction rule of (3 × albumin ([g/dL]) -  (2 - equivalent adult spleen size [cm]). This King's variceal prediction score had a favourable areas under the curve of 0.772 (0.677-0.867) compared to clinical prediction rule 0.732 (0.632-0.832). At the optimal cut-off of 76 this yielded a sensitivity and specificity of 72% and 73% and a positive and negative predictive value of 82% and 60%, respectively. In the validation cohort areas under the curve was 0.818 (0.654-0.995) with sensitivity and specificity of 78% and 73%, respectively.

CONCLUSIONS

Our new prediction score may be a useful tool in the selection of children with clinically significant varices eligible for a screening endoscopy.

Virologic Cure of Hepatitis C: Impact on Hepatic Fibrosis and Patient Outcomes

Treatment with direct-acting antiviral agents has revolutionized the approach to hepatitis C. We are now able to obtain high sustained virological response (SVR) rates, even in the historically difficult-to-treat patient populations. SVR translates into improved clinical outcomes, particularly overall and liver-related mortality, and benefits are more striking in patients with cirrhosis. A 2.5- to 5-fold risk reduction in the incidence of hepatocellular carcinoma and improvement in complications derived from portal hypertension have been reported as well. It is hypothesized that the benefits from SVR occur largely due to regression of fibrosis, which arises from the halt on the fibrogenic stimuli and activation of extracellular matrix reabsorption signals. Non-invasive markers of fibrosis are being utilized to assess regression, but it is still unclear how accurate they are in this clinical scenario. Interventions aiming to improve liver wellness and screening for cirrhosis-related complications should continue to be the norm after SVR.

Platelet count to spleen diameter ratio non-invasively identifies severe fibrosis and cirrhosis in patients with autoimmune hepatitis

BACKGROUND AND AIM

Non-invasive markers are essential to assess the progression of chronic liver diseases to fibrosis/ cirrhosis and the effectiveness of therapeutic strategies. The aim of this study was to evaluate the ability of non-invasive markers to identify significant fibrosis, severe fibrosis, and cirrhosis in patients with autoimmune hepatitis (AIH).

METHODS

Seventy-six patients with AIH were enrolled in the study and analyzed for the following parameters of liver fibrosis: Fibrosis 4 score (FIB-4), aspartate aminotransferase (AST) to alanine aminotransferase (ALT) ratio (AAR), AST to platelet count ratio (APRI), and platelet count to spleen diameter (PC/SD) ratio. All patients underwent liver biopsy. The diagnostic accuracy of tests was evaluated by the area under the receiver operating characteristic curve (AUROC).

RESULTS

Among the 76 AIH patients, 55 (72.3%) had significant fibrosis (≥ F2), 37 (48.7%) had severe fibrosis (≥ F3), and 29 (38.2%) had cirrhosis (F4). PC/SD ratio (AUROC = 0.840) was superior to AAR (AUROC = 0.756), FIB-4 (AUROC = 0.702), and APRI (AUROC = 0.626) in discriminating between mild and significant fibrosis (≥ F2). The AUROCs of PC/SD ratio, FIB-4, AAR, and APRI were 0.884, 0.742, 0.731, and 0.707, respectively, for severe fibrosis (≥ F3); 0.968, 0.795, 0.744, and 0.723, respectively, for cirrhosis (F4). PC/SD ratio correctly identified 85.1% of patients with severe fibrosis, and 89.6% of patients with cirrhosis.

CONCLUSIONS

PC/SD ratio proved to be a simple non-invasive tool to correctly identify AIH patients with severe fibrosis and cirrhosis, thereby reducing the need for a liver biopsy in these patients.

Procollagen C-Proteinase Enhancer 1 (PCPE-1) as a Plasma Marker of Muscle and Liver Fibrosis in Mice

