NEPHROSIALIDOSIS - ULTRASTRUCTURAL AND LECTIN HISTOCHEMICAL-STUDY

The neuropathological findings in a Japanese male with nephrosialidosi s are reported. Clinically, coarse face, psychomotor retardation, macu lar cherry-red spot and proteinuria were noted at 1 year and 7 months. He was diagnosed to have nephrosialidosis on the basis of a deficienc y of alpha-neuraminidase activity in both lymphocytes and cultured ski n fibroblasts, and of severe glomerular and tubular involvement on ren al biopsy. He died of multiple organ failure at 8 years and 6 months. There were numerous vacuoles and storage materials in visceral organs, particularly in the glomerular and tubular epithelial cells of the ki dney and Kupffer cells as well as hepatocytes in the liver. Neuropatho logical examination revealed severe neuronal storage in the selected p art of the central nervous system; lower motor neurons of the brain st em and spinal anterior horn cells, as well as neurons in the basal nuc leus of Meynert. In the peripheral nervous system, sympathetic ganglia were severely affected. There was little or no neuronal storage in th e basal ganglia, cerebral cortex or cerebellum, and demyelination was not found. Electron microscopic examination showed fine wavy multilame llar structures in the spinal anterior horn cells or Zebra body-like s tructures in the neurons of the Meynert's basal nucleus. Lectin histoc hemistry was positive for wheat germ agglutinin, Ricinus communis aggl utinin-1 and peanut agglutinin within distended neurons.We conclude th at the neuropathological feature in nephrosialidosis is not specific e xcept for the selectiveness of the anatomical sites of involvement. It shares some aspects found in other types of sialidosis or galactosial idosis.