Deep sequencing and flow cytometric characterization of expanded effector memory CD8+CD57+ T cells frequently reveals T-cell receptor Vβ oligoclonality and CDR3 homology in acquired aplastic anemia

Haematologica. 2018 May;103(5):759-769. doi: 10.3324/haematol.2017.176701. Epub 2018 Feb 1.


Oligoclonal expansion of CD8+ CD28- lymphocytes has been considered indirect evidence for a pathogenic immune response in acquired aplastic anemia. A subset of CD8+ CD28- cells with CD57 expression, termed effector memory cells, is expanded in several immune-mediated diseases and may have a role in immune surveillance. We hypothesized that effector memory CD8+CD28-CD57+ cells may drive aberrant oligoclonal expansion in aplastic anemia. We found CD8+CD57+ cells frequently expanded in the blood of aplastic anemia patients, with oligoclonal characteristics by flow cytometric Vβ usage analysis: skewing in 1-5 Vβ families and frequencies of immunodominant clones ranging from 1.98% to 66.5%. Oligoclonal characteristics were also observed in total CD8+ cells from aplastic anemia patients with CD8+CD57+ cell expansion by T-cell receptor deep sequencing, as well as the presence of 1-3 immunodominant clones. Oligoclonality was confirmed by T-cell receptor repertoire deep sequencing of enriched CD8+CD57+ cells, which also showed decreased diversity compared to total CD4+ and CD8+ cell pools. From analysis of complementarity-determining region 3 sequences in the CD8+ cell pool, a total of 29 sequences were shared between patients and controls, but these sequences were highly expressed in aplastic anemia subjects and also present in their immunodominant clones. In summary, expansion of effector memory CD8+ T cells is frequent in aplastic anemia and mirrors Vβ oligoclonal expansion. Flow cytometric Vβ usage analysis combined with deep sequencing technologies allows high resolution characterization of the T-cell receptor repertoire, and might represent a useful tool in the diagnosis and periodic evaluation of aplastic anemia patients. (Registered at identifiers: 00001620, 01623167, 00001397, 00071045, 00081523, 00961064).

Trial registration: NCT00001620 NCT01623167 NCT00001397 NCT00071045 NCT00081523 NCT00961064.

Publication types

  • Research Support, N.I.H., Intramural

MeSH terms

  • Anemia, Aplastic / genetics
  • Anemia, Aplastic / immunology*
  • Anemia, Aplastic / pathology
  • CD57 Antigens / genetics
  • CD57 Antigens / immunology*
  • CD8-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / metabolism
  • Case-Control Studies
  • Clone Cells / immunology*
  • Clone Cells / metabolism
  • Clone Cells / pathology
  • Complementarity Determining Regions / genetics
  • Complementarity Determining Regions / immunology*
  • Flow Cytometry / methods
  • High-Throughput Nucleotide Sequencing / methods
  • Humans
  • Immunologic Memory / genetics
  • Immunologic Memory / immunology*
  • Receptors, Antigen, T-Cell, alpha-beta / genetics
  • Receptors, Antigen, T-Cell, alpha-beta / immunology*


  • CD57 Antigens
  • Complementarity Determining Regions
  • Receptors, Antigen, T-Cell, alpha-beta

Associated data