Evaluation of Various Rapid Immunochromatographic Assays Performed on Aircrews

Yi, Jongyoun

Abstract

BACKGROUND: Aviators are tested for the antigens and antibodies of hepatitis viruses or tumor markers when they visit the Aerospace Medical Center (AMC) for regular checkups. Although various enzyme immunoassay (EIA) or chemiluminescence immunoassay (CLIA) are currently the standard quantitative methods and are widely used, the clinical laboratory of AMC is currently using the rapid qualitative immunochromatographic assays (ICA) for these tests due to the lack of necessary equipment and high cost. The aim of our study was to evaluate the rapid ICAs in comparison with standard methods.
METHODS
With the cooperation of the Department of Laboratory Medicine in Seoul National University Bundang Hospital (SNUBH) where the standard methods (CLIA) had been used, serum specimens of SNUBH patients were collected and provided for AMC together with the results of six test items. The six items were HBsAg, anti-HBs, anti-HCV, alpha-fetoprotein (AFP), prostate-specific antigen (PSA), and carcinoembryonic antigen (CEA). The test results of these specimens by rapid ICAs were compared with those by the SNUBH methods.
RESULTS
When the SNUBH methods were regarded as a standard, sensitivity/specificity of each rapid ICA was HBsAg 95.1%/100%, anti-HBs 90.6%/92.6%, anti-HCV 97.5%/ 100%, AFP 75%/100%, PSA 66%/100%, and CEA 47.7%/100%, respectively.
CONCLUSION
The rapid ICA methods used at the AMC generally showed high specificity but low sensitivity which meant that the overall accuracy may be unsatisfactory. These ICAs were unsuitable for accurate confirmative diagnosis due to low negative predictive values. For several items whose sensitivities are particularly low, they could not be used as screening tests. If immunoassays are to be helpful for an accurate diagnosis, it is necessary to equip the AMC with an EIA or CLIA instrument.