Sarah M. Bauer, Germany
Universitätsklinikum Ulm Klinik für Kinder- und JugendmedizinPresenter of 1 Presentation
CONDITIONING FOR RETRANSPLANTATION FROM THE SAME DONOR AFTER PARTIAL AUTOLOGOUS RECONSTITUTION IN PATIENTS WITH PID: IMMUNOSUPPRESSION IS NOT REQUIRED
Abstract
Background and Aims
Autologous reconstitution of myeloid cells after allogeneic Hematopoietic Stem Cell Transplantation (HSCT) in patients with primary immunodeficiencies (PID) is associated with incomplete immunological reconstitution or recurrence of the primary disease. T cells can remain -at least in part- of donor origin. Conditioning before a second HSCT from the same donor in this situation is supposed to preserve established donor T-cell function, cause limited toxicity but to allow stable myeloid engraftment.
Methods
In a retrospective analysis we reviewed data of seven consecutive pediatric patients with different PIDs (SCID n=3, CGD, Griscelli syndrome, Reticular Dysgenesis, Leukocyte Adhesion Deficiency I), who underwent allogenic stem cell transplantation between 2005 and 2016. After initial myeloid engraftment, all patients experienced partial or complete autologous reconstitution of myeloid cells with remaining donor t-cells.
Results
Second stem cell grafts were administered at 5 to 38 months after the initial transplantation. Patients received a conditioning regimen containing predominantly myelosuppressive drugs or radioimmunotherapy avoiding immunosuppression or serotherapy before the administration of T-cell replete (n=2) or T-cell depleted (n=5) grafts from the same donor. Limited toxicity and neutrophil engraftment between day +13 to +22 was noted. No acute (>II°) or chronic GvHD occurred. All patients survived with a follow up of 6 to 118 months, with complete (n=5) or stable mixed (n=2) chimerism.
Conclusions
In summary these data demonstrate that a selective myelosuppressive conditioning regimen for retransplantation from the same donor after autologous myeloid reconsititution is a feasible approach to achieve stable myeloid engraftment with low toxicity or treatment related mortality.