抄録
Cellular components of bronchoalveolar lavage (BAL) fluid were studied in 26 sarcoid patients, 8 patients with farmer's lung, 10 healthy controls and 10 control patients. The investigations by Ga scintigraphy or transbronchial lung biopsy (TBLB) and measurement of serum angiotensin converting enzyme (SACE) activity were also carried out in 21 sarcoid patients and 8 patients with farmer's lung. Data were compared to evaluate the clinical usefulness of these diagnostic methods.
1) Percentage of foamy cells in alveolar macrophage fraction, percentage of lymphocytes and number of mast cells were increased significantly in BLA fluid from patients with farmer's lung as compared with that from sarcoid patients. These observations suggest that analysis of cellular component of BAL fluid is useful for differential diagnosis of these diseases.
2) Granulomatous lung lesions were frequently observed in specimens obtained by TBLB from patients with sarcoidosis and farmer's lung who showed abnormal Ga uptake in lung. In contrast, there was no significant difference in percentage of lymphocytes in BAL fluid between patients whose pulmonary Ga uptake was positive and those in whom pulmonary Ga uptake was negative.
To investigate the mechanism of pulmonary Ga accumulation in granulomatous lung disease, BAL was performed in 2 sarcoid patients and 3 patients with farmer's lung at 48 to 72hrs after Ga injection. The radioactivity in cell fractions was evaluated at 96hrs after Ga injection. Most of the radioactivity was found in macrophages, with little in lymphocytes. These results suggest that pulmonary Ga uptake in patients with sarcoidosis and farmer's lung reflects granuloma formation or accumulation of activated macrophages in lung, but not the intensity of T-cell alveolitis.
3) Some relationship among SACE, granulomatous lung lesions in specimens obtained by TBLB and abnormal Ga accumulation in lung or hilar lymphnodes in sarcoid patients was observed, suggesting that SACE might reflect the degree of granuloma formation in sarcoidosis.
