Antigenic release of paf-acether and beta-glucuronidase from alveolar macrophages of asthmatics

Alveolar macrophages (AM) from control (n = 12) and atopic patients (n = 19, 12 without treatment, 4 treated with theophylline and 3 with theophylline and corticosteroid) were compared for their capacity to release mediators. AM were purified by 2 h adherence and challenged with either ubiquitous allergen, specific sensitizing allergens, anti-IgG or anti-IgE serum. The release of paf-acether, lyso paf-acether and beta-glucuronidase was measured. Paf-acether and its lyso derivative were assayed on washed rabbit platelets. Enzyme and mediator releases were obtained after specific allergenic or anti-IgE serum challenge of AM from untreated atopic patients. No release of paf-acether was detected from AM, from control or treated atopic patients after in vitro immunological challenge, whereas that of lyso paf-acether was greatly reduced in both treated groups. Release was obtained by immunological challenge of AM from control patients after passive sensitization with atopic serum. The release of mediators with bronchoconstriction activity by AM could represent an alternative causal pathway in human asthma.