INFILTRATING CELL PROFILES OF SARCOID LESIONS IN THE MUSCLES AND PERIPHERAL-NERVES - AN IMMUNOHISTOLOGICAL STUDY

In order to study the pathological mechanisms of neuromuscular sarcoid osis, we carried out an immunohistochemical investigation in five case s (five muscle specimens and two sural nerve specimens). We evaluated the distribution of inflammatory mononuclear cells and major histocomp atibility complex (MHC) antigen expressions. Our data showed a dominan t infiltration of helper/inducer T cells (CD4-T cells), suggesting the importance of cell-mediated immune responses in neuromuscular sarcoid osis. However, we could not identify the distinct distributional patte rns of T cells as reported in sarcoid lymphadenitis. This result may b e attributed to the difference of the affected organs. Moreover, failu re to detect class II antigens in the muscle fibers may imply the diff erence in pathogenic mechanism between neuromuscular sarcoidosis and o ther inflammatory myopathies.