Specificity and polymorphism of diaminopeptidase IV in normal and neoplastic Tμ lymphocytes

Summary In this paper evidence is given for the selective occurrence of the enzyme Diaminopeptidase IV (DAP IV) in human T lymphocytes. This cell population was isolated from human blood and subjected to a cytochemical enzyme reaction. Extending this finding to T-cell leukemias shows that these leukemias can be classified as T cell-derived on the basis of cytochemical tests as well as comparing enzyme polymorphism.Abbreviations DAP IV Diaminopeptidase IV - AcE -naphthyl-acetate-esterase - IEF isoelectric focusing - T-CLL chronic lymphocytic leukemia of T type - B-CLL chronic lymphocytic leukemia of B type