Serum levels of YKL-40 and PIIINP as prognostic markers in patients with alcoholic liver disease

Research Progress of Fibroblasts in Human Diseases

Fibroblasts, which originate from embryonic mesenchymal cells, are the predominant cell type seen in loose connective tissue. As the main components of the internal environment that cells depend on for survival, fibroblasts play an essential role in tissue development, wound healing, and the maintenance of tissue homeostasis. Furthermore, fibroblasts are also involved in several pathological processes, such as fibrosis, cancers, and some inflammatory diseases. In this review, we analyze the latest research progress on fibroblasts, summarize the biological characteristics and physiological functions of fibroblasts, and delve into the role of fibroblasts in disease pathogenesis and explore treatment approaches for fibroblast-related diseases.

One-step detection of procollagen type III N-terminal peptide as a fibrosis biomarker using fluorescent immunosensor (quenchbody)

BACKGROUND

Procollagen type III N-terminal peptide (P-III-NP) is a fibrosis biomarker associated with liver and cardiac fibrosis. Despite the value of P-III-NP as a biomarker, its analysis currently relies on enzyme-linked immunosorbent assays (ELISA) and radioimmunoassays (RIA), which require more than 3 h. To facilitate early diagnosis and treatment through rapid biomarker testing, we developed a one-step immunoassay for P-III-NP using a quenchbody, which is a fluorescence-labeled immunosensor for immediate signal generation.

RESULTS

To create quenchbodies, the total mRNA of P-III-NP antibodies was extracted from early-developed hybridoma cells, and genes of variable regions were obtained through cDNA synthesis, inverse PCR, and sequencing. A single-chain variable fragment (scFv) with an N-terminal Cys-tag was expressed in E. coli Shuffle T7, resulting in a final yield of 9.8 mg L-1. The fluorescent dye was labeled on the Cys-tag of the anti-P-III-NP scFv using maleimide-thiol click chemistry, and the spacer arm lengths between the maleimide-fluorescent dyes were compared. Consequently, a TAMRA-C6-labeled quenchbody exhibited antigen-dependent fluorescence signals and demonstrated its ability to detect P-III-NP at concentrations as low as 0.46 ng mL-1 for buffer samples, 1.0 ng mL-1 for 2 % human serum samples.

SIGNIFICANCE

This one-step P-III-NP detection method provides both qualitative and quantitative outcomes within a concise 5-min timeframe. Furthermore, its application can be expanded using a 96-well platform and human serum, making it a high-throughput and sensitive method for testing fibrotic biomarkers.

Alcohol drinking modified the effect of plasma YKL-40 levels on stroke-specific mortality of acute ischemic stroke

OBJECTIVES

Our study aimed to evaluate the association between plasma human cartilage glycoprotein-39 (YKL-40) and stroke-specific mortality at two years in acute ischemic stroke patients according to the drinking status and amount of alcohol consumption. We further investigated the effect of the interaction between these conditions and YKL-40 levels on the outcome.

METHODS

We measured plasma YKL-40 levels in 3267 participants from the China Antihypertensive Trial in Acute Ischemic Stroke. Outcome data on stroke-specific mortality were collected at two years after stroke onset.

RESULTS

During the two years of follow-up, 208 (6.4 %) patients, including 44 drinkers and 164 nondrinkers, died of stroke-specific causes. The patients in the highest quartile of YKL-40 had a 3.52-fold (95 % CI: 1.15-10.76, P for trend = 0.006) risk of stroke-specific mortality compared with those in the lowest quartile among drinkers. However, no significant association between YKL-40 and the outcome was observed among nondrinkers (HR: 1.18, 95 % CI: 0.75-1.86, P for trend = 0.08). Alcohol drinking modified the effect of YKL-40 on the outcome (P for interaction = 0.04). Subgroup analyses revealed that each 1-unit increase in log-transformed YKL-40 was associated with a 72 % greater risk of stroke-specific mortality for light drinkers. This association was amplified with a 226 % increased risk of the outcome among heavy drinkers.

CONCLUSIONS

Elevated YKL-40 levels were associated with an increased risk of stroke-specific mortality at two years among drinkers with ischemic stroke. Drinking status substantially modified the effect of plasma YKL-40 levels on the outcome. This effect was amplified with the increased amount of alcohol consumption.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT01840072.

Association between serum cytokeratin 18 and N-terminal procollagen III propeptide in patients with biopsy-proven nonalcoholic fatty liver disease

Liver biopsy is still the gold standard in the staging of nonalcoholic fatty liver disease (NAFLD), which is the most common chronic liver disease worldwide. However, being an invasive method, liver biopsy has limited use in clinical practice. The aim of this study was to determine the relationship between serum levels of cytokeratin 18 (CK-M30) and N-terminal procollagen III propeptide (PIIINP) in patients with biopsy-proven NAFLD. The study was carried out on volunteers, including both healthy individuals and patients pre-diagnosed with NAFLD. The liver biopsies were re-assessed by applying the Steatosis, Activity, Fibrosis/Fatty Liver Inhibition of Progression (SAF/FLIP) algorithm. At the end of the study, frozen serum samples (-80 °C) were analyzed using commercial kits. CK18-M30 and PIIINP levels significantly differed in all study groups. There was no significant correlation between serum levels of CK18-M30 and PIIINP in healthy individuals but there was a significant positive correlation between CK18-M30 and PIIINP levels in NAFLD (NAFL-nonalcoholic steatohepatitis (NASH)) groups. CK18-M30 was better than PIIINP at distinguishing between NAFL and NASH. The results obtained for biopsy-proven NAFLD demonstrated that both PIIINP and CK18-M30 were partly associated with histological parameters and could aid in distinguishing between NASH and NAFL.

New Biomarkers in Liver Fibrosis: A Pass through the Quicksand?

Chronic liver diseases (CLD) stem from various causes and lead to a gradual progression that ultimately may result in fibrosis and eventually cirrhosis. This process is typically prolonged and asymptomatic, characterized by the complex interplay among various cell types, signaling pathways, extracellular matrix components, and immune responses. With the prevalence of CLD increasing, diagnoses are often delayed, which leads to poor prognoses and in some cases, the need for liver transplants. Consequently, there is an urgent need for the development of novel, non-invasive methods for the diagnosis and monitoring of CLD. In this context, serum biomarkers-safer, repeatable, and more acceptable alternatives to tissue biopsies-are attracting significant research interest, although their clinical implementation is not yet widespread. This review summarizes the latest advancements in serum biomarkers for detecting hepatic fibrogenesis and advocates for concerted efforts to consolidate current knowledge, thereby providing patients with early, effective, and accessible diagnoses that facilitate personalized therapeutic strategies.

Global prevalence, incidence, and outcomes of alcohol related liver diseases: a systematic review and meta-analysis

BACKGROUND

Alcohol related liver disease (ARLD) is one of the major chronic liver diseases worldwide. This review aimed to describe the global prevalence, incidence, and outcomes of ARLD.

METHODS

Medline, Embase, The Cochrane Library, and China National Knowledge Infrastructure (CNKI) were searched from inception to May 31, 2022. The language was restricted to English or Chinese. According to the criteria, articles describing the basic characteristics of the population were selected. Two reviewers extracted the data independently.

RESULTS

A total of 372 studies were identified: 353 were used for prevalence analysis, 7 were used for incidence analysis, and 114 were used to for outcome analysis. The prevalence of ARLD worldwide was 4.8%. The prevalence in males was 2.9%, which was higher than female (0.5%). Among the ethnic groups, the percentage was highest in Caucasians (68.9%). Alcoholic liver cirrhosis comprised the highest proportion in the disease spectrum of ARLD at 32.9%. The prevalence of ascites in ARLD population was highest (25.1%). The ARLD population who drinking for > 20 years accounted for 54.8%, and the average daily alcohol intake was 146.6 g/d. About 59.5% of ARLD patients were current or former smokers, and 18.7% were complicated with hepatitis virus infection. The incidence was 0.208/1000 person-years. The overall mortality was 23.9%, and the liver-related mortality was 21.6%.

CONCLUSION

The global prevalence of ARLD was 4.8% and was affected by sex, region, drinking years, and other factors. Therefore, removing the factors causing a high disease prevalence is an urgent requisite.

TRIAL REGISTRATION

PROSPERO Nr: CRD42021286192.

Clinical Significance of Serum Collagen Type IV and Procollagen Type III N-Peptide Levels in Diagnosis and Differential Diagnosis of Lymphedema

Background: Lymphatic endothelial cells production or modification were closely related to the extracellular matrix (ECM) molecules. The serum hyaluronic acid (HA), laminin (LN), procollagen type III N-peptide (PIIINP), and collagen type IV (CGIV) levels were researched to explore the clinical significance of serum ECM proteins in the diagnosis and differentiation of lymphedema. Methods: Fifty-five patients were enrolled. They were divided into primary lymphedema (PLE), secondary lymphedema (SLE), and venous edema (VE) groups. Twenty-two healthy controls were also recruited as normal control (NC). Serum HA, LN, PIIINP, and CGIV levels of all subjects were assessed using chemiluminescence immunoassay. Statistical analysis and receiver operating characteristic (ROC) curves were used to data analysis. Results: The serum levels of CGIV were significantly decreased in both PLE and SLE groups compared with those in the NC group. Reduced serum CGIV levels were associated with the severity of lymphedema. The serum levels of CGIV and PIIINP were identified decreased in both PLE and SLE groups compared with those in the VE group. However, the levels of serum HA and LN were not observed significantly changed in both PLE and SLE groups than those in NC or VE group. Furthermore, ROC curve indicated that serum CGIV and PIIINP were capable of providing good diagnostic and differential diagnostic efficacy at the most appropriate cutoff point value. Conclusion: The serum levels of CGIV may have clinical significance in the diagnosis of lymphedema. CGIV and PIIINP may play a role in the differentiation of lymphedema from VE.

