Following allogeneic stem cell transplantation (alloSCT), most patients experience a period of profound and prolonged T cell deficiency due to the immune suppression and/or T cell depletion (TCD... Show moreFollowing allogeneic stem cell transplantation (alloSCT), most patients experience a period of profound and prolonged T cell deficiency due to the immune suppression and/or T cell depletion (TCD). In this period the patients are at risk for developing infectious complications by reactivation of endogenous herpes like viruses cytomegalovirus (CMV), Epstein-Barr virus (EBV) and varicella zoster virus (VZV). Reactivation of endogenous CMV is the most frequently occurring herpes virus reactivation following alloSCT. Approximately 60% of alloSCT recipients are seropositive for CMV and are therefore at risk for endogenous reactivation of latent CMV. CMV reactivation can lead to potentially fatal CMV disease, comprising CMV pneumonitis, CMV colitis or CMV encephalitis. The aim of this thesis was to evaluate factors that influence the incidence of CMV disease after TCD alloSCT. These factors include the conditioning regimen, serostatus of the donor, pharmacological intervention following alloSCT and adoptive T cell transfer for treatment of refractory CMV reactivation or CMV disease. Show less