INCREASED EXPRESSION OF ADHESION MOLECULES (ICAM-1 AND LFA-1) ON ALVEOLAR MACROPHAGES FROM ASTHMATIC-PATIENTS

In the airways inflammation observed in asthma, activated macrophages are present in increased numbers. Adhesion molecules are required for the cell:cell contacts between leukocytes and endothelial cells or oth er leukocytes, and they are induced by inflammatory stimuli. We studie d the expression of two adhesion molecules (ICAM-1 and LFA-1) on alveo lar macrophages recovered by bronchoalveolar lavage from 11 normal sub jects and 13 asthmatic patients by using immunocytochemistry. Two spec ific monoclonal antibodies were used, and the reaction was revealed by the alkaline phosphatase-antialkaline phosphatase (APAAP) method. The percentage of cells expressing ICAM-1 or LFA-1 was significantly incr eased in asthmatic patients, as compared with normal subjects (P<0.001 and P<0.002, respectively; Mann-Whitney U test), and there was a sign ificant correlation with the percentage of cells expressing both marke rs in asthma (P<0.03, Spearman rank test). This study highlights the i mportance of macrophages in the inflammation of asthma and suggests th at macrophage interactions with other cells play a role in this inflam mation.