Expression of CD10 on lymphoid cells associated with thymoma.
BACKGROUND
The thymoma is a mixture, in varying proportions, of epithelial and lymphoid cells. The aim of this study was to detect immature T-lineage components of lymphoid cells infiltrating thymoma tissue.


METHODS
Tissue-infiltrating lymphoid cells (N = 10) and normal thymocytes (TC, N = 3) were retrieved from surgical specimens. The surface antigens of these lymphocytes were examined with flow cytometry.


RESULTS
CD3 was detected on 48 +/- 19% of tissue-infiltrating lymphoid cells and 66 +/- 16% of TC, while CD19 was expressed on neither. CD4 and CD8 were co-expressed on 70 +/- 21% of Tissue-infiltrating lymphoid cells and 68 +/- 28% of TC. CD10 was expressed on 22 +/- 10% of tissue-infiltrating lymphoid cells, but was not expressed on TC (5 +/- 3%, p = 0.0003). Two-color analysis showed that the CD10+ fraction was weakly stained with CD3. It was also stained with anti-CD38 and anti-CD4, but not with anti-CD34.


CONCLUSIONS
Tissue-infiltrating lymphoid cells included CD10-positive T-lineage cells. This fraction corresponds to very immature thymocyte subsets. These observations suggest that the epithelial component of a thymoma either inhibits the normal differentiation of T-lineage cells, or attracts immature T-lineage cells of bone-marrow origin.
Nakajima
J
J
Department of Cardiothoracic Surgery, Faculty of Medicine, University of Tokyo, Japan.
Takamoto
S
S
Kohno
T
T
Ohtsuka
T
T
Matsumoto
J
J
D000328:Adult; D000368:Aged; D019070:Cell Lineage; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D015260:Neprilysin / Q000032:analysis*; D013945:Thymoma / Q000276:immunology*; D013953:Thymus Neoplasms / Q000276:immunology*
D015260:Neprilysin