- HCV core antigen testing offers a potentially cost-saving alternative to HCV RNA assays for diagnosis, but may not adequately determine sustained virologic response at 12 weeks post-therapy (SVR12).
Why this matters
- Cost savings for national screening programs could translate to improved access to direct-acting antivirals.
- Study of 10,006 serum samples tested for HCV antibodies by commercial laboratories in Ontario, Canada.
- Data for 202 patients treated for HCV in Canada, Germany, and the USA.
- Funding: Abbott Diagnostics, Toronto Centre for Liver Disease.
- Screening study:
- 75 of 80 HCV RNA+ samples also tested positive for core antigen (sensitivity, 94%; 95% CI, 86%-98%); the remaining 5 showed low-level viremia.
- No HCV RNA-negative samples were core antigen-positive (specificity, 100%; 95% CI, 94%-100%).
- Clinical cohort:
- 1% of baseline samples (2/202) tested negative for HCV core antigen (HCV RNA, 468 and >2,000,000 IU/mL, respectively).
- Core antigen showed good concordance with HCV RNA at 12 weeks post-therapy (r=0.97; P<.0001 but patients with svr12 tested positive and relapse negative.>
- Use of HCV core antigen vs HCV RNA testing to confirm diagnosis yielded cost-savings of $0.29-3.70 CAD per patient screened, depending on use of confirmatory HCV RNA.
- Retrospective design.