Virus-specific ImmunoTherapy Following Allogeneic Stem Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (HSCT) is the only treatment option for several haematological diseases. In spite of substantial progress in this field, viral infections, mainly cytomegalovirus (CMV) and adenovirus (HAdV) in the context of delayed immunoreconstitution remain life threatening complications. Weekly screening of high-risk patients and preemptive virostatic treatment has become a current strategy. Unfortunately, treatment with virostatic drugs is associated with substantial nephro- and myelo-toxicity and of limited effectiveness. Human adenovirus (HAdV) and cytomegalvirus (CMV) disseminated infections are associated with mortality rates of up to 50%-60% despite virostatic treatment. All HSCT patients at the St. Anna Children's Hospital undergo weekly viral quantitative PCR-screening for HAdV and CMV and weekly PB FACS (Fluorescence Activated Cell Sorter)-Analysis according to the local HSCT-diagnostic SOP (Standard Operating Procedure) from day -7 until day +100 Patients with HAdV or CMV viremia will receive preemptive treatment with either gancyclovir (in case of isolated CMV-viremia) or Cidofovir (in case of HAdV viremia or combined HAdV/CMV infection). In case of increasing viremia ≥ 1log despite antiviral treatment for two weeks or stable with 10E6 viral load and the absence of virus specific T-cells in the recipient, the treating physician will check, if the patient is eligible for seVirus-T-cell infusion (see inclusion criteria). Study Design: Mononuclear Donor-Cells from peripheral blood (100 ml extra donation) will be cryopreserved at the time-point of HSCT. In case of progredient viremia these cells will be stimulated with interleukin-15 and peptides out of the virus molecule, virusspecific T-Cells are enriched for 2-3 logs-teps and potentially alloreactive cells diluted at the same time. This new approach reduces the risk of graft-versus-host-disease (GvHD) and enables the infusion of virus-specific T-cells also from haploidentical donors.