Immunophenotypic identification of Sezary cells in peripheral blood.
Despite anecdotal literature that Sezary cells express the CD4+ CD7- immunophenotype, no formal validation has been published establishing the use of this immunophenotype for clinical or experimental purposes. Consequently, the only method presently available for Sezary cell identification is nuclear contour analysis, a labor-intensive procedure not generally available at most major medical centers. In this study, the accuracy of CD4+ CD7- subset quantitation for the identification of Sezary cells was examined. The study found that the percentage of CD4+ CD7- cells is elevated in many Sezary syndrome/MF patients relative to normal, healthy individuals. In addition, CD4+ CD7- enumeration correlates with enumeration by nuclear contour analysis in most patients (11 of 15) with elevated CD4/CD8 ratios. The CD4+ CD7- subset also correlates with the expression of other aberrant immunophenotypes, such as CD3low or CD4low. Lastly, CD4+ CD7- subset quantitation correlates with the number of clonal T lymphocytes, as measured using V beta-specific T-cell receptor monoclonal antibodies. The study found this method to be exceptionally accurate, with two caveats: (1) the absence of an expanded CD4+ CD7- subset in patients with a normal CD4/CD8 ratio is uninformative; and (2) in approximately 25% of patients with an elevated CD4/CD8 ratio, the Sezary cells are CD7+.
Bogen
S A
SA
Department of Pathology and Laboratory Medicine, Boston University Medical Center, MA 02118, USA.
Pelley
D
D
Charif
M
M
McCusker
M
M
Koh
H
H
Foss
F
F
Garifallou
M
M
Arkin
C
C
Zucker-Franklin
D
D
D019011:Antigens, CD7 / Q000276:immunology*; D016516:CD4-CD8 Ratio; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000473:pathology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000473:pathology; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D015203:Reproducibility of Results; D012751:Sezary Syndrome / Q000097:blood / Q000473:pathology*; D012878:Skin Neoplasms / Q000097:blood / Q000473:pathology*
D019011:Antigens, CD7