title: Frequency analysis of TRBV subfamily sjTRECs to characterize T-cell reconstitution in acute leukemia patients after allogeneic hematopoietic stem cell transplantation.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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 ± 20.97%) or at week 16 post-HSCT (38.33 ± 9.03%) were significantly lower than those in donors (47.92 ± 13.82%) or recipients at pre-HSCT (45.83 ± 14.03%). However, frequencies of TRBV subfamily sjTRECs in recipients at week 30 post-HSCT (42.71 ± 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Institute of Hematology, Medical College, Jinan University, Guangzhou 510632, PR China.
authors.forename: Xiuli
authors.initials: X
authors.lastname: Wu
authors.forename: Kanger
authors.initials: K
authors.lastname: Zhu
authors.forename: Xin
authors.initials: X
authors.lastname: Du
authors.forename: Shaohua
authors.initials: S
authors.lastname: Chen
authors.forename: Lijian
authors.initials: L
authors.lastname: Yang
authors.forename: Jufeng
authors.initials: J
authors.lastname: Wu
authors.forename: Qifa
authors.initials: Q
authors.lastname: Liu
authors.forename: Yangqiu
authors.initials: Y
authors.lastname: Li
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000970:Antineoplastic Agents / Q000627:therapeutic use; D005434:Flow Cytometry; D015329:Gene Rearrangement, T-Lymphocyte; D006086:Graft vs Host Disease / Q000235:genetics / Q000276:immunology; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods*; D006801:Humans; D007938:Leukemia / Q000235:genetics* / Q000276:immunology / Q000601:surgery*; D007951:Leukemia, Myeloid / Q000235:genetics / Q000276:immunology / Q000601:surgery; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000378:metabolism; D008875:Middle Aged; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics / Q000276:immunology / Q000601:surgery; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D013950:Thymus Gland / Q000276:immunology / Q000378:metabolism; D013997:Time Factors; D019172:Transplantation Conditioning / Q000379:methods; D014184:Transplantation, Homologous; D014740:Vidarabine / Q000031:analogs & derivatives / Q000627:therapeutic use; D055815:Young Adult
chemical_list: D000970:Antineoplastic Agents; D016693:Receptors, Antigen, T-Cell, alpha-beta; D014740:Vidarabine; C024352:fludarabine