Increase in Concentration of Soluble CD86 After Segmental Allergen Challenge in Patients With Allergic Asthma

Study objective To investigate the effects of segmental allergen challenge on the concentration of soluble CD86 (sCD86) in BAL fluids in patients with allergic asthma. Methods BAL fluid and peripheral blood were collected at baseline, 24 h after segmental saline solution or allergen challenge by fiberoptic bronchoscopy and venepuncture, respectively, from 10 patients with allergic asthma. Total and differential cell counts in BAL fluid were performed, and sCD86 levels in both BAL fluid and serum were measured by enzyme-linked immunosorbent assay. Results In allergic asthmatics, there was no significant increase in BAL sCD86 concentrations after saline solution challenge (median, 2.0 IU/L; 25th to 75th percentiles, 0 to 3.4) compared with baseline control subjects (median, 1.2 IU/L; 25th to 75th percentiles, 0 to 3.6 IU/mL; p=0.735); however, sCD86 concentrations were significantly elevated after allergen challenge (median, 8.1 IU/L; 25th to 75th percentiles, 4.4 to 17.0 IU/mL; p Conclusions These data indicate that allergen challenge results in a significant local accumulation of sCD86 within the airways, and that the local release of sCD86 may play a role in allergen-induced inflammatory processes in the asthmatic airways.