FALSE-POSITIVE HIV ANTIGENS RELATED TO EMERGENCE OF A 25-30 KD PROTEIN DETECTED IN ORGAN RECIPIENTS

Objective: The routine screening of organ donors for HIV-1 since 1985 has markedly reduced the risk of acquiring infection in organ recipients. However, commercial HIV-1 p24-antigen assays reveal false-positive reactivity in certain recipients. This observation will be discussed here. Methods: Post-transplantation sera collected sequentially from different organ recipients were tested for HIV antigen: 79 samples were from 14 kidney recipients, 57 from seven bone-marrow allografts and 18 from two heart recipients. Neutralization assays to determine specificity were performed on reactive samples. Immunoblots prepared from sera containing high levels of antigens were tested by Western blot using polyclonal anti-HIV sera. Results: Abbott HIV-1-EIA kits detected non-neutralizable antigens in early post-transplantation sera from 12 kidney, five bone-marrow and two heart recipients. Using in-house immunoblots prepared from positive non-neutralizing antigen sera, a 25-30 kD protein was detected and shown to be the cause of the false HIV antigen cross-reactivity. Conclusion: False-positive HIV antigens related to the emergence of a 25-30 kD protein in early post-transplantation sera are detectable in transplant recipients.