Intraocular levels of interleukin 17A (IL-17A) and IL-10 as respective determinant markers of toxoplasmosis and viral uveitis.

Uveitis is a potentially blinding inflammatory disease. Thirty to 50% of uveitis cases are considered idiopathic. The present study sought to determine the intraocular cytokine patterns in the different etiological types of uveitis in order to better understand their immunological regulation and to determine whether the cytokine pattern may be a useful diagnostic tool. From a multicenter institutional prospective study, the clinical and biological data from patients with uveitis of various etiologies, determined after a complete workup, were compared with those from a control group of cataract patients. A multiplex assay was used to assess the profiles of 27 cytokines and chemokines in aqueous humor samples from these patients. In total, 62 patients with infectious or noninfectious uveitis and 88 controls were included. After a complete workup, the cause of uveitis remained unknown in 25 patients (40% idiopathic uveitis). Interleukin 1β (IL-1β) levels were markedly increased in viral uveitis, as were IL-10 levels, whereas IL-17A levels were augmented in toxoplasmic uveitis. Based on the cytokine pattern, the patients were reassigned to specific groups. At the end of the study, the diagnosis of idiopathic uveitis was still valid in only 11 patients (18%). The observation that some markers are specific to certain diseases enables a better understanding of the disease pathogenesis and paves the way for new diagnostic methods aimed to identify inflammatory markers, which may perhaps be targeted by therapy.