Abstract
Purpose :
Diabetic retinopathy (DR) is the most common microvascular complication of diabetes mellitus and is the leading cause of visual impairments in developed countries. The DR is characterized by enhanced vascular permeability and tissue ischemia which are driven by inflammatory mediators and retinal neovascularization. Circulating angiogenic cells (CACs) play a significant role in neovascularization as these cells migrate to the site of injury, where they can aid in vascular repair by autocrine and paracrine mechanisms. In the present study, we explored the association between the levels of circulating CACs, inflammatory factors, and the progression of DR in diabetic patients.
Methods :
We recruited individuals with different severities of DR, i.e., mild, moderate, and severe, non-proliferative diabetic retinopathy (NPDR) and proliferative DR (PDR). Additionally, two other groups were also included; individuals with diabetes but no DR and healthy controls. First, mononuclear cells (MNCs) were isolated from the whole blood, followed by staining for CD34 and CD45 antigens along with inflammatory antigens, namely, TLR2, TLR4, TLR8, CD11c, and CD14. Then, with the help of flow cytometry, we measured the CD34+ CD45mid cells (CACs) along with inflammatory markers in different DR conditions.
Results :
The circulating CD34+ CD45mid cells showed a differential pattern with varying degrees of DR; specifically with the PDR individuals, there was a six-fold increase in the CD34+ CD45mid population compared to the healthy subjects. Additionally, circulating inflammatory markers like TLR2, TLR4 and TLR8 were also found to be enhanced in individuals with DR, irrespective of the severity of DR.
Conclusions :
In the present study, we found a strong association between circulating CACs, inflammatory markers, and severity of DR. Hence, early identification of these peripheral blood biomarkers and their circulating levels in diabetic patients could be used as a helpful tool for the pathogenesis of DR.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.