Familial adult onset of Krabbe's disease resembling hereditary spastic paraplegia with normal neuroimaging.

Krabbe's disease (globoid cell leucodystrophy) is a disorder involving the white matter of the peripheral and central nervous systems. Mutations in the gene for the lysosomal enzyme galactocerebrosidase (GALC) result in low enzymatic activity and decreased ability to degrade galactolipids found in myelin. The disease is classically of infantile onset, but adult onset cases have been reported. Magnetic resonance imaging (MRI) of the brain shows characteristic abnormalities. A unique family with Krabbe's disease is described, with proven GALC deficiency but normal MRI. A neurological phenotype is present in heterozygotes and the family shows the extent of homozygotic phenotypic diversity that can be seen in this disorder.

Cutting edge: Inhibition of hepatitis B virus replication by activated NK T cells does not require inflammatory cell recruitment to the liver.

We have previously reported that intrahepatic NK T cells activated by alpha-galactosylceramide inhibit hepatitis B virus replication noncytopathically in the liver of transgenic mice. This effect is mediated by antiviral cytokines directly produced by activated NK T cells and/or by other cytokine-producing inflammatory cells that are recruited into the liver. In this study, we demonstrated that IFN-gamma produced by activated NK T cells induced parenchymal and nonparenchymal cells of the liver to produce high levels of CXC chemokine ligands 9 and 10, which mediated the intrahepatic recruitment of lymphomononuclear inflammatory cells. Recruitment of these cells was not necessary for the antiviral activity, indicating that direct activation of the intrahepatic resident NK T cell is sufficient to control viral replication in this model.