Serum pro-collagen III peptide levels are related to lobular necrosis in untreated patients with chronic hepatitis C

Biomarkers of liver fibrosis

Liver fibrosis is the final common pathway for almost all causes of chronic liver injury. Liver fibrosis is now known to be a dynamic process having significant potential for resolution. Therefore, fibrosis prediction is an essential part of the assessment and management of patients with chronic liver disease. As such, there is strong demand for reliable liver biomarkers that provide insight into disease etiology, diagnosis, therapy, and prognosis in lieu of more invasive approaches such as liver biopsy. Current diagnostic strategies range from use of serum biomarkers to more advanced imaging techniques including transient elastography and magnetic resonance imaging. In addition to these modalities, there are other approaches including the use of novel, but yet to be validated, biomarkers. In this chapter, we discuss the biomarkers of liver fibrosis including the use of invasive and noninvasive biomarkers and disease-specific biomarkers in various chronic liver diseases.

Molecular serum markers of liver fibrosis

Fibrosis is a hallmark histologic event of chronic liver diseases and is characterized by the excessive accumulation and reorganization of the extracellular matrix (ECM). The gold standard for assessment of fibrosis is liver biopsy. As this procedure has various limitations, including risk of patient injury and sampling error, a non-invasive serum marker for liver fibrosis is desirable. The increasing understanding of the pathogenesis of hepatic fibrosis has suggested several markers which could be useful indicators of hepatic fibrogenesis and fibrosis. These markers include serum markers of liver function, ECM synthesis, fibrolytic processes, ECM degradation and fibrogenesis related cytokines. Recently, neo-epitopes, which are post-translational modifications of proteins, have been successfully used in bone and cartilage diseases which are characterized by extensive ECM remodeling. Increasing numbers of studies are being undertaken to identify neo-epitopes generated during liver fibrosis, and which ultimately might be useful for diagnosing and monitoring fibrogenesis. To date, the metalloproteinases generated fragment of collagen I, III, IV and VI have been proven to be elevated in two rat models of fibrosis. This review summarizes the recent efforts that have been made to identify potentially reliable non-invasive serum markers. We used the recently proposed BIPED (Burden of disease, Investigative, Prognostic, Efficacy and Diagnostic) system to characterize potential serum markers and neo-epitope markers that have been identified to date.

Diabetic fatty liver disease is associated with specific changes in blood-borne markers

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) can lead to cirrhosis and hepatocellular carcinoma and is strongly associated with obesity and insulin resistance. The aim of this study was to assess if plasma markers associated with NAFLD are increased in people with concomitant diabetes compared with those without.

METHODS

A total of 68 participants were recruited from diabetes and liver clinics. Fatty liver disease was indicated by routine blood tests and ultrasonography. Forty-seven participants had type 2 diabetes; of them, 18 had no fatty liver disease as defined previously (DNoFLD) and 29 had fatty liver disease (DFLD); the remaining 21 had fatty liver disease but no diabetes (NonDFLD). Serum samples were analyzed for adiponectin (APN), alanine and aspartate aminotransferases and plasma for cholesterol, triglyceride, hyaluronic acid (HA), procollagen peptide III, alkaline phosphatase and fibrinogen.

RESULTS

Hyaluronic acid and procollagen peptide III were significantly higher and adiponectin significantly lower in DFLD than NonDFLD and DNoFLD, the difference being particularly marked for hyaluronic acid and APN. There was no difference in these markers between NonDFLD and DNoFLD and no association between any plasma or serum marker and ultrasound grade of steatosis.

CONCLUSION

We have identified markers of hepatic steatosis that appear to be specific for people with type 2 diabetes. A further longitudinal study is merited to assess the role of these markers in understanding the progression of hepatic steatosis and fibrosis in people with and without diabetes.

Splenectomy enhances the anti-fibrotic effect of bone marrow cell infusion and improves liver function in cirrhotic mice and patients

BACKGROUND

In 2003, we initiated a clinical trial to examine autologous bone marrow cell infusion (ABMi) therapy for cirrhotic patients and reported the clinical effect of the therapy. To analyze how splenectomy may potentiate the effects of bone marrow cell infusion on cirrhosis, we performed a mouse study and a clinical trial on patients with cirrhosis.

METHODS

In mice, we analyzed the effect of splenectomy on bone marrow cell infusion in four experimental groups (group A, splenectomy + bone marrow cell infusion + CCl(4); group B, sham operation + bone marrow cell infusion + CCl(4); group C, splenectomy + CCl(4); group D, sham operation + CCl(4)). In clinical, we compared the effect of splenectomy on ABMi therapy.

