Hematopoietic stem cell transplantation in patients with Hurler syndrome - myeloablative conditioning efficiency
Background. Allogenic hematopoietic stem cell transplantation (allo-HSCT) for patients with mucopolysaccharidosis is the radical method of therapy nowadays. Myeloablative conditioning regimens allow to achieve good engraftment and do not compromise clinical status of a patient. Aim - to show effectiveness of allo-HSCT with myeloablative conditioning for patients with Hurler syndrome (HS). Patients and methods. We analyzed 23 allo-HSCT at 22 patients with HS which were performed in 2002-2015. HSCT from unrelated donors (10/10 and 9/10) were performed in 18 cases. Transplant: bone marrow - 73.9 % (n = 17); peripheral blood stem cells - 17.4 % (n = 4); cord blood (CB) - 8.7 % (n = 2). Age median - 1.86y.o. (10 months - 3.8years). Conditioning regimen: Busulphan/Treosulphan + Fludarabine + Thiotepa/Melphalan and Antithymocyte Immunoglobulin +/- Rituximab (in case of HSCT from unrelated donor). Results. 19 patients are alive now. 15 patients have complete donor’s chimerism now. All patients have good answer on general disease (best answer correlated with minimal interval between diagnosis and HSCT). Primary graft failure was in one case of CB transplantation. Graft rejection was diagnosed in 3 cases. Causes of death were infection complications in all cases. Results improved during last 5 years - good infection control and therapy of infection and immune complications. Median of follow-up is 48.62 (8-130) months, overall survival 83.2 %, event-free survival - 71.5 %. Conclusion. Our results suggested that allo-HSCT with myeloablative conditioning (with Melphalan inclusion) for the patients with HS is effective way of therapy to stop neurodegeneration processes. Optimization of prevention and treatment of infection complications and graft-versus-host disease allows to improve significantly results of HSCT.