lactoferrin and Retinal-Diseases

Biochemical changes in the vitreous in different vitreoretinal disorders have not yet been thoroughly studied. Using enzyme-linked immunosorbent analysis (ELISA), we established mean values and 95% confidence intervals for six proteins of physiologic human vitreous: albumin (293 +/- 18 mg/l), transferrin (73.7 +/- 6.6 mg/l), immunoglobulin G (IgG), (33.5 +/- 3 mg/l), alpha 1-antitrypsin (14.1 +/- 2.9 mg/l), alpha 1-acid glycoprotein (4 +/- 0.7 mg/l), and lactoferrin (less than 50 micrograms/l). These six proteins were also determined in vitreous aspirates from patients with idiopathic proliferative vitreoretinopathy (n = 10), traumatic proliferative vitreoretinopathy (n = 10), and proliferative diabetic retinopathy (n = 15). The pattern of protein levels varied widely within each of the disorders. An analysis of absolute protein levels showed significant differences in total protein and alpha 1-antitrypsin levels between controls and pathologic vitreous samples. We observed differences in transferrin between controls and proliferative diabetic retinopathy (PDR), and differences in alpha 1-acid glycoprotein between controls and both types of proliferative vitreoretinopathy (PVR). The single disorders themselves could not be differentiated by any of the proteins. When the relative contribution of single proteins to total vitreal protein was compared, albumin was lower in all three disorders than in controls. Transferrin was lower in traumatic PVR than in controls, in PDR, or in idiopathic PVR. Our results indicate that the three vitreoretinal disorders studied are characterized by a breakdown of blood-ocular barriers.

Topics: Albumins; alpha 1-Antitrypsin; Animals; Diabetic Retinopathy; Enzyme-Linked Immunosorbent Assay; Eye Diseases; Eye Proteins; Humans; Immunoglobulin G; Lactoferrin; Orosomucoid; Rabbits; Rats; Retinal Diseases; Transferrin; Vitreous Body

Transferrin, recently detected in preretinal membranes, may contribute to cell proliferation by iron donation for mitosis. We have investigated whether lactoferrin, the second iron-binding protein of the human vitreous, could play a similar role in proliferative intraocular disorders (PID). Using immunochemistry, however, we could not label lactoferrin in surgically obtained membrane specimens from patients with idiopathic proliferative vitreoretinopathy (PVR), traumatic PVR, and proliferative diabetic retinopathy (n = 15). The amounts of both proteins in normal human vitreous, as measured by enzyme-linked immunosorbent assay, were 73.7 +/- 6.6 mg/l for transferrin but below 50 micrograms/l for lactoferrin. Transferrin was also determined in 35 vitreous aspirates from patients with PID. The highest levels were found in idiopathic PVR (846 +/- 256 mg/l), followed by proliferative diabetic retinopathy (405 +/- 121) and traumatic PVR (197 +/- 83 mg/l). A statistically significant difference between the three types of PID and physiologic vitreous, respectively, was not observed. The total vitreal protein, however, was significantly elevated in all three groups of PID.

Topics: Cell Membrane; Diabetic Retinopathy; Enzyme-Linked Immunosorbent Assay; Humans; Immunohistochemistry; Iron; Lactoferrin; Lactoglobulins; Retinal Diseases; Transferrin; Vitreous Body