Accurate quantification using the new RoboGene HDV RNA Quantification Kit 3.0: A European multicenter study

Background: The management of chronic hepatitis delta requires reliable test systems for the detection and quantification of hepatitis delta virus (HDV) RNA. The aim of this study was to obtain comparable results between seven European laboratories using the new RoboGene HDV RNA Quantification Kit 3.0 (Roboscreen GmbH) in combination with different test systems consisting of different nucleic acid extraction and amplification/detection platforms. Methods: Correction factors (CFs) were determined to harmonize HDV RNA concentrations using the 1st WHO International Standard for HDV RNA (WHO IS HDV RNA). Limits of detection (LODs) were determined using a dilution series of the WHO IS HDV RNA. Reference material was used for accuracy testing. In addition, 20 dilutions of plasma sample pools obtained from untreated chronic hepatitis D patients were analyzed. Results: The CFs ranged from 14 to 10,000 depending on the test system used. The calculated CFs were used for subsequent quantification. LODs ranged from <2.2 to >575 IU/mL. When accuracy was determined, the two lowest HDV RNA concentrations were not detected by the test system with the lowest sensitivity. When dilutions of pooled samples were tested, 7 of 140 results were reported as negative from all centers. Conclusions: Test-specific CFs must be determined to harmonize HDV RNA quantification. Appropriate platforms for HDV RNA extraction are essential to achieve an adequate detection limit. Both high sensitivity and accurate quantification are important for the accurate monitoring of the response to existing anti-HDV treatment and for clinical trials of novel anti-HDV drugs.