A specific enzyme immunoassay (EIA) for the diagnosis of hepatitis C virus (HCV) infection was developed by recombinant DNA technology. Abbott HCV EIA was used to detect antibody to HCV (anti-HCV) in non-transfused and multiply-transfused thalassemia patients. None of 11 non-transfused patients had anti-HCV but 3 of 52 (5.8%) multiply-transfused patients had anti-HCV. This study showed that the prevalence rate of HCV infection is low in thalassemia patients. However, it is still important to identify hepatitis C virus infected patients in high risk groups because hepatitis C is associated with chronic hepatitis, cirrhosis and hepatocellular carcinoma.
The identification of the Hepatitis C virus using molecular cloning techniques, besides making the term Non-A Non-B Hepatitis obsolete, enables the development of specific assays for the detection of antibodies in HCV-infected individuals, thus making it possible to obtain sero-epidemiological data of the disease. The carriage of Hepatitis C antibody varies worldwide. The disease is most prevalent in intravenous drug abusers or haemophiliacs. Parenteral transmission is the most important route of transmission. Sexual, intra-familial and perinatal transmissions are uncommon. About 40% could be community-acquired (sporadic). Diagnostic tests include enzyme-linked immunosorbant (ELISA) anti-HCV assay, recombinant immunoblot assay, HCV-RNA by polymerase chain reaction and HCV-Ag. More than 50% of acute cases becomes chronic and runs a benign and indolent course. About 20% progress to cirrhosis and some of these develop hepatocellular carcinoma. Several published trials have consistently shown that treatment with interferon in some patients is useful. There is however a relapse rate of 50%. Further trials with interferon and other anti-viral agents like ribavirin are awaited for more effective treatment.
A pilot study to determine the seroprevalence of anti-HCV among children from Kuala Lumpur, Malaysia, was conducted using microparticle enzyme immunoassay. Serum samples were obtained randomly from children, aged between one to 16 years of age, admitted to the paediatric unit of University of Malaya Medical Centre, Kuala Lumpur for various medical reasons. Of the 179 samples assayed, only one was positive, giving the prevalence rate of 0.6%. It is reasonable to conclude that the seroprevalence of anti-HCV among children from Kuala Lumpur is low, less than 1%.
The Serodia-HCV Particle Agglutination (HCV-PA) for the detection of HCV antibodies was compared with the Enzyme Immunoassay Test (UBI HCV EIA) for possible in-house use. A total of 150 specimens were analysed using UBI HCV EIA and Serodia-HCV PA. Of these, 80 (53.3%) were both PA and EIA positive and 59 (39.3%) were negative by both techniques. Eleven sera (7.4%) were found to be EIA-positive but PA-negative. These 11 discordant sera were further tested by the LiaTek-HCV III Immunoassay (Organon Teknika). Ten were found to be line immunoassay negative and one was line immunoassay positive. Failure of the PA to detect the HCV positive serum meant that a small proportion of HCV antibody positives may be missed by the PA test. We conclude that (i) EIA should continue to be the first line screening test in our laboratory, (ii) PA with its 100% specificity could be a useful supplementary screen for all EIA-positive sera and finally (iii) line immunoassay could be used on sera to resolve discordant results in the EIA and PA assays.
Hepatocellular carcinoma (HCC) is the third most common cause for cancer death in the world, now being especially linked to chronic hepatitis C virus (HCV) infection. This case-control study consisting of 65 HCC patients and 82 patients with other malignant tumours as controls was conducted to determine the association of HCV markers with HCC. Serum of each participant was obtained for detection of HCV Ab and RNA by DNA enzyme immunoassay (DEIA). Twenty six per cent (26.0%) of HCC patients had positive anti-HCV which was significantly greater than the control group (p=0.001). HCC patients significantly have a risk of exposure to HCV infection almost 3 times than the control group (OR=2.87, 95% C.I=1.1-7). Anti-HCV seropositive rate was significantly (p=0.03) higher among old age HCC patients and increases with age. Males with HCC significantly showed to have more than 9 times risk of exposure to HCV infection (OR=9.375, 95 % CI=1.299-67.647) than females. HCV-RNA seropositive rate was (70.8%) significantly higher among HCC patients compared to (22.2%) the control group (p=0.019). The most prevalent genotype (as a single or mixed pattern of infection) was HCV- 1b. This study detected a significantly higher HCV seropositive rate of antibodies and RNA in HCC patients.
