Impact of sensitivity difference between two widely used HDV RNA quantification assays on the management of HDV-infected patients treated with bulevirtide

BACKGROUND & AIM: Accurate hepatitis Delta virus (HDV) RNA quantification is crucial for diagnosing and managing HDV infection, especially for low viral loads. Here, we evaluate the sensitivity of two commonly used HDV RNA quantification assays - the new EurobioPlex EBX071 assay and the RoboGene 2.0 assay - in real-life conditions, and assess the impact on the management of HDV patients treated with Bulevirtide. Methods Frozen plasma samples that had already been quantified using the EBX071 assay were collected from three hospital laboratories, focusing specifically on low-level replicating samples. All samples were quantified using the RoboGene 2.0 assay, and sequential RNA quantifications were performed on 48 patients undergoing anti-HDV treatment with longitudinal HDV RNA testing. Results A total of 190 samples were included in the comparative analysis. The quantification results obtained using EBX071 and RoboGene 2.0 assays were concordant for the majority of samples. However, the RoboGene 2.0 assay was found to be more sensitive for a small proportion of patients with very low viremia (5-20 UI/mL). Conclusion The two HDV RNA quantification assays are generally equivalent, although RoboGene 2.0 is slightly more sensitive. Given the long duration of current treatments, however this difference should have minimal implications for the clinical management of chronic HDV patients.