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Upregulation of Bcl‐2 protein in the myasthenic thymus
Author(s) -
Onodera Junichi,
Nakamura Shozo,
Nagano Isao,
Tobita Muneshige,
Yoshioka Masaru,
Takeda Atsushi,
Oouchi Masahiro,
Itoyama Yasuto
Publication year - 1996
Publication title -
annals of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.764
H-Index - 296
eISSN - 1531-8249
pISSN - 0364-5134
DOI - 10.1002/ana.410390414
Subject(s) - myasthenia gravis , thymoma , hyperplasia , antigen , pathology , medicine , biology , endocrinology , immunology
We examined the expression of Fas antigen and Bcl‐2 protein in thymic tissue surgically resected from 10 patients with myasthenia gravis, using immunocytochemical techniques. Histologically, thymic tissues from 7 myasthenia gravis patients showed hyperplasia, while 3 other patients had thymomas. In hyperplastic thymic tissue, immunoreactivity for Fas antigen was observed mainly in the network of medullary epithelial cells. In contrast, expression of Fas antigen was rare in the cortex. Fas antigen was also detected to some degree in thymoma tissue from 3 patients. Bcl‐2 protein was highly expressed in the medullary thymocytes in the hyperplastic thymic tissue, whereas its staining was quite low in myasthenia gravis thymomas. The number of Bcl‐2‐positive thymocytes in the medulla was significantly greater in the hyperplastic myasthenia gravis thymic tissue than in the control thymic tissue. These findings suggest that Bcl‐2 protein may be upregulated in the myasthenia gravis thymus and that this phenomenon may be related to impaired apoptotic cell death of autoreactive thymocytes in myasthenia gravis.