Utility of flow cytometry immunophenotyping and DNA ploidy studies for diagnosis and characterization of blood involvement in CD4+ Sézary's syndrome.
OBJECTIVE
The exact immunophenotypic criteria for the identification of Sézary cells in the blood are still poorly defined.


METHODS
We analyzed the immunophenotype and DNA cell content of blood T cells in a series of 18 consecutive cases of Sézary's syndrome (SS), 21 normal individuals and 10 patients with reactive erythroderma, and correlated them with molecular and morphological findings.


RESULTS
Phenotypically abnormal CD3+/TCRalphabeta+/CD4+ T cells were found in all SS patients but in none of the reactive erythroderma cases; small diploid, or less frequently hypodiploid Sézary's cells coexisted with large nearly tetraploid Sézary's cells in some cases. The most frequent phenotypic aberrations consisted in decreased expression of CD3/TCRalphabeta (94%), CD4 (94%), CD7 (100%) and/or CD2 (83%). In addition, Sézary's cells were constantly CD28+ and CD5+ and they did not express natural-killer associated (NKa) antigens. Phenotypic heterogeneity was a common finding and phenotypic changes over time were frequently observed. In contrast to what was found in patients with reactive erythroderma, flow cytometry analysis of the T-cell receptor (TCR) repertoire revealed a major TCR-Vbeta expansion in all SS cases.


CONCLUSIONS
The presence of CD28+/CD5+/NKa-/CD4+ T cells expressing abnormally low levels of CD3, TCRalphabeta, CD4, CD7 and/or CD2 would support the diagnosis of SS in patients with erythroderma. Further analyses on larger series of patients are necessary in order to cover less frequent phenotypic patterns, establish the preferential usage of specific TCR-Vb families and investigate the specificity of these phenotypic abnormalities for diagnosing SS.
Lima
Margarida
M
Serviço de Hematologia, Unidade de Citometria, Hospital Geral de Santo António, Rua D Manuel II, s/n, 4099-001 Porto, Portugal. mmc.lima@clix.pt
Almeida
Julia
J
dos Anjos Teixeira
Maria
M
Queiros
Maria Luís
ML
Santos
Ana Helena
AH
Fonseca
Sónia
S
Balanzategui
Ana
A
Justica
Benvindo
B
Orfao
Alberto
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015704:CD4 Antigens / Q000096:biosynthesis*; D018791:CD4 Lymphocyte Count; D016516:CD4-CD8 Ratio / Q000639:trends; D015496:CD4-Positive T-Lymphocytes / Q000737:chemistry / Q000378:metabolism / Q000473:pathology; D004273:DNA, Neoplasm / Q000032:analysis*; D003873:Dermatitis, Exfoliative / Q000097:blood / Q000235:genetics / Q000473:pathology; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D005500:Follow-Up Studies; D015333:Gene Rearrangement, beta-Chain T-Cell Antigen Receptor / Q000235:genetics; D006801:Humans; D016130:Immunophenotyping / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011003:Ploidies; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics; D012751:Sezary Syndrome / Q000097:blood* / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D012878:Skin Neoplasms / Q000097:blood* / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D016176:T-Lymphocyte Subsets / Q000737:chemistry / Q000378:metabolism / Q000473:pathology
D015704:CD4 Antigens; D004273:DNA, Neoplasm; D016693:Receptors, Antigen, T-Cell, alpha-beta