Objective: To compare the differences of the T helper cell reconstitution kinetics between HLA matched or HLA mismatched allo-HSCT through exploring the reconstitution kinetics of CD4+ CD25+Foxp3+ cells (CD4+ Treg), CD8+CD25+Foxp3+ cells (CD8+Treg), CD4+CD25-CD127+ conventional T cells (Tcon) and the secretion of IL-17a and IFN-γ in CD4+ T cells (Th17 and Th1 cells) or CD8+ T cells (Tc17 and Tc17 cells) post allogeneic hematopoietic stem cells transplantation (allo-HSCT).
Methods: From December 2011 to October 2012, the peripheral blood (PB) of 20 patients undergoing HLA matched (10 patients) or mismatched (10 patients) allo- HSCT without acute graft-versus-host disease (aGVHD) and of 10 related healthy donors were collected to analyze the expression of CD25+Foxp3+, IL-17a, IFN-γ and CD127 expression through 8-colour Flow cytometer.
Results: (1) The reconstitution kinetics of CD3+ T cells, CD4+ T cells, CD8+ T cells absolute numbers were comparable within 2 month post HLA matched and mismatched transplantation. (2)The absolute numbers of CD4+ Treg cells[+30 d, 8.46 (0.36-27.41) cells/μl 1.10 (0.04-8.03) cells/μl, P<0.05; +60 d, 8.50 (1.16-36.20) cells/μl vs 2.73 (0.34-6.84) cells/μl, P<0.05], Tcon cells[+30 d, 72.69 (3.85-211.73) cells/μl vs 13.41 (0.48-96.17) cells/μl, P<0.05; +60 d, 100.85 (16.28-267.20) cells/μl vs 47.75 (6.34-143.04) cells/μl, P<0.05], as well as Th17 cells[+30 d, 2.34 (0.02-6.87) cells/μl vs 0.20 (0.02-1.34) cells/μl, P<0.05; + 60 d, 1.90 (0.36- 7.82) cells/μl vs 0.46 (0.03-1.39) cells/μl, P<0.05]and Tc17 cells[+ 30 d, 1.08 (0.07-15.03) cells/μl vs 0.25 (0.01- 0.81) cells/μl, P<0.05;+60 d, 1.85 (0.63-26.57) cells/μl vs 0.46 (0.01-3.66) cells/μl, P<0.05]within 2 month post HLA matched HSCT were significantly higher than those post HLA- mismatched HSCT. However, the absolute numbers of Th1 cells or Tc1 cells within 2 month post HLA-matched or HLA-mismatched HSCT were comparable. (3) The ratio of Th1 and Th17 cells, or the ratio of Tc1 and Tc17 cells were significantly higher within 2 month post HLA-mismatched allo-HSCT compared to those post HLA-matched HSCT.
Conclusion: The reconstitution kinetics of T helper cells subset were different at early stage post HLA-matched or HLA-mismatched allo-HSCT, which might be help to explain the different rate or the different involved organ of the acute graft-versus-host diseases (aGVHD) post HLA-matched or -mismatched allo-HSCT.