Serum and leukocyte lactate dehydrogenase activity in leukaemias

Lactate dehydrogenase (LHD) content of serum and leukocytes was examined in 42 haematologically normal healthy volunteers and in 34 patients suffering from various types of leukaemia. All patients were studied at the time of presentation and before any therapeutic intervention. Serum LDH was elevated in all types of leukaemia. In acute myeloid leukaemia (AML) a significant elevation of leukocyte LDH activity (p less than 0.005) was noted. In acute lymphoblastic leukaemia leukocyte (ALL), LDH was significantly elevated when compared to normal lymphocyte LDH (p less than 0.01) levels, but not when compared to total normal leukocyte LDH levels. In chronic leukaemias, leukocyte LDH levels were not significantly different from the normal. Comparison of LDH isoenzyme pattern in peripheral blood cells with that of serum, both in normal and in leukaemia cases showed more "M" type enzyme in the cells than in the serum. However, the "M" type enzyme was significantly elevated only in AML cases (p less than 0.005). Serum LDH and peripheral blood leukocyte count compared in normal subjects and in leukaemia cases showed no correlation.