Current non-invasive diagnostic methods of fibrosis are limited in their ability to identify early and intermediate stages of fibrosis and assess the efficacy of therapy. New biomarkers of fibrosis are therefore constantly sought for, leading us to evaluate procollagen C-proteinase enhancer 1 (PCPE-1), a fibrosis-related extracellular matrix glycoprotein, as a plasma marker of fibrosis. A sandwich ELISA that permitted accurate measurements of PCPE-1 concentrations in mouse plasma was established. Tissue fibrosis was assessed using histochemical, immunofluorescence, and immunoblotting analyses for type I collagen and PCPE-1. The normal plasma concentration of PCPE-1 in 6 weeks to 4 months old mice was ~200 ng/ml (189.5 ± 11.3 to 206.8 ± 13.8 ng/ml). PCPE-1 plasma concentrations in four and 8.5 months old mdx mice displaying fibrotic diaphragms increased 27 and 40% respectively relatively to age-matched control mice, an increase comparable to that of the N-propeptide of procollagen type III (PIIINP), a known blood marker of fibrosis. PCPE-1 plasma levels in mice with CCl4-induced liver fibrosis increased 34 to 50% relatively to respective controls and reflected the severity of the disease, namely increased gradually during the progression of fibrosis and went down to basal levels during recovery, in parallel to changes in the liver content of collagen I and PCPE-1. The results favor PCPE-1 as a potential new clinically valuable fibrosis biomarker.

High Prevalence of Liver Fibrosis in Patients with Human Immunodeficiency Virus Monoinfection and Human Immunodeficiency Virus Hepatitis-B Co-infection as Assessed by Shear Wave Elastography: Study at a Teaching Hospital in Kenya

Objectives:

The aim of this study was to determine the prevalence of liver fibrosis in patients with human immunodeficiency virus (HIV) monoinfection versus those with HIV hepatitis-B virus (HBV) co-infection as assessed with shear wave elastography (SWE) in a tertiary sub-Saharan Africa hospital.

Materials and Methods:

A total of 105 consecutive patients, 70 with HIV monoinfection and 35 with HIV-HBV co-infection, had liver elastography obtained using SWE to assess for the presence of liver fibrosis the cutoff of which was 5.6 kPa. Assessment of aspartate aminotransferase-to-platelet ratio index (APRI) score (a noninvasive serum biomarker of liver fibrosis) in these patients was also done.

Results:

The prevalence of liver fibrosis was significantly higher (P < 0.0001) in patients with HIV-HBV co-infection, 25.7%, compared to those with HIV monoinfection, 7.1%. APRI score was greater in patients with HIV-HBV co-infection than those with HIV monoinfection. HIV co-infection with HBV accelerates progression to liver fibrosis. Association of a low cluster of differentiation 4 (CD-4) count with advanced fibrosis supports earlier starting of antiretroviral therapy to prevent rapid progression of liver disease in HIV-positive patients.

Conclusion:

In view of the high prevalence of liver fibrosis in patients with HIV-HBV co-infection, regular monitoring of the disease progression is recommended.

Plasma levels of growth-related oncogene (CXCL1-3) associated with fibrosis and platelet counts in HCV-infected patients

BACKGROUND

Fibrosis progression in hepatitis C virus (HCV)-infected patients varies greatly between individuals. Chemokines recruit immune cells to the infected liver and may thus play a role in the fibrosis process.

AIM

To investigate plasma levels of a diverse chemokine panel in relation to liver fibrosis.

METHODS

African-American and Caucasian HCV genotype 1 infected patients were treated with peginterferon (pegIFN) and ribavirin (RBV) for 48 weeks (VIRAHEP-C cohort). Plasma levels of 13 cytokines were studied at baseline (n = 386). Subsequently, GROα levels were assessed in a sub cohort (n = 99) at baseline, and at 4 and 12 weeks after start of pegIFN/RBV treatment.

RESULTS

Increased severity of fibrosis (Ishak fibrosis score 0-2 vs. 3-6) was associated with increased plasma IP-10 (CXCL10) and IL-8 (CXCL8) levels, and decreased plasma levels of the chemokine growth-related oncogene (GRO, CXCL1-3). Plasma GRO levels were also positively correlated with platelet counts, and were higher in African-American as compared to Caucasian patients. In response to pegIFN/RBV treatment, GROα levels increased in Caucasian but not African-American patients from week 4 onwards.

CONCLUSIONS

The association with severity of fibrosis and platelet count positions plasma GRO as a potential biomarker for liver fibrosis in HCV-infected patients. The secretion of GRO by platelets may explain the correlation between GRO plasma level and platelet count. The ethnic difference in GRO levels both pre-treatment and in response to pegIFN/RBV might be driven by a genetic polymorphism in GROα associated with higher plasma levels and more common in the African-American population.

Hepatic ADC map as an adjunct to conventional abdominal MRI to evaluate hepatic fibrotic and clinical cirrhotic severity in biliary atresia patients

OBJECTIVES

Hepatic apparent diffusion coefficient (ADC) values and ADC-related indices were correlated with the Mayo risk score for primary biliary cirrhosis (MRSPBC) and METAVIR scores of liver specimens to determine the clinical and pathological significance of diffusion-weighted magnetic resonance imaging (DWMRI).

