Assessment of Serum Interleukin-29 Level in Patients with Diabetic Retinopathy: Case-Control Study

Abstract

Background: Diabetic retinopathy (DR) is a frequent consequence of diabetes and the largest cause of blindness among people in general. Diabetic retinopathy is a diabetic complication that happens in type 2 diabetes individuals who do not control their serum glucose levels. This condition is accompanied with inflammation in the ocular tissues.

Interleukin-29 (IL-29), a member of the type 3 interferon family, is involved in host defenses against microorganisms; however, little is known regarding its function in metabolic diseases. IL-29 had a crucial role in the etiology of diabetes-induced inflammation and insulin resistance.

Aim of the study: This research aims to assess the serum Interleukin-29 levels in the sera of type 2 diabetic retinopathy compared to diabetic patients and healthy participants.

Materials and Methods: A case-control study was carried out on 96 volunteers within ages (33-70) years old who were split into three groups 27 healthy control (HC), 36 patients with T2DM, and 33 patients with type II diabetic retinopathy (DR) patients. Serum levels of IL-29 and fasting insulin (FI) were measured by Enzyme-Linked Immunosorbent Assay (ELISA).

Results: The T2DM and DR groups exhibited a non-significant age difference; however, a slight BMI difference was observed between the patient and healthy individual groups. There was no significant difference in FSG among patient groups (P = 0.672); however, the T2DM and DR groups exhibited a significant difference when compared to healthy controls (P<0.001). Analysis of IL-29 levels among T2DM, control, and DR groups demonstrated significant differences (P<0.001). This study investigated the correlation between IL-29 and clinical biomarkers. FSG and HOMA-IR exhibited positive correlations with IL29 (r = 0.374, P<0.032, r = 0.356, P = 0.042, respectively), While IL-29 showed no statistically significant negative correlation in the DR patients group. The IL-29 ROC curve demonstrated an AUC of 0.849, signifying enhanced accuracy and stability in the diagnosis and stratification of diabetic retinopathy, with a cut-off value of 28. 46 pg/ml (P<0.001). The sensitivity of these variables is 0.909, while the specificity is 0. 667.

Conclusion: The study demonstrated that patients with diabetic retinopathy exhibited elevated serum interleukin-29 levels in comparison to both diabetic and healthy control groups, suggesting its potential involvement in the progression and pathogenesis of diabetic retinopathy as a predictive risk factor for this complication.