[Expression of IL-2 receptor in peripheral blood lymphocytes and bronchoalveolar lavage fluid (BAL) in patients with sarcoidosis].

Interleukin 2 (IL-2) and its receptor (IL-2R) plays the important role in the lymphocytic alveolitis in sarcoidosis. The aim of this study was the comparative analysis of expression of IL-2 receptor subunits: alpha chain (IL-2R alpha) and beta chain (IL-2R beta) in peripheral blood and broncho-alveolar lavage fluid (BAL) in patients with sarcoidosis. We examined 18 patients (aged 23 to 47 years, 8 women and 10 men) with sarcoidosis and 5 healthy persons (the control group consisted of 2 women and 3 men, aged 25 to 39 years). The expression of IL-2R was evaluated by immunophenotyping in ORTHO Cytoron Absolute flow cytometer. Comparing the patients group to the control group, we found in BAL fluid of sarcoidosis patients statistically higher number of lymphocytes with IL-2R alpha and IL-2R beta expression (p < 0.002), when the percentage of these lymphocytes was similar in both groups. In peripheral blood of sarcoidosis patients comparing to control group, we noted higher percentage of lymphocytes with expression of IL-2R alpha and IL-2R beta (more evident difference concerned IL-2R beta) but without statistical significance. We also compared BAL fluid to peripheral blood in patients group. We found in BAL fluid lower percentage of lymphocytes with expression IL-2R beta (p < 0.02) and no significant changes in percentage and number of lymphocytes IL-2R alpha+. Our data concerning IL-2 and IL-2R suggest the activation of T lymphocytes in the lung in sarcoidosis. They present only little reflection of immunological reactions, which take place in sarcoidosis infant. The above study should be completed in future by evaluation of the other activation markers including IL-2R gamma.