Determination of inmune response and inflammation mediators in tears: Changes in dry eye and glaucoma as compared to healthy controls.

OBJECTIVE

To determine the expression profile of immune response and inflammation (IRI) mediator molecules in tears from patients with dry eye (DE), and those suspected of having or have primary open-angle glaucoma (POAG) under treatment and compare them with healthy controls.

METHODS

A prospective observational cohort study including 107 participants sub-divided into: healthy controls (CG; n=30), patients with DE (DEG; n=41) and patients suspected of having or have POAG and on hypotensive treatment (POAG-G; n=36). Tear samples were collected by capillary to be processed using a multi-immunoassay system based on flow cytometry (Luminex R-200 ®), in order to determine the interleukins (IL): 1β, 2, 4, 5, 6, and 10, and the growth factors: Tumour necrosis alpha (TNF-α), vascular endothelial (VEGF), and granulocyte-macrophage colony stimulating- (GM-CSF). Data were processed using the SPSS 20.0 program.

RESULTS

Molecules that significantly increased in tears from DEG vs. POAG-G patients were: IL-1 (P=.01), IL-6 (P=.004), IL-10 (P=.04), whereas VEGF significantly decreased in the DEG. The POAG-G showed significantly higher IL-6 values (P<.0001) as compared to the CG. When comparing both the DEG and POAG-G, significant differences were observed in tear expression of IL-4 (P=.004), IL-6 (P=.002), TNF-α (P=.03), GM-CSF (P=.03), and VEGF (P=.002).

CONCLUSIONS

The increased expression of IRI mediators in tears from patients with DE or POAG strongly demonstrated the importance of immune response in both pathologies. However, the different molecules involved also suggest distinct signalling pathways for these processes that still require further research.