The Impact of Virtual Crossmatch on Cold Ischemic Times and Outcomes Following Kidney Transplantation

Background Prolonged cold ischemic time (CIT) in deceased donor kidney transplantation (DDKT) has been associated with adverse graft outcomes. Virtual crossmatch (VXM) facilitates reliable prediction of crossmatch results based on the profile of human leukocyte antigen antibodies of the recipient and the donor in reduced time compared with a physical crossmatch (PXM). We hypothesized a shorter CIT since the implementation of the VXM in recipients of DDKT. Methods We conducted a retrospective cohort study of consecutive adult recipients of DDKT. The data were analyzed for differences in CIT before and after the implementation of VXM. Results After the exclusion of 59 recipients (age less than 18 years and/or CIT ≥ 20 hours), our study compared outcomes of 81 PXMs from February to June 2018 against 68 VXMs from February to June 2019. There were no statistical differences between groups based on donor age ( P = .09), donor type ( P = .38), kidney donor profile index ( P = .43), or delayed graft function ( P = .20). Recipients with VXM were older (58 vs 51 years , P = .002) and had a higher estimated post-transplant survival score (59% vs 46% , P = .01). The CIT was significantly lower for the VXM group ( P = .04). Conclusion Our study demonstrated a significantly shorter CIT with VXM in DDKT recipients. Our study was limited with small sample size, but the trend of increased graft survival with higher estimated post-transplant scores and older recipients is encouraging as the donor pool expands with marginal kidneys and national sharing.