Sera from 80 Malaysians with confirmed hepatocellular carcinoma were tested for five markers of the hepatitis B virus, anti-HCV and anti-HDV by enzyme immunoassay, and alpha fetoprotein (AFP) was measured by radioimmunoassay. Of the patients, 98.8% had evidence of HBV infection and 75% were positive for HBsAg--which latter correlated with AFP raised above cut-off values of 500 ng/ml (P = 0.0001) and 200 ng/ml (P = 0.005). Males correlated significantly with the presence of HBsAg (P = 0.002). Thirty-one per cent of HBsAg positive patients were also positive for HBeAg and 74% for anti-HBe. Twenty per cent of the cases were concurrently positive for both HBsAg and anti-HBs. Six of 70 (8.6%) patients were positive for anti-HCV, of whom four were also positive for HBsAg. None of 67 patients tested for anti-HDV were positive. The results strongly indicate an important aetiological role for hepatitis B virus in causation of hepatocellular carcinoma among Malaysians.
We studied the presence of Hepatitis C Virus (HCV) antibodies in a defined Malaysian population and examined the association, if any, between HCV and the Hepatitis B Virus (HBV), using sensitive recombinant DNA second generation Enzyme Immunoassay (EIA) test kits. This sero-prevalence study comprised 1,434 sera from eleven distinct groups comprising intravenous drug users (IVDU), haemophiliacs, male homosexuals, female prostitutes, healthy blood donors, staff of dialysis unit and laboratory personnel, chronic renal failure patients undergoing dialysis (CRFD), patients with liver cirrhosis, chronic active hepatitis, chronic persistent hepatitis and primary liver cancer. Except in laboratory personnel and dialysis staff, HCV antibodies were detected in each group of patients ranging from 3% in blood donors to 85% in IVDU. The main modes of HCV transmission identified were parenteral drug use, transfusion and/or dialysis related. The HBV was found to be the major viral etiological agent in 75% of chronic liver disease (CLD); while in 10% of cases both HCV and HBV were detected. HCV was implicated as the sole viral agent in only a small proportion (1.5%) of patients with chronic liver disease.
Hepatitis C virus (HCV)-specific CD4+ and CD8+ T cells are key to successful viral clearance in HCV disease. Accumulation of exhausted HCV-specific T cells during chronic infection results in considerable loss of protective functional immune responses. The role of T-cell exhaustion in chronic HCV disease remains poorly understood. Here, we studied the frequency of HCV peptide-stimulated T cells expressing negative immune checkpoints (PD-1, CTLA-4, TRAIL, TIM-3 and BTLA) by flow cytometry, and measured the levels of Th1/Th2/Th17 cytokines secreted by T cells by a commercial Multi-Analyte ELISArray™ following in vitro stimulation of T cells using HCV peptides and phytohemagglutinin (PHA). HCV peptide-stimulated CD4+ and CD8+ T cells of chronic HCV (CHC) patients showed significant increase of CTLA-4. Furthermore, HCV peptide-stimulated CD4+ T cells of CHC patients also displayed relatively higher levels of PD-1 and TRAIL, whereas TIM-3 was up-regulated on HCV peptide-stimulated CD8+ T cells. Whereas the levels of IL-10 and TGF-β1 were significantly increased, the levels of pro-inflammatory cytokines IL-2, TNF-α, IL-17A and IL-6 were markedly decreased in the T cell cultures of CHC patients. Chronic HCV infection results in functional exhaustion of CD4+ and CD8+ T cells likely contributing to viral persistence.