Plasma lactic dehydrogenase and phosphohexose isomerase in leukemia.

By M. C. BLANCHAER, P. T. GREEN, J. P. MACLEAN AND M. J. HOLLENBERG W IDE ACCEPTANCE of serum glutamic oxaloacetic transaminase estimations1 for the detection of myocardial infarction has stimulated interest in the possible diagnostic uses of other plasma enzymes, including lactic acid dehydrogenase ( LD ) and phosphohexose isomerase ( PHI ) . Both of these enzymes play a role in the intracellular process of glycolysis.2 Abnormally elevated plasma levels have been found in hepatocellular disease,3’4 myocardial infarction3 and neoplastic disease, including certain types of leukemia. Plasma LD was found to be raised in acute stem cell leukemia3 and chronic myelocytic leukemia, btit was normal in two of the three cases of chronic lymphocytic leukemia reported. Isracls and Delory7 found that the plasma PHI was increased in chronic myelocytic leukemia, but not in the chronic lymphocytic type nor in the leukocytosis of infections. In the present work the plasma LD has been examined in various types of leukemia in relation to the plasma PHi levels, the response to treatment and the presence of hemolytic disease.