Differential expression of CD3 and CD7 in T-cell malignancies: a quantitative study by flow cytometry |
| |
Authors: | Lia,Ginaldi ,Estella,Matutes ,Nahla,Farahat ,Massimo,De Martinis ,Ricardo,Morilla & Daniel,Catovsky |
| |
Affiliation: | Academic Department of Haematology and Cytogenetics, The Royal Marsden Hospital and Institute of Cancer Research, London |
| |
Abstract: | Most T-cell antigens are expressed on normal and neoplastic T lymphocytes and for this reason it is not easy to distinguish between the immunophenotype of normal and malignant T cells. We have addressed this problem by comparing the levels of expression of CD3 and CD7 on T lymphocytes from 18 healthy donors with those of 61 cases of T-cell leukaemia using quantitative flow cytometry with a method that converts fluorescence intensity into number of antigen molecules per cell. Normal T lymphocytes expressed 124 ± 25 CD3 and 20 ± 3 × 103 CD7 molecules per cell. The mean CD3 values were significantly lower in all types of T-cell leukaemia than in normal T cells ( P < 0.05), with the exception of Sezary syndrome. The lowest CD3 values were found in T-lymphoblastic leukaemia (T-ALL), 30 ± 21 × 103, and adult T-cell leukaemia/lymphoma (ATLL), 38 ± 31 × 103, followed by T-prolymphocytic leukaemia (T-PLL), 92 ± 47 × 103, and granular lymphocyte leukaemia (GLL), 95 ± 21 × 103. In contrast, the number of CD7 molecules was significantly higher in T-ALL, 35 ± 7 × 103 ( P < 0.01), and T-PLL, 29 ± 12 × 103, than the normal controls ( P < 0.01), whereas ATLL and GLL showed a low CD7 expression, 13 ± 3 and 12 ± 3 × 103, respectively. Our results show that the quantitative analysis of CD3 and CD7 and their combined evaluation may enable a distinction between normal and leukaemic T cells and could facilitate the monitoring of minimal residual disease. This study has also defined the T prolymphocyte as a cell of intermediate maturity between thymic derived and peripheral T lymphocytes. |
| |
Keywords: | quantitative flow cytometry T lymphocytes T-cell leukaemias CD3 and CD7 antigens |
|
|