Quantitation of HCV-replication using one-step competitive reverse transcription-polymerase chain reaction and a...

Area of Science:

• Virology
• Molecular Biology
• Clinical Diagnostics

Background:

• Hepatitis C virus (HCV) infection is a major cause of chronic liver disease.
• Accurate quantification of HCV viremia is crucial for assessing disease progression and treatment efficacy.
• Existing methods for HCV RNA quantification have limitations in routine clinical application.

Purpose of the Study:

• To establish and validate a novel solid-phase assay for the colorimetric detection of competitively amplified HCV-cDNA.
• To evaluate the utility of this assay for quantifying HCV viremia in clinical samples from patients with chronic hepatitis C.
• To compare the performance characteristics of the new assay with conventional nested polymerase chain reaction (PCR).

Main Methods:

• Development of a competitive PCR assay utilizing an internal standard with a lac operator sequence.
• Quantification of amplified competitor using a lac I-repressor/beta-galactosidase fusion protein.
• Calibration of the assay using external HCV wild-type standards and testing of clinical serum samples.

Main Results:

• The assay's performance, including sensitivity and specificity, was found to be identical to conventional nested PCR.
• The reduction in competitor amplification directly correlated with the concentration of HCV-RNA in patient samples.
• The assay successfully quantified viral titers in serum samples from patients with chronic hepatitis C, including those undergoing interferon therapy.

Conclusions:

• The developed colorimetric assay provides a reliable and time-saving method for quantifying HCV viremia.
• This assay demonstrates potential for routine application in monitoring antiviral treatment efficacy.
• The system may also be valuable for studying the relationship between plus- and minus-stranded HCV-RNA in infected tissues.