Serum lysozyme activity in patients with lung carcinoma subjected to radiotherapy.

Lysozyme activity was determined in undiluted and diluted sera of 30 patients with lung carcinoma and of 40 healthy individuals. Blood was collected before radiotherapy, in half of its course, just after completion of radiotherapy, and three weeks and three months later. In the controls the same time spacing was kept. Lysozyme was found to be increased both in undiluted and diluted sera. Enhancement of the lysozyme activity may be due to the presence of immune complexes (antigen--antibody) which are probably responsible for the release of the enzyme from the viable neutrophils. High activity in diluted sera indicates an increase of lysozyme inhibitors in sera of cancer patients. Radiotherapy has not induced significant changes in the enzyme, either during its course of after its completion as confirmed by three-month observation. Taking into consideration the role of the lysozyme in anticancer mechanisms it appears that determination of its activity may be of value in the course of cancer disease.