Effect of autologous and homologous serum and circulating immune complexes on monocyte functions of patients with solid tumours.

Some functions of monocytes (phagocytosis, bactericidal capacity, handling of endocytosed 51Cr-SRBC and chemotaxis) were studied in fifty patients with solid tumours and in fifty controls. In the presence of autologous serum, the catabolism of endocytosed 51Cr-SRBC and the phagocytic capacity were similar in tumour and control monocytes, while the bactericidal capacity of tumour monocytes was increased. In the presence of pooled AB sera the catabolism and the bactericidal capacity were decreased in tumour monocytes as compared with autologous serum. Tumour sera did not enhance the functions of normal monocytes. Inactivation of pooled tumour or AB sera resulted in decrease of bactericidal capacity in tumour and control monocytes. Using the Clq-binding test, we detected circulating immune complexes in 36% of sera. The presence or absence and the quantity of such complexes did not correlate with the different functions studied in either tumour or normal monocytes. Finally, the chemotactic activity of monocytes was studied using the migration under agarose technique. No difference was found between tumour and control monocytes. On the other hand, the presence of a chemotactic inhibitor was not revealed in tumour sera. These observations suggest that monocytes from tumour patients require factor(s) present in autologous serum as well as autologous cellular component(s) to achieve normal functions.