OBJECTIVE: To characterize the inflammatory cells, the expression pattern of adhesion molecules (ICAM-1 and VCAM-1), membrane attack complex (C5b-9), and major histocompatibility complex (MHC) antigens in muscle biopsy of mixed connective tissue disease (MCTD). METHOD: We studied 14 patients with MCTD, and compared to 8 polimyositis (PM) patients, 5 dermatomyositis (DM) and 4 dystrophies. Inflammatory cells were examined for CD4+, CD8+, memory and naive T cells, natural killer cells, and macrophages. Expression of MHC-I and -II, ICAM-1, VCAM-1 and C5b -9 were characterized on muscle fibers and vessels. RESULTS: Morphological analysis displayed a pattern of PM. Immunohistochemical study revealed a decreased number of capillaries, predominance of CD4+ and B cells in perivascular regions and predominance of CD8+ and CD45RO+ in endomysial regions. The expression of MHC-I on vessels and on degenerated muscle fibers, MHC-II expression on vessels and perifascicular muscle fibers, and the expression of ICAM-1 / VCAM-1 on endothelial cells indicated both vascular and cellular-immune mediated processes causing the muscular lesion. CONCLUSION: Our findings revealed a mixed mechanism in MCTD, both vascular involvement as DM, and cell-mediated like PM.
OBJECTIVE: To characterize the inflammatory cells, the expression pattern of adhesion molecules (ICAM-1 and VCAM-1), membrane attack complex (C5b-9), and major histocompatibility complex (MHC) antigens in muscle biopsy of mixed connective tissue disease (MCTD). METHOD: We studied 14 patients with MCTD, and compared to 8 polimyositis (PM) patients, 5 dermatomyositis (DM) and 4 dystrophies. Inflammatory cells were examined for CD4+, CD8+, memory and naive T cells, natural killer cells, and macrophages. Expression of MHC-I and -II, ICAM-1, VCAM-1 and C5b -9 were characterized on muscle fibers and vessels. RESULTS: Morphological analysis displayed a pattern of PM. Immunohistochemical study revealed a decreased number of capillaries, predominance of CD4+ and B cells in perivascular regions and predominance of CD8+ and CD45RO+ in endomysial regions. The expression of MHC-I on vessels and on degenerated muscle fibers, MHC-II expression on vessels and perifascicular muscle fibers, and the expression of ICAM-1 / VCAM-1 on endothelial cells indicated both vascular and cellular-immune mediated processes causing the muscular lesion. CONCLUSION: Our findings revealed a mixed mechanism in MCTD, both vascular involvement as DM, and cell-mediated like PM.
Authors: Maria Casal-Dominguez; Iago Pinal-Fernandez; Andrea M Corse; Julie Paik; Jemima Albayda; Livia Casciola-Rosen; Cheilonda Johnson; Sonye K Danoff; Lisa Christopher-Stine; Eleni Tiniakou; Andrew L Mammen Journal: Neurology Date: 2019-03-01 Impact factor: 9.910