Hyaladherins May be Implicated in Alcohol-Induced Susceptibility to Bacterial Pneumonia

Although the epidemiology of bacterial pneumonia and excessive alcohol use is well established, the mechanisms by which alcohol induces risk of pneumonia are less clear. Patterns of alcohol misuse, termed alcohol use disorders (AUD), affect about 15 million people in the United States. Compared to otherwise healthy individuals, AUD increase the risk of respiratory infections and acute respiratory distress syndrome (ARDS) by 2-4-fold. Levels and fragmentation of hyaluronic acid (HA), an extracellular glycosaminoglycan of variable molecular weight, are increased in chronic respiratory diseases, including ARDS. HA is largely involved in immune-assisted wound repair and cell migration. Levels of fragmented, low molecular weight HA are increased during inflammation and decrease concomitant with leukocyte levels following injury. In chronic respiratory diseases, levels of fragmented HA and leukocytes remain elevated, inflammation persists, and respiratory infections are not cleared efficiently, suggesting a possible pathological mechanism for prolonged bacterial pneumonia. However, the role of HA in alcohol-induced immune dysfunction is largely unknown. This mini literature review provides insights into understanding the role of HA signaling in host immune defense following excessive alcohol use. Potential therapeutic strategies to mitigate alcohol-induced immune suppression in bacterial pneumonia and HA dysregulation are also discussed.

Antiplatelet drugs and liver fibrosis

Liver fibrosis results from an imbalance between extracellular matrix formation and degradation. The background of liver fibrosis is chronic inflammation and subsequent microcirculation disturbance including microthrombosis. Platelets actively participate in liver fibrosis not only as a part of the clotting system but also by releasing granules containing important mediators. In fact, platelets may play a dual role in the pathophysiology of liver fibrosis as they are able to stimulate regeneration as well as aggravate the destruction of the liver. Recent studies revealed that antiplatelet therapy correlates with inhibition of liver fibrosis. However, liver impairment is associated with extensive coagulation disorders thus the safety of antiplatelet therapy is an area for detailed exploration. In this review, the role of platelets in liver fibrosis and accompanying hemostatic disorders are discussed. Additionally, results of animal and human studies on antiplatelet drugs in liver disorders and their potential therapeutic utility are presented.

Cellular protein markers, therapeutics, and drug delivery strategies in the treatment of diabetes-associated liver fibrosis

Liver fibrosis is the excessive accumulation of extracellular matrix due to chronic injuries, such as viral infection, alcohol abuse, high-fat diet, and toxins. Liver fibrosis is reversible before it progresses to cirrhosis and hepatocellular carcinoma. Type 2 diabetes significantly increases the risk of developing various complications including liver diseases. Abundant evidence suggests that type 2 diabetes and liver diseases are bidirectionally associated. Patients with type 2 diabetes experience more severe symptoms and accelerated progression of live diseases. Obesity and insulin resistance resulting from hyperlipidemia and hyperglycemia are regarded as the two major risk factors that link type 2 diabetes and liver fibrosis. This review summarizes possible mechanisms of the association between type 2 diabetes and liver fibrosis. The cellular protein markers that can be used for diagnosis and therapy of type 2 diabetes-associated liver fibrosis are discussed. We also highlight the potential therapeutic agents and their delivery systems that have been investigated for type 2 diabetes-associated liver fibrosis.

Chitinase 3-like-1 contributes to acetaminophen-induced liver injury by promoting hepatic platelet recruitment

Background

Hepatic platelet accumulation contributes to acetaminophen (APAP)-induced liver injury (AILI). However, little is known about the molecular pathways involved in platelet recruitment to the liver and whether targeting such pathways could attenuate AILI.

Methods

Mice were fasted overnight before intraperitoneally (i.p.) injected with APAP at a dose of 210 mg/kg for male mice and 325 mg/kg for female mice. Platelets adherent to Kupffer cells were determined in both mice and patients overdosed with APAP. The impact of α-chitinase 3-like-1 (α-Chi3l1) on alleviation of AILI was determined in a therapeutic setting, and liver injury was analyzed.

Results

The present study unveiled a critical role of Chi3l1 in hepatic platelet recruitment during AILI. Increased Chi3l1 and platelets in the liver were observed in patients and mice overdosed with APAP. Compared to wild-type (WT) mice, Chil1-/- mice developed attenuated AILI with markedly reduced hepatic platelet accumulation. Mechanistic studies revealed that Chi3l1 signaled through CD44 on macrophages to induce podoplanin expression, which mediated platelet recruitment through C-type lectin-like receptor 2. Moreover, APAP treatment of Cd44-/- mice resulted in much lower numbers of hepatic platelets and liver injury than WT mice, a phenotype similar to that in Chil1-/- mice. Recombinant Chi3l1 could restore hepatic platelet accumulation and AILI in Chil1-/- mice, but not in Cd44-/- mice. Importantly, we generated anti-Chi3l1 monoclonal antibodies and demonstrated that they could effectively inhibit hepatic platelet accumulation and AILI.

Conclusions

We uncovered the Chi3l1/CD44 axis as a critical pathway mediating APAP-induced hepatic platelet recruitment and tissue injury. We demonstrated the feasibility and potential of targeting Chi3l1 to treat AILI.

Funding

ZS received funding from NSFC (32071129). FWL received funding from NIH (GM123261). ALFSG received funding from NIDDK (DK 058369). ZA received funding from CPRIT (RP150551 and RP190561) and the Welch Foundation (AU-0042-20030616). CJ received funding from NIH (DK122708, DK109574, DK121330, and DK122796) and support from a University of Texas System Translational STARs award. Portions of this work were supported with resources and the use of facilities of the Michael E. DeBakey VA Medical Center and funding from Department of Veterans Affairs I01 BX002551 (Equipment, Personnel, Supplies). The contents do not represent the views of the US Department of Veterans Affairs or the US Government.

Chitinase 3-like 1 is a profibrogenic factor overexpressed in the aging liver and in patients with liver cirrhosis

Older age at the time of infection with hepatitis viruses is associated with an increased risk of liver fibrosis progression. We hypothesized that the pace of fibrosis progression may reflect changes in gene expression within the aging liver. We compared gene expression in liver specimens from 54 adult donors without evidence of fibrosis, including 36 over 40 y old and 18 between 18 and 40 y old. Chitinase 3-like 1 (CHI3L1), which encodes chitinase-like protein YKL-40/CHI3L1, was identified as the gene with the greatest age-dependent increase in expression in liver tissue. We investigated the cellular source of CHI3L1 in the liver and its function using liver tissue specimens and in vitro models. CHI3L1 expression was significantly higher in livers of patients with cirrhosis of diverse etiologies compared with controls represented by patients who underwent liver resection for hemangioma. The highest intrahepatic CHI3L1 expression was observed in cirrhosis due to hepatitis D virus, followed by hepatitis C virus, hepatitis B virus, and alcohol-induced cirrhosis. In situ hybridization of CHI3L1 messenger RNA (mRNA) identified hepatocytes as the major producers of CHI3L1 in normal liver and in cirrhotic tissue, wherein hepatocytes adjacent to fibrous septa showed higher CHI3L1 expression than did those in more distal areas. In vitro studies showed that recombinant CHI3L1 promotes proliferation and activation of primary human hepatic stellate cells (HSCs), the major drivers of liver fibrosis. These findings collectively demonstrate that CHI3L1 promotes liver fibrogenesis through a direct effect on HSCs and support a role for CHI3L1 in the increased susceptibility of aging livers to fibrosis progression.

Evaluation of Chitinase 3-like 1 (CHI3L1) as a noninvasive biomarker of hepatic fibrosis in patients with Hepatitis B virus-related compensated chronic liver disease

BACKGROUND

Liver biopsy is the gold-standard method for diagnosing and staging liver fibrosis, but the procedure is invasive, not available in the primary health care facilities, and not free from complications. Noninvasive serum biomarkers of hepatic fibrosis are the current research focus.

OBJECTIVES

To assess the correlation between serum Chitinase 3-like 1 (CHI3L1) levels and histological severity in patients with Hepatitis B Virus (HBV)-related compensated chronic liver disease (CLD).

MATERIAL AND METHODS

This cross-sectional study evaluated 50 treatment-naïve patients with chronic hepatitis B with compensated CLD. Liver biopsy was done, and hepatic fibrosis was categorized using the METAVIR scoring system; we divided the study subjects into three groups; group 1 included subjects with F0 and F1, group 2 having F2 group 3 having F3 and F4. Serum CHI3L1 was measured in all by immunoassay.

