Ecto-5′-Nucleotidase as a Leukemia Marker

Abstract

In recent years an ever increasing set of cell surface and other markers has been used to classify and subclassify leukemic blast cells. Among these the socalled biochemical markers — mainly enzyme activities — have gained importance. One of these enzymes is terminal deoxynucleotidyl transferase but many enzymes of purine metabolism are also used (for a survey see Blatt et al¹). 5′-Nucleotidase (5′-N) as an ectoenzyme has the double advantage of being testable by an ordinary enzyme assay on intact cells and at the same time being detectable by immunological methods as a surface structure. We have characterized leukemic cells using 5′-N not as an isolated marker but rather within a battery of other markers detectable by immunological means like specific antisera or rosetting assays.