A COMPARISON OF LYMPHOCYTE POPULATIONS IN LUNG-TISSUE AND IN BRONCHOALVEOLAR LAVAGE FLUID OF RATS AT VARIOUS TIMES DURING THE DEVELOPMENT OF BLEOMYCIN-INDUCED PULMONARY FIBROSIS

  • 1 January 1984
    • journal article
    • research article
    • Vol. 129  (2) , 279-283
Abstract
Lymphocyte populations were compared in lung lavage fluid and in lung tissue during the development of bleomycin-induced pulmonary fibrosis. At various times after bleomycin treatment, animals were killed and lavaged and lung tissue cells were extracted. Lymphocyte populations were identified by immunofluorescent techniques, using monoclonal antibodies and quantitated on the fluorescence-activated cell sorter. Normal control rat lung tissue was comprised of 91% T-cells (helper-to-suppressor cell ratio of .apprx. 1:1) and 9% B-cells. After bleomycin administration, a significant increase in the percentage of B-cells in lung tissue was observed within 3 days, with peak levels (.apprx. 28%) occurring at 7 days. Changes in the T-cell subset populations were also observed in lung tissue; at 14 days after the administration of bleomycin, the helper-to-suppressor T-cell ratio was 2:1; at 30 and at 120 days, the ratio was reversed to 1:2. These represent significant changes from the 1:1 ratio found in control animals. No lymphocytes were observed in the lavage fluid of control animals or in animals at 30 and 120 days after bleomycin treatment. Significant populations of lymphocytes were found in the lavage fluid at 3, 7 and 14 days after bleomycin treatment. These lymphocytes consisted of .apprx. 90% T-cells (helper-to-suppressor cell ratio of 1:1) and 10% B-cells. There were no significant changes in the lymphocyte populations found in the lavage fluid after the administration of bleomycin. Specific lymphocyte populations are changing in lung tissue during the development of the fibrotic process, whereas this shift in populations does not occur in the lymphocytes populations found in lavage fluid.