EVALUATION OF PHAGOCYTIC-ACTIVITY IN NEOPLASTIC PATIENTS TREATED WITHSUBCUTANEOUS RECOMBINANT IL-2

Immunostimulating and immunosuppresive events have been noted during r IL-2 immunotherapy and cell-mediated immune deficiencies have been rep orted in the neutrophil and monocyte functions, determining a high inc idence of infections in patients during intravenous rIL-2 treatment. T he phagocytic activity of monocytes/macrophages and granulocytes was e valuated in 10 advanced solid tumor patients treated with subcutaneous rIL-2. Several indirect parameters of phagocytosis were also consider ed, such as Neopterin, Beta2 microglobulin, IL-2 soluble receptor, and the C3 and C4 fractions of the complement system. A decreased phagocy tosis was demonstrated after subcutaneous rIL-2 administration togethe r with an increase of indirect parameters of granulocyte/macrophage ac tivity. Therefore, cellular activation does not seem to correspond to actual phagocytosis which is probably due to IL-2-induced secondary cy tokines or to rIL-2 inhibitory effects.