Removal of Autologous Activated CD4 Positive T Lymphocytes Also Result in Increased Colony-Forming Units (CFUs) in Patients with Myelodysplastic Syndromes.

Abstract 4862

Autologous activated CD4⁺ T lymphocytes (CD4⁺/CCR5⁺ double positive cells) in BMNC of 29 MDS patients were depleted or plused in in vitro cultures. That cultures with removed CD4⁺/CCR5⁺ cells exhibited significantly increased CFU generation. Conversely, the 4-fold CD4⁺/CCR5⁺ T lymphocyte-plused BMNC exhibited no colonies at all in in vitro cultures. After CD4⁺/CCR5⁺ depleted in vitro cultures, the clonal cells increased in patients with chromosome 5q– or 20q–, kept almost unchanged in patients with trisomy 8, but dramatically decreased in patients with monosomy 7. In addition, after the removal of CD4⁺/CCR5⁺ T cells, better CFUs generation were found in those patients who were with higher BM Th1 (CD4⁺/IFNγ⁺) cells or hypocellularity, or bearing DR15 allele. We concluded that selective removal of autologous activated CD4⁺ T-cells can increase the generation of CFUs, while the increased CFU consisting of residual normal hemopoiesis or clonal hemopoiesis kept unconcluded.