Patients with lysosomal storage disorders have visceral, skeletal, and
neurological abnormalities and a limited life expectancy. Bone marrow
transplantation has been used to correct the metabolic defects and le
ads to metabolic improvements in most patients However, the long-term
effect of such therapy is uncertain. We analysed the data from 63 pati
ents transplanted for lysosomal storage diseases. The transplant-relat
ed mortality was 10% if an HLA-identical sibling marrow donor was avai
lable (n=40) and 20-25% if mismatched tissue was used. Data on the eff
ect of bone transplantation on biochemical and clinical variables were
available in 29 of the 63. 28 had a follow-up duration of 1.0-10.2 ye
ars; 1 patient died of disease progression in the first year after sta
ble engraftment. 13 patients who had severe neurological symptoms at t
he time of transplantation showed disease progression. Engraftment of
bone marrow in 5 patients with non-neuronopathic Gaucher's disease led
to complete disappearance of symptoms. 11 patients had skeletal sympt
oms because of various mucopolysaccharidoses (MPSs). There was stabili
sation of the skeletal lesions during the observation period of 1.4-6.
4 years, but none of the patients showed significant regression of the
skeletal symptoms. The visceral features (hepatosplenomegaly, cardiac
hypertrophy, and upper airway obstruction) in these patients abated a
fter transplantation. We could not evaluate the biochemical and clinic
al variables in 34 patients because of graft rejection, transplant-rel
ated mortality, or follow-up of less than 1 year. There were significa
nt beneficial effects of bone marrow transplantation in patients with
non-neuronopathic Gaucher's disease, Stabilisation of disease was obse
rved in patients with MPS-I and MPS-II; this potential benefit needs t
o be confirmed by longer follow-up, Bone marow transplantation was not
effective if severe neurological symptoms were already present at the
time of transplantation.