Figure 1.

Association between the immunogenicity of first transplant donor HLA mismatches and posttransplant HLA ‐specific sensitization expressed as calculated reaction frequency ( cRF ). HLA‐specific alloantibodies were detected using single‐antigen HLA beads (mean fluorescence intensity cut‐off threshold of 2000); the likelihood of identifying an antibody‐compatible organ donor (cRF) was determined by comparing individual patient HLA‐specific antibody profiles with the HLA types of 10 000 consecutive UK deceased organ donors. Panel (A) shows peak cRF levels while on the waiting list attributable to antibodies against HLA‐A, ‐B, and ‐C considered collectively according to the immunogenicity of donor HLA class I mismatches expressed by the failed kidney transplant, as assessed by amino acid mismatch score (AMS), eplet mismatch score (EpMS), and electrostatic mismatch score (EMS). Panel (B) shows peak cRF levels while on the waiting list attributable to antibodies against HLA‐DRB1, ‐DRB3/4/5 and ‐DQ, considered collectively according to the immunogenicity of donor HLA class II mismatches present on the failed kidney transplant, as assessed by AMS, EpMS and EMS. Panel (C) shows peak cRF levels while on the waiting list attributable to antibodies against HLA class I and class II considered collectively according to the immunogenicity of donor HLA class I and class II mismatches present on the failed kidney transplant, as assessed by AMS, EpMS, and EMS. Patients were categorized according to the likelihood of identifying an antibody‐compatible organ donor as cRF 0–15%, cRF 16–50%, cRF 51–84%, and cRF 85–100%. Patients were grouped in quantiles of the variable of interest (AMS, EpMS, or EMS) and within each group the number of patients is shown.