Neuromuscular Unit, Medical Research Center, Polish Academy of Sciences, Pawinskiego 5 str., 02-106 Warsaw, Poland. neurmyol@cmdik.pan.pl
Abstract
OBJECTIVE: Sporadic inclusion body myositis (sIBM) is a chronic acquired inflammatory myopathy. The cause of sIBM remains unknown and its pathogenesis is controversial. There is a hypothesis [Karpati and Carpenter 1993] that the rimmed vacuoles result from nuclear breakdown, and IBM filaments are formed from components of the nuclear matrix.
MATERIAL AND METHODS: For nuclear membrane protein detection, six IBM patients were studied using immunohistochemical and immunochemical techniques.
RESULTS: It was demonstrated that in the interior of 10-15% myonuclei emerin and lamin A/C inclusions appeared constantly. This finding indicated an abberant localization of lamin A/C epitopes, the presence of presumptive lamin A (67 KDu) and emerin as in the affected nuclei.
CONCLUSION: We support the suggestion that truncated, changed lamin A protein takes part in nuclear disintegration and rimmed vacuole formation.