The effect of sera from 107 patients with
gastrointestinal cancer on macrophage chemotaxis was studied using a modified Boyden chamber technique. A macrophage
chemotactic inhibitory factor (CIF) was found in sera of advanced
cancer patients. The CIF activity was significantly stage-related, and increased especially in patients with negative cutaneous responsiveness in purified
protein derivative,
dinitrochlorobenzene and
keyhole limpet hemocyanin skin tests, and with low circulating T-lymphocyte levels. In addition, the CIF was found to suppress neutrophil as well as macrophage chemotaxis. suppress neutrophil as well as macrophage chemotaxis. The mode of action and the characteristics of the CIF were investigated, and the following results were obtained. (1) The CIF directly interacted with macrophages and neutrophils and suppressed their chemotactic activities without apparent cytotoxic effect on these cells. (2) On
Pevikon block electrophoresis, the CIF activity was most prominent in the
alpha-globulin region, although considerable heterogeneity and broadness of the CIF bands were observed. (3) Dialysis and lyophilization had no effects on the CIF activity. On heating at 56 degree for 30 min, the CIF activity seemed to be decreased. This study indicates that CIF in
cancer patients may be detrimental to the host immune defense against
tumor growth by producing defects of macrophage and neutrophil chemotaxis in vivo.