What can be revealed by extending the sensitivity of HBsAg detection to below the present limit?☆

Received 10 August 2007; received in revised form 6 March 2008; accepted 21 March 2008. published online 22 April 2008.

Background/Aims

We investigated what can be revealed by extending the sensitivity of HBsAg detection to below the present limit.

Methods

We examined the sensitivity of this immunoassay in comparison with real-time PCR detection of HBV DNA using serially diluted sera from HBV carriers. Low HBsAg was measured in 210 healthy volunteers and 368 patients with non-B chronic liver diseases who were negative for HBsAg by a standard EIA method.

Results

The radical immunoassay was able to detect HBsAg at a concentration of 0.025ng/ml. Low HBsAg was positive in 6 of 210 normal volunteers (2.86%), 5 of 65 non-B, non-C cirrhosis patients (7.69%), 6 of 62 non-B, non-C hepatocellular carcinoma patients (9.68%: p=0.04 vs. volunteers), 12 of 134 chronic hepatitis C patients (8.96%: p<0.02 vs. volunteers), and 11 of 107 hepatocellular carcinoma patients complicated by chronic hepatitis C (10.28%: p<0.008 vs. volunteers). Although no HBV DNA was positive in healthy volunteers, 9 patients with non-B chronic liver diseases were positive for HBV DNA by real-time PCR analysis.

Conclusions

Increasing the sensitivity of HBsAg detection to below the present limit has revealed that infection with HBV, including occult HBV, is far more endemic than suspected previously.

Associate Editor: R.P. Perrillo

Keywords: Electron spin resonance, Non-B chronic liver diseases, Occult HBV, Radical immunoassay, Real-time PCR, Clinical research

1 Department of Gastroenterology, Course of Internal Medicine and Therapeutics, Yamagata University Faculty of Medicine, Yamagata University Health Administration Center, 1-4-12 Kojirakawa-machi, Yamagata 990-8560, Japan

2 Murayama Public Health Center, Yamagata Prefecture, Japan

3 Medical Microbiology, Theodor Bilharz Research Institute, Giza, Egypt

4 Tohoku Seiki Industries, Ltd., Yamagata, Japan

5 Institute for Life Support Technology, Yamagata Public Corporation for Development of Industry, Yamagata, Japan

6 Department of Clinical Molecular Informative Medicine, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan

Corresponding author. Tel.: +81 23 628 4151; fax: +81 23 628 4157.

☆ The authors who have taken part in the research of this paper declared that they do not have a relationship with the manufacturers of the materials involved either in the past or present and they did not receive funding from the manufacturers to carry out their research. Dr. Kainuma is an employee of Tohoku Seiki Industries, Ltd., Yamagata, Japan.

PII: S0168-8278(08)00237-7

doi:10.1016/j.jhep.2008.03.019

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