METHODS

Thirty-two patients with biliary atresia (BA; mean age 461 days, range 11-4616 days) received magnetic resonance examinations from March 2009 to August 2013. A free-breathing DWMRI sequence was performed with the single-shot echo-planar imaging technique with b = 0 and 500 s/mm(2) in all 32 BA patients and 24 controls. We used the ordinal logistic regression test and Spearman rank correlation test to analyse the relationships between the MRSPBC and METAVIR fibrosis scores and right liver-to-psoas ADC ratios (LTPARs).

RESULTS

BA patients had significantly lower LTPARs in both hepatic lobes than controls (p < 0.01). Right LTPARs, showing moderate intraobserver agreement (intraclass correlation coefficient = 0.736) and interobserver reliability (intraclass correlation coefficient = 0.659), were negatively correlated with MRSPBC and METAVIR fibrosis scores (R(2) = 0.398, p = 0.024 and R(2) = 0.628, p < 0.001, respectively).

CONCLUSION

Right LTPARs may be used for long-term follow-up of cirrhosis severity in BA patients.

KEY POINTS

• Hepatic ADC values by DWI correlates well with clinical/pathologic fibrosis scores • Periodic, non-invasive, quantitative imaging follow-up of patients with biliary cirrhosis is feasible • Information on cirrhosis severity could help decide on management options in children with BA • ADC values may be useful in this regard.

Applicability and accuracy improvement of transient elastography using the M and XL probes by experienced operators

Transient elastography (TE) is the reference method to obtain liver stiffness measurements (LSM), but no results are obtained in 3.1% and unreliable in 15.8%. We assessed the applicability and diagnostic accuracy of TE re-evaluation using M and XL probes. From March 2011 to April 2012 868 LSM were performed with the M probe by trained operators (50-500 studies) (LSM1). Measurements were categorized as inadequate (no values or ratio <60% and/or IQR/LSM >30%) or adequate. Inadequate LSM1 were re-evaluated by experienced operators (>500 explorations) (LSM2) and inadequate LSM2 using XL probe (LSMXL). Inadequate LSM1 were obtained in 187 (21.5%) patients, IQR/LSM >30% in 97 (51%), ratio <60% in 24 (13%) and TE failed to obtain a measurement in 67 (36%). LSM2 achieved adequate registers in 123 (70%) of 175 registers previously considered as inadequate. Independent variables (OR, 95%CI) related to inadequate LSM1 were body mass index (1.11, 1.04-1.18), abdominal circumference (1.03, 1.01-1.06) and age (1.03, 1.01-1.04) and to inadequate LSM2 were skin-capsule distance (1.21, 1.09-1.34) and abdominal circumference (1.05, 1.01-1.10). The diagnostic accuracy (AUROC) to identify significant fibrosis improved from 0.89 (LSM1) to 0.91 (LSM2) (P = 0.046) in 334 patients with liver biopsy or clinically significant portal hypertension. A third evaluation (LSMXL) obtained adequate registers in 41 (93%) of 44 patients with inadequate LSM2. Operator experience increases the applicability and diagnostic accuracy of TE. The XL probe may be recommended for patients with inadequate values obtained by experienced operators using the M probe. http://clinicaltrials.gov (NCT01900808).

Results of the 4th scientific workshop of the ECCO (Group II): markers of intestinal fibrosis in inflammatory bowel disease

The fourth scientific workshop of the European Crohn's and Colitis Organization (ECCO) focused on intestinal fibrosis in inflammatory bowel disease (IBD). The objective was to better understand basic mechanisms and markers of intestinal fibrosis as well as to suggest new therapeutic targets to prevent or treat fibrosis. The results of this workshop are presented in three separate manuscripts. This section describes markers of fibrosis in IBD, identifies unanswered questions in the field and provides a framework for future studies addressing the unmet needs in the field of intestinal fibrosis.

The frequency and determinants of liver stiffness measurement failure: a retrospective study of "real-life" 38,464 examinations

Objective

To investigate the frequency and determinants of liver stiffness measurement (LSM) failure by means of FibroScan in “real-life” Chinese patients.

