Aim  

To investigate the expression of CD18 on neutrophils from patients with various stages of diabetic retinopathy (DR) and to determine the possibility of using it as a marker of disease development.

Research design and methods  

Levels of CD18 on neutrophils were measured by flow cytometry in 10 patients with DR stage 1, 14 patients in stages 2–4, 14 patients in stage 5 and 10 non-diabetic healthy subjects (control).

Results  

Mean channel fluorescence (MCF) of CD18 on neutrophils from the control, stage 1, stages 2–4 and stage 5 groups were 1.36±0.17, 2.99±1.44, 3.13±1.10 and 4.11±1.62, respectively. The difference among them was significant (P=0.00). The highest was from the stage 5 group, then stages 2–4 and stage 1. The least was from the control group (trend test, P=0.00). This trend remained after adjusting for confounding variables. This trend was only significant in type 2 when subjects were divided according to diabetic type, even after adjusting for confounding factors. Multiple linear regression against the level of CD18 MCF by stage of DR and covariates revealed a significant and independent association with the stage of DR (β=0.33; P=0.01).

Conclusion  

Elevated levels of CD18 on neutrophils were present in each stage of DR in type 2 diabetic patients. The more severe the disease, the higher the level was. CD18 may be a marker of the development of DR in type 2 diabetes.