[Hepatitis B and C: mechanisms of virus-induced liver pathogenesis and tumorigenesis]

Plasminogen as a Marker for Assessing Thrombotic Risk During Hepatitis in Cameroon: Case-Control Study

Background and Aims

The liver synthesizes coagulation factors, anticoagulants, proteins involved in fibrinolysis, and the platelet production regulator, thrombopoietin, from megakaryocytes. Importantly, hepatic dysfunction that arises from hepatitis may perturb the clotting process. This study aims to determine these patients' plasminogen levels and hemostasis disorders to assess the thrombotic risk.

Methods

An analytical case-control study was carried out over 6 months. The study included hepatitis B, C, and D patients from Bafoussam Regional Hospital and Laquinitie Hospital in Douala-Cameroon, compared to healthy controls, to evaluate differences in hemostasis and thrombotic risk. Control tests were performed using the immunochromatographic and ELISA methods. Blood Count was performed by flow cytometry method. And determination of d-dimer and plasminogen by nephelometry and ELISA respectively; finally the evaluation of the enzymatic activity of alanine aminotransferase and aspartate aminotransferase (ALT and AST) by the spectrophotometric kinetic method. The results were recorded in an Excel spreadsheet and analyzed using the statistical software R version 4.1.1.

Results

The population size was 340 participants including 162 controls (47.7%) and 178 (52.3%) cases of which 136 cases of hepatitis B (76.4%), 26 cases of hepatitis C (14.6%), and 16 cases of hepatitis D (9%). The sex ratio was 3.15 in favor of men; including 1.7 in cases and 9.1 in controls. All patients had a thrombotic risk characterized by a decrease in plasminogen levels compared to controls (p < 0.001). 13.5% of the population had thrombocytopenia compared to none among controls (p < 0.001). The following parameters are associated with risk of developing thrombosis in this study in particular Hepatitis (aOR = 3; 95% CI [1.01-5.2]; p < 0.03), plasminogen decrease (aOR = 3; 95% CI [1.01-5.2]; p < 0.03), shortening cephalin time activator (CTA) (aOR = 1.5; 95% CI [1.1-5.2]; p < 0.04), and decreased hemoglobin (aOR = 2.1; 95% CI [1.1-5.1;]; p < 0.03).

Conclusion

This study shows a decrease in plasminogen in patients during hepatitis. It suggests it is an important element to evaluate the thrombotic risk although the exploration of other coagulation tests should be associated with it for a complete and exhaustive evaluation and a better final diagnosis.

Micro-PET imaging of hepatitis C virus NS3/4A protease activity using a protease-activatable retention probe

Hepatitis C virus (HCV) NS3/4A protease is an attractive target for direct-acting antiviral agents. Real-time tracking of the NS3/4A protease distribution and activity is useful for clinical diagnosis and disease management. However, no approach has been developed that can systemically detect NS3/4A protease activity or distribution. We designed a protease-activatable retention probe for tracking HCV NS3/4A protease activity via positron emission topography (PET) imaging. A cell-penetrating probe was designed that consisted of a cell-penetrating Tat peptide, HCV NS3/4A protease substrate, and a hydrophilic domain. The probe was labeled by fluorescein isothiocyanate (FITC) and 124I in the hydrophilic domain to form a TAT-ΔNS3/4A-124I-FITC probe. Upon cleavage at NS3/4A substrate, the non-penetrating hydrophilic domain is released and accumulated in the cytoplasm allowing PET or optical imaging. The TAT-ΔNS3/4A-FITC probe selectively accumulated in NS3/4A-expressing HCC36 (NS3/4A-HCC36) cells/tumors and HCV-infected HCC36 cells. PET imaging showed that the TAT-ΔNS3/4A-124I-FITC probe selectively accumulated in the NS3/4A-HCC36 xenograft tumors and liver-implanted NS3/4A-HCC36 tumors, but not in the control HCC36 tumors. The TAT-ΔNS3/4A-124I-FITC probe can be used to represent NS3/4 protease activity and distribution via a clinical PET imaging system allowing. This strategy may be extended to detect any cellular protease activity for optimization the protease-based therapies.

Mesenchymal stem cells-based therapy in liver diseases

Multiple immune cells and their products in the liver together form a complex and unique immune microenvironment, and preclinical models have demonstrated the importance of imbalances in the hepatic immune microenvironment in liver inflammatory diseases and immunocompromised liver diseases. Various immunotherapies have been attempted to modulate the hepatic immune microenvironment for the purpose of treating liver diseases. Mesenchymal stem cells (MSCs) have a comprehensive and plastic immunomodulatory capacity. On the one hand, they have been tried for the treatment of inflammatory liver diseases because of their excellent immunosuppressive capacity; On the other hand, MSCs have immune-enhancing properties in immunocompromised settings and can be modified into cellular carriers for targeted transport of immune enhancers by genetic modification, physical and chemical loading, and thus they are also used in the treatment of immunocompromised liver diseases such as chronic viral infections and hepatocellular carcinoma. In this review, we discuss the immunological basis and recent strategies of MSCs for the treatment of the aforementioned liver diseases. Specifically, we update the immune microenvironment of the liver and summarize the distinct mechanisms of immune microenvironment imbalance in inflammatory diseases and immunocompromised liver diseases, and how MSCs can fully exploit their immunotherapeutic role in liver diseases with both immune imbalance patterns.