Transforming growth factor-β in renal disease with glycogen storage disease I

We report a 14-year-old patient with Japanese glycogen storage disease I (GSD-I) who was found to have proteinuria. Renal biopsy revealed massive tubular atrophy and interstitial fibrosis with mononuclear cell infiltration, but the glomeruli were almost normal. The epithelial cells of tubules contained periodic acid-Schiff-positive glycogen deposits digested by diastase. In an immunohistological study, transforming growth factor (TGF)-β expression was increased in tubular epithelial cells compared with a normal control kidney specimen. These data suggest that increased TGF-β expression is involved in the pathophysiology of renal interstitial fibrosis in a patient with GSD-I.