Bone-Marrow Transplantation in the Maroteaux–Lamy Syndrome (Mucopolysaccharidosis Type VI): Biochemical and Clinical Status 24 Months after Transplantation

A 13-year-old girl with the severe form of the Maroteaux–Lamy syndrome (mucopolysaccharidosis Type VI, arylsulfatase B deficiency) has had successful reconstitution with bone marrow from her HLA-MLC-matched sister who had normal arylsulfatase B activity. Full engraftment has been present for 24 months. The following biochemical and clinical changes have occurred: arylsulfatase B activity in peripheral lymphocytes and granulocytes increased to normal levels, and the activity in serial liver-biopsy specimens increased from about 3 per cent of the mean normal level 43 days after transplantation to about 16 per cent at 600 days. Urinary excretion of acid mucopolysaccharide decreased. Ultrastructural evidence of accumulated dermatan sulfate was no longer detectable in bone-marrow cells; in peripheral-blood lymphocytes, granulocytes, or platelets; or in Ito cells of liver. Twenty-four months after engraftment, hepatosplenomegaly was substantially decreased and cardiopulmonary function was normal. Visual acuity and joint mobility were also improved. The patient returned to school and continued to perform well in academic studies. Thus, bone-marrow transplantation provided a source of enzymatically normal cells, which have altered the metabolic and clinical course of the disease. (N Engl J Med 1984; 311:1606–11.) BONE-marrow transplantation has proved effective for the treatment of aplastic anemia, refractory leukemias, and congenital immunodeficiency disorders. 1 2 3 4 More recently, several other disorders, including β-thalassemia, chronic granulomatous disease, actin-neutrophil dysfunction, and thrombasthenia, have been successfully treated by bone-marrow transplantation. 1 2 3 4 Physiologically, transplanted bone-marrow stem cells differentiate and provide a source of donor osteoclasts, as well as donor reticuloendothelial cells, in the liver, lung, and intestine of the recipient. 5 6 7 Bone-marrow transplantation in osteopetrosis, an inherited disease resulting from osteoclast dysfunction, has resulted in the restoration of normal osteoclast-monocyte function and clinical improvement in several patients. 7 , 8 Thus, it has been suggested that bone-marrow transplantation . . .