Induced sputum for identifying sarcoidosis in patients with uveitis

Objective: To evaluate the value of the induced sputum technique in diagnosing sarcoidosis as the cause of uveitis. Design: Comparative case series. Participants: Seventeen patients with uveitis. Two control groups were used. The first included 10 patients with sarcoid without uveitis; the second included 5 healthy volunteers. Testing: Sputum was induced by a 20-minute inhalation of 3.5% saline using an ultrasonic nebulizer. Samples were studied by differential counts of 200 cells on cytopreps stained by Giemsa. T lymphocyte subset analyses were done by fluorescence-activated cell sorter using the monoclonal antibodies CD4 (T helper cells) and CD8 (T suppressor-cytotoxic cells). Angiotensin-converting enzyme (ACE) serum levels were obtained. Main Outcome Measures: A CD4/CD8 ratio >2.5 and an ACE level >145 μl/ml/minute were considered to be abnormal. Results: The difference in the CD4/CD8 ratios in the induced sputum examination between the group of patients with an elevated ACE level and the group of patients with an ACE level within normal limits was statistically significant (P = 0.0001). Conclusions: The induced sputum examination showed increased CD4/CD8 ratios in patients with uveitis who also had elevated ACE levels, suggesting the presence of sarcoidosis.