RELATIONSHIP BETWEEN PLASMA-CELL LEVELS AND PROFILE OF BRONCHOALVEOLAR LAVAGE FLUID IN PATIENTS WITH SUBACUTE EXTRINSIC ALLERGIC ALVEOLITIS

Background-Plasma cells are usually absent in bronchoalveolar lavage ( BAL) fluid. Extrinsic allergic alveolitis is associated with increased numbers of T and B lymphocytes in BAL fluid, as well as the presence of a few plasma cells. The aim of this study was to investigate whethe r there is a relationship between the presence of plasma cells and oth er cells, and immunoglobulin levels in BAL fluid of patients with extr insic allergic alveolitis. Methods-Thirty non-smoking patients with ex trinsic allergic alveolitis who had a bronchoalveolar lavage 2-7 days after their last exposure to the causative antigen were selected, retr ospectively. Results-Patients suffering from extrinsic allergic alveol itis with plasma cells in the BAL fluid (n = 18) had increased absolut e numbers of lymphocytes, eosinophils and mast cells, a decreased perc entage of alveolar macrophages and lower CD4/CD8 ratio, as well as hig her immunoglobulin levels, when compared with patients with extrinsic allergic alveolitis having no plasma cells in the BAL fluid (n = 12). Conclusions-The results suggest a relationship between the presence of plasma cells and the other constituents in BAL fluid and a more inten se alveolitis. In addition there was a positive relationship between t he number of plasma cells in BAL fluid and immunoglobulin levels. Thes e data support the concept of local production of immunoglobulins by p lasma cells in the lung following antigen exposure in susceptible indi viduals.