Influence of sera from patients affected by neoplasia on some human macrophage functions.

It has been repeatedly reported that several functions of mononuclear cells are impaired in patients affected by neoplasia. Moreover, inhibitory activity of serum and tumor extracts on macrophages have been described. In a previous study, we found a marked impairment of the intrinsic antiviral activity of macrophages derived from monocytes isolated from peripheral blood of patients with breast carcinoma or melanoma compared with that from blood of normal subjects. The aim of the present work was to study whether this impairment was due to circulating inhibitory factors. Macrophages were differentiated in vitro in sera from patients with neoplasia and in sera from healthy donors and then challenged with herpes simplex virus type 2 (HSV-2). Macrophages from normal subjects, incubated with sera from patients, were significantly impaired in their intrinsic antiviral activity. These results support the possibility that circulating inhibitory factors influence the functionality of mononuclear phagocytes in the tumor-bearing host.