RESULT

Among 50 patients, only one had METAVIR score F0, seven had F1, 33 had F2, nine had F3, and none had METAVIR score F4. The median value of CHI3L1 was 460.8 (IQR 340.1-570.3) in all study subjects; 359.5 (IQR 272.8-526.9) in group 1, 450.0 (IQR 307.75-5332.0) in group 2, and 1355.5 (IQR 530.75-1580.5) in the group 3. The difference in median CHI3L1 across the groups was statistically significant. Serum aspartate aminotransferase (AST) and the AST to Platelet Ratio Index (APRI) score had significant positive correlations with CHI3L1 levels. CHI3L1 also had significant positive correlations with METAVIR scores.

CONCLUSION

This study found a positive correlation between serum CHI3L1 level and hepatic histological severity in patients with HBV-related compensated CLD. Further larger-scale research is needed to establish the fact.

Macrophages as a source of fibrosis biomarkers for non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease/steatohepatitis (NAFLD/NASH) are becoming major liver diseases worldwide. Liver fibrosis and cirrhosis are among the most significant risk factors of hepatocellular carcinoma (HCC) and associated with the long-term prognosis of NAFLD patients. To stratify the risk of HCC in NAFLD patients clinically, the discovery of non-invasive fibrosis markers is needed urgently. Liver macrophages play critical roles in the regulation of inflammation and fibrosis by interacting with hepatic stellate cells (HSCs) and other immune cells. Thus, it is rational to explore feasible biomarkers for liver fibrosis by focusing on macrophage-related factors. We examined serum factors comprehensively in multiple cohorts of NAFLD/NASH patients to determine whether they were correlated with the biopsy-proven fibrosis stage. We found that the serum levels of interleukin (IL)-34, YKL-40 and soluble Siglec-7 (sSiglec7) were closely associated with liver fibrosis and served as diagnostic biomarkers in patients with NAFLD/NASH. In the NAFLD liver, IL-34 was produced by activated fibroblasts, and YKL-40 and sSiglec-7 were secreted from macrophages. The sensitivity and specificity of these markers to detect advanced liver fibrosis varied, supporting the notion that the combination of these markers with other modalities is an option for clinical application.

Chitinase-3 like-protein-1 function and its role in diseases

Non-enzymatic chitinase-3 like-protein-1 (CHI3L1) belongs to glycoside hydrolase family 18. It binds to chitin, heparin, and hyaluronic acid, and is regulated by extracellular matrix changes, cytokines, growth factors, drugs, and stress. CHI3L1 is synthesized and secreted by a multitude of cells including macrophages, neutrophils, synoviocytes, chondrocytes, fibroblast-like cells, smooth muscle cells, and tumor cells. It plays a major role in tissue injury, inflammation, tissue repair, and remodeling responses. CHI3L1 has been strongly associated with diseases including asthma, arthritis, sepsis, diabetes, liver fibrosis, and coronary artery disease. Moreover, following its initial identification in the culture supernatant of the MG63 osteosarcoma cell line, CHI3L1 has been shown to be overexpressed in a wealth of both human cancers and animal tumor models. To date, interleukin-13 receptor subunit alpha-2, transmembrane protein 219, galectin-3, chemo-attractant receptor-homologous 2, and CD44 have been identified as CHI3L1 receptors. CHI3L1 signaling plays a critical role in cancer cell growth, proliferation, invasion, metastasis, angiogenesis, activation of tumor-associated macrophages, and Th2 polarization of CD4+ T cells. Interestingly, CHI3L1-based targeted therapy has been increasingly applied to the treatment of tumors including glioma and colon cancer as well as rheumatoid arthritis. This review summarizes the potential roles and mechanisms of CHI3L1 in oncogenesis and disease pathogenesis, then posits investigational strategies for targeted therapies.

Review article: the signalling and functional role of the extracellular matrix in the development of liver fibrosis

BACKGROUND

Patients with liver fibrosis show a large heterogeneity, and for that reason effective treatments are still lacking. Emerging data suggest that there is more to fibrosis than previously understood. Opposed to earlier belief of being a passive scaffold for cells to reside in, the extracellular matrix (ECM) is now known to hold both signalling and functional properties important for the development of fibrosis. The interaction between the ECM and the collagen-producing cells determines the course of the disease but is still poorly understood. Exploring the dynamics of this interplay will aid in the development of effective treatments.

AIM

To summarise and discuss the latest advances in the pathogenesis of liver fibrosis as well as key mediators of early disease progression.

METHODS

Through literature search using databases including PubMed and Google Scholar, manuscripts published between 1961 and 2019 were included to assess both well-established and recent theories of fibrosis development. Both pre-clinical and clinical studies were included.

RESULTS

Fibrosis alters the structure of the ECM releasing signalling fragments with the potential to escalate disease severity. In a diseased liver, hepatic stellate cells and other fibroblasts, together with hepatocytes and sinusoidal cells, produce an excessive amount of collagens. The cell-to-collagen interactions are unique in the different liver aetiologies, generating ECM profiles with considerable patient-monitoring potential.

CONCLUSIONS

The local milieu in the injured area affects the course of fibrosis development in a site-specific manner. Future research should focus on the dissimilarities in the ECM profile between different aetiologies of liver fibrosis.

Chitinases and Chitinase-Like Proteins in Obstructive Lung Diseases - Current Concepts and Potential Applications

Chitinases, enzymes that cleave chitin’s chain to low molecular weight chitooligomers, are widely distributed in nature. Mammalian chitinases belong to the 18-glycosyl-hydrolase family and can be divided into two groups: true chitinases with enzymatic activity (AMCase and chitotriosidase) and chitinase-like proteins (CLPs) molecules which can bind to chitin or chitooligosaccharides but lack enzymatic activity (eg, YKL-40). Chitinases are thought to be part of an innate immunity against chitin-containing parasites and fungal infections. Both groups of these hydrolases are lately evaluated also as chemical mediators or biomarkers involved in airway inflammation and fibrosis. The aim of this article is to present the current knowledge on the potential role of human chitinases and CLPs in the pathogenesis, diagnosis, and course of obstructive lung diseases. We also assessed the potential role of chitinase and CLPs inhibitors as therapeutic targets in chronic obstructive pulmonary disease and asthma.

Sick fat: the good and the bad of old and new circulating markers of adipose tissue inflammation

Adipose tissue (AT) is one of the largest endocrine organs contributing to metabolic homeostasis. The functional pleiotropism of AT depends on its ability to secrete a large number of hormones, cytokines, extracellular matrix proteins and growth factors, all influencing many local and systemic physiological and pathophysiological processes. In condition of chronic positive energy balance, adipocyte expansion, hypoxia, apoptosis and stress all lead to AT inflammation and dysfunction, and it has been demonstrated that this sick fat is a main risk factor for many metabolic disorders, such as type 2 diabetes mellitus, fatty liver, cardiovascular disease and cancer. AT dysfunction is tightly associated with aberrant secretion of bioactive peptides, the adipocytokines, and their blood concentrations often reflect the expression in the AT. Despite the existence of an association between AT dysfunction and systemic pro-inflammatory state, most of the circulating molecules detectable in obese and dysmetabolic individuals do not identify specifically the condition of sick fat. Based on this premise, this review provides a concise overview of "classic" and novel promising adipocytokines associated with AT inflammation and discusses possible critical approaches to their interpretation in clinical practice.

Chitinase 3-like 1 deficiency ameliorates liver fibrosis by promoting hepatic macrophage apoptosis

AIM

Chitinase 3-like 1 (CHI3L1), an 18-glycosyl hydrolase-related molecule, is a member of the enzymatically inactive chitinase-like protein family. Serum levels of CHI3L1 are strongly correlated with hepatic fibrosis progression during many liver diseases. Therefore, this protein could be involved in the development of hepatic fibrosis pathology; however, its role has not been elucidated. We aimed to elucidate its role in the pathophysiology of liver fibrosis.

METHODS

Chitinase 3-like 1-deficient (Chi3l1-/- ) mice were given carbon tetrachloride twice per week for 4 weeks or fed a methionine choline-deficient diet for 12 weeks to generate mouse liver fibrosis models. Human fibrotic liver tissues were also examined immunohistochemically.

RESULTS

In human and mouse fibrotic livers, CHI3L1 expression was mainly localized to hepatic macrophages, and the intrahepatic accumulation of CHI3L1+ macrophages was significantly enhanced compared to that in control livers. In the two mouse models, hepatic fibrosis was significantly ameliorated in Chi3l1-/- mice compared to that in wild-type mice, which was dependent on hepatic macrophages. The accumulation and activation of hepatic macrophages was also significantly suppressed in Chi3l1-/- mice compared to that in wild-type mice. Furthermore, apoptotic hepatic macrophages were significantly increased in Chi3l1-/- mice. Chitinase 3-like 1 was found to inhibit hepatic macrophage apoptosis by suppressing Fas expression and activating Akt signaling in an autocrine manner, which resulted in hepatic macrophage accumulation and activation, exaggerating liver fibrosis.

