Abnormal polarization of T lymphocyte induces negative hematopoietic regulation in myelodysplastic syndromes / 中华血液学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To explore polarization of T lymphocyte and its relationship with apoptosis of marrow cells in patients with myelodysplastic syndromes (MDS).</p><p><b>METHODS</b>Measurements of Th1, Th2, Tc1, Tc2 subsets in bone marrows from 34 patients with MDS and 13 normal controls were performed by flow cytometry. INF-gamma and TNF-alpha in marrow serum were determined by ELISA (Enzyme-linked immunosorbent assay). Apoptosis index of marrow cells was detected by TUNEL (TdT-mediated dUTP nick end labeling). Correlations between Th1, Th2, Tc1, Tc2 subsets and INF-gamma, TNF-alpha levels as well as apoptosis index were analyzed, and relationship between TNF-alpha, INF-gamma levels and apoptosis index was also investigated.</p><p><b>RESULTS</b>(1) The percentage of Th1 cells [(10.1 +/- 1.6)%], Tc1 cells [(24.0 +/- 3.6)%] and Tc1/Tc2 ratio (50.0 +/- 11.1) was significantly increased in patients with MDS than in normal controls [(4.0 +/- 0.5)%, (5.8 +/- 0.6)% and 13.4 +/- 2.7, respectively]. Levels of INF-gamma [(58.6 +/- 21.7) microg/L] and TNF-alpha [(15.7 +/- 3.8) microg/L] in marrow serum of MDS patients was markedly elevated compared to normal controls [0 and (0.3 +/- 0.2) microg/L, respectively]. An increased apoptosis index of nucleated cells was observed in MDS patients [(7.8 +/- 1.5)%] as compared to controls [(2.1 +/- 0.3)%, P < 0.05]. The Th1 cell percentage showed a positive correlation with the levels of INF-gamma and TNF-alpha (r = 0.38, P < 0.05 and r = 0.39, P < 0.05, respectively), and with apoptotic index of nucleated marrow cells in MDS patients (r = 0.33, P < 0.05). Furthermore, a positive correlation was observed between INF-gamma, TNF-alpha levels and apoptotic index of marrow cells (r = 0.74, P < 0.01 and r = 0.73, P < 0.01, respectively). (2) Th1, Tc1 cells and Tc1/Tc2 ratio in MDS-RCMD patients was markedly elevated (P < 0.01) but did not in RCMD-RS, RAEB-1 and RAEB-2 patients as compared to normal controls. (3) An elevation in the percentages of Th1, Tcl and Tc1/ Tc2 ratio was detected in patients with IPSS lower-risk but did not in higher-risk group as compared to controls. (4) Increased Th1 and Tc1 percentages and Th1/Th2 and Tc1/Tc2 ratios were observed in RCMD patients with normal karyotype, but did not in those with abnormal karyotype. Conclusions Th1/Th2 and Tc1/Tc2 in bone marrow of MDS patients were unbalanced, polarizing to type I reaction especially in patients with RCMD subtype, IPSS lower-risk and normal karyotype. The increased Th1 cells in bone marrow may account for the increased apoptosis of nucleated marrow cells in MDS, through proapoptotic cytokines such as INF-gamma and TNF-alpha.</p>