Hepatitis C virus: Screening, diagnosis, and interpretation of laboratory assays

Abstract

An estimated 3% of the world population is infected with Hepatitis C virus (HCV), a hepatotropic RNA virus, transmitted primarily via the blood route. The major modes of transmission of the virus include injection drug use, unsafe injection practices, blood transfusion etc. HCV causes chronic hepatitis in about 80% of those infected by it. The mainstay in diagnosing infection with HCV is to initially screen high risk groups for antibodies to HCV (anti-HCV). The inclusion of serum to cut-off ratio (S/CO) in recent guidelines is helpful in deciding the supplemental assay to be used to confirm initially reactive screening results. Nucleic acid amplification tests (NAT) are used as confirmatory tools, and also to determine viral load prior to initiating treatment. Quantitative NAT has replaced qualitative assays. Genotyping is an important tool in clinical management to predict the likelihood of response and determine the optimal duration of therapy. The impact of this infection has begun to emerge in India. The problem of professional blood donation despite an existing law against it, and flourishing unsafe injection practices, are potential sources for the spread of hepatitis C in our country. All health care practitioners need to understand how to establish or exclude a diagnosis of HCV infection and to interpret the tests correctly. In the absence of a preventive or therapeutic vaccine, and also of post-exposure prophylaxis against the virus, it is imperative to diagnose infection by HCV so as to prevent hepatic insult and the ensuing complications that follow, including primary hepatocellular carcinoma (HCC). This review aims to help blood bank staff regarding options for diagnosis and management of donors positive for HCV.

Hepatite C

“…O termo hepatite em si, só foi introduzido no século XVII por Bianchi, no seu trabalho científico denominado "Historia hepática sem thoriaet práxis omniusmorborum hepatites et bílis"publicado em 1725 7 . Somente em 1989, após pesquisas envolvendo a área de biologia celular, Choo et al 61 identificaram então, o genoma de um suposto agente viral responsável por 90% das hepatites pós-transfusionais não A e não B, a qual denominaram de vírus da hepatite C, com características próprias que o diferencia dos demais vírus hepatotrópicos [6][7][8] .…”

Deceased tissue donor serology and molecular testing for HIV, hepatitis B and hepatitis C viruses: a lack of cadaveric validated tests

“…Many platforms and techniques are able to detect HIV, HBV and HCV infection markers, such as Enzyme linked immuno sorbent assay (ELISA), Chemiluminescent assay (CLIA) (Chen and Kaplan 2006;Sommese et al 2014), Eletrochemiluminescent assay (ECLIA) (Wang and Wang 2013), Recombinant imunoblot assay (RIBA), Western blot and nucleic acid test (NAT) (Chigurupati and Murthy 2015a;Gupta et al 2014;Kumar et al 2015). The expansion of technology as it relates to laboratory routines presents difficult choices in regards to which technique and platform is most appropriate for use due to lack of studies which compare them.…”

Prediction of HCV load using genotype, liver biomarkers, and clinical symptoms by a mathematical model in patients with HCV infection

“…Aside from sequencing methods, real‐time PCR is among the most sensitive techniques for HCV genotyping. The major limitation of the HCV core Ag assay is that it offers a lower sensitivity than the RT‐PCR method …”

“…The major limitation of the HCV core Ag assay is that it offers a lower sensitivity than the RT-PCR method. 5,[9][10][11] Besides these limitations, the methods used to quantify viral load are very expensive and require specialized equipment. Likewise, they are not currently suitable for low-resource areas that have a high prevalence of HCV.…”