Corrigendum to: “Mast cell numbers in airway smooth muscle and PC20AMP in asthma and COPD”

The authors regret that an essential sentence is missing in the Materials and methods section, which may lead to misunderstandings. This should be corrected as follows: ‘‘Materials and methods’’, section ‘‘Bronchoscopy and processing of the biopsies’’. The last part: ‘‘Tryptase positive cells were countedy as the number of positive cells per area smooth muscle.’’ Should be replaced by: ‘‘Tryptase positive cells were counted in two random, but representative sections of one biopsy per patient with at least an 80 mm interval. The area of smooth muscle was determined by grid counting using an eyepiece graticule (crosspoints each 100 mm at 10 10). In this way, we evaluated per subject a mean (SD) area of 0.59 (0.40)mm. Mast cells within and in direct juxtaposition with smooth muscle were counted. Mast cell number was expressed as the number of tryptase positive cells per area smooth muscle.’’