Association of serum proinflammatory factors with clinical response to ranibizumab for diabetic macular edema.

The present study aimed to investigate the role of circulating plasma inflammatory factors as predictors for the clinical response to anti-vascular endothelial growth factor (VEGF) injections in patients with diabetic macular edema (DME). An observational clinical study was conducted with 58 participants confirmed to have DME involving the foveal center. Participants with a central retinal thickness (CRT) of 320 µm or greater were treated with intravitreal Ranibizumab. CRT, best-corrected visual acuity (BCVA) and vessel density were assessed at 3-month intervals during follow-up. The mean LogMAR BCVA significantly improved from 0.88±0.50 at baseline to 0.681±0.491 at month 3 (P<0.001), while the CRT value decreased from 568.66±105.87 µm at baseline to 450.26±90.22 µm at month 3 (P<0.001). Of the cases, 62.07% showed a favorable anatomic response and 46.55% exhibited a favorable visual acuity response. IL-17 was linked to a limited anatomic response (P=0.02) and also negatively correlated with a favorable BCVA response (P=0.018). Similar associations were observed for IL-8, which was associated with a limited anatomic response (P<0.001) and was negatively associated with a favorable BCVA response (P=0.023). Cases that improved by at least two visual acuity lines had notably lower intercellular adhesion molecule (ICAM)-1 concentrations (P=0.046). Multivariate logistic regression analysis identified IL-17 and IL-8 as independent risk factors significantly associated with CRT (IL-17, P=0.003; IL-8, P=0.043), while IL-17 and ICAM-1 were independent risk factors significantly associated with BCVA (IL-17, P=0.030; ICAM-1, P=0.029). In conclusion, elevated levels of serum IL-17, IL-8 and ICAM-1 at baseline are linked to a restricted clinical response to anti-VEGF therapy for DME.