Serological diagnosis of caprine lentivirus infection by recombinant immunoassays

Recombinant major core protein p25 (rP25) and transmembrane protein gp40 (rTM) of the ovine lentivirus (OLV) were used as immobilized antigens in enzyme-linked immunosorbent assays (ELISAs) for the detection of antibodies against caprine arthritis-encephalitis virus (CAEV). The sensitivity and specificity of these assays were compared with an agar gel immunodiffusion (AGID) test and a whole-virus ELISA. The results showed that the rTM ELISA was more effective than rP25 ELISA or AGID test in identifying CAEV antibodies in goat populations. The rTM ELISA had similar sensitivity and specificity as the whole-virus ELISA, with an overall concordance of 87.5%. When data for rP25 and rTM were combined, the overall test agreement between whole-virus ELISA and combined recombinant ELISAs increased to 89.3%. The high quantity and purity characteristic of recombinant proteins should make them suitable as routine diagnostic antigens for CAEV and OLV serology.