Abstract
Purpose:
The aim of this study was to evaluate the aqueous humor and plasma levels of inflammatory cytokines in patients with glaucoma submitted to trabeculectomy, in a Brazilian population, in order to investigate their role in glaucoma pathogenesis.
Methods:
This case-control study recruited 31 POAG patients submitted to trabeculectomy and 34 controls who underwent cataract surgery, as control group. The plasma and the aqueous humor were collected pre and intra-operatively, respectively. The inflammatory cytokines IL-α, IL1-β, IL-6, TNF-α, vascular endothelial growth factor (VEGF) and the adhesion molecule E-selectin (Sel-E) were measured by flow cytometry, using the cytometric bead array flex set. The TGF-β2 levels were determined by ELISA. The associations related above were evaluated using Mann-Whitney test. P-values <0.05 were considered statistically significant.
Results:
Concentrations of IL1-β and TGF-β2 were below limits of detection of the method and were not evaluated. There was no difference between cases and controls when comparing VEGF and Sel-E in both plasma and aqueous humor samples. IL-α and TNF-α cytokines were elevated in plasma of glaucomatous patients when compared to controls (p=0,0037 and p=0,0233, respectively), but this difference could not be observed in the aqueous humor (p=0.3564 and p=0.7767, respectively). The IL-6 cytokine was significantly lowered in the aqueous humor of POAG patients, when compared to controls (p=0,001), but its levels were below limits of detection in plasma samples.
Conclusions:
This study suggests differences in cytokine levels in plasma and aqueous humor of glaucomatous patients when compared to controls. Specifically IL-α and TNF-α were higher in plasma and IL-6 was lower in the aqueous humor among POAG patients. This cytokine profile may represent an abnormal inflammatory and immune environment, which could be contributing to glaucomatous pathogenesis.
Keywords: 557 inflammation •
633 outflow: trabecular meshwork •
568 intraocular pressure