Methods

A total of 38,464 “real-life” Chinese patients in 302 military hospital of China through the whole year of 2013, including asymptomatic carrier, chronic hepatitis B, chronic hepatitis C, liver cirrhosis (LC), alcoholic liver disease, autoimmune liver disease, hepatocellular carcinoma (HCC) and other, were enrolled, their clinical and biological parameters were retrospectively investigated. Liver fibrosis was evaluated by FibroScan detection. S probe (for children with height less than 1.20 m) and M probe (for adults) were used. LSM failure defined as zero valid shots (unsuccessful LSM), or the ratio of the interquartile range to the median of 10 measurements (IQR/M) greater than 0.30 plus median LSM greater or equal to 7.1 kPa (unreliable LSM).

Results

LSM failure occurred in 3.34% of all examinations (1286 patients out of 38,464), among them, there were 958 cases (2.49%) with unsuccessful LSM, and 328 patients (0.85%) with unreliable LSM. Statistical analyses showed that LSM failure was independently associated with body mass index (BMI) greater than 30 kg/m², female sex, age greater than 50 years, intercostal spaces (IS) less than 9 mm, decompensated liver cirrhosis and HCC patients. There were no significant differences among other diseases. By changing another skilled operator, success was achieved on 301 cases out of 1286, which reduced the failure rate to 2.56%, the decrease was significant (P<0.0001).

Conclusions

The principal reasons of LSM failure are ascites, obesity and narrow of IS. The failure rates of HCC, decompensated LC, elder or female patients are higher. These results emphasize the need for adequate operator training, technological improvements and optimal criteria for specific patient subpopulations.

Acoustic radiation force impulse elastography and serum fibrosis markers in chronic hepatitis C

OBJECTIVE

Liver biopsy (LB) remains the gold standard for the assessment of liver fibrosis, although it is invasive and can have complications. The present study compares several noninvasive methods of fibrosis assessment in chronic hepatitis C (CHC), including acoustic radiation force impulse (ARFI) elastography, aspartate aminotransferase:platelet ratio index (APRI), Forns, FIB-4, and King scores versus percutaneous LB.

MATERIAL AND METHODS

This prospective study enrolled 51 untreated CHC patients. Biological tests necessary for the calculation of the scores (according to the classic formulas) were performed within a week of LB. The time interval between LB and tissue stiffness, assessed according to the Metavir score, was <6 months. Cutoff values were determined using area under receiver-operating characteristic curves (AUROC).

RESULTS

The best test for predicting significant fibrosis (F ≥2 Metavir) was ARFI elastography with an AUROC of 0.90, followed by FIB-4 (AUROC = 0.86), King (AUROC = 0.85), Forns (AUROC = 0.84), and APRI (AUROC = 0.82). For a cutoff of 1.31 m/s, ARFI had 89.3% sensitivity (Se) and 87% specificity (Sp). The best test for predicting cirrhosis was ARFI elastography with an AUROC of 0.98, followed by FIB-4 (AUROC = 0.94), King (AUROC = 0.90), APRI (AUROC = 0.82), and Forns (AUROC = 0.81). For a cutoff of 1.95 m/s, ARFI had 100% Se and 95.2% Sp.

CONCLUSION

ARFI elastography had very good accuracy for the assessment of liver fibrosis. It was more effective than APRI, Forns, King, and FIB-4 scores for the prediction of significant fibrosis and cirrhosis in CHC patients.

Medical therapy of stricturing Crohn's disease: what the gut can learn from other organs - a systematic review

Crohn’s disease (CD) is a chronic remitting and relapsing disease. Fibrostenosing complications such as intestinal strictures, stenosis and ultimately obstruction are some of its most common long-term complications. Despite recent advances in the pathophysiological understanding of CD and a significant improvement of anti-inflammatory therapeutics, medical therapy for stricturing CD is still inadequate. No specific anti-fibrotic therapy exists and the incidence rate of strictures has essentially remained unchanged. Therefore, the current therapy of established fibrotic strictures comprises mainly endoscopic dilation as well as surgical approaches. However, these treatment options are associated with major complications as well as high recurrence rates. Thus, a specific anti-fibrotic therapy for CD is urgently needed. Importantly, there is now a growing body of evidence for prevention as well as effective medical treatment of fibrotic diseases of other organs such as the skin, lung, kidney and liver. In face of the similarity of molecular mechanisms of fibrogenesis across these organs, translation of therapeutic approaches from other fibrotic diseases to the intestine appears to be a promising treatment strategy. In particular transforming growth factor beta (TGF-β) neutralization, selective tyrosine kinase inhibitors, blockade of components of the renin-angiotensin system, IL-13 inhibitors and mammalian target of rapamycin (mTOR) inhibitors have emerged as potential drug candidates for anti-fibrotic therapy and may retard progression or even reverse established intestinal fibrosis. However, major challenges have to be overcome in the translation of novel anti-fibrotics into intestinal fibrosis therapy, such as the development of appropriate biomarkers that predict the development and accurately monitor therapeutic responses. Future clinical studies are a prerequisite to evaluate the optimal timing for anti-fibrotic treatment approaches, to elucidate the best routes of application, and to evaluate the potential of drug candidates to reach the ultimate goal: the prevention or reversal of established fibrosis and strictures in CD patients.