RESULTS

We observed significantly increased average serum albumin levels and higher expression of green fluorescent protein (GFP), matrix metalloproteinase 9 (MMP9), and proliferating cell nuclear antigen in the livers of group A. We observed MMP9/GFP double-positive cells in the cirrhotic livers. A significant decrease in the liver fibrosis areas was observed in group A. Splenectomy enhanced the repopulation of bone marrow cells into the cirrhotic liver and improved the liver microenvironment via expression of MMP9 secreted from repopulating GFP-positive cells. Next, we performed a clinical trial to compare the effect of splenectomy on the efficacy of ABMi therapy. Cirrhotic patients who underwent splenectomy before ABMi therapy tended to have a greater improvement in liver function.

CONCLUSION

ABMi therapy with splenectomy may be an effective therapeutic modality for cirrhosis.

Circulating markers of liver fibrosis progression

INTRODUCTION

Fibrogenesis is a typical reaction of the liver to injury. In the case of overstimulation of fibrogenesis clinically significant fibrosis and, eventually, cirrhosis occur. Treatment of liver cirrhosis is limited, therefore it is important to screen and monitor patients at risk of cirrhosis. Noninvasive parameters are ideal for this purpose due to their risk profile and repeatability.

METHODS

Systematic review of literature.

RESULTS

Among large number of proposed biomarkers, there is a distinct difference between two groups or classes. Class I biomarkers are associated with the process of fibrogenesis, their presence in the serum is the result of the increased turnover of extracellular matrix. Class II biomarkers and their combinations are mostly markers of liver function or structural damage. We have identified 27 Class I and 13 Class II biomarkers that have been proposed in the literature. We have evaluated in detail those which reached limited clinical application.

CONCLUSION

General clinical acceptance of these biomarkers is low because of various drawbacks. Simple and readily available biomarkers have low accuracy in predicting liver fibrosis and more advanced markers have low cost-benefit ratio. Therefore liver biopsy remains the "gold standard" for diagnosis of fibrosis. However potential noninvasive alternatives exist and their implementation could be valuable.

Diagnosis and quantitation of fibrosis

Hepatic fibrosis is the final common pathway for many different liver insults. Originally considered to be irreversible, hepatic fibrosis is now known to be a dynamic process with a significant potential for resolution. The diagnosis and quantitation of fibrosis have traditionally relied on liver biopsy. However, there are a number of drawbacks including the invasive nature of the procedure, sampling error, and interobserver variability. This article reviews the current role of liver biopsy in the assessment of hepatic fibrosis and discusses the role of the newer noninvasive methods including serum markers and radiologic tests.

Immunodetection of collagen types I, II, III, and IV for differentiation of liver fibrosis stages in patients with chronic HCV

The current study is aimed at evaluating serum collagens and other serum biochemical markers as useful, non-invasive markers of hepatic fibrosis associated with chronic hepatitis C virus (HCV). Collagen types I, II, III, and IV were detected in serum using ELISA and Western blot techniques. The ELISA levels of collagen I, II, III, and IV increased significantly with the progression of fibrosis staging. Based on receiver-operating characteristic (ROC) curve analysis, the collagen type III (70 kDa) and type IV (200 kDa) were more useful than other serum bio-markers for differentiating severe fibrosis from mild fibrosis. Multivariate discriminant analysis (MDA) selected a fibrosis discriminant score (FDS) = [2.345 + Collagen III (microg/mL) x 1.923 + Collagen IV (microg/mL) x 1.544 + ALT (U/mL) x 0.005] - [albumin(g/L) x 0.046]. The FDS correctly classified 87% of the severe fibrosis patients at a cut-off score = 2.2 (i.e., more than 2.2 indicated severe fibrotic liver and less than 2.2 indicated mild fibrotic liver) with specificity of 97%. In a validation study, the FDS was applied to the second cohort of patients and the results were reproduced without significant difference. In conclusion, the developed four-parameter based FDS is useful for identifying severe liver fibrosis in patients with chronic HCV infection.

