T-cell clonality assessment by next-generation sequencing improves detection sensitivity in mycosis fungoides

J Am Acad Dermatol. 2015 Aug;73(2):228-36.e2. doi: 10.1016/j.jaad.2015.04.030. Epub 2015 Jun 3.


Background: T-cell receptor (TCR) clonality assessment is a principal diagnostic test in the management of mycosis fungoides (MF). However, current polymerase chain reaction-based methods may produce ambiguous results, often because of low abundance of clonal T lymphocytes, resulting in weak clonal peaks that cannot be size-resolved by contemporary capillary electrophoresis (CE).

Objective: We sought to determine if next-generation sequencing (NGS)-based detection has increased sensitivity for T-cell clonality over CE-based detection in MF.

Methods: Clonality was determined by an NGS-based method in which the TCR-γ variable region was polymerase chain reaction amplified and the products sequenced to establish the identity of rearranged variable and joining regions.

Results: Of the 35 MF cases tested, 29 (85%) showed a clonal T-cell rearrangement by NGS, compared with 15 (44%) by standard CE detection. Three patients with MF had follow-up testing that showed identical, clonal TCR sequences in subsequent skin biopsy specimens.

Limitations: Clonal T-cell populations have been described in benign conditions; evidence of clonality alone, by any method, is not sufficient for diagnosis.

Conclusion: TCR clonality assessment by NGS has superior sensitivity compared with CE-based detection. Further, NGS enables tracking of specific clones across multiple time points for more accurate identification of recurrent MF.

Keywords: T-cell clonality; T-cell receptor rearrangement; cutaneous T-cell lymphoma; molecular diagnostics; mycosis fungoides; next-generation sequencing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Cloning, Molecular / methods
  • DNA, Neoplasm / genetics
  • Databases, Factual
  • Electrophoresis / methods
  • Female
  • Genetic Predisposition to Disease*
  • Humans
  • Male
  • Middle Aged
  • Molecular Sequence Data
  • Mycosis Fungoides / diagnosis*
  • Mycosis Fungoides / genetics*
  • Neoplasm Recurrence, Local / genetics
  • Neoplasm Recurrence, Local / pathology
  • Polymerase Chain Reaction / methods
  • Prognosis
  • Receptors, Antigen, T-Cell / genetics*
  • Retrospective Studies
  • Skin Neoplasms / diagnosis*
  • Skin Neoplasms / genetics*


  • DNA, Neoplasm
  • Receptors, Antigen, T-Cell