CONCLUSIONS

Chitinase 3-like 1 exacerbates liver fibrosis progression by suppressing apoptosis in hepatic macrophages. Therefore, this might be a potential therapeutic target for the treatment of liver fibrosis.

Roles of chitinase 3-like 1 in the development of cancer, neurodegenerative diseases, and inflammatory diseases

Chitinase 3-like 1 (CHI3L1) is a secreted glycoprotein that mediates inflammation, macrophage polarization, apoptosis, and carcinogenesis. The expression of CHI3L1 is strongly increased by various inflammatory and immunological conditions, including rheumatoid arthritis, multiple sclerosis, Alzheimer's disease, and several cancers. However, its physiological and pathophysiological roles in the development of cancer and neurodegenerative and inflammatory diseases remain unclear. Several studies have reported that CHI3L1 promotes cancer proliferation, inflammatory cytokine production, and microglial activation, and that multiple receptors, such as advanced glycation end product, syndecan-1/αVβ3, and IL-13Rα2, are involved. In addition, the pro-inflammatory action of CHI3L1 may be mediated via the protein kinase B and phosphoinositide-3 signaling pathways and responses to various pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin-1β, interleukin-6, and interferon-γ. Therefore, CHI3L1 could contribute to a vast array of inflammatory diseases. In this article, we review recent findings regarding the roles of CHI3L1 and suggest therapeutic approaches targeting CHI3L1 in the development of cancers, neurodegenerative diseases, and inflammatory diseases.

Chitinase-3-like-1 deficiency attenuates ethanol-induced liver injury by inhibition of sterol regulatory element binding protein 1-dependent triglyceride synthesis

OBJECTIVE

Alcohol overconsumption and abuse lead to alcoholic liver disease (ALD), which is a major chronic liver disease worldwide. Chitinase-3-like protein 1 (CHI3L1) have an important role in the pathogenesis of inflammatory disease. However, the role of CHI3L1 in ALD has not yet been reported. In the present study, we investigated the effect of CHI3L1 on chronic plus binge ethanol-induced liver injury.

METHODS

CHI3L1 knock out (KO) mice and their littermate control mice based on C57BL/6 (10-12 weeks old) were fed on a Lieber-DeCarli diet containing 6.6% ethanol for 10 days. And, CHI3L1 siRNA or CHI3L1 expressing vector was transfected HepG2 cells were treated with ethanol or without.

RESULTS

Ethanol-induced hepatic triglyceride (TG) levels and the mRNA levels of TG synthesis-related genes such as acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS) and stearoyl-CoA desaturase-1 (SCD1) were decreased in the liver of CHI3L1 knock out (KO) mice and the HepG2 cells transfected with CHI3L1 siRNA. Increased mRNA level and activation of SREBP1 which is transcription factor of ACC, FAS and SCD1 by ethanol feeding were reduced in the liver of ethanol-fed CHI3L1 KO mice. Moreover, ethanol-induced SREBP1 luciferase activity and mRNA level of SREBP1, ACC, FAS and SCD1 were also decreased in the HepG2 cells transfected with CHI3L1 siRNA, while those were further increased in the HepG2 cells treated with recombinant human CHI3L1. Furthermore, oxidative stress and up-regulated pro-inflammatory cytokines by ethanol were recovered in the liver of ethanol-fed CHI3L1 KO mice.

CONCLUSION

Our finding suggest that inhibition of CHI3L1 suppressed ethanol-induced liver injury through inhibition of TG synthesis, and the blocking of oxidative stress and hepatic inflammation induced SREBP1 activity could be significant.

Comparison of chitinase-3-like protein 1, aspartate aminotransferase-to-platelet ratio index, and fibrosis-4 index with shear-wave elastography

BACKGROUND

In the past, there has been an exponential increase in the potential biomarkers that can be used for staging of liver fibrosis. In light of intraobserver and intralobular variations, criticism has been directed at liver biopsy, and its efficacy has been challenged. Shear-wave elastography (SWE) has become a routine method for pre-assessment of liver fibrosis. Serum markers such as chitinase-3-like protein 1 (CHI3L1) also known as YKL-40, aspartate aminotransferase-to-platelet ratio index, and fibrosis-4 (Fib-4) index have been researched as potential alternates to detect liver fibrosis.

STUDY

A total of 150 enrolled patients with chronic hepatitis underwent serum analysis to estimate CHI3L1 or YKL-40 level, aspartate aminotransferase-to-platelet ratio index, and Fib-4 index. These patients also underwent SWE.

RESULTS

The distribution of fibrosis grade according to SWE was F0: 46 patients, F1: 31 patients, F2: 16 patients, F3: four patients, and F4: 53 patients. Receiver operating characteristic curve analysis for F0-F1 versus F2-F3, F0-F1 versus F4, and F2-F3 versus F4 gave area under curve values of 0.56 (P>0.05), 0.76 (P<0.01), and 0.75, respectively (P<0.01) for aspartate aminotransferase-to-platelet ratio index; of 0.65 (P<0.05), 0.78 (P<0.01), and 0.7, respectively (P<0.05) for Fib-4 index; and 0.98, 0.99, and 0.95, respectively (P<0.01 for all) for CHI3L1.

CONCLUSION

CHI3L1 could be used as a preliminary tool to assess mild/absent fibrosis from significant fibrosis and cirrhosis.

An Evaluation of the Collagen Fragments Related to Fibrogenesis and Fibrolysis in Nonalcoholic Steatohepatitis

Fibrosis, resulted from the imbalance of fibrogenesis and fibrolysis, is a key readout of disease progression in nonalcoholic steatohepatitis (NASH) and reflects mortality risk. Non-invasive biomarkers capable of diagnosing fibrosis stages and monitoring fibrosis changes in NASH patients are urgently needed. This study is to evaluate collagen formation and degradation biomarkers, reflective of fibrogenesis or fibrolysis, in patients with biopsy proven NASH. Collagen formation biomarker PRO-C3 and PRO-C6 levels were significantly higher in patients with advanced fibrosis stage 3–4 than those with fibrosis stage 0–2. Elevated PRO-C3 levels were also associated with severe lobular inflammation and ballooning, but not with steatosis. Multivariate logistic regression analysis identified PRO-C3 and PRO-C6 to be independently related to fibrosis stage. PRO-C3 showed similar performance to identify patients with advanced fibrosis in discovery and validation cohorts. Furthermore, in a longitudinal study cohort with paired biopsies, mean PRO-C3 increased with worsening of fibrosis and decreased with fibrosis improvement. The results suggest that PRO-C3 may be a potentially useful biomarker in identifying patients with advanced fibrosis and active fibrogenesis, as well as in assessing changes in fibrosis over time. It is worthy of further evaluation to confirm its diagnostic value and clinical utility.

Alcoholic liver disease

Alcoholic liver disease (ALD) is the most prevalent type of chronic liver disease worldwide. ALD can progress from alcoholic fatty liver (AFL) to alcoholic steatohepatitis (ASH), which is characterized by hepatic inflammation. Chronic ASH can eventually lead to fibrosis and cirrhosis and in some cases hepatocellular cancer (HCC). In addition, severe ASH (with or without cirrhosis) can lead to alcoholic hepatitis, which is an acute clinical presentation of ALD that is associated with liver failure and high mortality. Most individuals consuming >40 g of alcohol per day develop AFL; however, only a subset of individuals will develop more advanced disease. Genetic, epigenetic and non-genetic factors might explain the considerable interindividual variation in ALD phenotype. The pathogenesis of ALD includes hepatic steatosis, oxidative stress, acetaldehyde-mediated toxicity and cytokine and chemokine-induced inflammation. Diagnosis of ALD involves assessing patients for alcohol use disorder and signs of advanced liver disease. The degree of AFL and liver fibrosis can be determined by ultrasonography, transient elastography, MRI, measurement of serum biomarkers and liver biopsy histology. Alcohol abstinence achieved by psychosomatic intervention is the best treatment for all stages of ALD. In the case of advanced disease such as cirrhosis or HCC, liver transplantation may be required. Thus, new therapies are urgently needed.

Diagnosis and staging of fibrosis in patients with chronic hepatitis C: comparison and critical overview of current strategies

In the past years, what has always been considered undisputed true in liver fibrosis staging has been challenged. Diagnostic performance of histological evaluation has proven to be significantly influenced by sample- and observer-related variabilities. Differentiation between lower levels of fibrosis remains difficult for many, if not all, test modalities, including liver biopsy but, perhaps, such a distinction is not indispensable in light of current therapeutic approaches. Biomarkers and elastography offer, nonetheless, high predictive values for advanced fibrosis and cirrhosis and correlate well with liver-related outcomes. Necroinflammation, steatosis, and hemodynamic changes may significantly interfere with elastography-based techniques, and longitudinal follow-up strategies must be tailored in light of these findings. Knowledge of different test modalities and diagnostic performance indicators can allow for better clinical decision-making and resource allocation.

Serum YKL-40 as a biomarker for liver fibrosis in chronic hepatitis B patients with normal and mildly elevated ALT

Purpose

YKL-40 is a chitinase-like protein expressed in multiple tissues including liver and is reported as a fibrosis marker. This study aimed to determine whether YKL-40 could serve as a diagnostic marker for the assessment of liver fibrosis in chronic hepatitis B patients with normal and mildly elevated ALT.

