COMPARISON OF THE NEUMODX® AND ARTUS HBV QS-RGQ® ASSAYS FOR THE QUANTIFICATION HBV DNA IN CLINICAL SAMPLES

BACKGROUND-AIMHepatitis B virus (HBV) is a major global health problem affecting more than 250 million people and causing nearly one millionHBV-related human deaths annually. Plasma/serum HBV DNA load monitoring is essential to manage the disease and evaluate thetreatment response. In this study, we aimed to compare the NeuMoDx HBV Quant Assay (NMD, QIAGEN GmbH) with the artus HBVQS-RGQ Assay (Artus, QIAGEN GmbH) using residual plasma samples and to evaluate the discordant results.METHODSThe study included 200 patient plasma samples analyzed with the NMD assay in 2019-2020 and stored at -80°C in the MicrobiologyLaboratory of Dokuz Eylül University Hospital. Samples of 100 patients containing HBV DNA (32 samples between 100-1000 IU/ml,33 samples between 1000-10000 IU/ml, 35 samples >10000 IU/ml) and 100 HBV DNA negative samples were retrospectivelyanalyzed by artus in 2022. Discordant results were evaluated by cobas 6800 HBV DNA Test (Cobas, Roche Diagnostics)RESULTSExcellent agreement (: 0.92) was found between NMD and Artus tests. Of the 100 samples that were HBV DNA negative by NMD,93 were negative and 7 were positive (<32 IU/ml) by Artus. All seven discordant samples were positive for HBsAg. With the Cobastest, 5 samples were positive (<34 IU/ml), one sample was negative and one sample was invalid due to insufficient volume. Of the100 HBV DNA positive samples detected by NMD, 99 were positive and 1 was negative with the Artus assay. This sample was alsoHBV DNA negative by the Cobas test.The difference between NMD and Artus results was ε0.5 log10 (0.55-1.65) in 23 samples. Cobas test used for discordant samplesshowed a better agreement with NMD results. In 12 samples with HBV DNA >10,000 IU/mL, there was a significant differencebetween HBV DNA log10 values determined by three different assays (p:0.002).CONCLUSIONSNMD and Artus HBV assays had comparable performance. Discordant results in quantitation were more frequent in samples withhigh viral load, however would not affect patient management. The use of frozen and retested samples may be the reason for thepositive results below LLQ with Cobas and artus.