A prospective study to evaluate the clinical specificity of the cobas® MPX test kit for screening for HIV RNA, HCV RNA, and HBV DNA in blood donation samples using the cobas® 6800 system in HBV endemic areas

• New-gen Roche Cobas® MPX sets global HIV, HCV, and HBV screening standards. • Cobas® MPX excels in high HBV areas, boosting transfusion safety. • Exceptional HBV detection enhances insights for further research. Nucleic acid testing (NAT) is widely used for screening blood donors for infectious diseases to enhance transfusion safety. Roche's advanced cobas® MPX assay detects human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B virus (HBV) using the cobas® 6800/5800 Systems, based on real-time PCR technology, providing improved sensitivity. This study aims to evaluate the clinical sensitivity and specificity of the cobas® MPX assay and its effectiveness in identifying infected donors in HBV endemic areas, particularly those with occult HBV infection (OBI). A total of 12,067 donor samples from the Dalian Blood Center (DLBC, northern China) were tested for HIV, HCV, and HBV using both the cobas® MPX assay on the cobas® 6800 system and the previous generation cobas® TaqScreen MPX test v2.0 on the cobas s 201 system as the reference method. Testing was conducted using individual-donation testing (IDT) and primary pool of six donations (PP6), following the manufacturer's instructions and the operational procedures of the instruments. Samples with inconsistent results underwent repeated confirmation tests. Cobas® MPX demonstrated 100.00% overall percent agreement (95% CI, 99.22%-100.00%) for IDT and 99.89% (95% CI, 99.82%-99.95%) for PP6. Kappa coefficients were 1.0 for IDT and 0.76 for PP6. Cobas® MPX specificity was 100.00% (95% CI, 99.22%-100.00%) for IDT and 99.99% (95% CI, 99.94%-100.00%) for PP6. Sensitivity was 100.00% (95% CI, 2.50%-100.00%) for IDT and 86.67% (95% CI, 68.36%-95.64%) for PP6. A total of 12 HBV NAT-yield cases were detected by cobas® MPX. Cobas® MPX demonstrated outstanding sensitivity and specificity in screening HIV, HCV, and HBV in routine blood donations, particularly enhancing occult HBV detection in endemic regions.