gms | German Medical Science

Purpose: To investigate various cytokines from the undiluted vitreous of patients undergoing an intravitreal combination therapy including a core vitrectomy.

Methods: Interleukin-6 (IL-6), interleukin-7 (IL-7), interleukin 8 (IL-8), angiopoetin-1 (ANG-1), monocyte chemoattractant protein-1 (MCP-1), pigment epithelium-derived factor (PEDF) and vascular endothelial growth factor A (VEGF-A) were assessed with high-sensitive enzyme-linked immunosorbent assay (ELISA) from 78 exudative age-related macular degeneration patients (AMD), 28 diabetic retinopathy patients (DR) and 24 negative controls from patients with idiopathic floaters. Absolute concentrations were compared between the diseases and within each disease conducting a subgroup analysis. Changes in spectral-domain optical coherence tomography (SD-OCT) were also correlated with significant cytokine findings.

Results: IL-6 concentrations were significantly higher in DR vs controls (mean: 25.2 vs 16.55 pg/ml; p<0.05) and correlated significantly with CMT in DR (r=0.39; p<0.04). IL-7 concentrations were significantly higher in AMD and DR compared to controls (mean: 28.92 and 24.12 vs 17.70 pg/ml; p<0,001). IL-8 concentrations were significantly higher in DR vs AMD (mean: 20.86 vs 7.76; p<0.0001). ANG-1 was significantly increased in ischemic diabetic macular edema (DME) vs non-ischemic DME (mean: 174.42 vs 85,05 pg/ml; p<0,011). MCP-1 was significantly increased in AMD and DR comparing to controls (mean: 739.27 and 651.73 vs 383,35pg/ml; p<0,011). MCP-1 was significantly elevated in non-ischemic DME (p<0.03) and correlated positively with CMT in this group of patients (r=0.79; p<0.02). MCP-1 was also increased in AMD patients with massive vitreous bleeding (p<0.05). PEDF concentrations were significantly higher in AMD and DR compared to controls (mean: 113185.64 and 124496.43 vs 75038.96 pg/ml; p<0.02). PEDF correlated positively with AvT in AMD (r=0.22; p=0,058) and with CMT in DR (r= 0.41; p<0.03). PEDF strongly correlated with AvT in ischemic DME (r=0.78; p<0.03). VEGF-A concentrations were significantly higher in DR vs AMD and controls (mean: 266.45 vs 12.24 and 1.64 pg/ml; p<0.00001).

Conclusions: The key target cytokine VEGF-1 demonstrated low concentrations and unsuitable correlations with SD-OCT changes in both diseases. Significant findings were observed in contrast for IL-6, Ang-1, MCP-1 and PEDF, the natural antagonist of VEGF-1.