We read with great interest the article by La Distia Nora and associates. They report clinical manifestations of 77 patients with intraocular inflammation (uveitis and scleritis) and positive QuantiFERON–TB Gold In-Tube test in a country nonendemic for tuberculosis.
A critical finding of this paper is that in their 77 patients with a positive QuantiFERON Gold test in-tube, La Distia Nora and associates found that 9 patients (12%) were confirmed to have a diagnosis of sarcoidosis. The importance of this possible association and possibility of false-positive results is further discussed by Pepple and associates in the accompanying editorial in the same issue of the Journal .
We simultaneously published a study where we evaluated bronchoalveolar lavage findings in a group of 109 patients with clinical signs of ocular sarcoidosis (uveitis) from a country nonendemic for tuberculosis. Analyzing our results, we found an unexpected high frequency (20.0%) of positive tuberculin skin tests in the 95 patients who were tested for tuberculin skin test. We therefore analyzed our data in the context of possible tuberculosis infection. We compared the characteristics of patients for several parameters, including age, sex, angiotensin converting enzyme, bilateral hilar lymphadenopathy, and bronchoalveolar lavage findings, and found no statistical difference between results of patients with positive and those with negative tuberculin skin test. None of the patients had positive culture or polymerase chain reaction for mycobacterium tuberculosis in their alveolar fluid.
Our results, based on tuberculin skin test, are in agreement with the results of La Distia Nora and associates, based on QuantiFERON–TB Gold In-Tube test. They might support the possible association between ocular sarcoidosis and latent tuberculosis infections. They also underline the difficult differential diagnosis between ocular signs of sarcoidosis and tuberculosis in a country nonendemic for tuberculosis. This raises important questions regarding the diagnosis and management of uveitis patients with a diagnosis compatible with sarcoidosis and a latent tuberculosis infection. Our results are also in agreement with Pepple and associates, who suggested that sarcoidosis should be suspected in patients with positive QuantiFERON and no evidence of tuberculosis.