Impairment of monocyte functions in advanced head and neck cancer

Depression of cell-mediated immunity is well established in most malignancies and especially in head and neck cancers, and much information is available concerning the defect in helper T lymphocyte function. We now report on impairment of the monocyte-macrophage system. Compared with normal controls we found that patients displayed, on one hand, an increased number of peripheral blood monocytes and, on the other hand, a smaller percentage of HLA-DR+ monocytes. Such peripheral blood monocytes normally failed to secrete factors, including interleukin 1 (IL-1). In addition, we observed that the in vivo induced blastogenesis of peripheral blood lymphocytes from patients, which is spontaneously depressed, is partly restored by medium containing IL-1. We cannot exclude, however, that the observed monocyte dysfunction involves other cytokines. Whether such an immune deficiency is due to secondary malnutrition or to the malignancy (or both) remains unclear.