Characterization of soluble FAS, FAS ligand and tumour necrosis factor-alpha in patients with chronic HCV infection

Background: There are limited reports on the role of the cell surface receptor Fas and its ligand molecule in mediating apoptosis during infection with the hepatitis C virus (HCV). Objectives: The aims of this study were (1) to assess the susceptibility of the Fas antigen expressed on peripheral blood mononuclear cells to Fas ligand-induced-death in patients with chronic HCV infection and (2) to investigate the correlation between the plasma levels of soluble Fas (sFas), soluble Fas ligand (sFasL), tumour necrosis factor-alpha (TNF-alpha), alanine amino transferase (ALT), and HCV viral load. Study design: The susceptibility of peripheral blood mononuclear cells from 17 subjects with chronic HCV infection to Fas ligand induced cell death was assessed using a water soluble tetrazolium assay. The plasma levels of associated markers such as sFas, sFasL, and TNF-alpha were quantified using immunoassays. ALT values were obtained from hospital records. Viral loads were quantified using a commercially available quantitative assay - the Amplicor Monitor (version 2.0). Controls for comparison included a group of healthy individuals and individuals infected with the human immunodeficiency virus 1. Results: The percentage of cell death induced in hepatitis C virus infected individuals was lower than that seen in the healthy control group. Patients infected with HCV had higher average values of sFas and TNF-alpha as compared to both control groups. Plasma levels of sFas in patients with chronic HCV infection showed significant positive correlations to ALT and TNF-alpha levels. TNF-alpha levels also showed a significant positive correlation with ALT levels. Conclusions: PBMC in HCV infection exhibit decreased susceptibility to Fas ligand induced cell death. This may signify a means by which HCV escapes immune surveillance. This phenomenon merits further investigation. The strong correlations observed between plasma sFas, ALT and TNF-alpha suggest a potential role for these markers as an alternative to an invasive liver biopsy

Evaluation of a Rapid Assay as an Alternative to Conventional Enzyme Immunoassays for Detection of Hepatitis C Virus-Specific Antibodies

A rapid membrane flow-through immunoassay to detect antibodies to hepatitis C virus was compared with a commercial enzyme immunoassay (EIA) and microparticle enzyme immunoassay (MEIA) using 2,590 serum samples. Sensitivity and specificity of the “rapid assay” in comparison to the EIA/MEIA were 99.3 and 99.0%; the correlation coefficient being 0.91. This assay is suitable where infrastructure and laboratory expertise are limited

HCV genotype 4 - an emerging threat as a cause of chronic liver disease in Indian (South) patients

Background: Hepatitis C virus (HCV) genotyping is relevant for the delivery of effective antiviral therapy. HCV genotypes are geographically restricted with genotype 4, which is resistant to therapy, traditionally considered to be confined to the Middle East and Africa. We report here on the occurrence of HCV genotype 4 in Indian (South) patients. Objectives: (1)To highlight the occurrence of HCV genotype 4 in the patient population attending a tertiary care hospital in south India. (2)To ascertain the difference in HCV viral loads and alanine aminotransferase (ALT) values between patients infected with HCV genotype 4 and those infected with the other two most commonly detected genotypes in this patient population viz., HCV genotypes 1 and 3. (3)To assess the genetic relatedness of the Indian strains to Genbank sequences, which we report for the first time. Study design: The study group consisted of 125 HCV infected, untreated patients who had been genotyped using type specific primers. Eight of the nine samples classified as HCV genotype 4 by this technique were subjected to nucleotide sequencing. Viral load estimations were carried out. Information on possible risk factors and ALT values were obtained from hospital records. Statistical analyses were carried out to compare viral loads and ALT values across genotypes. A phylogenetic tree was constructed and the genetic relatedness of the strains was assessed through sequence analysis. Results: HCV genotype 4 was detected in nine of 125 (7.2%) patients. Eight of the nine were subjected to nucleotide sequencing and all strains were confirmed as HCV genotype 4. Six of the eight strains were closely related, with two strains being phylogenetically diverse. Conclusions: HCV genotype 4 is detected in a significant minority of HCV infected patients in India. This finding should be considered in designing strategies prior to initiation of therapy in Indian patients infected with HCV

Distribution of the different genotypes of HCV among patients attending a tertiary care hospital in South India

Background: Genotyping of the hepatitis C virus (HCV) and assessment of viral load is important for designing therapeutic strategies and region specific diagnostic assays. Objectives: To determine the distribution of HCV genotypes among patients attending a tertiary care hospital in south India, and to correlate this with viral load. Study design: Ninety HCV RNA positive patients were recruited for the study. HCV genotyping was carried out using type-specific primers from the core region of the viral genome [J. Clin. Microbiol. 35 (1997) 201]. Viral load estimations were carried out using the Amplicor HCV Monitor (Versions 1.5 and 2, Roche Diagnostics, Branchburg, NJ, USA). Clinical details were elicited from patients' hospital records. Results: Genotype 3 was detected most frequently (62.2%) followed by infection with HCV genotype 1 (18.8%). There was no significant difference seen in alanine aminotransferase (ALT) values between the two genotypes. Genotype 1 was associated with a significantly higher viral load as compared with genotype 3 (P=0.001). Parenteral transmission accounted for 61% of all infection caused. Infection with genotype 1 was significantly associated with a history of haemodialysis (P=0.01). Genotype 3 was detected more frequently in patients from east India, as compared with its detection in patients from south India (P=0.004). Similarly, genotype 1 was detected with greater frequency in individuals from south India as compared with patients from east India (P=0.004). The concordance between Ohno's genotyping assay and nucleotide sequencing, for genotypes 1 and 3, was 75%. Conclusions: HCV genotypes 1 and 3 accounted for 81% of HCV infections in patients from this geographical region. HCV genotype distribution showed regional differences and genotype 1 was associated with higher viral loads. Parenteral transmission was the major route for acquisition of HCV infection. Ohno's type-specific primer based genotyping assay can be used for distinguishing between HCV genotype 1 and non-1 HCV genotypes in laboratories that do not possess nucleotide sequencing facilities