Increased hepatic stiffness as consequence of high hepatic afterload in the Fontan circulation: a vascular Doppler and elastography study

Hepatic dysfunction is a recognized complication after Fontan palliation of congenital heart disease. We sought to quantitatively measure hepatic stiffness and vascular Doppler indices using ultrasound (US) and shear wave elastography (SWE) in a Fontan cohort. Subjects were prospectively recruited for echocardiography and real-time hepatic duplex US with SWE for hepatic stiffness (kPa). Doppler peak velocities, velocity time integral, resistive, pulsatility, acceleration indices (RI, PI, AI), and flow volume were measured in celiac artery, superior mesenteric artery, and main portal vein (MPV). A subset underwent cardiac catheterizations with liver biopsy. Correlations were explored between SWE, duplex, hemodynamic, and histopathologic data. In all, 106 subjects were studied including 41 patients with Fontan physiology (age 13.8 ± 6 years, weight 45.4 ± 23 kg) and 65 controls (age 15.0 ± 8.4 years, weight 47.9 ± 22 kg). Patients with Fontan physiology had significantly higher hepatic stiffness (15.6 versus 5.5 kPa, P < 0.0001), higher celiac RI (0.78 versus 0.73, P = 0.04) superior mesenteric artery RI (0.89 versus 0.84, P = 0.005), and celiac PI (1.87 versus 1.6, P = 0.034); while MPV flow volume (287 versus 420 mL/min in controls, P = 0.007) and SMA AI (829 versus 1100, P = 0.002) were lower. Significant correlation was seen for stiffness with ventricular end-diastolic pressure (P = 0.001) and pulmonary artery wedge pressure (P = 0.009). Greater stiffness correlated with greater degrees of histopathologic fibrosis. No significant change was seen in stiffness or other duplex indices with age, gender, time since Fontan, or ventricular morphology.

CONCLUSION

Elevated hepatic afterload in Fontan, manifested by high ventricular end-diastolic pressures and pulmonary arterial wedge pressures, is associated with remarkably increased hepatic stiffness, abnormal vascular flow patterns, and fibrotic histologic changes. The MPV is dilated and carries decreased flow volume, while the celiac and superior mesenteric arterial RI is increased. SWE is feasible in this population and shows promise as a means for predicting disease severity on liver biopsy.

Enzyme-linked immunosorbent assay characterization of basal variation and heritability of systemic microfibrillar-associated protein 4

Background

Microfibrillar-associated protein 4 (MFAP4) is a systemic biomarker that is significantly elevated in samples from patients suffering from hepatic cirrhosis. The protein is generally localized to elastic fibers and other connective tissue fibers in the extracellular matrix (ECM), and variation in systemic MFAP4 (sMFAP4) has the potential to reflect diverse diseases with increased ECM turnover. Here, we aimed to validate an enzyme-linked immunosorbent assay (ELISA) for the measurement of sMFAP4 with an emphasis on the robustness of the assay. Moreover, we aimed to determine confounders influencing the basal sMFAP4 variability and the genetic contribution to the basal variation.

Methods

The sandwich ELISA was based on two monoclonal anti-MFAP4 antibodies and was optimized and calibrated with a standard of recombinant MFAP4. The importance of pre-analytical sample handling was evaluated regarding sample tube type, time, and temperature conditions. The mean value structure and variance structure was determined in a twin cohort including 1,417 Danish twins (age 18-67 years) by mixed-effect linear regression modeling.

Results

The practical working range of the sandwich ELISA was estimated to be 4-75 U/ml. The maximum intra- and inter-assay variation was estimated to be 8.7% and 6.6%, respectively. Sample handling and processing appeared to influence MFAP4 measurements only marginally. The average concentration of sMFAP4 in the serum was 18.9 ± 8.4 (SD) U/ml in the twin cohort (95% CI: 18.5-19.4, median sMFAP4 17.3 U/ml). The mean structure model was demonstrated to include waist-hip ratio, age, and cigarette smoking status in interactions with gender. A relatively low heritability of h² = 0.24 was found after applying a model including additive genetic factors and shared and non-shared environmental factors.