Improved Liver Function in Patients with Liver Cirrhosis After Autologous Bone Marrow Cell Infusion Therapy

We here report nine liver cirrhosis (LC) patients that underwent autologous bone marrow cell infusion (ABMI) from the peripheral vein. Subjects were patients with LC with total bilirubin of less than 3.0 mg/dl, platelet count of more than 5 (10(10)/l), and no viable hepatocellular carcinoma on diagnostic imaging. Autologous bone marrow (BM; 400 ml) was isolated from the ilium under general anesthesia. Mononuclear cells (MNCs) were separated by cell washing and were infused via the peripheral vein. MNC characteristics were confirmed by fluorescence-activated cell sorting analysis (CD34, CD45, and c-kit). After ABMI therapy, liver function was monitored by blood examination for 24 weeks. From 400 ml of BM, we obtained 7.81 +/- 0.98 x 10(9) MNCs. After washing, 5.20 +/- 0.63 x 10(9) MNCs were infused into patients with LC. Significant improvements in serum albumin levels and total protein were observed at 24 weeks after ABMI therapy (p < .05). Significantly improved Child-Pugh scores were seen at 4 and 24 weeks (p < .05). alpha-Fetoprotein and proliferating cell nuclear antigen (PCNA) expression in liver biopsy tissue was significantly elevated after ABMI therapy (p < .05). No major adverse effects were noted. In conclusion, ABMI therapy should be considered as a novel treatment for patients with decompensated LC.

Role of liver biopsy in management of chronic hepatitis C: a systematic review

This systematic review addresses 2 questions pertinent to the need for pretreatment liver biopsy in patients with chronic hepatitis C: how well do liver biopsy results predict treatment outcomes for chronic hepatitis C? How well do biochemical blood tests and serologic measures of fibrosis predict the biopsy findings in chronic hepatitis C? Medline and other electronic databases were searched from January 1985 to March 2002. Additional articles were sought in references of pertinent articles and recent journals and by querying experts. Articles were eligible for review if they reported original human data from a study that used virological, histological, pathologic, or clinical outcome measures. Paired reviewers assessed the quality of each eligible study and abstracted data. Studies suggested that advanced fibrosis or cirrhosis on initial liver biopsy is associated with a modestly decreased likelihood of a sustained virological response (SVR) to treatment. Also, studies relatively consistently showed that serum aminotransferases have modest value in predicting fibrosis on biopsy; that extracellular matrix tests hyaluronic acid and laminin may have value in predicting fibrosis, and that panels of tests may have the greatest value in predicting fibrosis or cirrhosis. Biochemical and serologic tests were best at predicting no or minimal fibrosis, or at predicting advanced fibrosis/cirrhosis, and were poor at predicting intermediate levels of fibrosis. Thus, evidence suggests that liver biopsy may have some usefulness in predicting efficacy of treatment in patients with chronic hepatitis C, and biochemical blood tests and serologic tests currently have only modest value in predicting fibrosis on liver biopsy.

Role of liver biopsy in management of chronic hepatitis C: a systematic review

This systematic review addresses 2 questions pertinent to the need for pretreatment liver biopsy in patients with chronic hepatitis C: how well do liver biopsy results predict treatment outcomes for chronic hepatitis C? How well do biochemical blood tests and serologic measures of fibrosis predict the biopsy findings in chronic hepatitis C? Medline and other electronic databases were searched from January 1985 to March 2002. Additional articles were sought in references of pertinent articles and recent journals and by querying experts. Articles were eligible for review if they reported original human data from a study that used virological, histological, pathologic, or clinical outcome measures. Paired reviewers assessed the quality of each eligible study and abstracted data. Studies suggested that advanced fibrosis or cirrhosis on initial liver biopsy is associated with a modestly decreased likelihood of a sustained virological response (SVR) to treatment. Also, studies relatively consistently showed that serum aminotransferases have modest value in predicting fibrosis on biopsy; that extracellular matrix tests hyaluronic acid and laminin may have value in predicting fibrosis, and that panels of tests may have the greatest value in predicting fibrosis or cirrhosis. Biochemical and serologic tests were best at predicting no or minimal fibrosis, or at predicting advanced fibrosis/cirrhosis, and were poor at predicting intermediate levels of fibrosis. Thus, evidence suggests that liver biopsy may have some usefulness in predicting efficacy of treatment in patients with chronic hepatitis C, and biochemical blood tests and serologic tests currently have only modest value in predicting fibrosis on liver biopsy.

