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Evaluation of the new cobas® HCV genotyping test based on real-time PCRs of three different HCV genome regions
Insights
The cobas® HCV GT assay accurately identifies most hepatitis C virus (HCV) genotypes, offering a faster, automated option for clinical diagnostics. While generally reliable, it showed limitations with specific low-titer subtypes.
Area of Science:
- Virology
- Molecular Diagnostics
- Clinical Laboratory Science
Background:
- Hepatitis C virus (HCV) genotype determination is crucial for effective anti-HCV treatment.
- Accurate differentiation of HCV subtypes, such as 1a and 1b, is a clinical necessity.
- Evaluating new diagnostic tools is essential for advancing HCV management.
Purpose of the Study:
- To assess the performance of the cobas® HCV GT assay for hepatitis C virus (HCV) genotyping.
- To compare the cobas® HCV GT assay against established comparator assays.
- To determine the clinical utility of the cobas® HCV GT assay in routine diagnostics.
Main Methods:
- The cobas® HCV GT assay utilizes primer-specific real-time polymerase chain reaction (PCR).
- Comparative analysis involved the TRUGENE® HCV 5'NC Genotyping Kit and VERSANT® HCV Genotype 2.0 Assay.
- Assay accuracy was validated using proficiency panels and 183 residual clinical samples.
Main Results:
- The cobas® HCV GT assay correctly identified common HCV subtypes (1a, 1b, 3a) but struggled with low-titer subtype 5a.
- Concordant results were obtained for 160 out of 183 clinical samples; 7 yielded indeterminate results.
- The new assay demonstrated a shorter overall time-to-result with comparable hands-on time.
Conclusions:
- The cobas® HCV GT assay exhibits good performance and is suitable for routine diagnostic laboratories.
- Its high level of automation contributes to fast and reliable results.
- The assay offers an efficient option for HCV genotyping, despite limitations with certain subtypes.
Background:
Determination of the hepatitis C virus (HCV) genotype and discrimination between HCV subtypes 1a and 1b is still mandatory prior to anti-HCV treatment initiation. The aim of this study was to evaluate the performance of the recently introduced cobas® HCV GT assay (Roche) and to compare it to two comparator assays.
Methods:
The cobas® HCV GT assay is based on primer-specific real-time polymerase chain reaction (PCR). For comparison, the TRUGENE® HCV 5'NC Genotyping Kit (Siemens) and the VERSANT® HCV Genotype 2.0 Assay (Siemens) were employed. Accuracy of the new assay was determined using proficiency panels. For clinical evaluation, 183 residual clinical samples obtained from patients with chronic hepatitis C infection were included.
Results:
When accuracy was tested, panel members containing HCV subtypes 1a, 1b, and 3a were identified as expected; however, the new assay failed to identify low titer panel members containing HCV subtype 5a correctly. Of 183 clinical samples, 160 gave concordant results. For seven samples, an indeterminate result was reported with the cobas® HCV GT assay and the remaining 16 samples were found discordant with one of the comparator assays. When time-to-results of the assays were compared, the new assay showed shorter total time and similar hands-on time per sample.
Conclusions:
The cobas® HCV GT assay showed a good performance and proved to be suitable for use in the routine diagnostic laboratory. Due to the high level of automation, fast and reliable results are obtained with short hands-on time.
