Comparative study of spinal cord ubiquitin expression in post-poliomyelitis and sporadic amyotrophic lateral sclerosis

This study addresses the suggested possible pathogenetic relationship between the late-onset muscular atrophy in patients with the prior diagnosis of poliomyelitis and amyotrophic lateral sclerosis (ALS). For this purpose we applied immunohistochemical techniques to determine the presence of pathological structures that were stained for ubiquitin (a protein involved in degenerative processes) in the spinal cords of patients with a history of poliomyelitis and compared the results with those of ALS, a condition in which cytoplasmic ubiquitin-positive inclusions are invariably found in the anterior horn cells. Our results indicate that post-poliomyelitis patients have no ubiquitinreactive inclusion bodies in these cells; however, some immunopositive globular and cord-shaped structures are seen in less-affected areas. Similar structures were also found in the spinal cords from patients with ALS and from normal individuals. Our findings would suggest that the pathogenesis of late muscular atrophy in post-poliomyelitis patients is dissimilar to that of ALS.