Methods

Six hundred and eighty-five patients with chronic hepatitis B infection were enrolled in this study from October 2013 to March 2016. All patients underwent liver biopsy and then staged based on Ishak histological system. Serum YKL-40 levels were measured by Human Magnetic Luminex Assays.

Results

Among chronic hepatitis B patients with normal and mildly elevated ALT, almost more than 30% of patients have significant liver fibrosis. Serum YKL-40 levels increased significantly in parallel with the progression of fibrosis in patients with ALT less than two times the upper limit of normal range (P < 0.0001). Multivariate analysis revealed that serum YKL-40, hyaluronic acid, PLT, and AST were independently associated with significant fibrosis. We established a novel YKL-40-based fibrosis model for patients with ALT less than two times the upper limit of normal range (ULN). YKL-40 model was superior to APRI, FIB-4, Forns’ index, and Hui model for diagnosis of significant fibrosis in patients with ALT < 2ULN, with AUROCs of 0.786 [95% confidence interval (CI) 0.726–0.846] in the training group, 0.831 (95%CI 0.752–0.910) in the validation group and 0.801 (95%CI 0.753–0.849) in the entire cohort.

Conclusion

Serum YKL-40 is a feasible biomarker of liver fibrosis in chronic hepatitis B patients. YKL-40 model was superior to APRI, FIB-4, Forns’ index and Hui model for diagnosis of significant fibrosis in patients with normal and mildly elevated ALT.

Electronic supplementary material

The online version of this article (10.1007/s15010-018-1136-2) contains supplementary material, which is available to authorized users.

Progress in non-invasive detection of liver fibrosis

Liver fibrosis is an important pathological precondition for hepatocellular carcinoma. The degree of hepatic fibrosis is positively correlated with liver cancer. Liver fibrosis is a series of pathological and physiological process related to liver cell necrosis and degeneration after chronic liver injury, which finally leads to extracellular matrix and collagen deposition. The early detection and precise staging of fibrosis and cirrhosis are very important for early diagnosis and timely initiation of appropriate therapeutic regimens. The risk of severe liver fibrosis finally progressing to liver carcinoma is >50%. It is known that biopsy is the gold standard for the diagnosis and staging of liver fibrosis. However, this method has some limitations, such as the potential for pain, sampling variability, and low patient acceptance. Furthermore, the necessity of obtaining a tissue diagnosis of liver fibrosis still remains controversial. An increasing number of reliable non-invasive approaches are now available that are widely applied in clinical practice, mostly in cases of viral hepatitis, resulting in a significantly decreased need for liver biopsy. In fact, the non-invasive detection and evaluation of liver cirrhosis now has good accuracy due to current serum markers, ultrasound imaging, and magnetic resonance imaging quantification techniques. A prominent advantage of the non-invasive detection and assessment of liver fibrosis is that liver fibrosis can be monitored repeatedly and easily in the same patient. Serum biomarkers have the advantages of high applicability (>95%) and good reproducibility. However, their results can be influenced by different patient conditions because none of these markers are liver-specific. The most promising techniques appear to be transient elastography and magnetic resonance elastography because they provide reliable results for the detection of fibrosis in the advanced stages, and future developments promise to increase the reliability and accuracy of the staging of hepatic fibrosis. This article aims to describe the recent progress in the development of non-invasive assessment methods for the staging of liver fibrosis, with a special emphasize on computer-aided quantitative and deep learning methods.

High serum N-terminal propeptide of procollagen type III concentration is associated with liver diseases

INTRODUCTION

N-terminal propeptide of procollagen type III (PIIINP) is generated during the synthesis of type III collagen. PIIINP can be measured in the serum as an indicator of liver fibrosis and cirrhosis.

AIM

To evaluate the effect of liver diseases of different aetiologies and clinical severity of liver cirrhosis on the serum level of PIIINP.

MATERIAL AND METHODS

Patients with alcoholic cirrhosis (AC) - 63 subjects, non-alcoholic cirrhosis (NAC) - 31 and toxic hepatitis (HT) - 33 were studied. Cirrhotic patients were classified according to the Child-Pugh scale. The samples were analysed using the ELISA method.

RESULTS

The level of PIIINP was significantly higher in patients with alcoholic cirrhosis, non-alcoholic cirrhosis, and toxic hepatitis in comparison to the control group. There were no significant differences in the serum PIIINP levels between liver diseases and according to the severity of liver cirrhosis. PIIINP has the highest diagnostic power for the diagnosis of toxic hepatitis. The highest sensitivity was reached in alcoholic cirrhosis, but other diagnostic values (specificity, positive predictive value (PPV), negative predictive value (NPV), diagnostic accuracy (ACC)) in alcoholic cirrhosis were lower than that in toxic hepatitis. In the diagnosis of non-alcoholic cirrhosis PIIINP has low sensitivity, specificity, PPV, NPV, and ACC.

CONCLUSIONS

The serum PIIINP shows the alterations in liver diseases in comparison to healthy controls, but not between diseases. Taking the above into account we can suggest that PIIINP may be a useful test for the detection of liver diseases.

Glycoprotein YKL-40 Levels in Plasma Are Associated with Fibrotic Changes on HRCT in Asbestos-Exposed Subjects

YKL-40 is a chitinase-like glycoprotein produced by alternatively activated macrophages that are associated with wound healing and fibrosis. Asbestosis is a chronic asbestos-induced lung disease, in which injury of epithelial cells and activation of alveolar macrophages lead to enhanced collagen production and fibrosis. We studied if YKL-40 is related to inflammation, fibrosis, and/or lung function in subjects exposed to asbestosis. Venous blood samples were collected from 85 men with moderate or heavy occupational asbestos exposure and from 28 healthy, age-matched controls. Levels of plasma YKL-40, CRP, IL-6, adipsin, and MMP-9 were measured with enzyme-linked immunosorbent assay (ELISA). Plasma YKL-40 levels were significantly higher in subjects with asbestosis (n = 19) than in those with no fibrotic findings in HRCT following asbestos exposure (n = 66) or in unexposed healthy controls. In asbestos-exposed subjects, plasma YKL-40 correlated negatively with lung function capacity parameters FVC (Pearson's r −0.259, p = 0.018) and FEV₁ (Pearson's r −0.240, p = 0.028) and positively with CRP (Spearman's rho 0.371, p < 0.001), IL-6 (Spearman's rho 0.314, p = 0.003), adipsin (Spearman's rho 0.459, p < 0.001), and MMP-9 (Spearman's rho 0.243, p = 0.025). The present finding suggests YKL-40 as a biomarker associated with fibrosis and inflammation in asbestos-exposed subjects.

Chitinase 3-like-1 deficient donor splenocytes accentuated the pathogenesis of acute graft-versus-host diseases through regulating T cell expansion and type I inflammation

Acute graft-versus-host disease (aGVHD) is a major complication following transplantation, limiting the success of this therapy. Chitinase 3-like-1 (CHI3L1), a member of the glycosyl hydrolase 18 family, plays a critical role in bacterial infections, allergic disease and a variety of malignancies. Here, we investigated whether CHI3L1 could affect the pathogenesis of aGVHD in a mouse allo-HCT model. In this study, we show that CHI3L1 deficiency in donor T cells increased the severity of aGVHD through enhancing systemic and local inflammation. In addition, we found that aGVHD induced by CHI3L1-knockout (CHI3L1-KO) donors resulted in massive expansion of donor CD3⁺ T cells, release of Th1-related cytokines and chemokines, and significant inhibition of CD4⁺CD25⁺Foxp3⁺ regulatory T cells (Tregs) without changing the suppressive ability of donor Tregs remarkably. Expression of PERK1/2 and PAkt increased both in the skin and intestine from CHI3L1-KO splenocytes-treated aGVHD mice. Moreover, at mRNA and protein levels, we defined several molecules that may account for the enhanced ability of CHI3L1-KO splenocytes to migrate into target organs and produce Th1-related cytokines and chemokines, such as CXCL9, CXCL11, IFN-γ and TNF-α. Therefore, these results imply that CHI3L1 levels in donor cells may be related to the risk of aGVHD and targeting CHI3L1 may be a promising clinical strategy to control aGVHD.

Correlation of Chitinase 3-Like 1 Single Nucleotide Polymorphisms with Hepatocellular Carcinoma in Taiwan

Hepatocellular carcinoma (HCC) is the second leading cause of cancer death in Taiwan. Multiple risk factors, such as chronic hepatitis B or C virus infection, carcinogen exposure, cirrhosis, and various single-nucleotide polymorphisms (SNPs), are considered to contribute to hepatocarcinogenesis. Chitinase-3-like protein 1 (CHI3L1), a biomarker implicated in inflammation and tissue remodeling, plays a promoting role in angiogenesis, antiapoptosis, and cell proliferation. This study investigated the role of CHI3L1 SNPs in HCC susceptibility and clinicopathology. Real-time polymerase chain reaction was used to analyze four SNPs of CHI3L1 in 343 patients with HCC and 686 cancer-free controls. We found associations with HCC susceptibility in CHI3L1 rs880633 polymorphism carriers with genotypes (TC+CC). We observed that HCC patients had lower frequencies of CHI3L1 rs6691378 polymorphisms with the variant genotype GA+AA than the wild-type carriers with distant metastasis and positive HBsAg did. In 200 HBsAg negative HCC patients, we observed that the CHI3L1 rs4950928 polymorphisms carriers with the variant genotype CG+GG had higher frequencies of vascular invasion. Finally, carriers of CHI3L1 rs6691378 and 10399805 polymorphisms with the variant genotypes GA+AA showed lower levels of alpha-fetoprotein in HCC laboratory status. In conclusion, our results indicate that patients with CHI3L1 rs880633 variant genotypes TC+CC are at a higher risk of HCC. CHI3L1 polymorphisms rs880633 or rs4950928 may be potential candidates for predicting poor HCC prognosis and clinical status.

