Utility of the Abbott RealTime HCV Genotype Plus RUO assay used in combination with the Abbott RealTime HCV Genotype...

Area of Science:

• Hepatology
• Virology
• Clinical Diagnostics

Background:

• Accurate Hepatitis C virus (HCV) genotype (GT) determination and subtype (ST) differentiation are essential for effective direct-acting antiviral (DAA) therapy selection.
• Current diagnostic methods may present challenges in precise GT and ST identification, impacting treatment decisions.

Purpose of the Study:

• To retrospectively compare the distribution of HCV GT and ST results using the Abbott RealTime HCV Genotype II assay (HCVGT II) alone versus in combination with the Abbott RealTime HCV Genotype Plus RUO assay (HCVGT Plus).
• To evaluate the impact of combining these assays on routine clinical specimen testing in a reference laboratory setting.

Main Methods:

• A retrospective analysis compared HCV GT and ST results from two periods: Period 1 (June 2014-January 2016) using HCVGT II alone, and Period 2 (January 2016-January 2017) using HCVGT II in combination with HCVGT Plus (HCVGT II/Plus).
• A total of 44,127 specimens were analyzed in Period 1, and 25,361 specimens in Period 2.

Main Results:

• The combined HCVGT II/Plus assay significantly reduced the frequency of GT 1 results lacking ST (0.4%) compared to HCVGT II alone (5.5% in Period 1, 5.3% in Period 2; p < 0.01).
• The HCVGT II/Plus combination also identified 38 specimens with HCV GT 6 reactivity, which were previously reported as 'HCV detected' (n=17) or GT 1 (n=21) by HCVGT II alone.

Conclusions:

• Combining the HCVGT II and HCVGT Plus assays significantly improves the accuracy of Hepatitis C virus (HCV) genotype and subtype determination in a reference laboratory.
• This enhanced diagnostic approach reduces ambiguous results for GT 1 and enables the identification of previously undetected GT 6, optimizing patient management and DAA therapy selection.