Report of 100 hurler syndrome patients receiving 115 bone marrow transplants

Hurler syndrome (MPS 1 H), deficiency of a-L-iduronidase enzyme activity, leads to severe dementia, characteristic facial features, hepatosptonomegaly, cardiac disease, severe skeletal abnormalities, hydrocephalus, and premature death usually by 5 years of age due to accumulation of glycosaminoglycan substrate. Engraftment following bone marrow transplantation (BMJ) provides enzyme and leads to major improvement in symptoms and longevity (COGENT III. 1995; 2540). Various myeloablatrve, marrow manipulation, graft versus host disease (GVHD) prophylaxis regimens and stem cell sources were used. Results according to bone marrow donor type are shown below. Donor pts/BMTs aBVH(%) cGVHD(%) Engraft(%) Survival(%) Identical° 27/30 32 0 95 74 Related° 26/27 46 20 64 54 Unrelated⁺ 40/51 30 18 63 49 Unmlated^† 7/7 43 0 100 63 acute GVHD: Grade II-IV, chronic GVHD: extensive; °in preparation; + in press, BLOOD 1996; † BLOOD 1994; 84:394a (abstract) Variation in treatment protocols precludes identification of the optimal preparative methodology. These results are best described as Phase l/ll studies. To Improve the outcomes for future patients, permanent engraftment rates must be enhanced and GVHD must be minimized or eliminated. An international cooperative study is needed to address these issues.