Profound deficiency in normal circulating T cells in erythrodermic cutaneous T-cell lymphoma.
METHODS
To accurately assess tumor burden in cutaneous T-cell lymphoma as well as to determine the number of residual normal circulating T cells, it is necessary to accurately distinguish malignant cells. Because cutaneous T-cell lymphoma cells regularly display many normal phenotypic markers of T cells (CD2+, CD3+, CD4+) these surface proteins have been of limited value. We have used a set of monoclonal antibodies with specificity for those T-cell receptor proteins containing variable regions on the beta chain to distinguish normal from malignant T cells in patients with cutaneous T-cell lymphoma.


RESULTS
The results revealed an unanticipated and profound expansion of the malignant cell populations (59% to 87% of blood T cells) in six patients with total T-cell counts in the normal or near normal range. By subtracting the percentages of malignant T cells, identified in this manner, from the total T-cell counts, we found that the residual normal T-cell compartments were small (0 to 0.155 x 10(9)/L) in four of the six patients. Sézary cell counts by peripheral blood smear analysis by routine light microscopy underestimated the number of malignant T cells. Markedly elevated CD4/CD8 ratios (10 to 90) occurred in all cases, reflecting expansion of the CD4+ malignant population and parallel reduction of the normal residual CD8+ subset.


CONCLUSIONS
Patients with erythrodermic cutaneous T-cell lymphoma often have markedly depressed levels of normal blood T cells, to the range seen in advanced acquired immunodeficiency syndrome, and absolute numbers of malignant cells substantially exceed those recognized with less sensitive techniques.
Heald
P
P
Department of Dermatology, Yale University School of Medicine, New Haven, Conn.
Yan
S L
SL
Edelson
R
R
D016516:CD4-CD8 Ratio; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D007958:Leukocyte Count; D016410:Lymphoma, T-Cell, Cutaneous / Q000097:blood*; D011948:Receptors, Antigen, T-Cell / Q000302:isolation & purification; D012751:Sezary Syndrome / Q000097:blood*; D012878:Skin Neoplasms / Q000097:blood*; D013601:T-Lymphocytes / Q000276:immunology / Q000473:pathology*
D011948:Receptors, Antigen, T-Cell