Asian Cardiovasc Thorac Ann 2005;13:149-152
© 2005 Asia Publishing EXchange Ltd
Rearrangement of T-Cell Receptor Beta and Gamma Genes in Thymoma
Jun Nakajima, MD,
Jun Matsumoto, MD,
Eriho Takeuchi, MD,
Takeshi Fukami, MD,
Shinichi Takamoto, MD
Department of Cardiothoracic Surgery, Faculty of Medicine, University of Tokyo, Tokyo, Japan
For reprint information contact: Jun Nakajima, MD Tel: 81 3 3815 5411 Fax: 81 3 5684 3989 Email: nakajima-tho{at}h.u-tokyo.ac.jp, Department of Cardiothoracic Surgery, Faculty of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
To investigate the differentiation stage of tumor-infiltrating lymphocytes in thymoma tissue, we performed Southern blot analysis of T-cell receptor beta and gamma genes in thymomas resected from 19 patients. At the same time, we conducted flow cytometric analysis of T-cell surface markers and examined the clinicopathological features of the thymomas. We found that the incidence of T-cell receptor gamma gene rearrangement was significantly higher in Masaoka stage I thymomas (11 of 12 cases) than in stage II or III invasive thymomas (3 of 7 cases). Moreover, gamma gene rearrangement was observed in all 10 type AB and B1 thymoma specimens and in 4 of 6 type B2 thymoma specimens. The 2 specimens of type B3 thymomas, which were classified as stage III, showed neither gamma nor beta gene arrangement and were single-positive for CD4 or CD8. Six thymoma specimens that showed beta gene rearrangement expressed both CD4 and CD8. In conclusion, thymomas have the capability of T-lineage cell differentiation, except for a subset of invasive thymomas with malignant characteristics.
Copyright © 2005 by the Asia Publishing EXchange Ltd.
