Current Concepts of Biliary Atresia and Matrix Metalloproteinase-7: A Review of Literature

Biliary atresia (BA) is a rare cholangiopathy of infancy in which the bile ducts obliterate, leading to profound cholestasis and liver fibrosis. BA is hypothesized to be caused by a viral insult that leads to over-activation of the immune system. Patients with BA are surgically treated with a Kasai portoenterostomy (KPE), which aims to restore bile flow from the liver to the intestines. After KPE, progressive liver fibrosis is often observed in BA patients, even despite surgical success and clearance of their jaundice. The innate immune response is involved during the initial damage to the cholangiocytes and further differentiation of the adaptive immune response into a T-helper 1 cell (Th1) response. Multiple studies have shown that there is continuing elevation of involved cytokines that can lead to the progressive liver fibrosis. However, the mechanism by which the progressive injury occurs is not fully elucidated. Recently, matrix metalloproteinase-7 (MMP-7) has been investigated to be used as a biomarker to diagnose BA. MMPs are involved in extracellular matrix (ECM) turnover, but also have non-ECM related functions. The role of MMP-7 and other MMPs in liver fibrosis is just starting to be elucidated. Multiple studies have shown that serum MMP-7 measurements are able to accurately diagnose BA in a cohort of cholestatic patients while hepatic MMP-7 expression correlated with BA-related liver fibrosis. While the mechanism by which MMP-7 can be involved in the pathophysiology of BA is unclear, MMP-7 has been investigated in other fibrotic pathologies such as renal and idiopathic pulmonary fibrosis. MMP-7 is involved in Wnt/β-catenin signaling, reducing cell-to-cell contact by shedding of E-cadherin, amplifying inflammation and fibrosis via osteopontin (OPN) and TNF-α while it also appears to play a role in induction of angiogenesis This review aims to describe the current understandings of the pathophysiology of BA. Subsequently, we describe how MMP-7 is involved in other pathologies, such as renal and pulmonary fibrosis. Then, we propose how MMP-7 can potentially be involved in BA. By doing this, we aim to describe the putative role of MMP-7 as a prognostic biomarker in BA and to provide possible new therapeutic and research targets that can be investigated in the future.

Viral eradication reduces all-cause mortality, including non-liver-related disease, in patients with progressive hepatitis C virus-related fibrosis

BACKGROUND AND AIM

Eradication of hepatitis C virus (HCV) with interferon (IFN)-based therapy has been reported to reduce all-cause mortality in patients with chronic HCV infection. However, the impact of HCV eradication on non-liver-related mortality and causes of death has not been sufficiently investigated in patients with progressive HCV-related fibrosis.

METHODS

We enrolled 784 chronic HCV patients with progressive liver fibrosis (aspartate aminotransferase to platelet ratio index >1). Cause of death, incidence of hepatocellular carcinoma, and all-cause mortality including non-liver-related mortality were analyzed.

RESULTS

Of these 784 patients, 170 achieved sustained virological response (SVR) (eradication of HCV) with IFN-based therapy (IFN-SVR), and 614 did not receive IFN-based therapy (non-IFN patients, chronic HCV infection). The median follow-up duration was 10.3 years. Two hundred seventy-three patients died during follow-up (liver-related death, n = 171; non-liver-related death, n = 102). The mortality rate from non-liver-related disease was 63.6% (7/11) in IFN-SVR patients and 36.3% (95/262) in non-IFN patients, respectively. In multivariate analysis, the eradication of HCV associated with not only hepatocellular carcinoma incidence (hazard ratio (HR), 0.162; 95% confidence interval (CI), 0.092-0.284), and all-cause mortality (HR, 0.094; 95% CI, 0.047-0.187), but non-liver-related mortality (HR, 0.286; 95% CI, 0.127-0.644) as well.

CONCLUSIONS

Eradication of HCV reduced both liver-related and non-liver-related mortality in patients with progressive HCV-related fibrosis.

High immunocompetence in chronic hepatitis patients with normal alanine transaminase levels and and negative hepatitis B e-antigen for the progression of liver fibrosis

INTRODUCTION

This study aimed to investigate the role of immunocompetence in chronic hepatitis B (CHB) patients with normal alanine transaminase (ALT) levels and negative hepatitis B e antigen (HBeAg) in the risk assessments of the progression of liver fibrosis.

METHODS

We collected the clinical data of 57 patients with CHB, with normal ALT levels and negative HBeAg from December 2020 to December 2022. With hepatitis B virus (HBV) DNA > 20 IU/mL and ALT ≤ 40 U/L, these patients had never undergone antiviral therapy. The levels of CD4+ , CD4+ CD25+ , CD8+ , and CD4+ CD25+ CD127LOW regulatory T cells (Tregs) in the patients were detected using flow cytometry; the liver stiffness measurement (LSM) values of the patients were detected using Fibroscan.

RESULTS

There was a statistically significant difference between the levels of fibrosis-4 (FIB-4) and hepatitis B surface antigen (HBsAg) when the cutoff point was HBsAg ≥ 1500 (p < .001). FIB-4 was negatively correlated with HBsAg (R = -0.291, p = .028) and positively correlated with age (R = 0.787, p < .001). LSM was negatively correlated with Treg but this correlation was not statistically significant (p > .05). Findings based on the analysis using logistic regression were as follows: (i) age was the independent risk factor when FIB-4 was used as the indicator for assessing liver fibrosis; (ii) Treg was the independent risk factor when LSM was used as the indicator for assessing liver fibrosis. When Treg was used to predict liver fibrosis, the cutoff value, diagnostic efficacy, area under the receiver operating characteristic (ROC) curve, and p value of the ROC curve were 6.875, 0.641, 0.84, and .027, respectively.

CONCLUSION

Age and Treg are independent risk factors for progressive liver fibrosis. The cutoff value of Treg > 6.81 indicates the need for timely antiviral treatment and can serve as an indicator for evaluating liver fibrosis.