The enzyme, catalase, has been studied in normal leukocytes, and in leukocytes from patients with leukemia and infective states. Examination of both granulocyte-rich and lymphocyte-rich fractions prepared from normal leukocyte populations showed the catalase activity of normal granulocytes to be higher than that of normal lymphocytes.
In acute and chronic myeloid leukemia, catalase levels were found to be higher than the range for normal granulocytes, whereas in acute and chronic lymphatic leukemia, the levels were of the same order as those for normal lymphocytes.
Low catalase values were found in infective leukocytosis, suggesting that young granulocytes may have lower activities than the mature cells. The significance of the changes in leukocyte catalase activity in myeloid leukemia are discussed in relation to cell age.