7-OR

Abstract

The aim of the study is to develop a new flow cytometry method based method for simultaneous detection of donor specific IgG and CFAb in a single reaction. CFXM: 0.1X10 6 donor PBMCs were incubated with 30 ul recipient serum along with SAPE-Bio-C1q for 30’. After washes, the cells were incubated with the stain mix of APC-CD19, PerCP-CD3, and FITC-anti-IgG for an additional 30’. The final cells were acquired and analyzed on a Canto-II flow cytometer. The fluorescence intensities of PE and FITC were proportionately correlated to the concentrations of CFAbs and IgG bound respectively on the T and B cells. IgG-FXM: Regular flow cytometry XM procedure. Microcytotoxicity crossmatch CDC-XM ): ASHI procedure. A total of 83 samples were tested in parallel by CFXM and IgG-FXM; and 82 T-XM and 68 B-XM were also performed by CDC-XM. The result of CFXM-IgG showed a good correlation with regular IgG-FXM (P < 0.0001) except less serum used(30 ul/test). The CFXM-C1q picked up all positive CDC-FXMs (N = 65) and identified 25 additional positive XMs with negative CDC-XMs. The 25 samples all had LMX-IgG+ DSAs by SAB. Two pos CDC-XMs positive and CFXM-C1q negative samples proved to be false positive by CDC-XM with no LMX-IgG DSA.[figure1] A new combo flow cytometry crossmatch (CFXM) has been successfully developed by integrating standard IgG FXM with C1q-FXM to simultaneously detect donor specific IgG Ab and CFAb in a single reaction. It provides both FXM and CDC-XM results simultaneously leveraging the sensitivity of the FXM while eliminating the need for CDC-XM.