Comparative immunohistochemical study on the expression of αβ crystallin, ubiquitin and stress-response protein 27 in ballooned neurons in various disorders

This report deals with a comparative study on the expression of αβ crystallin, ubiquitin, stress-response protein 27 (srp 27), srp 72 and phosphorylated neurofilament protein (pNFP) by ballooned neurons in Pick's disease, Creutzfeldt-Jakob disease (CJD), amyotrophic lateral sclerosis (ALS), leptomeningeal carcinomatosis, anterior spinal artery syndrome and pellagra. Immunohistochemical techniques were used. αβ Crystallin was expressed by the majority of ballooned neurons of Pick's disease and CJD, but not by those of the other disorders. Ubiquitin and srp 27 expression was also restricted to abnormal neurons of Pick's disease and CJD, but the proportion of stained cells was less than that expressing αβ-crystallin. There was no evidence of ballooned neurons expressing srp 72. Except for those of pellagra patients, phosphorylated neurofilament protein (pNFP) was detected in most abnormal neurons. Our results suggest that the mechanisms involved in formation and maintenance of swollen neurons in Pick's disease and CJD may be different than those of ballooned neurons in the other entities studied.