Hepatic fibrosis in the mucopolysaccharidoses

The mucopolysaccharidoses are a group of clinically progressive, heritable, lysosomal storage disorders. Many organ systems are affected due to widespread accumulation of incompletely degraded mucopolysaccharide. The novel finding of hepatic fibrosis in each of six cases of mucopolysaccharidosis examined at autopsy (including examples of Hurler syndrome, Hunter syndrome, and Sanfilippo syndrome) is described. In each instance, the liver was diffusely involved by fibrosis that outlined the lobules, and there was extensive hepatocyte and Kupffer cell vacuolization. The pattern of hepatic fibrosis is not explained by either cardiac failure or drug toxicity. It is hypothesized that the hepatic fibrosis is due to the abnormal accumulation of a hepatotoxic metabolite. The frequency and severity of liver disease in the mucopolysaccharidoses deserve further study. In particular, with the advent of bone marrow transplantation as therapy for some of the mucopolysaccharidoses, the question of whether cirrhosis develops in these patients and, if so, what its rate of progression is, should be addressed.