Читать книгу Graves' Orbitopathy - Группа авторов - Страница 68

These are characterized by sparse mononuclear cell infiltrates, both focal and diffuse, within the muscle endomysium and the fatty connective tissue [3]. The majority of cells are T lymphocytes, CD4+ or CD8+, and also CD45RO+ and CD45RB+. B lymphocytes are only occasionally observed. A few mast cells are present with a perivascular distribution. Macrophages are increased in early disease and less so in late disease. HLA-DR expression by interstitial cells – including fibroblasts, but not muscle fibres – are observed in both early and late stages. As lymphocytes, plasma cells and macrophages increase in number, fibroblasts within the interstitium enlarge and proliferate producing collagen and mucopolysaccharides. Muscles become enlarged, firm and rubbery. Microscopically, they appear as oedematous and fibrous with an increase in fat content, mucin and water. Proliferation of fibroblasts within the perimysium may subsequently lead to a scarring process with muscle atrophy, fibrosis, and sclerosis. It is noticeable that muscle fibres are relatively spared in GO, with the changes affecting mainly the connective tissue between the fibres.

Fig. 2. Opposite contribution of extramusclar (a) and muscle (b) swelling of the retrobulbar tissues.