Minor salivary gland biopsy in diagnosing ocular sarcoidosis

Background To ascertain the sensitivity, specificity, and positive and negative predictive value of minor salivary gland biopsy in subsets of patients with uveitis consistent with ocular sarcoidosis. Method Minor salivary gland biopsies performed in 230 patients with uveitis of indeterminate origin but clinically compatible with ocular sarcoidosis were reviewed. The biopsy results were analysed together with clinical features of uveitis and with the results of other relevant examinations, such as serum levels of angiotensin-I-converting enzyme and lysozyme, tuberculin skin test, chest radiography or CT scan, pulmonary function tests and bronchoalveolar lavage. Results Only seven of the 230 patients with uveitis had sarcoid granulomas on the minor salivary gland biopsy. All seven of these patients had a granulomatous uveitis and a compatible chest x-ray with sarcoidosis. The profitability of minor salivary gland biopsy can be improved by limiting the procedure to patients having granulomatous uveitis and a compatible chest x-ray. In these conditions, the positivity rate of minor salivary gland biopsy increased from 3% to 24% without loss of sensitivity. Conclusion Minor salivary gland biopsy is most useful for assessing the diagnosis of sarcoid uveitis in a second-line investigation for patients with granulomatous uveitis and a radiologic pattern compatible with sarcoidosis.