Calibration of qualitative HBsAg assay results for quantitative HBsAg monitoring

Abstract Background: The usual criteria for analysis of hepatitis B surface antigen (HBsAg) are detection of HBsAg and result confirmation by antibody neutralization. We observed that with the Immulite 2000 HBsAg assay [Diagnostics Product Corporation (DPC)] a relatively high percentage of weakly reactive (WR) samples did not pass the neutralization step. Methods: For each of 3 lots of Immulite 2000 HBsAg reagent (DPC), we collected and analyzed HBsAg data from ∼3000 to 4000 patient blood samples and compared these data with HBsAg data from 3393 samples tested with the Abbott Auszyme assay. For 127 samples with initially WR detection signals (relative signal/cutoff index of 1.00–2.5) on the Immulite 2000 HBsAg assay, we then measured hepatitis B (HB) viral load and/or other HB serologic markers. Results: The Immulite 2000 HBsAg assay produced more initially reactive results than the Abbott Auszyme method. Many of these reactive samples, however, were WR and did not meet the confirmation criteria in the neutralization test. Moreover, DNA PCR testing indicated that 22 of the 38 WR samples (58%) that did meet the confirmation criteria had no detectable HB viral DNA. Conclusions: Immulite 2000 HBsAg assay results include a unique group of WR samples that are associated with both false-positive and false-negative results, regardless of neutralization status, and require careful interpretation. WR HBsAg samples should be reported as confirmed HBsAg reactive only if the samples not only meet the neutralization criteria but also are positive for other HB serologic markers such as anti-HB core total and anti-HB core IgM.

Download Full-text

Performance evaluation of a new next-generation high-sensitive architect HBsAg assay

Clinica Chimica Acta ◽

10.1016/j.cca.2019.03.1166 ◽

2019 ◽

Vol 493 ◽

pp. S555

Author(s):

E. Sickinger ◽

H. Braun ◽

J. Schultess ◽

M. Oer

Keyword(s):

Performance Evaluation ◽

Next Generation ◽

Hbsag Assay

Download Full-text

Analytical Performance of the Sysmex HISCL HBsAg Assay and Comparison with the Roche Elecsys HBsAg II Quant Assay in the Quantification of Hepatitis B Surface Antigen

Medicina ◽

10.3390/medicina57121307 ◽

2021 ◽

Vol 57 (12) ◽

pp. 1307

Author(s):

Joonhong Park ◽

Taewon Bae ◽

Yonggon Cho ◽

Dalsik Kim ◽

Jaehyeon Lee

Keyword(s):

Comparative Evaluation ◽

Hepatitis B Surface Antigen ◽

Reference Value ◽

Analytical Performance ◽

Clinical Samples ◽

Limit Of Quantification ◽

Highly Sensitive ◽

Hbsag Assay ◽

Allowable Error ◽

Assay Precision

Background and Objectives: This study aims to estimate the analytical performance of the Sysmex HISCL HBsAg assay and to assess the analytical correlation with the Roche Elecsys HBsAg II quant assay with clinical samples and the WHO International Standard (IS). Materials and Methods: The intra-assay precision, linearity, assay limitation, accuracy, and comparative evaluation of the HISCL HBsAg assay were estimated. Results: Extrapolating from the plot of the average total allowable error versus the reference value, an accuracy goal of 20% would be achieved around a limit of quantification (LoQ) of 0.014867 IU/mL. The percentage of biases for each level of the WHO IS measured by the two assays were less than 15%, except for the WHO 3rd IS, for which the HISCL HBsAg assay achieved a percentage of bias of 33%. In the comparative evaluation, Passing–Bablok regression analysis did not reveal any significant deviation from linearity between the two assays (y = −48.6998 + 1.9206x; p = 0.79 by the CUSUM test for linearity). The mean difference of the quantitative HBsAg level between the two assays was 1762.5 IU/mL in the Bland–Altman plot. Conclusions: The HISCL HBsAg assay, with a highly sensitive LoQ of 0.03 IU/mL, showed similar analytical performance in HBsAg quantification to the Elecsys HBsAg II quant assay and may be helpful in obtaining better diagnoses and therapeutic strategies for treating HBV infections.

Download Full-text