QuantiFERON-TB gold test: a valuable diagnostic tool for tubercular uveitis in non-endemic regions

PURPOSE: To investigate the diagnostic challenges of tubercular uveitis, given the frequent absence of pulmonary involvement and the limited accuracy of ocular detection methods. METHODS: We conducted a retrospective analysis of real-world data from 2285 uveitis patients who underwent QFT screening between 2013 and 2022 at a tertiary care centre in Germany. RESULTS: Among the 2285 screened patients, 172 (7.5%) uveitis patients tested QFT-positive. 17 patients were diagnosed with clinically active tuberculosis disease (TBD) and 155 patients with clinically inapparent tuberculosis infection (TBI). TBD patients were younger (40 vs. 58 years; p = 0.005), more likely to originate from Southeast Asia region (56.3% vs. 43.7%; p < 0.005), and more frequently presented with clinical symptoms (17.6% vs. 1.3%; p < 0.005). No differences were observed in the prevalence of tuberculosis (TB)-suspicious findings on chest X-ray (35.3% vs. 17%; p = 0.08) or CT (71.4% vs. 31.6%; p = 0.06). None of the 98 sputum samples yielded a positive result. Microbiological confirmation was achieved in 4 cases via bronchoscopy. Among TBI patients (n = 155), idiopathic inflammatory uveitis was diagnosed in 109 cases (70.3%), while an alternative aetiology was identified in 46 (29.7%). Posterior uveitis was the predominant subtype in both groups (TBD 65.6% vs. TBI 40.8%; p = 0.03). In TBD patients, the prevalence of bilateral involvement was significantly higher (93.8% vs. 64.0%; p = 0.001), and active retinal vasculitis was significantly more common (75.5% vs. 14.5%; p < 0.005). CONCLUSION: This study highlights the importance of TB screening, even in non-endemic regions, as evidenced by the prevalence of QFT positivity and active TB cases in uveitis patients.