The role of cyclophilin A and VEGF in the pathogenesis and recurrence of pterygium.

PURPOSE: Pterygium is defined as overgrowth of abnormal conjunctival tissue on the cornea. Many proinflammatory cytokines and various growth factors have been implicated in the pathogenesis of pterygium. Cyclophilin A (CyPA) is a protein that is used by cyclosporin A (CsA) as the intracellular receptor and is secreted in response to inflammatory stimuli. Vascular endothelial growth factor (VEGF) is the most important angiogenic factor. This study aimed to assessment CyPA and VEGF immunoreactivity in pterygium specimens.

MATERIAL AND METHODS: In this cross-sectional study, 32 primary pterygium samples, 25 recurrent pterygium samples and 25 normal bulbar conjunctiva samples were included. The histopathological features, CyPA and VEGF immunoreactivity of surgically excised pterygium specimens were compared with control conjunctiva specimens obtained from normal bulbar conjunctiva.

RESULTS: CyPA immunoreactivity in vascular endothelial cells, epithelial cells, and stromal cells was remarkably higher in pterygium specimens than control conjunctiva specimens ( p  = 0.004, p  = 0.012, p  = 0.001, respectively). Morever, VEGF immunoreactivity in endothelial cells was remarkably higher in pterygium specimens than control conjunctiva specimens ( p  < 0.001). When recurrent and primary pterygium specimens were compared, CyPA and VEGF immunoreactivity was remarkably higher in recurrent pterygium ( p  = 0.001, p  = 0.001, respectively). Pearson correlation showed that CyPA immunoreactivity correlated with stromal vascularity, stromal inflammation, and mast cell count in pterygium specimens.

CONCLUSION: This study aimed to assess CyPA and VEGF may have a important function in the pathogenesis and recurrence of pterygium.