Serum YKL-40 as a marker of liver fibrosis in patients with non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a common cause of chronic non-viral liver disease. YKL-40, chitinase-like protein expressed in multiple tissues including liver, is involved in cell proliferation, inflammation and remodeling of the extracellular matrix. The aim of this study was to assess whether serum YKL-40 levels are associated with liver fibrosis in NAFLD patients. Serum YKL-40 levels were quantified in 111 NAFLD patients and 23 HCC patients with NAFLD. To identify the source of YKL-40, immunofluorescence staining of liver specimens from NAFLD patients was performed. Serum YKL-40 levels in NAFLD patients increased in accordance with the progression of liver fibrosis. Multivariate analysis revealed that YKL-40 was one of the independent factors significantly associated with severe fibrosis (F3-4). We established a new predictive model for fibrosis of NAFLD, using logistic regression analysis: YKL-40 based fibrosis score = −0.0545 + type IV collagen 7s * 0.3456 + YKL-40 * 0.0024. Serum YKL-40 levels of HCC patients with non-cirrhotic NAFLD were significantly higher than those without HCC. Immunofluorescence staining showed that YKL-40 was expressed by macrophages in liver tissue of NAFLD patients. In conclusion, macrophage-derived YKL-40 is a feasible biomarker of liver fibrosis in NAFLD patients.

Estimation of Serum YKL-40 by Real-Time Surface Plasmon Resonance Technology in North-Indian Asthma Patients

BACKGROUND

Many studies reported for estimating serum YKL-40 using ELISA or RIA methods. This study introduces the plausible utilization of real-time surface plasmon resonance (SPR) technology in investigating the expression of serum YKL-40 protein levels and ELISA method for serum IgE in bronchial asthma.

METHODS

A commercially available BIAcore 2000 instrument, based on SPR technology, was utilized for assessing serum YKL-40 levels in a control sample size of 45 and active sample size of 97. Antibody immobilization was optimized to obtain the best sensor performance and a sensitive analytic detection. A commercially available ELISA kit was utilized for detecting serum IgE to estimate allergic condition-associated asthma.

RESULTS

The results of SPR technology could distinctly classify with highly statistical significance, the asthma severities by estimating the elevated levels of YKL-40 in blood sera of minute quantities (up to 0.33 ng/ml), and thus differentiates superior utility in comparison with ELISA method. No statistically significant correlation of YKL-40 and IgE was observed.

CONCLUSIONS

Serum YKL-40 may be used as a protein marker in classifying asthma severity by applying SPR technology as a reliable, label-free, highly sensitive, and cost-effective tool.

Iron overload correlates with serum liver fibrotic markers and liver dysfunction: Potential new methods to predict iron overload-related liver fibrosis in thalassemia patients

BACKGROUND

Early detection of liver fibrosis in thalassemia patients and rapid initiation of treatment to interfere with its progression are extremely important.

OBJECTIVE

This study aimed to find a sensitive, easy-to-detect and noninvasive method other than liver biopsy for early detection of liver fibrosis in thalassemia patients.

METHODS

A total of 244 Chinese Thalassemia patients with non-transfusion-dependent thalassemia (NTDT, n = 105) or thalassemia major (TM, n = 139) and 120 healthy individuals were recruited into the present study, and blood collagen type IV (C IV), precollagen type III (PIIINPC) and hyaluronic acid (HA), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and ferritin were measured. Liver iron concentration was determined by MRI. The correlation of serum markers with liver iron load and liver function was evaluated.

RESULTS

Serum C IV, PIIINPC and HA were significantly elevated in Chinese patients with NTDT and further elevated in TM patients. Moreover, C IV, PIIINPC and HA were also positively correlated to serum ferritin and liver iron concentration and further elevated during the progression to multi-organ damage in NTDT patients. Finally, serum ferritin and liver iron concentration were significantly correlated with liver dysfunction determined by AST and ALT.

CONCLUSION

Taken together, our results indicate that monitoring serum C IV, PIIINPC and HA is a potentially sensitive method to predict the risks for iron overload-related liver fibrosis in Chinese thalassemia patients.

Role of inflammatory marker YKL-40 in the diagnosis, prognosis and cause of cardiovascular and liver diseases

This review summarizes present evidence for the role of YKL-40 in the diagnosis, prognosis and cause of cardiovascular and alcoholic liver disease. The question of whether YKL-40 is merely a marker or a causal factor in the development of cardiovascular and liver disease is addressed, with emphasis on the Mendelian randomization design. The Mendelian randomization approach uses genetic variants associated with lifelong high plasma YKL-40 levels that are largely unconfounded and not prone to reverse causation. Thus, the approach mimics a controlled double-blind randomized trial, but it uses genetic variants rather than a drug and placebo, and like a blinded trial, it allows inference about causality. Moreover, the review also covers background on the molecular biology and functions of YKL-40, YKL-40 levels in healthy individuals and reference range, and the role of YKL-40 as a biomarker of cardiovascular and alcoholic liver disease. YKL-40 is a plasma protein named after its three N-terminal amino acids, Y (tyrosine), K (lysine) and L (leucine), and its molecular weight of 40 kDa. It is produced by local inflammatory cells in inflamed tissues, such as lipid-laden macrophages inside the vessel wall and perhaps also hepatic stellate cells. Observational studies show that plasma YKL-40 levels are elevated in patients with cardiovascular and liver disease and are associated with disease severity and prognosis. Furthermore, elevated plasma YKL-40 levels in apparently healthy individuals are associated with a 2-fold increased risk of future ischemic stroke and venous thromboembolism, but not with myocardial infarction, suggesting that YKL-40 could play a role in the formation of embolisms rather than atherosclerosis per se. Further, elevated YKL-40 levels combined with excessive alcohol consumption are associated with 10-years risk of alcoholic liver cirrhosis of up to 7%, suggesting that YKL-40 can be used as a strong noninvasive marker of predicting alcoholic liver cirrhosis. Importantly, in Mendelian randomization studies, genetically elevated plasma YKL-40 levels were not associated with risk of cardiovascular and alcoholic liver disease, thus suggesting that plasma YKL-40 does not play a causal role in the development of these diseases. Despite this, plasma YKL-40 levels may play a role in disease progression after diagnosis, and inhibition of YKL-40 activity might be a novel therapy in some cardiovascular and liver diseases.

CHI3L1 Is a Liver-Enriched, Noninvasive Biomarker That Can Be Used to Stage and Diagnose Substantial Hepatic Fibrosis

Liver fibrosis is a major disease that is primarily caused by hepatitis virus infections, toxins, and alcohol abuse. Diagnosing and staging liver fibrosis are critical in guiding the treatment of chronic liver diseases, according to several international and Chinese guidelines. Liver biopsy is the gold standard for diagnosing and staging liver fibrosis, but it is invasive and suffers from several limitations. Consequently, much research has focused on the search for a noninvasive serum biomarker of fibrosis. In this study, we determined that Chitinase 3-like 1 (CHI3L1) is an abundantly expressed liver gene whose expression is highly enriched in the liver. We then compared serum levels of CHI3L1 among patients with various stages of liver fibrosis, as determined by liver biopsies, and found that the CHI3L1 levels were able to differentiate early stages of liver fibrosis (S0-S2) from late stages of liver fibrosis (S3-S4). We further showed that CHI3L1 is a good marker of substantial fibrosis, with areas under the ROC curves (AUCs) of 0.94 for substantial (S2, S3, S4) fibrosis and 0.96 for advanced (S3, S4) fibrosis. Finally, we showed that CHI3L1 is superior to hyaluronic acid (HA), type III procollagen (PCIII), laminin (LN), and type IV collagen (CIV), which are also serum biomarkers of liver fibrosis, in identifying advanced liver fibrosis in patients with HBV-related liver fibrosis in China.

Plasma Pro-C3 (N-terminal type III collagen propeptide) predicts fibrosis progression in patients with chronic hepatitis C

BACKGROUND & AIMS

Fibrogenesis results in release of certain extracellular matrix protein fragments into the circulation. We evaluated the diagnostic and prognostic performance of two novel serological markers, the precisely cleaved N-terminal propeptide of type III collagen (Pro-C3) and a peptide of helical collagen type III degradation (C3M), in chronic hepatitis C (CHC) patients.

