Ola Mahmoud

The Role of Fas/Fas Ligand System in the Pathogenesis of Liver Cirrhosis and Hepatocellular Carcinoma

Background The Fas receptor/ligand system including soluble forms is the most important apoptotic initiator in the liver. Dysregulation of this pathway may contribute to abnormal cell proliferation and cell death and is regarded as one of the mechanisms preventing the immune system from rejecting the tumor cells. Objectives To analyze the role of Fas system Fas/ Fas ligand (Fas/ FasL) in the multi-step process of hepatic fibrosis/carcinogenesis, and to use of the serum markers as possible candidate biomarkers for early detection of hepatocellular carcinoma (HCC). Patients and Methods Ninety patients were enrolled: 30 cases of chronic hepatitis C (CHC) without cirrhosis, 30 cases of CHC with liver cirrhosis, and 30 cases of HCC and hepatitis V virus (HCV) infection. Ten wedge liver biopsies, taken during laparoscopic cholecystectomy, were served as normal controls. Serum soluble Fas (sFas) levels were measured using ELISA technique; Fas and FasL proteins were detected in hepatic tissue by indirect Immuno-histochemical technique (IHC); electron microscopic (EM) and immune electron microscopic examinations were performed for detection of Fas expression on lymphocytes. Results Hepatic expression of both Fas and FasL as well as expression of Fas on separated lymphocytes were significantly increased in the diseased groups (P < 0. 01) compared to the control specimens. The highest expression was noticed in CHC specimens, particularly with the necro-inflammatory activity and advancement of the fibrosis. The sFas in cirrhotic patients and HCC were significantly higher than that in normal controls and CHC without cirrhosis group (P < 0.01). Conclusions Apoptosis and the Fas system were significantly involved in the process of converting liver cirrhosis into hepatocellular carcinoma. Down-regulation of Fas expression, up regulation of FasL expression in hepatocytes, and elevation of serum sFas levels were important in tumor evasion from immune surveillance, and in hepatic carcinogenesis.

Prevalence of HBV genotypes among Egyptian hepatitis patients

Phylogenetic analysis has led to the classification of hepatitis B virus into eight genotypes, designated A to H. The genotypes have differences in biological properties and show heterogeneity in their global distribution. These attributes of the genotypes may account not only for differences in the prevalence of hepatitis B virus mutants in various geographic regions, but also makes them responsible for differences in the clinical outcome and response to antiviral treatment in different population groups. Africa is one of the highly endemic regions of HBV with five genotypes (A–E) identified. Almost all patients in the Mediterranean area are infected with genotype D. However, there is little information of genotype distribution in Egypt. A total of 140 Egyptian patients with hepatitis B surface antigen (HBsAg) positive were enrolled in this study. Of the 140 patients, only 100 patients were HBV DNA positive and only these were included in the study. They were classified into 20 patients with acute hepatitis (AH), 75 patients with chronic active hepatitis (CAH) and 5 patients with hepatocellular carcinoma (HCC). HBV genotypes were determined using INNO-LiPA methodology which is based on the reversed hybridization principle. This study showed that genotype D constituted 87% of the total infections (75 CAH cases, 7 AH cases and 5 HCC cases). The other 13% showed mixed infections of D/F. These findings show that the most prevalent genotype in Egypt is genotype D especially in CAH and HCC patients while the mixed type D/F is only encountered in AH.

T Regulatory Cell Responses to Immunization with a Soluble Egg Antigen in Schistosoma mansoni-Infected Mice

The aim of the study is to characterize the phenotypes of CD4+ CD25+ T regulatory cells within the liver granulomas and association with both Foxp-3 gene expression and splenic cytokines. Naïve C57BL/6 mice were intravenously injected with multiple doses of the soluble egg antigen (SEA) 7 days before cercarial infection. The immunized and infected control groups were sacrificed 8 and 16 weeks post-infection (PI). Histopathology, parasitological parameters, splenic phenotypes for T regulatory cells, the FOXP-3 expression in hepatic granuloma using real-time PCR, and the associated splenic cytokines were studied. Histopathological examination of the liver revealed remarkable increase in degenerated ova within hepatic granuloma which decreased in diameter at weeks 8 and 16 PI (P<0.01). The percentage of T regulatory cells (CD4+ CD25+) increased significantly (P<0.01) in the immunized group compared to the infected control at weeks 8 and 16 PI. The FOXP-3 expression in hepatic granulomas increased from 10 at week 8 to 30 fold at week 16 PI in the infected control group. However, its expression in the immunized group showed an increase from 30 at week 8 to 70 fold at week 16 PI. The splenic cytokine levels of pro-inflammatory cytokines, IFN-γ, IL-4, and TNF-α, showed significant decreases (P<0.05) compared to the infected control group. In conclusion, the magnitude and phenotype of the egg-induced effects on T helper responses were found to be controlled by a parallel response within the T regulatory population which provides protection in worm parasite-induced immunopathology.

Tissue factor expression on blood monocytes in patients with hepatitis C virus-induced chronic liver disease

Chronic liver disease (CLD) is a worldwide common pathology characterised by an inflammatory and fibrotic process leading to progressive evolution from chronic hepatitis to cirrhosis. Monocytes play a crucial role in the pathogenesis of inflammation and fibrosis in chronic liver diseases. Activated monocytes increase the expression of tissue factor, a key glycoprotein that participates in haemostatic and inflammatory processes. This study aims to assess the expression of tissue factor on activated peripheral blood monocytes in patients with hepatitis C virus (HCV)-induced CLD in relation to the degree of hepatic insufficiency and haemostatic imbalance. The current study included 60 patients with HCV-induced CLD, categorised after Child–Pugh into four groups: Child A, B, C and C during acute attack of haematemesis, 15 patients each, and 15 healthy subjects were included as normal controls. Immunophenotype characterization was carried out by flow cytometric analysis for identification of monocytes tissue factor expression (CD142) on activated blood monocytes population (CD11b and CD14) in different groups studied. Data demonstrated significant increase (p < 0.05) in the expression of each of CD11b, CD14 and CD142 revealing monocytes activation and increased expression of tissue factor on peripheral blood monocytes in different groups of patients especially cases during acute attack of haematemesis, compared to healthy subjects. Increased monocytes tissue factor expression in patients with HCV may play a key role in the intensification of the inflammatory and immunological processes in conjunction with activation of the coagulation mechanisms. The interaction of all these phenomena may trigger bleeding by perturbing the unstable haemostasis in frail patients with chronic liver disease.