Lactate dehydrogenase isoenzyme patterns of human lymphatic and myeloid leukemic leukocytes

The isoenzymes of lactate dehydrogenase (LDH) of human leukocytes were studied in 20 patients with chronic lymphatic leukemia and 10 patients with chronic myeloid leukemia. The separation of isoenzymes was performed with agar gel electrophoresis. Isoenzymes were visualized with nitroblue tetrazolium salt and the activities estimated by direct photometric assay. The activity of isoenzyme V was low in lymphatic leukemia and high in myeloid leukemia. It seems that there is a biochemical difference between the LDH isoenzyme pattern of chronic lymphatic and myeloid leukemia, especially in the activity of LDH v.