Presence of macrophages(M) and macrophage-lymphocyte contacts are essential for the development of the cell-mediated or humoral immune reactions. Estimation of the functional activity of the immunocompetent cells in patients(P) with BA is very important. We investigated MLRos formation in blood leukocyte cultures of 25 P with BA (11- atopic, 14- infection related asthma) before and after treatment, 1 P with allergic rhinitis in clinical remission and 20 heathy donors. We determined percentage of M contacted with lymphocytes(L) to the total amount of M. In healthy donors M were contacted with 1 or 2 L and rarely with 3 and more L. In P with BA amount of MLRos was significantly increased (70,2 ± 2,4 %), most M were contacted with 3-5 and more L. Total amount of T L was decreased and amount of B L was normal. In cases of atopic BA serum Ig E level was significantly increased and skin allergy tests were positive. Amount of MLRos was not reliably different between P with atopic or infection related BA. Research of P with BA in dynamic revealed significant decrease of MLRos (48,3 ± 6,0%) after treatment. In P with allergic rhinitis amount of MLRos was high (78%). Though she was clinically in remission, in 2 days she developed acute attack of allergic rhinitis. Increased amount of MLRos preceded clinical relapse. Our study shows that MLRos formation represents functional activity of L and M and can be widely applied in clinical practice for estimation of immune reactivity of organism, for revealing of immune conflict in P with BA, for evaluation of the effectiveness of treatment and maintenance therapy, stability of obtained remission or for revealing of impending relapse.