Purpose: To evaluate the usefulness of the interferon-gamma release assay (IGRA) for diagnosing tuberculosis(TB)-related uveitis (TRU).
Methods: Records from 181 patients with ocular signs and symptoms suggestive of TRU and intraocular inflammationof unknown etiology were reviewed. All subjects underwent clinical and laboratory testing, includingIGRA, to rule out presence of underlying disease. A diagnosis of presumed TRU was made based on an internist’sTB diagnosis and a patient’s response to anti-TB therapy. Sensitivity, specificity, and positive predictivevalues of IGRA for TRU diagnosis were calculated. Clinical characteristics were compared between patientswith positive and negative IGRA results.
Results: The sensitivity and specificity of IGRA for TRU were 100% and 72.0%, respectively. Mean age, percentageof patients with retinal vasculitis, and the anatomic type of uveitis were significantly different betweenpatients with positive and negative IGRA results (all p ≤ 0.001). Positive IGRA rates and false-positive rateswere significantly different between age and anatomic type groups (both p = 0.001). The positive predictivevalue of the IGRA among patients with intraocular inflammation was high (70%) when all of younger age (≤40years), posterior uveitis, and retinal vasculitis were present.
Conclusions: The IGRA is useful for diagnosing TRU in the Korean population, especially when it is used as ascreening test. Clinical characteristics, including younger age (≤40 years), posterior uveitis, and retinal vasculitisin IGRA-positive patients, increase the likelihood of the patient having TRU.