Leukocytes in the peripheral blood after bone marrow transplantation (BMT).

The total white blood cell (WBC) count in peripheral blood (A) decreased markedly on day 4, but recovered between day 7 and day 14 in both allogeneic and syngeneic BMT rats. The number of WBCs in the peripheral blood was higher on day 21 in allogeneic BMT rats than in syngeneic BMT rats. WBCs in the peripheral blood decreased again in allogeneic BMT rats on day 28, which may be because of recruitment of WBCs to GVHD organs. Almost all circulating leukocytes in allogeneic BMT rats on day 28 after BMT (B) expressed donor-type RT1A^a, indicating that circulating leukocytes in peripheral blood originated from the donor (Gray; no staining, Black; anti-RT1A^a,b). In peripheral blood, CD6+ T-cells (C), CD8+ T-cells (D), CD4+ T-cells (E), and ED1+ macrophages levels (F) recovered between day 7 and day 21 after BMT in both syngeneic and allogeneic BMT rats. The number of CD6+ T-cells and CD8+ T-cells was significantly higher on day 21 in allogeneic BMT rats than in syngeneic BMT rats. The number of CD4+ T-cells and CD68+ macrophages was similar in both syngeneic and allogeneic BMT rats. *P<0.05, **P<0.01.