Conclusions

The described ELISA provides robust measures of the liver fibrosis marker sMFAP4. The low heritability and the relatively limited basal variation suggest that increased sMFAP4 reflects disease-induced processes.

Variation between Canadian centres in the uptake of treatment for hepatitis C by patients coinfected with HIV: a prospective cohort study

BACKGROUND

Uptake of treatment for hepatitis C virus (HCV) is low in Canada despite its publicly funded health care system. We explored the uptake of HCV treatment within the Canadian Co-infection Cohort to determine if some treatment centres have been more successful than others at starting patients with HIV-HCV coinfection on HCV treatment.

METHODS

We estimated the variation between 16 centres in the uptake of HCV treatment using a Weibull time-to-event model with adjustment for patient characteristics that are thought likely to influence the uptake of treatment. We asked the principal investigator at each centre about access to hepatitis-related specialists and services and the importance of various criteria when determining if a patient with HIV-HCV coinfection should receive treatment for HCV.

RESULTS

Among 681 untreated patients in the Canadian Co-infection Cohort, 163 patients with HIV-HCV coinfection started HCV treatment over a period of 1827 patient-years (9 per 100 patient-years). Even after adjustment for case mix, there was still appreciable variation in treatment uptake between centres, with mean hazard ratios of 0.43 (95% credible interval 0.11-1.3) and 3.6 (95% credible interval 1.7-8.4) for the centres least and most likely to start an average patient with HIV-HCV coinfection on HCV treatment. The most important criteria reported by principal investigators for determining eligibility for treatment were severity of fibrosis, current psychiatric comorbidities, current alcohol intake, past HCV treatment and a history of reinfection with HCV. However, the opinions were wide-ranging: 8 of the 15 criteria elicited both the responses "less important" and "very important."

INTERPRETATION

The magnitude of the centre effects and diverse opinions about the importance of treatment eligibility criteria suggest that provider-related barriers to HCV treatment uptake are as important as patient-related barriers.

Detecting fibrosis without a liver biopsy: getting to the fat of the issue

It is critical to assess the degree of liver fibrosis for clinical management. However, liver biopsy has many drawbacks and is invasive. Promising non-invasive methods including serum markers and new imaging studies to predict liver fibrosis have been developed in past decades. This editorial provides a succinct overview and update of the new non-invasive technologies, especially the three-dimensional magnetic resonance imaging (3-D MRI) that has been studied by Dr. Kawamura's group in Japan. It also highlights the merit and weakness of this 3D-MRI technology in predicting liver fibrosis and indicates future studies to understand where 3D-MRI fits into the current armamentarium of non-invasive serum-based and imaging technologies.

Role of liver biopsy in the era of direct-acting antivirals

An accurate assessment of the degree of fibrosis or presence of cirrhosis is critical both for the appropriate management of, and to provide prognosis for, patients with chronic hepatitis C infection. In the new era of direct acting antivirals, large numbers of patients may enter therapy, and although liver biopsy remains the gold standard, it is not practical in all settings. In recent years, a variety of noninvasive methods have been developed that may obviate the need for liver biopsy in most settings. Indirect laboratory formulas, tests, panels of biomarkers and imaging modalities may accurately stage the degree of fibrosis in hepatitis C monoinfection, hepatitis C/HIV coinfection, and post-transplant recurrent hepatitis C.

Treatment indication and response to standard of care with peginterferon and ribavirin in acute and chronic HCV infection

Great strides have been made in the treatment of hepatitis C virus (HCV) infection in the past decade. Although there is much focus on the development of new direct-acting antivirals (DAA), interferon and ribavirin remain the backbone of therapy for both acute and chronic HCV infections. While DAA therapy will likely eventually largely replace interferon, in much of the world and for genotype non-1 patients, peginterferon and ribavirin remain first-line therapy. Interferon-based therapy is highly effective in acute HCV with high response rates with short courses of therapy. Unfortunately once infection progresses to chronicity, treatment success rates drop off considerably. The indications, pre-treatment evaluation and efficacy of peginterferon and ribavirin therapy in the treatment of acute and chronic HCV infection are discussed with strategies to improve outcomes and manage adverse events.