Analytical and clinical evaluation of a novel assay for anti-HBc IgG measurement in serum of subjects with overt and occult HBV infection

Objectives: We assessed the analytical and clinical performance of the Lumipulse® G HBcAb-N (Fujirebio, Japan) assay for IgG antibodies to hepatitis B core antigen (anti-HBc IgG) measurement in serum of subjects with overt and occult HBV infection (OBI). Materials/methods: Serum anti-HBc IgG was assessed in 181 anti-HBc-positive subjects: 119 chronic hepatitis B (CHB) patients in different infection phases and 62 subjects (35 CHB and 27 OBI) with available liver specimens for HBV covalently-close-circular (ccc) DNA analysis. Results: The anti-HBc IgG assay showed a linear dynamic range (R2 = 0.9967); lower limit of detection and quantitation were 0.5 IU/mL and 0.8 IU/mL. Reproducibility was 4.9% and accuracy 98.7%. Anti-HBc IgG levels varied according to HBV infection phase, linearly declined during antiviral treatment and resulted correlated to intrahepatic HBV cccDNA (r = 0.752, P b 0.001). Conclusions: The quantitative anti-HBc IgG assay exhibited appropriate analytical performance and may represent a diagnostic complement in CHB patients and OBI subjects.