120-P: DESIGN OF A SPECIFIC, SENSITIVE ASSAY FOR THE DETECTION OF ANTI-VIMENTIN ANTIBODY USING Luminex® BEAD-BASED TECHNOLOGY

Abstract

Aim The intermediate filament vimentin is not normally exposed to the immune system, however when exposed, anti-vimentin antibodies (AVA) can be provoked. AVA have been implicated in the development of cardiac allograft vasculopathy (CAV), limiting the long-term benefits of cardiac transplantation. Our aim was to develop a more specific and sensitive assay for the detection of AVA than currently available. Methods A Luminex® multiplexed assay for AVA was designed and validated by parallel testing with a commercially available ELISA for AVA. Sera titration and competitive inhibition with soluble vimentin were used to assess sensitivity and specificity. Pre- and post-transplant sera from forty-six patients were tested under IRB approval. Post-transplant sera were obtained within 12 months after transplantation. Results In parallel titration studies, the bead-based assay was found to be twice as sensitive as the commercially available ELISA. Competitive inhibition studies of five sera resulted in a mean of 60% ± 28% reduction of antibody binding, confirming the Luminex® assay specificity. The incidence of AVA in per-transplant sera was 47.8%.[figure1] Conclusions A Luminex® bead based assay for AVA was developed that is both specific and twice as sensitive as a commercially available ELISA that may have future clinical application. Although a high incidence of AVA among cardiac transplant candidates was observed pre-transplant, longer term studies will be needed to confirm any association with CAV post-transplant.