Evaluation of Performance Characteristics of Commercially Available Tests for Diagnosing Hepatitis B Surface Antigenemia


ABSTRACT:BACKGROUND:A number of serologic immunoassays techniques have been developed in diagnostic virology with different degrees of sensitivity and specificity for the detecting hepatitis B virus (HBV) antigens and their relevant antibodies.OBJECTIVE:This study was designed to apply and assess the sensitivity and specificity of different commercially available laboratory techniques for detecting hepatitis B surface antigen(HBsAg).METHODS:One hundred and twenty-one sera samples were collected from National Center for Blood transfusion, Gastroenterology and Liver Diseases Hospital, Central Public Health Laboratories and Teaching Laboratories. According to the manufacturer’s practical instructions, a group of commercially available laboratory methods for detecting HBsAg were applied , including enzyme linked immunosorbent assay (ELISA), enzyme linked fluorescent assay(ELFA), immunochromatographic assay(ICA), and latex agglutination test(LAT).RESULT:Among ELISA, ELFA, ICA, and LAT methods for detecting HBsAg, the 3rd generation ELISA was proved to have very high specificity (no false negative results) and the least one that has necessitated few confirmatory repetitions. ELFA versus ELISA has showed relatively lower sensitivity (more false negative results). However, similar to ELISA, ELFA showed very high specificity. Immunochromatographic assay (ICA) confidentially appeared to be a good, rapid and simple technique with comparable sensitivity and specificity to ELISA and ELFA techniques. Although LAT was introduced as a rapid, simple and cheap technique for HBsAg screening, it showed frank lower sensitivity and specificity that deranged it from competing with all those tested techniques.CONCLUSION:The concomitant use of ELFA with ELISA compensates its relatively lower sensitivity in front of ELISA. Latex agglutination test for HBsAg has relatively lower sensitivity and specificity than all other tests. For its comparable performance characteristics to ELISA, the use of ICA is ideally suited for HBsAg screening, in respect to its lower cost, rapidity, simplicity and no need for expensive equipments