P130 Rapid virtual crossmatch assessment using histotrac database

Abstract

Aim The aim of this study was to develop a Virtual Crossmatch (VXM) tool utilizing our HLA database program Histotrac. The goal was to quickly visualize a patient’s current and historical anti-HLA antibody history, PRA, HLA match, sensitizing events and most recent serum. Following a director’s interpretation the program will order the test and generate a clinical report for distribution to the requesting transplant professional. Methods For this study we used our labs database system Histotrac. A customized program was generated based on the several factors we requested needed to be visualized in order to make a virtual crossmatch assessment. Flow PRA and single antigen bead testing were performed using One Lambda reagents and analyzed using Fusion software. All current and historical anti-HLA antibody data from Kidney, Heart, and Lung patients were sent from Fusion to Histotrac database thru a direct interface. Local donors were HLA typed by RTPCR using SABR kits. For imports, donor HLA typing was reviewed in DonorNet including the attached HLA typing report. All donor HLA data was entered into Histotrac and required to run the VXM tool. Results Our lab receives on average 250 VXM per month requiring an hour to complete each one from initial request to report. The VXM tool displays the current DSA MFI and searches all historical samples to identity the peak MFI for each DSA >1000 MFI. In validation, the VXM tool was refined to be 100% accurate compared to manual review. The VXM tool was able to decrease this time to 30 min per VXM and 15 min if the donor HLA typing was added in advance. With our transplant centers running VXM on 5 patients per donor this could be completed in 30 min saving an average of 2 h 30 min. Conclusions Virtual Crossmatch has become a widely utilized method for assessing donor-recipient compatibility in the absence of a physical crossmatch. We have developed a VXM tool that is capable of rapidly assessing a patient’s current and historic anti-HLA antibody history compared to a donor HLA typing. This procedure is able to significantly decrease the on call time required by the lab from initial request to virtual crossmatch report sent out. Furthermore, this shortens the time to where transplant coordinators and physicians receiving this information can assess donor organ offers and living donor paired exchanges.