Could different aqueous humor and plasma cytokine profiles help differentiate between ocular sarcoidosis and ocular tuberculosis?

Objective and design: A cross-sectional single-center study was conducted to assess cytokine levels in aqueous humor (AH) and plasma of three different uveitis entities: definite ocular sarcoidosis (OS), definite OS associated with QuantiFERON®-TB Gold test positivity (Q + OS) and presumed tubercular uveitis (TBU). Subjects: Thirty-two patients (15 OS, 5 Q + OS, 12 TBU) were included. Methods: Quantification of selected cytokines was performed on blood and AH samples collected before starting any treatment. Statistical analysis was conducted using the Kruskal–Wallis test, the Mann–Whitney or Fisher test and the Principal Component Analysis (PCA). Results: IL-6, IL-8 and IP-10 levels were higher in AH samples than in peripheral blood. In AH samples, BLC, IL-8 and IP-10 were significantly higher in definite OS than in presumptive TBU. There were no statistically significant differences in terms of cytokine levels between Q + OS and presumptive TBU. PCA showed a similar cytokine pattern in the latter two groups (IFNγ, IL-15, IL-2, IP-10, MIG), while the prevalent expression of BLC, IL-10 and MIP-3 α was seen in definite OS. Conclusions: The different AH and plasma cytokine profiles observed in OS compared to Q + OS and TBU may help to differentiate OS from TBU in overlapping clinical phenotypes of granulomatous uveitis (Q + OS).