Systemic Modulatory Effects Of The Treatment With Il-2 Of Lung Metastasis.

2560 Background: IL-2 is a drug that is employed in the treatment of several tumors due to its capacity of restore or increase the regulatory and effector function of the immune system. These effects have been demonstrated with the administration of the drug by intravenous and subcutaneous ways. Recently, it has been observed that the inhaled IL-2 administration is effective in the treatment of lung and renal cell carcinoma metastasis. However, it is unknown if this therapeutic effect is accompanied of systemic and local modulatory effects. Objectives: To compare spontaneous and mitogen-induced apoptosis in lymphocytes of renal carcinoma patients before and after treatment with inhaled IL-2. Methods: Peripheral blood mononuclear cells were purified from 7 patients with renal carcinoma before and after treatment with inhaled IL-2. The cells were characterized in a FACScalibur analyzer using fluorocrome-labeled monoclonal antibodies. The AI (or percentage of apoptotic cells, AI x 100) was calculated for T-cells expressing CD3, CD4, CD8, CD56, HLA-DR, CD25 and CD45RO/CD45RA antigens and NK-cells (CD3-CD56+ or CD3-CD16+). These AI were determined after 24 hours of culture under two conditions: without exogenous apoptosis inducers and in the presence of phytohemagglutinin. Comparisons between patients were carried out using the Wilcoxon test and were considered significant when p < 0.05. Results: A significant decrease in spontaneous ex vivo apoptosis was found in peripheral blood lymphocytes from renal carcinoma patients after treatment with inhaled IL-2 with respect to pretreatment values. This decrease occurred in T-cells and also in CD45RO expressing cells from both CD4+ and CD8+ subsets. A decrease of apoptosis was also observed in CD25+ expressing cells from CD3+, CD4+ and CD8+ subsets. A decrease in AI was found in mitogen induced apoptosis of CD25+ cells from CD3+, CD4+ and CD8+ subsets. Conclusions: The treatment with inhaled IL-2 has immunomodulatory effects that are observed at systemic level reducing the apoptosis of cells from several memory and activated T-cell subsets. No significant financial relationships to disclose.