Changes in the methodology of pre-heart transplant human leukocyte antibody assessment: an analysis of the United Network for Organ Sharing database

BackgroundWe sought to investigate temporal trends in the methodology of human leukocyte antibody assessment in heart transplantation. MethodsThe United Network for Organ Sharing database was queried from June 2004 to March 2013 to obtain pre-heart transplantation human leukocyte antibody results. The % panel reactive antibody for class I and II antibodies was recorded along with the methodology of assessment. Allosensitization was defined as class I and/or II panel reactive antibody of 10%. The primary outcome measure was graft survival. ResultsDuring the study period, 12858 patients with available data underwent heart transplantation. The prevalence of allosensitization increased, with 16.8% in 2005-2006 sensitized at the time of transplantation compared to 23.1% in 2010-2011 (p<0.001); this occurred in conjunction with an increase in the utilization of flow cytometry (77.2% in 2005-2006; 97.0% in 2010-2011, p<0.001). Using multivariable analysis, a positive pre-heart transplantation panel reactive antibody by flow cytometry independently predicted graft loss. ConclusionsThere has been a recent increase in flow cytometric assessment of human leukocyte antibodies prior to heart transplantation, which may be associated with an increase in the prevalence of pre-transplant patients being characterized as allosensitized. Flow cytometry may identify patients with the highest likelihood of graft loss.