Hexosaminidase isoenzyme profiles in leukemic cells.

The isoenzyme profiles of hexosaminidase in leukemic cells from 39 patients were examined with DEAE-Sephadex chromatography. There was a clear difference in the isoenzyme composition between normal lymphocytes and granulocytes. In acute non-T/non-B lymphocytic leukemia (ALL) a characteristic alteration was found in the intermediate forms of hexosaminidase (Hex I), which was significantly higher than those of normal lymphocytes (p less than 0.001). Subtypes of Hex I (Hex i1-i4) and the heterogeneity of their abnormal expression in ALL was demonstrated. There was no type-specific alteration of the isoenzyme profiles in T-cell leukemia. Leukemic cells of acute myelocytic leukemia (AML) had significantly higher Hex P component than granulocytes (p less than 0.01) and ALL cells (p less than 0.01). The increase of Hex P was evident in childhood AML. There was a significant difference in Hex P level between childhood AML and adult myelo(mono)genous leukemia (p less than 0.001). Chronic myelo(mono)genous leukemia showed similar isoenzyme compositions to normal granulocytes. The isoenzyme profiles in acute undifferentiated leukemia differed from those in other types of leukemia. Isoenzyme analysis might be useful for probing the nature and the intrinsic biochemical abnormality of leukemic cells.