284 Long-Term Outcome After Hematopoietic Stem Cell Transplantation (HCT) in Patients Affected by Mucopolysaccharidosis I Hurler (MPS IH)

Aims: To evaluate the long-term effect of HCT in MPS IH pts. Patients and methods: 6 MPS IH (median age at diagnosis 1.2 yrs, 0.5–1.5) pts underwent 8 B- and T-depleted HCTs (after autologous reconstitution 2 pts received a second HCT) at a median age of 1.7 yrs (1.2–2.5). Heart, pulmonary, eye, ear, bone and neurological involvement was periodically evaluated. Results: At a median follow-up of 4.2 yrs (2.8–5.3), 5 out of 6 pts (mean age 6.3 yrs, 5.3–6.9) are alive (one pt died 1 yr after HCT), 4 complete and 1 partial chimeras, all with normal enzymatic activity and a reduction in the excretion of urinary glycosaminoglicans. Patients showed a reduction in hepatosplenomegaly and in respiratory infection and stabilisation of corneal cloudings. Joint mobility clearly improved. Hearing was normal in one patient, the other 4 had hearing loss which stabilised in 1 and improved in 3 pts. Cardiac involvement was stable in 2 and slight improved in 3 cases. X-ray showed a stability in genu-valgum in 4/4 and in kyphosis in 2/2 cases. The cerebral MRI was stable in 2 and improved in 2 pts. The basal median developmental quotient (Griffiths scale) of 89 (70–93) decreased during the first year after HCT and then stabilised reaching a median of 74 (53–82) after a median of 3.0 yrs (1.5–3.3). Conclusions: HCT represent a good therapeutic option for selected MPS IH patients and could determine an improvement in the natural history of the disease influencing the cardiac, joint and pulmonary function but also bone and the central nervous system involvement.