Premium
Comparison of purine degradative enzymes and terminal deoxynucleotidyl transferase in T cell leukaemias and in normal thymic and post‐thymic T cells
Author(s) -
Ma D. D. F.,
Massaia M.,
Sylwestrowicz T. A.,
Price G.,
Hoffbrand A. V.
Publication year - 1983
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1111/j.1365-2141.1983.00451.x
Subject(s) - terminal deoxynucleotidyl transferase , purine nucleoside phosphorylase , adenosine deaminase , t cell , microbiology and biotechnology , thymocyte , biology , cell , precursor cell , leukemia , immunology , purine , enzyme , biochemistry , tunel assay , immunohistochemistry , immune system
S ummary . Adenosine deaminase (ADA), ecto 5’ nucleotidase (5′NT), purine nucleoside phosphorylase (PNP) and terminal deoxynucleotidyl transferase (TdT) were measured in the cells of patients with acute or chronic T cell leukaemia and compared with normal putative prothymocytes (large, blast‐like cortical thymocytes), cortical and medullary thymocytes and peripheral blood T lymphocytes. Distinct patterns of enzyme activities were found in the individual types of T cell leukaemia. Mean ADA, TdT and 5′NT activities in thymic acute lymphoblastic leukaemia (Thy‐ALL) were 41·9 u/10 8 cells, 31·1 u/10 8 cells and 4·7 u/10 6 cells respectively; in chronic T cell leukaemia they were 7·1 u/10 8 cells, 0·6 u/10 8 cells and 18·1 u/10 6 cells respectively. Mean PNP activity was similar between these two groups of leukaemia (68·6 u/10 6 cells in Thy‐ALL and 77·9 u/10 6 cells in chronic T cell leukaemia). The activities of these four enzymes in OKT4 + chronic T cell leukaemia did not differ significantly from those in the OKT8 + chronic T cell leukaemia cases. The activities of TdT, ADA, PNP and 5′NT in Thy‐ALL closely resembled those in normal immature thymocytes, and in the chronic T cell leukaemias showed a similar pattern of enzyme activities to that of mature T lymphocytes. These findings are consistent with surface phenotypic studies of T cell malignancies which suggest that different T cell leukaemias represent malignant proliferation of T cell clones arrested at different stages of T cell differentiation. They also demonstrate the value of biochemical markers in defining the different subtypes of acute and chronic leukaemia.