RESUMEN
To explore the difference of negative regulatory factors among T lymphocyte subsets in bone marrow (BM) of myelodysplastic syndromes (MDS) and their relations to apoptotic gene Fas, different lymphocyte subsets in BM were categorized by monoclonal antibodies with 3 color fluorescence using flow cytometry, and the intracellular cytokines such as tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma) were determined following marrow cells culture. Then Fas mRNA of bone marrow mononuclear cells (BMMNC) were examined by RT-PCR. The results showed that TNF-alpha, IFN-gamma levels in BM of MDS both increased, the former produced by cells CD4+CD45RO+, CD8+CD45RO+, the latter by cells CD4+CD45RO+, CD8+CD45RO+, CD8+CD45RA+, in which the cells CD8+CD45RO+ were dominant. Fas mRNA expression had relationship with IFN-gamma produced by T cells but not with TNF-alpha. It is concluded that in hematopoietic microenvironment of MDS, not only the T lymphocyte subsets are in disorder, but also negative regulatory factors secreted by T lymphocyte increase. T lymphocytes play an important role in producing IFN-gamma in patients with MDS.