Tear cytokines as potential biomarkers in non-infectious uveitis: post hoc analysis of a randomised clinical trial

Tear and Plasma Levels of Cytokines in Patients with Uveitis: Search for Active Disease Biomarkers

“…In addition, in 2014, the American Uveitis Society supported the use of biologic agents (infliximab and adalimumab) as a first- or second-line immunomodulatory therapy, depending on the cause underlying the non-infectious uveitis, in the treatment of sight-threatening non-infectious uveitis. Our outcome is concordant with previous uveitis investigations in which the tear profile was analysed, emphasising that tear TNF-α levels do not reflect the concentrations within the eye [ 21 , 31 ]. However, we must consider that the TNF-α percentage of detection in tears is not constant in the literature, varying from 1% to 100% [ 32 , 33 , 34 , 35 , 36 ].…”

“…However, the potential limitations of these studies are also known, as the obtaining of aqueous and vitreous samples carried significant risk, and it remains unclear whether the expression of cytokines and chemokines in the serum is the same in the eye. Hence, new studies have explored the potential value of tear samples [ 20 , 21 , 22 , 31 , 45 , 46 ], as it is a non-invasive procedure; it is hypothesised that it could be used not only as a possible biomarker of uveitis activity but also as a predictive biomarker of response to the treatment, but the results have been controversial.…”

“…Türkçüoğlu et al [ 45 ] investigated the potential association between the IL-2 tear and serum levels and the Behçet disease activity, finding no association of disease activity with serum and tear IL-2 levels. In the same way, Shirinsky et al [ 31 ] evaluated the possible link between the IL-6, IL-8 and IL-10 cytokine tear levels and eye inflammation during treatment, and they did not find any link between the tear cytokine levels and changes in eye inflammation during the treatment. However, they reported that the baseline IL-10 concentration was a significant and independent predictor of clinical response to treatment.…”

“…They also concluded that not only could IL-6 be a potential biomarker associated with the entity, but it could also be used as a prognosis factor, although new research confirming their outcomes should be necessary to verify their findings. Further investigations with a higher number of patients and a correlation between the grade of activity and its chronicity could be of interest, as it has been stated that IL-6 and IL-8 tear levels are highly correlated with the duration of chronic eye inflammation [ 31 ].…”

The acute phase response protein SERPINA3 is increased in tear fluid from the unaffected eyes of patients with unilateral acute anterior uveitis

“…In addition, biomarkers have been described for extra-ocular conditions, including multiple sclerosis and Parkinson’s disease [ 3 ], thereby extending the potential usefulness of tear fluid biomarkers. There are relatively few studies on tear fluid biomarkers in uveitis [ 4 , 7 , 19 , 22 ], but novel biomarkers were recently suggested for Behcet’s disease and acute, non-infectious uveitis [ 18 , 25 ]. Definite tear biomarkers for uveitis are yet to be established.…”