Abstract

Since the Fleming's observation of bacteriolytic element in nasal mucus in 1922, lysozyme has been found to be present in various biologic fluids such as serum, urine, tear, colostrum etc. It is known to be a hydrolytic enzyme acting specifically on the structural unit of cell wall of various bacteria. In the formed elements of blood, lysozyme activity has been identified in monocytes, monoblasts and mature neutrophils and their precursors as far back as progranulocytes. Increased concentrations of lysozyme were reported in the serum and urine of patients suffering from monocytic and myelomoncytic leukemias. The activities of lysozyme are normal or decreased in lymphocytic leukemia. Attempts have been made to correlate the serum lysozyme value with diagnostic and prognostic indices of acute leukemia. However, there has been no report on the serum lysozyme study in Korea. The author measured serum lysozyme level by means of turbidimetric assay on 48 specimens from 42 patients with leukemia and 30 from normal subjects. 1) In normal subjects, the mean value of lysozyme was 7.46㎍/㎖ and the range was 3.25～11.25㎍/㎖. 2) The highest mean serum lysozyme level was found in AMMoL patients(22.7㎍/㎖). Increased level was also observed in AMoL group(16.31㎍/㎖). 3) There was some correlation between serum lysozyme level and leukocyte count but it was not significant statistically (r=0.24). 4) The mean of the ratio of serum lysozyme/WBC count per ㎕×10-3 was above 4 in AMoL. The mean of the ratio in other types of leukemia was significantly different (p<0.005). 5) When lymphadenopathy accompanied by gum hypertrophy was present in AMMoL and AMoL, an increased serum lysozyme value was also observed. 6) When initial serum lysozyme level was high, the remission rate was low in AMMoL and AMoL. From the above results, it is concluded that the measurement of serum lysozyme value is an additional guide for the diagnosis and prognosis of acute leukemia.