[Quantitative determination of 5 vitreal proteins in the normal vitreous body and proliferative retinal diseases]

Abstract

While progress in vitreoretinal surgery has been very rapid in recent years, our understanding of the biochemistry of normal and pathological vitreous is still limited. Therefore, we developed non-competitive ELISA techniques for the quantification of five vitreal proteins which, together with vitreal collagen (300 mg/l), account for more than 70% of the total vitreal protein. Physiological levels of the individual proteins were determined as follows: albumin 293 +/- 18 mg/l, IgG 34 +/- 3 mg/l, transferrin 74 +/- 7 mg/l, alpha 1-antitrypsin 14 +/- 3 mg/l, alpha 1-acid glycoprotein 4 +/- 0.7 mg/l. Mean values for these proteins were also obtained in vitreous aspirates from patients with traumatic proliferative vitreoretinopathy (PVR) (n = 10), idiopathic PVR (n = 10) and proliferative diabetic retinopathy (PDR) (n = 15). Significant differences were found for total vitreal protein and alpha 1-antitrypsin between the control groups and the three vitreoretinal disorders, between the PDR and control group for transferrin, and between both types of PVR and controls for alpha 1-acid glycoprotein. Given the high plasma levels of the individual proteins quantified in this study and the uniform rise in total vitreal protein, a disturbancee of blood-retinal and blood-vitreal barriers seems to be an essential features of proliferative intraocular disorders. No disease-specific change in the protein pattern could be detected for the three disorders examined.