The Risks Associated with Blood Transfusion in Kidney Transplant Patients: A Retrospective Cohort Study Using Routinely Collected Data

Abstract

A blood transfusion may have important immunomodulatory effects and may carry certain risks which could be detrimental to the kidney transplant patient. The aim of this project is to examine the potential risks associated with post-transplant blood transfusions in kidney transplant recipients. We carried out a retrospective cohort study of all adult kidney transplant recipients at The Ottawa Hospital from 2002 to 2018 inclusive. We examined the risks for kidney transplant rejection, graft loss, death, infections and venous thromboembolic events (VTE) associated with the receipt of red blood cell transfusions (RBCTs) administered after kidney transplant. We calculated hazard ratios (HR) using Cox proportional hazards model with RBCT as a cumulative, time-varying exposure. Out of a total study population of 1,258 kidney transplants recipients, 37% received at least one RBCT. The receipt of a RBCT was not significantly associated with the risk for rejection, however it was associated with an increased risk for graft loss, death, infection and VTE. Important biases such as reverse causation and unmeasured confounding may account for some of these findings. That being said, our findings suggest clinicians should be judicious in their use of RBCT in kidney transplant patients.