Simultaneous detection of antibody to the human immunodeficiency virus and of the surface antigen of hepatitis B virus in human serum.

The human immunodeficiency virus (HIV) is the etiologic agent of AIDS. This retrovirus destroys selected classes of T lymphocytes, which results in progressive, severe immunodeficiency. Populations at high risk for AIDS are also at risk for hepatitis B [1]. ELISAs that detect the surface antigen of hepatitis B virus (HBsAg) and antibody to HIV are routinely used to monitor donated blood and blood products to prevent transmission of these serious infections [2, 3]. A single test that could detect HBsAg and antibody to HIV simultaneously would be desirable for the clinical laboratory. In this preliminary report, we describe a singlewell immunoassay with specificity for these two markers. The HIV component of the assay uses synthetic oligopeptides unique to the env region of HIV [4,5]. The antibody bound to the env oligopeptides (anti-HIV env) on the solid phase is then detected by a complex of env peptide, biotin, streptavidin, and horseradish peroxidase (HRPO). The env peptide assay was combined with a sandwichtype immunoassay to detect HBsAg. HBsAg bound to a monoclonal antibody on the solid phase is detected with a noncompeting HRPO-conjugated monoclonal antibody to HBsAg. This combination assay accurately detected HIV antibody and HBsAg in several panels of sera that had been characterized with separate licensed procedures for each of these components. Using antigen standards to quantitate sensitivity, the combination assay detected 1 ng of HBsAg.