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TCR Vβ repertoire analysis in CD56 + CD16 dim/− T‐cell large granular lymphocyte leukaemia: association with CD4 single and CD4/CD8 double positive phenotypes
Author(s) -
Karasawa Masamitsu,
Mitsui Takeki,
Isoda Atsushi,
Tsumita Yuki,
Irisawa Hiroyuki,
Yokohama Akihiko,
Handa Hiroshi,
Matsushima Takafumi,
Tsukamoto Norifumi,
Murakami Hirokazu,
Nojima Yoshihisa
Publication year - 2003
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1046/j.1365-2141.2003.04665.x
Subject(s) - cd8 , t cell receptor , cd16 , monoclonal antibody , biology , t lymphocyte , microbiology and biotechnology , immunology , lymphocyte , monoclonal , t cell , antigen , antibody , cd3 , immune system
Summary. We report 10 patients with T‐cell large granular lymphocyte (LGL) leukaemia: four patients had CD16 + CD56 − LGL lymphocytes (typical for LGL leukaemia), and six patients had CD56 + CD16 dim/− LGL lymphocytes (atypical). Among the CD56 + CD16 dim/− patients, LGL lymphocytes were CD4 + CD8 − in one patient, CD4/CD8 double positive (DP) in three, and CD4 − CD8 + in two. The CD4 + CD8 dim DP cells expressed a CD8αα homodimer. T‐cell receptor (TCR) Vβ complementarity‐determining region 3 (CDR3) size distribution analysis and direct sequencing identified at least 1 in‐frame clonal TCR Vβ transcript in each patient; three patients had two or three different clonal sequences. To determine whether these transcripts were translated into cell surface TCR, we performed flow cytometric analysis using Vβ monoclonal antibodies (mAbs). A single Vβ protein was identified in patients, even those with multiple in‐frame transcripts. Previous and present results suggest that CD56 + CD16 dim/− LGL leukaemia is more common than previously thought, and is associated with unusual phenotypes. When assessed using only molecular techniques, the monoclonal status of this disease may be misinterpreted as oligoclonal; thus, flow cytometric analysis using Vβ mAb is quite useful. Because mAbs do not cover the entire Vβ repertoire, assessing clonality using a combination of molecular methods and mAbs is preferable.