A FOLLOW-UP-STUDY OF PULMONARY-FUNCTION TESTS, BRONCHOALVEOLAR LAVAGECELLS, AND HUMORAL AND CELLULAR-IMMUNITY IN BIRD FANCIERS LUNG

Background and Objective: The long-term outcome of bird fancier's lung appears to be variable. The objective of this study is to clarify the sequelae of disease process in bird fancier's lung, with special refe rence to the humoral and cellular immune responses after avoidance of direct antigen exposure. Methods: Five patients with bird fancier's lu ng were studied for various parameters including pulmonary function te sts, cellular profiles of bronchoalveolar lavage (BAL) fluids, determi nations of antibodies in BAL fluids and sera, and antigen-induced prol iferation of peripheral and bronchoalveolar lymphocytes during the 5 y ears of follow-up. Results: Four of five patients showed improvement i n pulmonary function and one showed marked deterioration. This patient 's room was close to the pigeon coop where her son was breeding pigeon s, resulting in low-grade antigenic stimulation. Three patients demons trated an increase in CD8(+) cells in BAL fluid, but the remaining two showed an increase in CD4(+) cells. The levels of IgA antibodies rema ined unchanged, whereas IgG levels started declining after the first 3 years of follow-up. Antigen-induced proliferation of BAL lymphocytes from ail five patients and blood lymphocytes from four of five patient s became weaker and gradually approached normal levels. One patient ha d pulmonary fibrosis and showed significant reduction in pulmonary fun ctions but elevated reactivity of BAL lymphocytes to pigeon antigens. Conclusion: This follow-up study demonstrates persistence of sensitize d lymphocytes and antibody production in the respiratory tract and war rants careful evaluation of patients with bird fancier's lung, even af ter antigen avoidance.