Assessment of the cobas® HBV RNA investigational assay in the setting of nucleoside analog therapy cessation

J Med Virol. 2022 Dec;94(12):6116-6121. doi: 10.1002/jmv.28078. Epub 2022 Aug 30.


HBV RNA is used as a marker of cccDNA transcription and is applicable in the setting of nucleos(t)ide analog (NA) treatment, which suppresses HBV DNA. Traditional assays for quantification of HBV RNA rely on labor-intensive 3'RACE assays targeting the polyA tail. In this study, the high-throughput Roche cobas®HBV RNA investigational assay was assessed on the Roche cobas® 6800 automated platform. Of 969 samples collected for a NA treatment cessation trial, and tested on the cobas assay, 249 were analyzed for sensitivity, reproducibility, sample type applicability, and results were compared to a RACE-based assay. Results of 97 paired serum and plasma samples demonstrated an excellent correlation of 0.98. However, 14.5% of plasma samples yielded detectable (below the limit of quantification) results, when the paired serum was undetectable, and plasma was shown to yield a statistically significant (p < 0.001) greater mean 0.119 log10 copies/ml. Quantification of 152 samples showed good correlation (0.91) between the cobas and RACE assays. The cobas assay demonstrated superior lower limit of quantification, 10 copies/ml, which resulted in detection of 13.2% more samples than the RACE assay. Reproducibility and linear range of the automated assay were also confirmed. The Roche cobas assay for HBV RNA is sensitive and highly recommended.

Keywords: HBV RNA; RACE PCR; cobas 6800; nucleoside analog cessation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • DNA, Viral* / genetics
  • Hepatitis B virus* / genetics
  • Humans
  • Nucleosides / therapeutic use
  • RNA
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Viral Load / methods


  • DNA, Viral
  • Nucleosides
  • RNA