Objective: To investigate the distribution and clonality of TCR Va subfamily T cells in patients with acute promyelocytic leukemia (APL). Methods: The complementary determining region 3 (CDR3) of TCR Va 29 subfamily genes in peripheral blood mononuclear cells from 9 APL patients were amplified using RT-PCR. The positive products were further analyzed to identity the clonality of T cells by GeneScan technique. Results: One to seven of TCR Va subfamilies could be detected in peripheral blood T cells from 9 cases with APL, the frequent expression of Va subfamilies predominated in Vα3 and Va19. Clonal expanded T cells could be detected in 8 APL patients, which predominant used Va3, Va26 or Va27 (3 out of 8 cases). However, almost all Va subfamilies with polyclonal expansion could be detected in peripheral blood T cells from 10 cases of normal individuals. Conclusion: Remarkable skew distribution and clonal expansion of TCR Va subfamilies T cells is the common feature in patients with APL. Clonal expansion of T cells might reflect a response in host to APL cell associated antigen, whether these expanded T cells have the ability for specific cytotoxicity against APL cells, remains an open question.
Dongzhi Cen Yangqiu Li Shaohua Chen Lijian Yang Zhi Yu