20 research outputs found

    Evolution of T-cell clonality in a patient with Ph-negative acute lymphocytic leukemia occurring after interferon and imatinib therapy for Ph-positive chronic myeloid leukemia

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    <p>Abstract</p> <p>Introduction</p> <p>The development of Philadelphia chromosome (Ph) negative acute leukemia/myelodysplastic syndrome (MDS) in patients with Ph-positive chronic myeloid leukemia (CML) is very rare. The features of restrictive usage and absence of partial T cell clones have been found in patients with CML. However, the T-cell clonal evolution of Ph-negative malignancies during treatment for CML is still unknown.</p> <p>Objective</p> <p>To investigate the dynamic change of clonal proliferation of T cell receptor (TCR) VĪ± and VĪ² subfamilies in one CML patient who developed Ph-negative acute lymphoblastic leukemia (ALL) after interferon and imatinib therapy.</p> <p>Methods</p> <p>The peripheral blood mononuclear cells (PBMC) samples were collected at the 3 time points (diagnosis of Ph-positive chronic phase (CP) CML, developing Ph-negative ALL and post inductive chemotherapy (CT) for Ph-negative ALL, respectively). The CDR3 size of TCR VĪ± and VĪ² repertoire were detected by RT-PCR. The PCR products were further analyzed by genescan to identify T cell clonality.</p> <p>Results</p> <p>The CML patient who achieved complete cytogenetic remission (CCR) after 5 years of IFN-Ī± therapy suddenly developed Ph-negative ALL 6 months following switch to imatinib therapy. The expression pattern and clonality of TCR VĪ±/VĪ² T cells changed in different disease stages. The restrictive expression of VĪ±/VĪ² subfamilies could be found in all three stages, and partial subfamily of T cells showed clonal proliferation. Additionally, there have been obvious differences in VĪ±/VĪ² subfamily of T cells between the stages of Ph-positive CML-CP and Ph-negative ALL. The VĪ±10 and VĪ²3 T cells evolved from oligoclonality to polyclonality, the VĪ²13 T cells changed from bioclonality to polyclonality, when Ph-negative ALL developed.</p> <p>Conclusions</p> <p>Restrictive usage and clonal proliferation of different VĪ±/VĪ² subfamily T cells between the stages of Ph-positive CP and Ph-negative ALL were detected in one patient. These changes may play a role in Ph- negative leukemogenesis.</p

    Frequency analysis of TRBV subfamily sjTRECs to characterize T-cell reconstitution in acute leukemia patients after allogeneic hematopoietic stem cell transplantation

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    <p>Abstract</p> <p>Background</p> <p>Allogeneic hematopoietic stem cell transplantation (allo-HSCT) leads to a prolonged state of immunodeficiency and requires reconstitution of normal T-cell immunity. Signal joint T-cell receptor excision DNA circles (sjTRECs) are markers of developmental proximity to the thymus that have been used to evaluate thymic function related to T-cell immune reconstitution after HSCT. To assess the proliferative history in different T-cell receptor beta variable region (TRBV) subfamilies of T cells after HSCT, expansion of TRBV subfamily-naive T cells was determined by analysis of a series of TRBV-BD1 sjTRECs.</p> <p>Methods</p> <p>sjTRECs levels were detected by real-time quantitative polymerase chain reaction (PCR) in peripheral blood mononuclear cells (PBMCs) from 43 Chinese acute leukemia patients who underwent allo-HSCT. Twenty-three TRBV-BD1 sjTRECs were amplified by semi-nested PCR. Sixteen age-matched healthy volunteers served as normal controls.</p> <p>Results</p> <p>sjTRECs levels were low or undetectable in the first 6 weeks after allo-HSCT and increased after 8 weeks post HSCT; however, sjTRECs levels at week 20 post-HSCT were still less than normal controls. Frequencies of TRBV subfamily sjTRECs in PBMCs from recipients at week 8 post-HSCT (29.17 Ā± 20.97%) or at week 16 post-HSCT (38.33 Ā± 9.03%) were significantly lower than those in donors (47.92 Ā± 13.82%) or recipients at pre-HSCT (45.83 Ā± 14.03%). However, frequencies of TRBV subfamily sjTRECs in recipients at week 30 post-HSCT (42.71 Ā± 21.62%) were similar to those in donors and recipients at pre-HSCT. sjTRECs levels in donors had a positive linear correlation with sjTRECs levels in recipients within 8-12 weeks post-HSCT. Patients with acute graft-versus-host disease (GVHD) or chronic GVHD had profoundly reduced TRECs levels during the first year post-HSCT. Frequencies of BV22-BD1 sjTRECs and BV23-BD1 sjTRECs in patients with GVHD were significantly lower than those in recipients at pre-HSCT, and the frequencies of BV22-BD1 sjTRECs in patients with GVHD were significantly lower than those in donors.</p> <p>Conclusions</p> <p>Reconstitution of thymic output function resulted in a period of immunodeficiency, with low or undetectable TRECs after transplantation, although fludarabine-based dose-reduced conditioning regimens were used. GVHD could affect reconstitution of thymic output function and reduce sjTRECs levels and frequencies of TRBV-BD1 sjTRECs. Low frequency of BV22-BD1 and BV23-BD1 sjTRECs might be associated with GVHD.</p
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