During the acute phase following antigen challenge, in HSP animals and pediatric patients, compared to the controls, the frequency of CD4+ T cells significantly decreased (P < 0.05), the frequency of CD8+ T cells increased (rats and rabbits: P < 0.05; pediatric patients: P > 0.05), and the ratio of CD4/CD8 significantly decreased (rats: P < 0.01; rabbits and pediatric patients: P < 0.05). This evidence concerns the gene CD8A and hereditary spastic paraplegia.