| Abstract: | Asthma has been recognized to consist of hyperresponsive airways and cellular inflammation. Allergen bronchoprovocation (BPC) may define the early (EAR) and late-phase asthmatic response (LAR). The LAR has now been associated with increased nonspecific airway hyperresponsiveness and cellular inflammation consisting of neutrophils and eosinophils. We used BPC to demonstrate EAR and LAR in 12 subjects with seasonal allergic asthma. One normal subject and one subject with asthma who had been treated with allergy immunotherapy were challenged but did not respond. Plasma was sampled at frequent intervals during these aeroallergen challenges and assayed for eosinophil chemotactic activity (ECA) and neutrophil chemotactic activity (NCA). Of the 12 subjects with asthma who were challenged, nine had dual responses (both EAR and LAR), and three subjects demonstrated only an LAR. Those subjects who had dual airway responses had biphasic rises in both ECA (early = 267 +/- 28%; late = 286 +/- 28%) and NCA (early = 279 +/- 24%; late = 215 +/- 15%) in their plasma, whereas those subjects who demonstrated only an LAR had only a late rise in ECA (218 +/- 61%) and NCA (188 +/- 31%). The two individuals who did not respond to aeroallergen challenge demonstrated no change in their plasma chemotactic activity toward either eosinophils or neutrophils. Those individuals with the most severe LAR (greater than or equal to 1,000 mm2) had combined ECA plus NCA peak values of greater than 500%.(ABSTRACT TRUNCATED AT 250 WORDS) |
