ABSTRACT
Five dogs with mucopolysaccharidosis I, 3 of which had been treated with bone marrow transplantation (BMT), were evaluated for 20 months with electrocardiography, thoracic radiography, and M-mode and 2-dimensional echocardiography. Treated and untreated (control) dogs had widened P waves on ECG. Thoracic radiographs remained normal for all dogs throughout the study. Thickening of the mitral valve was observed on echocardiograms of dogs in both groups, but the untreated dogs appeared to have thicker valves. Concentrations of glycosaminoglycans in the mitral valves and myocardium were higher in control dogs than in treated dogs. Markedly large aortic root diameters were observed on echocardiograms in both untreated dogs, but aortic root diameters remained normal in treated dogs. Echocardiography, but not electrocardiography, was useful in monitoring heart enlargement in each dog. Dogs treated with BMT generally had less severe cardiac changes and slower disease progression than control dogs.
Subject(s)
Bone Marrow Transplantation/veterinary , Cardiomegaly/veterinary , Mucopolysaccharidosis I/veterinary , Animals , Bone Marrow Transplantation/pathology , Cardiomegaly/pathology , Echocardiography/veterinary , Electrocardiography/veterinary , Mucopolysaccharidosis I/pathology , Mucopolysaccharidosis I/surgery , Time Factors , Whole-Body Irradiation/veterinaryABSTRACT
A naturally occurring disease in Plott hound dogs, caused by deficiency of the lysosomal enzyme alpha-L-iduronidase, was used to study the feasibility of bone marrow transplantation therapy in a neurodegenerative storage disease. Three long-term survivors of transplantation with littermate marrow at 5 months of age (before clinical signs) had CNS enzyme activity, glycosaminoglycan storage, and light microscopic and ultrastructural changes evaluated 594, 628, and 740 days after treatment. Iduronidase activity in small amounts (1-3% of donor values) was detectable in brain tissue. Cerebrospinal fluid had higher iduronidase activity after transplantation (7-15% of donor values). Enzyme activity within the CNS resulted in significant reductions in stored glycosaminoglycans and resolution, to a large extent, of light microscopic and ultrastructural lesions observed in affected, untreated littermate control dogs.