Early detection of hepatitis B surface antigen--prototype of a new fully automated HBsAg microparticle enzyme immunoassay (MEIA)

HBsAg is the most important serological marker of acute and chronic hepatitis B infection. Therefore, sensitivity of the currently used detection systems for HBsAg is of major importance for blood screening, diagnosis of HBV infection and therapy monitoring of HBV infected individuals. A Prototype Microparticle Enzyme Immunoassay (MEIA) for qualitative determination of hepatitis B surface antigen (HBsAg) has recently been developed for the fully automated AxSYM analyzer with the intention to provide a test displaying improved sensitivity when compared to the currently marketed HBsAg assays. The present study was conducted to demonstrate sensitivity of the new Prototype AxSYM HBsAg MEIA and the corresponding, fully automated Prototype AxSYM HBsAg Confirmatory MEIA. Analytical sensitivity of the Prototype AxSYM HBsAg MEIA was assessed by testing quantitative HBsAg panels. Sensitivity for HBsAg subtypes ad and ay was found to be 0.15 ng/ml and 0.09 ng/ml, respectively. The detection level for HBsAg subtype ad Standard provided by the Paul Ehrlich Institute was estimated to be 0.03 PEI U/ml. Analysis of hepatitis B seroconversion panels suggests that the new Prototype AxSYM HBsAg MEIA significantly reduces the seroconversion window when being compared to other highly sensitive commercial HBsAg assays. The corresponding Prototype AxSYM HBsAg Confirmatory MEIA demonstrated the ability to confirm low titer seroconverters found reactive with the Prototype AxSYM HBsAg Screening MEIA.