Elevated vitreous body glial fibrillary acidic protein in retinal diseases.
OBJECTIVE
Increased expression of glial fibrillary acidic protein (GFAP) is a characteristic of gliotic activation (Müller cells and astrocytes) in the retina. This study assessed vitreous body GFAP levels in various forms of retinal pathology.


METHODS
This prospective study included 82 patients who underwent vitrectomy (46 retinal detachments (RDs), 13 macular hole (MHs), 15 epiretinal glioses (EGs), 8 organ donors). An established enzyme-linked immunosorbent assay (ELISA, SMI26) was used for quantification of GFAP.


RESULTS
The highest concentration of vitreous body GFAP in organ donors was 20 pg/mL and it was used as the cutoff. A significant proportion of patients suffering from RD (65 %) to EG (53 %) had vitreous body GFAP levels above this cutoff when compared to organ donors (0 %, p < 0.0001, p = 0.0194, respectively, Fisher's exact test) and MH (8 %, p < 0.0001, p = 0.0157, respectively). In RD and EG, vitreous body GFAP levels were correlated with axial length (R = 0.69, R = 0.52, p < 0.05 for both).


CONCLUSIONS
The data suggest that human vitreous body GFAP is a protein biomarker for glial activation in response to retinal pathologies. Vitreous body GFAP levels may be of interest as a surrogate outcome for experimental treatment strategies in translational studies.
Department of Ophthalmology, University of Erlangen-Nurnberg, Erlangen, Germany.
Anselm Gerhard Maria
AG
Jünemann
Department of General Ophthalmology, Medical University of Lublin, Lublin, Poland.|Medical Research Centre, Polish Academy of Science, Warsaw, Poland.
Robert
R
Rejdak
Department of Ophthalmology, University of Erlangen-Nurnberg, Erlangen, Germany.
Cord
C
Huchzermeyer
Department of Anatomy, Medical University of Lublin, Lublin, Poland.
Ryszard
R
Maciejewski
Medical Research Centre, Polish Academy of Science, Warsaw, Poland.
Pawel
P
Grieb
Department of Ophthalmology, University of Erlangen-Nurnberg, Erlangen, Germany.
Friedrich E
FE
Kruse
Department of Anatomy, Medical University of Lublin, Lublin, Poland.
Eberhart
E
Zrenner
Medical Research Centre, Polish Academy of Science, Warsaw, Poland.|Department of Neurology, Medical University of Lublin, Lublin, Poland.
Konrad
K
Rejdak
Expertise Center Neuro-ophthalmology, Free University Medical Center, Amsterdam, The Netherlands. a.petzold@ucl.ac.uk.|Department of Neuro-Ophthalmology, Moorfields Eye Hospital, City Road, London, UK. a.petzold@ucl.ac.uk.|UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK. a.petzold@ucl.ac.uk.
Axel
http://orcid.org/0000-0002-0344-9749
A
Petzold
D000368:Aged; D015415:Biomarkers / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism*; D005911:Gliosis / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012163:Retinal Detachment / Q000378:metabolism; D012164:Retinal Diseases / Q000378:metabolism*; D014019:Tissue Donors; D014821:Vitrectomy; D014822:Vitreous Body / Q000378:metabolism*
D015415:Biomarkers; D005904:Glial Fibrillary Acidic Protein
Biomarker; Epiretinal gliosis; Glial fibrillary acidic protein (GFAP); Müller cells; Retinal detachment; Vitreous