A toxicologist's guide to biomarkers of hepatic response

Biological markers (biomarkers) are used to recognize, characterize and monitor treatment-related responses following exposure to xenobiotics. Biomarkers serve three primary applications in toxicology: 1) to confirm exposure to a deleterious agent, 2) to provide a system for monitoring individual susceptibility to a toxicant, and 3) to quantitatively assess deleterious effects of a toxicant to an organism or individual. Because the liver is a general target for adverse effects of drugs and other chemicals, biomarkers of untoward hepatic response to xenobiotics are of particular interest to the pharmaceutical toxicologist. General requirements for the latter category of biomarkers are sample availability, target organ specificity, sensitivity for the toxicity of interest, accessibility, a relatively short half-life, and available detection systems. Biomarkers that can be assayed in biological fluids from both human and animal subjects are particularly desirable. Histologically, acute and subacute hepatic toxicity commonly involves necrosis, steatosis, cholestasis, vascular disorders, or multiple lesions. The purpose of this review is to summarize reported applications using clinical analytes and biochemical indicators of hepatic dysfunction with emphasis on those that show promise of supplementing or improving upon standard laboratory procedures. Liver function markers refer to peripheral indicators of hepatic synthetic and secretory activities, enterohepatic function, or perturbations of the hepatic uptake and clearance of circulating biomolecules. Liver injury biomarkers include various peripheral proteins released in response to a cellular damage or locally, proteins that are significantly altered within the liver. These include both circulating cytosolic, mitochondrial, or canalicular membrane markers, and the up-regulation or depletion of radical scavengers, modulators, and stabilizers of intracellular damage. Subsequent recovery from a toxic insult involves repair, regenerative, and proliferative responses that constitute the third class of biomarkers. Of these, protein markers found either in sera, plasma, or urine either during or just prior to the early manifestation of histological hepatic lesions are of greatest interest. Examples of a number of these markers, their documented applications in humans or animals, and potential advantages as well as limitations are presented.

The use of silymarin in the treatment of liver diseases

The high prevalence of liver diseases such as chronic hepatitis and cirrhosis underscores the need for efficient and cost-effective treatments. The potential benefit of silymarin (extracted from the seeds of Silybum marianum or milk thistle) in the treatment of liver diseases remains a controversial issue. Therefore, the objective of this review is to assess the clinical efficacy and safety of silymarin by application of systematic approach. 525 references were found in the databases, of which 84 papers were retained for closer examination and 36 were deemed suitable for detailed analysis. Silymarin has metabolic and cell-regulating effects at concentrations found in clinical conditions, namely carrier-mediated regulation of cell membrane permeability, inhibition of the 5-lipoxygenase pathway, scavenging of reactive oxygen species (ROS) of the R-OH type and action on DNA-expression, for example, via suppression of nuclear factor (NF)-kappaB. Pooled data from case record studies involving 452 patients with Amanita phalloides poisoning show a highly significant difference in mortality in favour of silibinin [the main isomer contained in silymarin] (mortality 9.8% vs 18.3% with standard treatment; p < 0.01). The available trials in patients with toxic (e.g. solvents) or iatrogenic (e.g. antispychotic or tacrine) liver diseases, which are mostly outdated and underpowered, do not enable any valid conclusions to be drawn on the value of silymarin. The exception is an improved clinical tolerance of tacrine. In spite of some positive results in patients with acute viral hepatitis, no formally valid conclusion can be drawn regarding the value of silymarin in the treatment of these infections. Although there were no clinical end-points in the four trials considered in patients with alcoholic liver disease, histological findings were reported as improved in two out of two trials, improvement of prothrombin time was significant (two trials pooled) and liver transaminase levels were consistently lower in the silymarin-treated groups. Therefore, silymarin may be of use as an adjuvant in the therapy of alcoholic liver disease. Analysis was performed on five trials with a total of 602 patients with liver cirrhosis. The evidence shows that, compared with placebo, silymarin produces a nonsignificant reduction of total mortality by -4.2% [odds ratio (OR) 0.75 (0.5 - 1.1)]; but that, on the other hand, the use of silymarin leads to a significant reduction in liver-related mortality of-7% [OR: 0.54 (0.3 - 0.9); p < 0.01]. An individual trial reported a reduction in the number of patients with encephalopathy of -8.7% (p = 0.06). In one study of patients with cirrhosis-related diabetes mellitus, the insulin requirement was reduced by -25% (p < 0.01). We conclude that available evidence suggests that silymarin may play a role in the therapy of (alcoholic) liver cirrhosis. Silymarin is has a good safety record and only rare case reports of gastrointestinal disturbances and allergic skin rashes have been published. This review does not aim to replace future prospective trials aiming to provide the 'final' evidence of the efficacy of silymarin.