Immunohistochemical demonstration of viral antigens in Japanese encephalitis.

Japanese encephalitis virus antigens were immunohistochemically demonstrated in formalin-fixed paraffin sections from an autopsied brain. Glial nodules were always associated with antigen-positive cell debris. Glia shrubs in the cerebellar cortex appeared to be formed along the apical dendrite of Purkinje cells. Most, but not all, of the neurons involved in neuronophagia were viral antigen positive. Antigenic masses were occasionally encountered in the center of so-called acellular plaques. Neurons with strong viral antigens were sporadically found in normal-appearing regions in the thalamus and cerebral cortex. Viral antigens were demonstrable only in neurons and not in glial or vascular endothelial cells.