T-LYMPHOCYTIC AND IMMATURE MACROPHAGE ALVEOLITIS IN ACTIVE PULMONARY TUBERCULOSIS

The phenotype of bronchoalveolar cells from 11 healthy subjects and fr om affected and unaffected lungs of 15 patients with pulmonary tubercu losis (PTB) was determined, An immature macrophage alveolitis was foun d in the affected lung and the unaffected lung versus controls as dete rmined by morphology and peroxidase activity, T lymphocytic alveolitis also was found in the affected but not the unaffected tuberculous lun g compared with healthy controls, The majority of alveolar lymphocytes in unaffected and affected PTB lungs were T cells expressing the cup T cell receptor, Alveolar T cells from both unaffected and affected lu ngs were activated, as determined by increased expression of CD69 and HLA-DR, Interleukin-2 receptor (IL-2R alpha) expression was, however, unchanged on alveolar lymphocytes from affected lung and was decreased in the unaffected lung, Thus, activated T lymphocytes and immature ma crophages in the tuberculous lung are basic to the local immunopathoge nesis of PTB.