Outcomes of transplantation using various hematopoietic cell sources in children with Hurler's syndrome after myeloablative conditioning

Jaap Jan Boelens, Mieke Aldenhoven, Duncan Purtill, Annalisa Ruggeri, Todd DeFor, Robert Wynn, Ed Wraith, Marina Cavazzana-Calvo, Attilio Rovelli, Alain Fischer, Jakub Tolar, Vinod K. Prasad, Maria Escolar, Eliane Gluckman, Anne O'Meara, Paul J. Orchard, Paul Veys, Mary Eapen, Joanne Kurtzberg and Vanderson Rocha

Key points

  • In Hurler Syndrome patients early referral for HCT, with the best available HLA-matched donor offers the best "event free survival".

  • In Hurler syndrome patients HCT with a well matched unrelated cord blood unit is particularly attractive as the unit is readily available.


We report transplantation outcomes on 258 children with Hurler syndrome (HS) after a myelo-ablative conditioning regimen from 1995 to 2007. Median age at transplant was 16.7 months and median follow-up was 57 months. The cumulative incidence (CI) of day-60 neutrophil recovery was 91%, day-100 acute-GvHD (grade II-IV), 25%, and 5-year chronic-GvHD, 16%. Overall survival (OS) and event free survival (EFS) at 5-years were 74% and 63%, respectively. EFS after HLA matched sibling donor (MSD) and 6/6 matched unrelated-cord blood (CB) were similar at 81%, 66% after 10/10 HLA matched unrelated donor (UD) and 68% after 5/6 matched CB. EFS was lower after transplantation of 4/6 matched unrelated CB (57%; p=0.031) and HLA mismatched UD (41%; p=0.007). Full donor chimerism (p=0.039) and normal enzyme levels (p=0.007) were higher after CB transplantation (92% and 98%, respectively) compared to the other grafts sources (69% and 59%, respectively). In conclusion, results of allogeneic transplantation for HS are encouraging with similar EFS rates after MSD, 6/6 matched unrelated-CB, 5/6-unrelated-CB and 10/10 MUD. The use of mismatched UD and 4/6 matched-unrelated CB was associated with lower EFS.

  • Submitted September 7, 2012.
  • Accepted January 25, 2013.