Killer cell (K) activity in human normal lymph node, regional tumour lymph node and inflammatory lymph node.

Human normal lymph nodes, irrespective of their anatomical site of origin, have a low K cell activity, which may not be detected except with the appropriate target cell and at high lymphocyte to target cell ratios (100:1). This very low killer cell activity is also found in all the homolateral axillary nodes of patients with clinical stage I and II carcinoma of the breast and in the regional draining nodes of a variety of solid tumours, whether small and localized or large and with extensive spread. In all cases proximity to the tumour and obious hyperplastic changes in the nodes have no modifying effect. This pattern of minimal reactivity is similarly found with tonsillar lymphocytes and with nodes draining inflammatory foci. The Fc and C3 receptors on surface membranes are dectected with ease, and pretreatment of lymphocytes by incubation, washing and enzymatic treatment fail to alter their reactivity, thus excluding effector cell inhibition by immune complexes. The killer cell activity of lymphocytes from the blood of breast tumor patients is similar to the activity of lymphocytes from healthy controls.