title: Severe perturbations of the blood T cell repertoire in polymyositis, but not dermatomyositis patients.
abstract: Polymyositis and dermatomyositis are diseases characterized by muscle weakness and muscle inflammatory infiltrates. Their pathogenesis remains unclear. A central role for endomysial autoaggressive CD8(+) T cells is suspected in polymyositis and for perivascular B cells in dermatomyositis. We compared the T cell repertoire of 10 polymyositis and 10 dermatomyositis patients by immunoscope, a method providing a global assessment of the T cell repertoire and a sensitive detection of clonal T cell expansions. Samples were analyzed qualitatively and quantitatively in the blood (unsorted cells and CD4(+) and CD8(+) cells) and in muscle infiltrates. Dramatic perturbations of the T cell repertoire were observed in the blood of polymyositis but not dermatomyositis patients (p < 0.0005), the latter being undistinguishable from controls. These perturbations were due to oligoclonal expansions of CD8(+) T cells and most blood clonal expansions were also found in muscle. These results indicate that the pathogenesis of polymyositis and dermatomyositis is different and reinforce the view that polymyositis but not dermatomyositis is an autoimmune CD8(+) T cell-mediated disease. Moreover, this method may be helpful for the differential diagnosis of polymyositis and dermatomyositis and for noninvasive follow-up of polymyositis patients.
authors.affiliation: Laboratoire de Biologie et Thérapeutique des Pathologies Immunitaires, Service de Médecine Interne, and Laboratoire de Neuropathologie, Hôpital Pitié-Salpêtrière, Paris, France.
authors.forename: O
authors.initials: O
authors.lastname: Benveniste
authors.forename: P
authors.initials: P
authors.lastname: Chérin
authors.forename: T
authors.initials: T
authors.lastname: Maisonobe
authors.forename: R
authors.initials: R
authors.lastname: Merat
authors.forename: O
authors.initials: O
authors.lastname: Chosidow
authors.forename: L
authors.initials: L
authors.lastname: Mouthon
authors.forename: L
authors.initials: L
authors.lastname: Guillevin
authors.forename: A
authors.initials: A
authors.lastname: Flahault
authors.forename: M C
authors.initials: MC
authors.lastname: Burland
authors.forename: D
authors.initials: D
authors.lastname: Klatzmann
authors.forename: S
authors.initials: S
authors.lastname: Herson
authors.forename: O
authors.initials: O
authors.lastname: Boyer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001327:Autoimmune Diseases / Q000097:blood / Q000175:diagnosis / Q000209:etiology / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000473:pathology; D002469:Cell Separation; D002999:Clone Cells / Q000473:pathology; D022801:Complementarity Determining Regions / Q000032:analysis*; D003882:Dermatomyositis / Q000097:blood / Q000175:diagnosis / Q000209:etiology / Q000276:immunology*; D003937:Diagnosis, Differential; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000276:immunology / Q000473:pathology; D017285:Polymyositis / Q000097:blood / Q000175:diagnosis / Q000209:etiology / Q000276:immunology*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000737:chemistry*; D012008:Recurrence; D016176:T-Lymphocyte Subsets
chemical_list: D022801:Complementarity Determining Regions; D016693:Receptors, Antigen, T-Cell, alpha-beta