Aim: A highly sensitive semi-automated immune complex transfer chemiluminescence enzyme immunoassay (ICT-CLEIA) for the detection of hepatitis B surface antigen (HBsAg) was recently developed. Our aim is to investigate clinical significance of ICT-CLEIA in patients with HBV.
Methods: Of 829 HB carriers in our hospital and 167 commercial panels, performance of ICT-CLEIA(detection range 0.0005-2.5 IU/mL) was compared with two quantitative HBsAg detection systems (Architect HBsAg QT assay [0.05-250 IU/mL] and HISCL HBsAg assay [0.03-2500 IU/mL]) and COBAS TaqMan HBV-DNA assay (CTM, 2.1 Log copies/ml) using serum samples from patients or panels.
Results: The ICT-CLEIA had good accuracy and reproducibility. The sensitivity of wild type and HBsAg escape mutants (I126S, D144A, G145R) by ICT-CLEIA was 2- -5 to 2- -6 times higher than that of Architect HBsAg QT. For clinical practice, ICT-CLEIA assay could detect HBsAg even in the presence of anti-HBs during window periods in acute hepatitis B panel. HBsAg has been detectable for around 9 years in a patient with HBsAg clearance by Architect. In a patient with HBV reactivation after bone marrow transplantation followed by systematic chemotherapy, HBsAg by ICT-CLEIA was detectable at the same time point when HBV-DNA was detected by PCR. In conclusion, the ICT-CLEIA assay permits not only an earlier detection of acute hepatitis B infection but also may be useful for monitoring hepatitis B patients.