Use of anti-neurofilament antibody to identify paired-helical filaments in inclusion-body myositis

Paired-helical filaments (PHF_s) are an important diagnostic criterion of the inclusion-body myositis (IBM) muscle biopsy; but, until now, their presence could be identified only by electronmicroscopy. In this report, we describe an easy immunocytochemical procedure, utilizing commercially available antibody, that enables reliable identification of muscle PHF_s by light microscopy. This procedure greatly facilitates diagnosis of IBM.