Abstract
Purpose :
Osteopontin (OPN), also known as early T lymphocyte-activating gene-1, is a phosphorylated acidic arginine-glycine-aspartate (RGD)-containing glycoprotein that binds to certain CD44 variants and integrin receptors expressed on a number of immune cells such as macrophages, neutrophils, and T cells. OPN acts as a multifunctional, proinflammatory cytokine that plays important roles in promoting inflammation, tissue remodeling, fibrosis, and angiogenesis. It has been recently indicated that serum and urinary OPN are increased in diabetic patients, and that OPN is involved in progression of diabetic retinopathy and nephropathy. In this study, we compared vitreous OPN level of patients with proliferative diabetic retinopathy (PDR) with their serum, and those in non-inflammatory or inflammatory vitreoretinal diseases.
Methods :
The study group consisted of 49 eyes with PDR, and the control group are 11 eyes with idiopathic epiretinal membrane (ERM) and 10 eyes with ocular sarcoidosis (Sar). Vitreous samples were obtained at the beginning of vitrectomy. Serum samples were also collected from 10 PDR patients before surgery. Vitreous and serum levels of OPN were measured by ELISA.
Results :
OPN was detected in all vitreous samples obtained from PDR, ERM, or Sar patients, while the detectable rate in serum from PDR patients was 6 out of 10 samples (60%). OPN level in the vitreous of PDR patients (932 ± 110 ng/ml) was significantly higher than that in the serum (52.9 ± 66.7 ng/ml), and those in ERM or Sar eyes (771 ± 110 ng/ml and 602 ± 282 ng/ml, respectively). vitreous OPN level in PDR eyes with vitreous hemorrhage (VH) (699 ± 253 ng/ml) was low rather than higih compared with that in PDR eyes without VH (932 ± 110 ng/ml) although it was not significant, and there was also no significant difference between PDR eyes with and without preoperative intravitreal injection of bevacizumab (763 ± 246 ng/ml and 718 ± 256 ng/ml, respectively).
Conclusions :
These results indicate that high level of OPN is contained in the vitreous of PDR compared with the serum or other inflammatory and noninflammatory vitreoretinal diseases.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.