Prognostic implication of interleukin-8, interferon gamma, and von willebrand factor as biochemical markers in diabetic retinopathy

Abstract EN

This clinical study was done to assess the serum levels of Interleukin-8, interferon gamma and vonWillebrand factor (vWF) in patients with and without diabetic retinopathy, and correlate their levels to the degree of retinopathy as interleukin-8 is angiogenic growth factor while interferon gamma is angiogenesis inhibitor and vW factor is an index of endothelial damage or dysfunction.

As well as corresponding changes in their serum levels after pan-retinal photocoagulation (PRP) by laser.

This study was conducted on 78 subjects, 58 diabetics and 20 healthy, age- and sex-matched "healthy controls.” The diabetics were both insulin and non-insulin dependent disease (28 and 30 respectively).

They M>ere classified into 3 groups: 20 of them were diabetics without retinopathy (group I), 20 with non-proliferative (background) diabetic retinopathy (group II), and 18 patients with proliferative diabetic retinopathy (group III).

This group was sub classified into 2 subgroups according to the treatment with laser or not.

IL-8, interferon gamma and vW factor serum levels were significantly higher in all groups of diabetics - including the background and proliferative diabetic retinopathy groups - in comparison with healthy control group (P<0.001).

WE found also that there were a statistical difference in the IL-8 and interferon gamma levels in patients with proliferative diabetic retinopathy without laser therapy and who received Laser therapy, that it was significantly lower in the later group (P<0.05).

In contrarily, there was a nonsignificant statistical difference in vW factor levels.

There was a positive correlation between serum IL-8 level and INF-gamma, vWF.

As well as, there was a positive correlation of vWF with INF-gamma and glycated heamoglobin.

The results of AN OVA study proved that vWF is the most sensitive discriminating parameter between diabetic patients with and without retinopathy, followed by INF-gamma and lastly IL-8 (F.ratiol93.957, P<0.001, followed by INF- gamma (F-ratio =9.39, P<0.001, then IL-8=4.7, P<0.05) From these results we concluded that patients with proliferative retinopathy demonstrate elevated peripheral markers of angiogenesis and endothelial dysfunction, suggesting a role for these processes in the pathogenesis of this condition.

As well as, the increase of these macrophage derived cytokines (IL-8 and INF-gamma), is a feature of the prediabetic stage.

The laser therapy has an effective role in the treatment of proliferative diabetic retinopathy, and both INF-gamma and IL-8 can be used as prognostic markers in follow up and monitoring the diabetic patients receiving laser therapy.

On the other hand, further studies are needed as IL-8 and INF-gamma levels were higher in diabetic patients with eye complications but didn’t correlate with the degree of retinopathy.

ANOVA results suggest that vWF is a good diagnostic marker and predictor of retinal complications as it can discriminate the diabetic patients with and without retinopathy, followed by INF-gamma and lastly IL-8.

So it can be used in follow up of diabetic patients for early detection of retinal complication together with fundus examination.