Tumor necrosis factor alpha and tumor necrosis factor receptor one a possible role in diabetic retinopathy

Abstract EN

Background : An elevated blood level of tumor necrosis factor alpha (TNF- a) is a validated marker of vascular inflammation which can result in the development of atherosclerosis.

It signals through cell surface recepots that could be present in soluble form (solubleTNF receptorsTNF - R).

Concentrations of both TNF and its soluble receptor strongly correlate with clinical stage and progression of inflammatory diseases.

However their role in the development and progression of diabetic microvascular complications such as diabetic retinopathy (DR) is still unclear.

Objectives : To examine the link between serum levels of both TNF a and s-TNF R I, and the development and progression ofDR, and whether there is any relation between serum levels of both markers in the disease.

Methods.

Sixty eight patients with type 2 diabetes and 20 non diabetic healthy subjects were included in the present study.

Patients group was divided according to degree of retinopathy into 3 subgroups: group with non - diabetic retinopathy (NDR) (mean age 45 ± 4.2y), group of non-proliferative DR (NPDR) (50.7 ± 6.6y), and group with proliferative DR (PDR) (56.1 ± 5.6y).

Serum levels of TNF a and sTNF-RI were assayed using commercially available ELISA kit.

Results : The mean serum TNF a & sTNF-RI levels increased with the stage ofDR and the highest levels were found in patients with PDR.

Patients with NPDR had also significantly higher serum levels of both TNF a & TNF-RI in comparison to control group (P < 0.01 for both), and in comparison with NDR group (P < 0.01 and < 0.05 respectively).

In addition, a highly significant positive correlation between TNFa and sTNF-RI was observed in group of PDR (p < 0.01).

Conclusion : TNF a and TNF-RI may play an important role in the pathophysiology of DR.

They may be early markers of the disease and hence they may serve as therapeutic targets for the treatment and/or prevention of such ocular microvascular complications of diabetes.