Analysis of acid esterase activity and polymorphism as an aid for the classification of human low-grade malignant non-Hodgkin's lymphomas.

Investigating a link between enzyme histochemical and recent immunohistochemical results, the authors studied the activity and the polymorphism of acid esterase (EC 3.1.1.6) in well defined human B-cell lymphomas. TWelve cases of chronic B-lymphocytic leukemia, 18 cases of centroblastic/centrocytic follicular lymphoma, and 17 cases of lymphoplasmacytic/lymphoplasmacytoid lymphoma, as diagnosed according to Kiel classification, were subjected to enzyme assay and isoelectric focusing of acid esterase. Enzyme values revealed no characteristic distribution among the lymphoma entities. The isoenzyme pattern, specific to normal human B-lymphocytes, were regularly detectable in all lymphoma entities. The results document the B-cell origin of the analyzed subsets of B-cell malignancies, although distinctive acid esterase patterns were lacking. The prevalence of three anodal isoenzymes in cases of chronic B-lymphocytic leukemia, hardly detectable in other lymphoma entities, were interpreted as the expression of a clonal proliferation, arrested at a certain differentiation stage of B-cells common for the majority of the tumor cells. Hence, further evidence is provided supporting the view that the studied entities represent B-cell neoplasias at different stages of differentiation expressing a variety of different markers.