Life-threatening pulmonary hemorrhages post bone marrow transplantation in Hurler syndrome. Report of three cases and review of the literature.

Hurler syndrome (MPS-IH) is an autosomal recessive mucopolysaccharide storage disorder caused by deficiency of lysosomal alpha-L-iduronidase (IDU) enzyme activity. This results in accumulation of heparan sulfate and dermatan sulfate substances. Untreated children develop progressive developmental deterioration and multisystem morbidity with a median survival of 5 years. Allogeneic bone marrow transplantation (BMT) is the only long-lasting treatment that ameliorates or halts the aggressive course of the disease. Pulmonary hemorrhage (PH) is an unusual complication of BMT and has not been previously reported in MPS-IH post-BMT. We report three children with MPS-IH with life-threatening PH around the time of engraftment. All needed intensive-care support and one child developed recurrent PH that required prolonged ventilation.