BRONCHOALVEOLAR LAVAGE CYTOLOGY AND IMMUNOCYTOLOGY IN PULMONARY TUBERCULOSIS

Limited data on the cellular and immunocytologic characteristics of br onchoalveolar lavage (BAL) fluid in pulmonary tuberculosis have been r eported. We therefore studied 40 patients with active disease. BAL flu id differential cell counts and lymphocyte subsets were determined. Th e findings were compared with data from 47 patients with active sarcoi dosis and 30 healthy control subjects. The proportion of lymphocytes w as increased in both diseases (p < 0.001 versus control subjects) but with no difference compared to one another. The CD4/CD8 ratio was norm al in 33 of 40 patients with pulmonary tuberculosis in contrast to sar coidosis, with an increased ratio in 33 of 47 patients. HLA-DR(+) T ly mphocytes were significantly increased in both pulmonary tuberculosis and sarcoidosis (p < 0.05 versus control group). The proportion of CD5 7(+) lymphocytes was normal in all study groups. We conclude that pulm onary tuberculosis and sarcoidosis are characterized by an increased p ercentage of lymphocytes in BAL fluid with a similar proportion of act ivated T cells. In contrast to active sarcoidosis, in which an elevate d CD4/CD8 ratio is characteristic, in the majority of pulmonary tuberc ulosis patients the CD4/CD8 ratio is within the normal range.