OBJECTIVE

To elucidate the differences of T helper cell subsets and expressions of B7 co-stimulatory molecules by alveolar macrophages (AM) between patients with allergic asthma and chronic obstructive pulmonary disease (COPD).

METHODS

Bronchoalveolar lavage fluid (BALF) cells were obtained from 16 normal control volunteers, 16 patients with allergic asthma and 16 patients with COPD. IFN-gamma and IL-4 levels in the supernatant of BLAF lymphocytes cultured with PHA were determined using sandwich ELISA and the CD80 (B7-1) and CD86 (B7-2) expressed by AM stimulated with LPS were determined using avdin-biotin complex technique.

RESULTS

In COPD group, IFN-gamma level was significantly higher than those of the control group and asthma group (P < 0.01). IFN-gamma in asthma group was lower than that of the control group (P < 0.01). IL-4 level and the ratio of AM expressing CD86 in asthma group were higher than those of the control group and COPD group (P < 0.01). The IL-4 level and ratio of AM expressing CD86 showed no significantly difference between COPD and control group (P > 0.05). The IL-4 levels in 3 groups were significantly positively correlated with the ratio of AM expressing CD86 (r = 0.61, P < 0.05). No difference of the ratio of AM expressing CD80 was found among three groups (P < 0.05).

CONCLUSION

Asthma is characterized by a predominance of Th2-type response in BALF T cells, and COPD of Th1-type response in BALF T cells. The increased expression of co-stimulation of CD86 in AM is probably involved in Th2-type response in the airway inflammation in allergic asthmatics.