Shifts of T4/T8 T lymphocytes from bal fluid and peripheral blood by clinical grade in patients with pulmonary tuberculosis

Objectives: We investigated the shifts of T4/T8 lymphocytes from BAL fluid (BALF) and peripheral blood by the clinical grade of pulmonary tuberculosis (TB), which is determined by factors such as extent of pulmonary involvement, fever, and loss of body weight. Materials and methods: In order to explore these questions, BALF was collected from 45 patients presenting with active pulmonary TB and 14 healthy control subjects. The percentages for T-lymphocyte subpopulations, including CD4⁺, CD8⁺, and CD3⁺ T cells, were measured using two-color flow cytometry. Results: A higher percentage of CD3⁺CD4⁺ T lymphocytes, with a relatively lower percentage of CD3⁺CD8⁺ T lymphocytes, was revealed for the patients with a higher grade of pulmonary TB, compared to patients with a lower grade of pulmonary TB, resulting in an increased BALF C4⁺/CD8⁺ ratio. By contrast, a higher percentage of CD3⁺CD8⁺ T lymphocytes with a relatively low percentage of CD3⁺CD4⁺ T lymphocytes was demonstrated for these patients with a higher grade of pulmonary TB, resulting in a decreased peripheral blood CD4⁺/CD8⁺ ratio. Conclusions: Our findings suggest that compartmentalization of the CD4⁺ T lymphocytes in the infected lungs may occur for patients with higher grades of pulmonary TB.