Protein kinase activity in lymphoid cells in various forms of lymphoproliferative disorders

: Activities of dipeptidyl-aminopeptidase IV, urokinase-like plasminogen activator, cathepsins B and L were studied in lymphoid cells of patients with various forms of lymphoproliferative disorders. Activity of the enzymes studied was found in all the T- and B-cell, although rate and ratio of the enzymatic activity were dissimilar in various cell types. The highest rate of activity exhibited cells at early stages of maturation obtained from patients with acute lymphoblastic leukemia, while low level of the proteinase activity was detected in cells of patients with chronic lymphoid leukemia, non-Hodgkin lymphoma, hairy cell leukemia and Sezary disease, corresponding to mature T- and B-subpopulations. As shown by analysis of the cells immunological phenotype and their proteolytic activity, the rate of lymphoid cells differentiation correlated with level of proteinases activity. Series of proteinases were firstly studied in human malignant lymphoid cells with known phenotype. The enzyme assay may be used in diagnosis and treatment of patients with lymphoproliferative disorders.