As an aid to understand the local immunity and pathological state of sarcoidosis in the lung, we studied the cellular components of broncho-alveolar lavage fluid (BAL) in 16 patients with sarcoidosis and the data were compared with those of 10 healthy controls.
The percentages of lymphocytes, T cells and Tr cells in BAL were increased in sarcoidosis (28.8±23.6%, 84.4±7.7% and 17.7±6.9% respectively) as compared with those in controls (7.6±5.6%, 72.4±10.0% and 2.9±2.1% respectively).
The absolute cell counts of lymphocytes, T cells and Tr cells in BAL were increased in sarcoidosis (1.4±1.4×105/ml, 1.2±1.3×105/ml and 1.6±1.6×104/ml respectively) as compared with those in controls (3.0±2.0×104/ml, 2.0±0.9×104/ml and 1.0±1.0×103/ml respectively). These tendencies were more remarkable in the active stage than in the inactive stage.
The phagocytic activity and nitroblue tetrazorium (NBT) reduction activity of pulmonary alveolar macrophages (PAM) were more elevated in sarcoidosis than in controls.
It was concluded that lymphocytes, T cells and Tr cells in BAL were increased in number in sarcoidosis and that the functions of pulmonary alveolar macrophages were activated in the disease.
