Of the different methods of TCD in current use, anti-thymocyte globulin has been associated with substantially elevated rates of EBV reactivation and PTLD.4, 12, 14, 16 Meanwhile, the anti-CD52 monoclonal Ab Campath is thought to confer a lower incidence of PTLD, reportedly 0.4–1.3% in initial studies.4, 5 Unlike anti-thymocyte globulin, which selectively depletes T cells, Campath targets all lymphocytes. This evidence concerns the gene CD52 and post-transplant lymphoproliferative disease.