Cytokine profile in aqueous humor and sera of patients with infectious or noninfectious uveitis.

Purpose: To determine the cytokine expression profile at the protein level in aqueous humor (AqH) and sera of patients with uveitis.

Methods: Patients with various clinical entities of strictly diagnosed infectious or noninfectious uveitis were tested. AqH and sera were collected from patients with uveitis. AqH was also collected during surgery from patients with cataract, as control specimens. Interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, and interleukin (IL)-2, -4, -5, and -10 were measured from nondiluted samples simultaneously, with microparticle-based flow cytometric analysis.

Results: In AqH IFN-gamma was the most abundant cytokine in both infectious (mean, 3240.5 pg/mL) and noninfectious (mean, 115.6 pg/mL) uveitis, and IL-10 was the second (mean, 402.1 pg/mL, infectious uveitis; 7.5 pg/mL, noninfectious uveitis). The expression level of other cytokines in AqH was generally higher in infectious uveitis than in noninfectious uveitis, but the levels were lower than that of IL-10. There was no remarkable difference, however, in the cytokine expression pattern in AqH of the different clinical entities of uveitis. Sera from patients with noninfectious uveitis contained IFN-gamma (mean, 45.0 pg/mL), but the other serum cytokines in both types of uveitis were low or under the detectable level.

Conclusions: IFN-gamma is the most abundant cytokine in infectious and noninfectious uveitis, with a remarkable difference between the two groups. The data suggest that cytokines in AqH of infectious uveitis are locally produced, whereas in noninfectious uveitis, IFN-gamma is produced both in the eye and the peripheral blood.