T-cell expansions in patients with multiple myeloma have a phenotype of cytotoxic T cells.
The presence of T-cell clones in peripheral blood has been previously shown to be associated with a survival advantage in patients with multiple myeloma and suggests that the expanded T-cell populations may be involved in an anti-tumour response. We studied the T-cell receptor (TCR) repertoire of 38 patients with myeloma to identify and characterize the expanded T-cell populations by flow cytometry. T-cell expansions were found in 79% of the patients. The expansions occurred randomly among the 21 variable regions of the TCR beta chain (Vbeta) studied, representing 62% of the V-beta repertoire, and were stable during an 18-month follow-up. The phenotype of the expanded V-beta populations was predominantly CD8+, CD57+, CD28- and perforin+, which differed significantly from the other non-expanded Vbeta populations. The expression of the apoptosis markers Fas (CD95) and bcl-2 were similar between the expanded and non-expanded Vbeta populations. In conclusion, expanded T-cell populations were frequent in patients with myeloma, they remained unchanged during follow-up and had phenotypic characteristics of cytotoxic T cells. These data add further support to the concept that the T-cell expansions may have an immunoregulatory role in myeloma.
Department of Clinical Chemistry, Turku University Central Hospital, Finland. maria.raitakari@tyks.fi
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M
Raitakari
R D
RD
Brown
D
D
Sze
E
E
Yuen
L
L
Barrow
M
M
Nelson
B
B
Pope
W
W
Esdale
J
J
Gibson
D E
DE
Joshua
D000368:Aged; D000704:Analysis of Variance; D018959:CD57 Antigens / Q000032:analysis; D016827:CD8 Antigens / Q000032:analysis; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D016014:Linear Models; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis; D008875:Middle Aged; D009101:Multiple Myeloma / Q000276:immunology*; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology*; D012016:Reference Values; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D018959:CD57 Antigens; D016827:CD8 Antigens; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D016693:Receptors, Antigen, T-Cell, alpha-beta; D054353:Perforin