Detection of antibodies to Kaposi's sarcoma-associated herpesvirus: a new approach using K8.1 ELISA and a newly developed recombinant LANA ELISA.

Detection of antibodies to Kaposi's sarcoma-associated herpesvirus (KSHV or Human herpesvirus 8) is a topic of ongoing controversy. KSHV expresses multiple antigens and host responses are highly variable. We have previously described an algorithm for determining KSHV infection based on K8.1 ELISA and LANA immunofluorescence assay (IFA). Here we describe the development of a recombinant ELISA for LANA and an improved testing strategy using ELISAs for LANA and K8.1. We assessed mammalian and baculovirus expression systems for the production of full-length recombinant LANA. We evaluated the performance of LANA ELISAs using human serum samples from several sources including blood donors and clinical patients diagnosed with Kaposi's sarcoma and compared them to LANA IFA. Both LANA ELISAs exhibited comparable sensitivity and specificity to LANA IFA but showed considerably greater reliability. The LANA ELISA can thus be used in conjunction with the previously described K8.1 ELISA to enable the highly sensitive and specific detection of antibodies to KSHV. Use of this testing strategy will provide a more accurate and reliable diagnostic assessment of KSHV status.