Acid hydrolases in B-chronic lymphocytic leukemia (B-CLL): a comparison with normal peripheral B lymphocytes and normal B-cell subset with the phenotype of B-leukaemic cells.

The acid phosphatase (AP), beta-glucuronidase (BG), and alpha-naphthyl-acetate esterase (ANAE) distribution and the morphology of stage 0 B-CLL lymphocytes were studied. The results were compared with the same hydrolase equipment and morphology of normal B-cell populations showing the B-CLL-like phenotype, and thus regardable as the possible counterpart of leukaemic cells. The functional and structural characters of the former were strikingly different from those of the latter. In fact the normal B-cell population with B-CLL-like phenotype showed an homogeneous enzyme pattern with predominant ANAE and a strictly lymphocytic cell morphology. In contrast, the leukaemic cells showed various and unrelated morphological and cytochemical features, thus forming apparent subgroups of B-CLL. The development of an irregular "switch on" mechanism in the blocked malignant cell clone, may account for these functional and structural maturation discrepancies. Moreover, the fact that in the leukaemic cells ANAE activity could be demonstrated only after the appearance of the other hydrolases, makes it a marker of functionally differentiated B lymphocytes.