Wait time deconstructed

Abstract

Transplant (TX) physicians often ask us: What effects do ABO and HLA antibody sensitization have on my patient’s ability to get an organ offer? This study attempts to answer that question by analyzing waitlist (WL) and TX patient data, ABO and HLA antigen frequency data over a 6 year period for the Tulane kidney transplant program. Data was stratified by presensitization, sex, ABO and TX status. We analyzed this data along with HLA antigen frequency and pertinent organ offer statistics to determine the projected wait time for a highly sensitized (99%) regraft patient with ABO = O. On average, presensitized Tulane WL patients wait 50% longer for an organ than unsensitized patients. The following table gives median wait time stratified by sex, ABO, and TX status. Using the above, ABO and HLA antigen frequencies and frequency and types of organ offers, we projected wait time until a compatible organ offer for a 99% CPRA, regraft male patient awaiting a standard criteria donor with ABO–O in excess of 14 years for an in-state offer. The wait for a regional or national offer is projected to be 63 months, but may be less in the future due to the new allocation system. Wait time is highly dependent on ABO and sensitization, but we also see a disparity in wait times for WL patients vs. TX patients pointing to the effect of HLA antigen frequency. All sensitization is not equal. Many still on the WL likely have less frequent HLA types and higher levels of HLA antibodies to common HLA antigens than those transplanted given all else equal. These data trends provide the TX physician a better understanding of factors affecting wait time. Download : Download full-size image The following table includes transplant (TX) vs. wait list (WL) patient data given in months wait time stratified by sex and CPRA level. Download : Download full-size image