Correlation between serum level of Delta Like Ligand 4 and different types of Diabetic Retinopathy and Maculopathy in Egyptian patients

Objectives Delta-like ligand-4 (DLL4) is responsible for normal physiological and pathological retinal vasculature. In this study, we aim to compare DDL4 serum levels in both healthy and diabetic patients. We also aim to correlate the severity of retinopathy and maculopathy with the level of serum DDL4. Patients and methods We analyzed prospectively the DDL4 serum level in 19 diabetic patients without clinical evidence of retinopathy (group 1), 19 diabetic retinopathy (DR) patients (group 2), and 19 control participants (group 3). Patients with DR (group 2) underwent other laboratory tests such as serum glycated hemoglobin, creatinine, and urine microalbuminuria. Also, Macular optical coherence tomography and fundus fluorescein angiography within 1 week of laboratory tests were done. Results The serum level of DLL4 was the lowest among patients with DR (group 2) (281.04±237.16 ng/l), followed by group 1 (220.81±94.18 ng/l). The highest serum levels of DLL4 were reported among patients in group 3 (457.52±351.00 ng/l) ( P =0.015). In group 2, the serum level of DLL4 showed statistically insignificantly higher values among nonproliferative retinopathy subgroup (243.63+/–121.8 ng/l) than the proliferative retinopathy subgroup (227.2 +/–59.5 ng/l). Negative insignificant correlation with central ischemia by fundus fluorescein angiography. Positive insignificant correlation with central foveal thickness by optical coherence tomography. Receiver operating characteristic curve analysis indicated that DLL4 was a potential biomarker for identifying both groups 1 and 2. Conclusion The level of serum DLL4 is found to be high in normal healthy eyes but decreases with progression of DR. Low serum DLL4 can point to more retinal ischemia with more proliferative changes including ischemic maculopathy.