Prevalence of Positive QuantiFERON-TB Gold In-Tube Test in Uveitis and its Clinical Implications in a Country Nonendemic for Tuberculosis.

Abstract

To report on the prevalence and clinical implications of positive QuantiFERON-Gold (QFT-G) test results in the diagnostic evaluation of a large cohort of consecutive patients with uveitis in the Netherlands. Retrospective cross-sectional study. This study included 710 consecutive patients who all underwent evaluation for uveitis including QFT-G testing. The ocular features, comorbidity, and abnormalities in diagnostic imaging and laboratory tests were registered for QFT-G-positive patients with uveitis. Of all patients, 13% (92/710) were positive for QFT-G. Previously treated tuberculosis (TB) was documented in 2 patients. Of all 92 QFT-G-positive patients, culture-proven active TB was observed in 1 case. The proportion of patients with uveitis of unknown etiology was higher in QFT-G-positive than in the QFT-G-negative patients (54/92, 59% vs 238/618, 39%; P = .0004). The uveitis features of QFT-G-positive patients were mainly nonspecific. Of all QFT-G-positive patients with uveitis, 17 patients had chest imaging changes suggesting either TB or sarcoidosis. Twenty-nine QFT-G-positive patients with otherwise unexplained uveitis completed antituberculous therapy (29/710; 4% of all included patients) with beneficial effect in most cases. The QFT-G tested positive in 13% of patients with uveitis in the Netherlands, whereas only sporadic patients had a documented previous or active TB infection. The proportion of patients with unexplained uveitis was higher in QFT-G-positive patients. Though the association between uveitis and a positive QFT-G test might be coincidental, the majority of treated QFT-G-positive patients with otherwise unexplained severe uveitis cause had a beneficial response to antituberculous therapy.