Anti-inflammatory cytokine and angiogenic factors levels in vitreous samples of diabetic retinopathy patients

PLoS One. 2018 Mar 27;13(3):e0194603. doi: 10.1371/journal.pone.0194603. eCollection 2018.

Abstract

Evaluation of cytokines in patients with diabetic retinopathy (DR) is important for the identification of future additive or alternative treatment options. Therefore, vitreous samples were obtained from patients with DR and patients with macular hole or macular pucker (control group) during 23-gauge-vitrectomy (n = 17/group). The levels of three pro-inflammatory (IL-1ß, IL-6, IFN-γ) and pleiotropic cytokines (IL-2, IL-4, IL-13) as well as VEGF, VEGF-A, and PGF were measured using an enzyme linked immunosorbent assay (ELISA). IL-1ß (p = 0.02) and IFN-γ (p = 0.04), two of the three tested pro-inflammatory cytokines, were elevated in the DR patients, while IL-6 (p = 0.51) level was comparable in both groups. Moreover, in DR samples, a trend towards an IL-13 down-regulation (p = 0.36) was observable. The IL-2 (p = 0.62) and IL-4 (p = 0.78) levels were comparable in both groups. All analyzed angiogenetic factors were up-regulated in DR patients (VEGF: p<0.001; VEGF-A: p = 0.002; PGF: p<0.001). The up-regulation of angiogenetic factors underline their importance in DR development. However, the interaction of the other cytokines showed an interesting pattern. Pro-inflammatory cytokines were also up-regulated, which could be evidence for inflammation processes in the diabetic retina. Furthermore, it seems that a counter response of immunomodulatory cytokines is in an initial process, but not strong enough to regulate the processes. Therefore, to support these anti-inflammatory mechanisms might be additive treatment option in the future.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Angiogenesis Inducing Agents / analysis*
  • Angiogenesis Inducing Agents / metabolism
  • Case-Control Studies
  • Cytokines / analysis*
  • Cytokines / metabolism
  • Diabetic Retinopathy / metabolism
  • Diabetic Retinopathy / pathology*
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Humans
  • Interferon-gamma / analysis
  • Interferon-gamma / metabolism
  • Interleukin-1beta / analysis
  • Interleukin-1beta / metabolism
  • Interleukin-6 / analysis
  • Interleukin-6 / metabolism
  • Male
  • Middle Aged
  • Placenta Growth Factor / analysis
  • Retina / metabolism
  • Up-Regulation
  • Vascular Endothelial Growth Factor A / analysis
  • Vascular Endothelial Growth Factor A / metabolism
  • Vitrectomy
  • Vitreous Body / metabolism*

Substances

  • Angiogenesis Inducing Agents
  • Cytokines
  • Interleukin-1beta
  • Interleukin-6
  • PGF protein, human
  • Vascular Endothelial Growth Factor A
  • Placenta Growth Factor
  • Interferon-gamma

Grants and funding

The study was in part supported by Bayer Vital GmbH. No additional external funding was received for this study. The funders had no role in the study design; collection, analysis, and interpretation of data; writing of the paper; and/or decision to submit for publication.