METHOD

Pro-C3 and C3M were measured by ELISA in plasma from CHC patients (n = 194) from a prior phase II antifibrotic trial (NCT00244751). Plasma samples and paired liver biopsies were obtained at baseline and after 1-year. Patients were stratified according to Ishak stages 2-4. Internal cross-validation was performed by bootstrap analysis.

RESULTS

Pro-C3 levels were significantly higher in CHC patients in Ishak stage 4 compared to stage 2 (P < 0.001) or 3 (P < 0.01). Pro-C3 could significantly distinguish moderate (stage 4) from mild fibrosis (stage 2/3) (AUC = 0.72, P < 0.001). Importantly, an overall significance in Pro-C3 (P = 0.007) levels was observed between the groups of -1, 0, +1 and +2 change in Ishak stage at 12 months. Pro-C3 was significantly increased in group +1 (P = 0.030) and +2 (P = 0.021) compared to group 0. No significant differences were observed for C3M. In multivariate analysis, only baseline Pro-C3, but not FibroTest, had an independent association with fibrosis progression.

CONCLUSIONS

Pro-C3 is a useful test to predict fibrogenesis and monitor disease progression. Moreover, it could differentiate mild from moderate disease. Pro-C3 may become a promising blood parameter be included in future studies for monitoring disease progression and eventually for evaluation of potential antifibrotic therapies.

Non-invasive diagnosis of advanced fibrosis and cirrhosis

Liver cirrhosis is a common and growing public health problem globally. The diagnosis of cirrhosis portends an increased risk of morbidity and mortality. Liver biopsy is considered the gold standard for diagnosis of cirrhosis and staging of fibrosis. However, despite its universal use, liver biopsy is an invasive and inaccurate gold standard with numerous drawbacks. In order to overcome the limitations of liver biopsy, a number of non-invasive techniques have been investigated for the assessment of cirrhosis. This review will focus on currently available non-invasive markers of cirrhosis. The evidence behind the use of these markers will be highlighted, along with an assessment of diagnostic accuracy and performance characteristics of each test. Non-invasive markers of cirrhosis can be radiologic or serum-based. Radiologic techniques based on ultrasound, magnetic resonance imaging and elastography have been used to assess liver fibrosis. Serum-based biomarkers of cirrhosis have also been developed. These are broadly classified into indirect and direct markers. Indirect biomarkers reflect liver function, which may decline with the onset of cirrhosis. Direct biomarkers, reflect extracellular matrix turnover, and include molecules involved in hepatic fibrogenesis. On the whole, radiologic and serum markers of fibrosis correlate well with biopsy scores, especially when excluding cirrhosis or excluding fibrosis. This feature is certainly clinically useful, and avoids liver biopsy in many cases.

Serum soluble urokinase plasminogen activator receptor in alcoholics: relation to liver disease severity, fibrogenesis, and alcohol use

BACKGROUND AND AIM

Heavy alcohol consumption may lead to development of liver disease and the need for non-invasive parameters for detecting those at risk is widely acknowledged.

METHODS

We measured serum soluble urokinase-type plasminogen activator receptor (suPAR) levels from 63 patients with alcoholic liver disease (ALD), 57 heavy drinkers without apparent liver disease, and 39 controls who were either moderate drinkers or abstainers.

RESULTS

The highest serum suPAR concentrations were detected in patients with ALD (P < 0.001) showing high diagnostic accuracy in differentiating ALD patients from heavy drinkers without liver disease (area under curve 0.921, P < 0.001). Levels of suPAR correlated positively with serum markers of fibrogenesis (aminoterminal propeptide of type III procollagen and hyaluronic acid) (P < 0.001), with clinical (combined clinical and laboratory index P < 0.01) and morphological (combined morphological index P < 0.05) indices of liver disease severity and with the stage of fibrosis (P < 0.01). The suPAR concentrations were also elevated in heavy drinkers when compared with healthy controls (P < 0.001).

CONCLUSION

The data indicate that serum suPAR concentrations are increased as a result of heavy alcohol consumption and further with development of ALD, showing a good diagnostic performance in detecting those with liver disease. The association with the histological severity of ALD and correlation with fibrosis indicates potential of serum suPAR also as a prognostic marker in ALD.

Alcoholic and non-alcoholic steatohepatitis

This paper is based upon the "Charles Lieber Satellite Symposia" organized by Manuela G. Neuman at the Research Society on Alcoholism (RSA) Annual Meetings, 2013 and 2014. The present review includes pre-clinical, translational and clinical research that characterize alcoholic liver disease (ALD) and non-alcoholic steatohepatitis (NASH). In addition, a literature search in the discussed area was performed. Strong clinical and experimental evidence lead to recognition of the key toxic role of alcohol in the pathogenesis of ALD. The liver biopsy can confirm the etiology of NASH or alcoholic steatohepatitis (ASH) and assess structural alterations of cells, their organelles, as well as inflammatory activity. Three histological stages of ALD are simple steatosis, ASH, and chronic hepatitis with hepatic fibrosis or cirrhosis. These latter stages may also be associated with a number of cellular and histological changes, including the presence of Mallory's hyaline, megamitochondria, or perivenular and perisinusoidal fibrosis. Genetic polymorphisms of ethanol metabolizing enzymes such as cytochrome p450 (CYP) 2E1 activation may change the severity of ASH and NASH. Alcohol mediated hepatocarcinogenesis, immune response to alcohol in ASH, as well as the role of other risk factors such as its co-morbidities with chronic viral hepatitis in the presence or absence of human immunodeficiency virus are discussed. Dysregulation of hepatic methylation, as result of ethanol exposure, in hepatocytes transfected with hepatitis C virus (HCV), illustrates an impaired interferon signaling. The hepatotoxic effects of ethanol undermine the contribution of malnutrition to the liver injury. Dietary interventions such as micro and macronutrients, as well as changes to the microbiota are suggested. The clinical aspects of NASH, as part of metabolic syndrome in the aging population, are offered. The integrative symposia investigate different aspects of alcohol-induced liver damage and possible repair. We aim to (1) determine the immuno-pathology of alcohol-induced liver damage, (2) examine the role of genetics in the development of ASH, (3) propose diagnostic markers of ASH and NASH, (4) examine age differences, (5) develop common research tools to study alcohol-induced effects in clinical and pre-clinical studies, and (6) focus on factors that aggravate severity of organ-damage. The intention of these symposia is to advance the international profile of the biological research on alcoholism. We also wish to further our mission of leading the forum to progress the science and practice of translational research in alcoholism.

Plasma YKL-40 in Inuit and Danes

AIMS

The aim of the present study was to investigate whether there are differences in plasma levels of YKL-40 between Inuit in Greenland and in Denmark and in Danes, as well as to study the relationship between alcohol intake, plasma YKL-40 and other factors in Inuit.

METHODS

Plasma YKL-40 levels were measured on 1645 people from The Greenland Population Study (a cross-sectional population study of Inuit from Denmark and West Greenland) and were compared with the plasma YKL-40 levels of 8899 people from The Copenhagen City Heart Study (a population-based, prospective study of the Danish general population).

RESULTS

The plasma concentrations of YKL-40 were significantly (P = 0.001) lower in Inuit living in Greenland (median 46 µg/l, range 10-2164, n = 1164) compared with the plasma YKL-40 levels of Inuit living in Denmark (median 63 µg/l, range 20-2827, n = 481) and of Danes living in Denmark (median 55 µg/l, range 10-2909, n = 8899). In Inuit, increased alcohol intake was significantly associated with increased plasma YKL-40 levels (P < 0.001), and high plasma YKL-40 levels were associated with high values of alkaline phosphatase and low values of albumin. Smoking, gender and bilirubin were not associated with the plasma YKL-40 level. High levels of YKL-40 and alcohol were associated with where people lived.

CONCLUSION

The plasma concentrations of YKL-40 are significantly lower in Inuit living in Greenland than Inuit and Danes living in Denmark. A number of factors, including different alcohol intake patterns, nutrition and genes may play a role in these findings.

YKL-40 and alcoholic liver and pancreas damage and disease in 86,258 individuals from the general population: cohort and mendelian randomization studies

BACKGROUND

We tested the hypothesis that observationally and genetically increased YKL-40 concentrations are associated with alcoholic liver and pancreas damage and disease.

METHODS

We performed cohort and mendelian randomization in 86,258 individuals from the Danish general population, with measured concentrations of plasma YKL-40 (n = 21 646) and CHI3L1 rs4950928 genotype (n = 84 738).

