Macrophage Phenotype in Induced Sputum in Asthma Subjects

Macrophages represent the most predominant immune effector cells in the alveolar spaces and conducting airways and are known to express activated phenotype. The study was aimed at assessing the differences in cellular profile and the expression of selected surface markers on sputum macrophages in asthma and healthy subjects. 17 healthy subjects (never smoked) and 10 mild asthma subjects treated with glucocorticosteroids were enrolled into the study. For macrophage phenotyping a immunocytochemistry method was used with commercially available antibodies anti: CD14, CD71, CD11b and CD54. The nonparametric Mann Whitney U test was applied for data comparison, p value < 0.05 being regarded as significant. The total number of cells were increased in asthma patients 4.81 ± 5.27 × 10⁶/ml vs. healthy 2.8 ± 2.15 × 10⁶/ml and it was statistically significant. Statistically significant increase in the percentage of eosinophils was observed in mild asthma subjects. No differences were found between the proportion in macrophages and lymphocytes. The macrophage phenothype in induced sputum differed in both groups. The expression of CD 11b was higher in asthma group and the difference was statistically significant. The proportion of macrophages with the expression of CD 14, CD 71 and CD54 was comparable in both groups. Macrophage phenotyping during glucocorticosteroid therapy is useful in the assessment of inflammatory process in asthma subject.