YKL-40-gene polymorphism affects acute cellular rejection and fibrosis progression after transplantation for hepatitis C virus-induced liver disease

CHI3L1 in the pathophysiology and diagnosis of liver diseases

Chitinase 3-like protein 1(CHI3L1) participates in physiological and pathophysiological process, such as cell survival, cell proliferation, tissue remodeling, angiogenesis, etc. Some studies demonstrated that CHI3L1 is liver-enriched and has better application value in staging liver fibrosis than platelet ratio index(APRI) and fibrosis-4 index(FIB-4) and that CHI3L1 can be used in monitoring the prognosis of hepatocellular carcinoma (HCC). In this review, we summarized the pathophysiological role and the diagnostic value of CHI3L1 in liver fibrosis in different background and HCC.

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.

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.

Early periportal sinusoidal fibrosis is an accurate marker of accelerated HCV recurrence after liver transplantation

BACKGROUND & AIMS

Significant liver fibrosis (F ⩾ 2) and portal hypertension (hepatic venous pressure gradient [HVPG] ⩾ 6 mmHg) 1 year after liver transplantation (LT) are predictors of severe hepatitis C recurrence. Periportal sinusoidal fibrosis (SF) is an early expression of the fibrogenic process in response to liver injury. We aimed to evaluate whether SF in early liver biopsies represents an early and accurate marker for identifying patients with severe HCV recurrence after LT.

METHODS

A total of 101 HCV LT patients with early biopsy (<6 months), and HVPG measurement and/or liver biopsy one year after LT were included. Early biopsies were stained with Sirius Red and SF was graded semi-quantitatively. Results were compared between groups (significant SF vs. non-significant SF) and correlated with the development of severe HCV recurrence one year after LT.

RESULTS

Patients with early significant SF had older donor age and higher necroinflammatory activity (NIA). The presence of early significant SF enabled identification of 78.9% and 90.6% of patients with F ⩾ 2 and HVPG ⩾ 6 mmHg, respectively, one year after LT. Donor age and NIA were independent predictors of significant fibrosis (F ⩾ 2) one year after LT, whereas donor age, ALT (3 months), NIA, and SF grade were independent predictors of portal hypertension (HVPG ⩾ 6).

CONCLUSIONS

Significant SF in early biopsies is a good predictor of severe hepatitis C recurrence. This histological finding, when combined with simple variables, may be useful to select the best candidates for early antiviral therapy after LT.