RESULTS

Increased YKL-40 was associated with increased alanine aminotransferase, bilirubin, alkaline phosphatase, γ-glutamyl transferase, erythrocyte mean corpuscular volume, C-reactive protein, and fibrinogen and with decreased albumin; coagulation factors II, VII, and X; and pancreatic amylase. The multifactorially adjusted hazard ratio for alcoholic liver cirrhosis comparing the 96%-100% vs 0%-33% YKL-40 percentile categories was 41 (95% CI 14-118). Corresponding ratios were 7.9 (5.1-12) for any alcoholic liver disease, 4.1 (1.7-10) for alcoholic pancreatitis, and 3.4 (1.9-6.1) for any pancreatitis. CHI3L1 rs4950928 genotype explained 14% of the variation in plasma YKL-40 concentrations but was not associated with alcoholic liver and pancreas damage or disease. A doubling in YKL-40 concentrations was associated with a multifactorially adjusted observational hazard ratio of 2.8 (2.4-3.3) for alcoholic liver cirrhosis and a corresponding genetic odds ratio of 1.1 (0.7-1.5). Corresponding risk estimates were 2.0 (1.8-2.2) observationally and 1.0 (0.8-1.1) genetically for any alcoholic liver disease, 1.4 (1.1-1.9) observationally and 1.1 (0.8-1.5) genetically for alcoholic pancreatitis, and 1.3 (1.1-1.6) observationally and 1.0 (0.8-1.3) genetically for any pancreatitis. Excessive alcohol consumption combined with YKL-40 concentrations in the top 5% was associated with 10-year risk of alcoholic liver cirrhosis of up to 7% in ever-smokers and 2% in never-smokers.

CONCLUSIONS

YKL-40 concentration within the top 5% was a marker for alcoholic liver cirrhosis, with no evidence to support a causal relationship.

TIMP-1 in patients with cirrhosis: relation to liver dysfunction, portal hypertension, and hemodynamic changes

OBJECTIVE

Cirrhotic portal hypertensive patients often develop hemodynamic complications and the diagnosis is often based on liver biopsy and measurements of the hepatic venous pressure gradient (HVPG). Potential noninvasive biomarkers for the severity of cirrhosis are the matrix metalloproteinase and their specific inhibitors such as tissue inhibitor of metalloproteinases-1 (TIMP-1). The aim of the study was to investigate TIMP-1 levels in cirrhosis in relation to the degree of liver dysfunction, portal hypertension, and hemodynamic changes.

MATERIALS AND METHODS

We retrospectively studied 84 patients with cirrhosis and 14 controls without liver disease. All individuals underwent a liver vein catheterization with a hemodynamic assessment. TIMP-1 was determined in arterial and hepatic venous plasma using an MAC-15 TIMP-1 ELISA.

RESULTS

Hepatic venous concentrations of TIMP-1 were significantly increased in patients compared to controls: 336 (166) ng/ml versus 145 (100) (median/IQ range) (p < 0.001) with a progressive increase throughout the Child classes (p < 0.001). Circulating TIMP-1 correlated significantly with indocyanine green clearance (r = -0.44, p < 0.0001), Child Turcotte score (r = 0.50, p < 0.0001), HVPG (r = 0.40, p < 0.0001), mean arterial pressure (r = -0.29, p = 0.008), and systemic vascular resistance (r = -0.23, p = 0.03). Receiver operating characteristic curve analysis enabled us to establish cutoff values for TIMP-1 with regard to portal hypertension.

CONCLUSIONS

TIMP-1 is significantly increased in patients with cirrhosis and correlates with the severity of the disease, degree of portal hypertension, and vasodilatory state. TIMP-1 is therefore a promising new noninvasive marker to predict hemodynamic-related complications in cirrhosis.

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.

Serum YKL-40 levels and chitotriosidase activity in patients with beta-thalassemia major

BACKGROUND

YKL-40 association with human disease has been the object of many years of investigation. β-thalassemia patients are affected by hepatic siderosis, which determines a fibrotic process and tissue remodelling. Chitotriosidase has been found to be increased in thalassemic patients returning to normal in patients submitted to bone marrow transplantation. YKL-40 is associated with macrophage activation in liver and in other tissues. The aim of the study was to analyse the level of serum YKL-40 and plasma chitotriosidase activity of patients with beta-thalassemia to assess whether their expression correlates with liver disease and degree of liver siderosis.

METHODS

Expression of YKL-40 and chitotriosidase as a marker of inflammation in 69 thalassemic patients were evaluated. We sought to investigate whether these two chitinases could be considered as a significant biomarker to evaluate therapy effectiveness.

RESULTS

Surprisingly we found normal value of YKL-40. We, also, analysed chitotriosidase activity in the same patients that was slightly increased as a consequence of macrophage activation.

CONCLUSIONS

These data would suggest a good treatment for these patients.

Procollagen type III aminoterminal propeptide as biomarker of host response in severe sepsis

PURPOSE

The purpose of this study is to test the hypothesis that procollagen type III aminoterminal propeptide (PIIINP) is early elevated in septic episodes and can indicate the acute organ dysfunction/failure characterizing severe sepsis.

MATERIALS AND METHODS

This prospective study included 107 consecutive septic patients (44 with sepsis, 13 with severe sepsis, and 50 with septic shock) and 45 controls. After blood sampling (within 48 hours after onset of septic episodes), serum was assayed. Patients were followed up, and their disease severity was daily evaluated.

RESULTS

Procollagen type III aminoterminal propeptide (median [range]) increased in patients with sepsis (9.4 [2.2-42.4] ng/mL) compared with controls (3.6 [1.9-4.9] ng/mL; P<.001), exhibiting further significant increase in patients with severe sepsis and septic shock (19.5 [6.0-52.4] and 20.2 [1.8-89.2] ng/mL, respectively; P<.01-.001 vs sepsis). Among biomarkers of host response severity, PIIINP was the sole that was independently associated with severe sepsis/septic shock (P=.01). The area under the receiver operating characteristic curve for PIIINP to predict which patients with sepsis would eventually develop severe sepsis/septic shock was 0.87; the cutoff of 12 ng/mL had sensitivity 82% and specificity 89%.

CONCLUSIONS

Increased serum PIIINP can signify severe sepsis/septic shock and predict which patients with sepsis will eventually develop severe sepsis/septic shock, thus representing a biomarker of risk stratification of patients with sepsis.

Intake of traditional Inuit diet vary in parallel with inflammation as estimated from YKL-40 and hsCRP in Inuit and non-Inuit in Greenland

BACKGROUND

Chronic low-grade inflammation is involved in the initiation and progression of atherosclerosis and ischemic heart disease. This was rare in pre-western Inuit who lived on a diet that consisted mainly of marine mammals rich in n-3 fatty acids.

OBJECTIVES

To assess the association between biomarkers of inflammation and the intake of traditional Inuit diet in addition to Inuit ethnicity.

METHODS

YKL-40 and hsCRP were measured in serum from 535 Inuit and non-Inuit living in the capital city Nuuk in West Greenland or in the main town or a settlement in rural East Greenland. Dietary habits were assessed by an interview-based food frequency questionnaire.

RESULTS

The participation rate was 95%. YKL-40 was higher in Inuit than in non-Inuit (p < 0.001), in Inuit with a higher intake of traditional Inuit diet (p < 0.001), and in Inuit from rural compared to urban areas (p < 0.001). It also rose with age (p < 0.001), alcohol intake (0.019) and smoking (p < 0.001). Inuit had higher hsCRP compared to non-Inuit (p = 0.003) and hsCRP increased in parallel with intake of traditional Inuit foods (p < 0.001). Alcohol associated with a decrease in hsCRP in Inuit (p = 0.004). YKL-40 and hsCRP increased with higher intakes of traditional Inuit diet after adjusting for ethnicity, gender, age, smoking, alcohol intake and BMI.

CONCLUSIONS

Biomarkers of inflammation vary in parallel with the intake of traditional Inuit diet. A diet based on marine mammals from the Arctic does not reduce inflammatory activity and it may be speculated that markers of inflammation reflect the disease rather than the cause of the disease.

The inflammatory biomarker YKL-40 at admission is a strong predictor of overall mortality

OBJECTIVES

YKL-40 is an inflammatory biomarker associated with disease activity and mortality in patients with diseases characterized by inflammation and tissue remodelling. The aim of this study was to describe the prognostic value of YKL-40 in an unselected patient population.

DESIGN

In consecutive patients admitted to hospital during a 1-year period, blood was collected and information regarding final diagnosis and mortality was collected. Median follow-up time was 11.5 years.

SETTING

District hospital, Copenhagen, Denmark.

PATIENTS

A total of 1407 patients >40 years of age were admitted acutely.

MAIN OUTCOME MEASURE

All-cause mortality.

RESULTS

Median YKL-40 was increased in patients (157 μg L(-1) , range 13-7704 μg L(-1) ) compared to healthy controls (40 μg L(-1) , range 29-58 μg L(-1) ; P < 0.001). Patients with YKL-40 in the highest quartile had a hazard ratio (HR) of 7.1 [95% confidence interval (CI) 4.2-12.0] for all-cause mortality in the first year and 3.4 (95% CI 2.8-4.2) in the total study period, compared to those in the lowest quartile (HR = 1). The HR for death for all patients with YKL-40 above the normal age-corrected 95th percentile was 2.1 (95% CI 1.6-2.7) after 1 year and 1.5 (95% CI 1.3-1.7) during the total study period, compared to patients with YKL-40 below the age-corrected 95th percentile. The results of multivariable analysis showed that YKL-40 was an independent biomarker of mortality; this was most significant in the first year. YKL-40 was a marker of prognosis in all disease categories. The HR for death was increased in patients with YKL-40 above the normal age-corrected 95th percentile in healthy subjects independent of type of disease (all P < 0.001).

CONCLUSION

The level of YKL-40 at admission is a strong predictor of overall mortality, independent of diagnosis and could be useful as a biomarker in the acute evaluation of all patients.