False-positive reactions to HCV antibody after aortic graft replacement for aortic dissection: False-positive reactions due to anti-bovine serum albumin antibody produced by surgical adhesive

Abstract

Positive turning reactions to the HCV antibody measured with an S assay kit were observed in some cases after aortic graft replacement (AGR) for aortic dissection. BioGlue used in AGR contains bovine serum albumin (BSA), which has been reported to induce the production of the anti-BSA antibody. Generally, one of the causes of immunoassay kits showing false-positive results is nonspecific reactants including heterophilic antibodies. We hypothesized that the false-positive reactions to the HCV antibody might be induced by the anti-BSA antibody. The subjects were 4 patients with AGR (AGR group) and 10 patients with general surgery (non-AGR group). BioGlue was used only in the AGR group. Both groups were negative for the HCV antibody, as measured with the S assay kit preoperatively, and received blood transfusions during surgeries. In the AGR group, the HCV antibody measured with two assay kits including the S assay kit was positive and the antibody measured with three other assay kits was negative 2 months after AGR, but HCV core antigens were negative. In the non-AGR group, the HCV antibody measured with the S assay kit was negative 2 months after surgery. The anti-BSA antibody titers were considerably higher in the AGR group (219–692 ng/mL) than in the healthy volunteer group (10–85 ng/mL). Therefore, it was proved that the anti-BSA antibody was produced from the BSA component of BioGlue in AGR for aortic dissection. The false-positive reactions to the HCV antibody measured with the S assay kit were due to the anti-BSA antibody. Medical technologists should understand the reaction characteristics of each assay kit for heterophilic antibodies such as the anti-BSA antibody.