The depressing effect of tumour on bactericidal capacity of plasma and leukocytes

Leukocyte--plasma suspensions and plasma from tumour patients have been tested in vitro against staphylococcus aureus for bactericidal capacity. Blood was collected during surgical intervention from peripheral vein and from the nearest point of vein to tumour. Second collection of peripheral blood was done 2--3 weeks later after surgery. Decrease of bactericidal activity of plasma has been found in blood collected from vein near the tumour. We can suggest that tumours release some factors disturbing the bactericidal capacity or that the tumour absorbs some factors of plasma or changes the functions of granulocytes.