Major histocompatibility complex and inflammatory cell subtype expression in inflammatory myopathies and muscular dystrophies.
BACKGROUND
In inflammatory myopathies muscle biopsy is a crucial diagnostic test. Misinterpretation between inflammatory myopathies and muscular dystrophies with inflammation is known.


METHODS
Thirty-one patients clinically and pathologically diagnosed to have polymyositis and dermatomyositis and 16 patients of muscular dystrophy with inflammation were studied for MHC-I, MHC-II, CD4 and CD8 expression in skeletal muscle tissue.


RESULTS
MHC-I upregulation was noted in all samples of PM and DM. Interstitial and perivascular inflammation in PM were predominantly CD8+ cells, in dermatomyositis, interstitial and perimysial perivascular inflammatory cells were CD4+ T cells and CD8+ T cells were seen around endomysial vessels. Interestingly MHC-I upregulation was seen in all 16 cases of muscular dystrophy with presence of inflammation.


CONCLUSIONS
The pattern of MHC-I and II expression appeared to be similar in both inflammatory myopathies as well as in muscular dystrophies with inflammation and hence differentiating them on MHC - I expression was difficult.
Madhu
M
Nagappa
Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, Karnataka, India.
Atchayaram
A
Nalini
Gayathri
G
Narayanappa
D000293:Adolescent; D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000473:pathology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007249:Inflammation / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D008285:Major Histocompatibility Complex / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D009136:Muscular Dystrophies / Q000175:diagnosis* / Q000276:immunology / Q000378:metabolism; D009220:Myositis / Q000175:diagnosis* / Q000276:immunology / Q000378:metabolism; D055815:Young Adult