Evaluation of transforming growth factor-beta1 gene expression in pterygium tissue of atopic patients

Background: The exact pathogenesis of pterygium is still not fully understood. Growth factors are considered to play an important role in the formation of pterygium. Transforming growth factor (TGF)-β1 is considered to be one of the main mediators of fibroblast stimulation and tissue remodeling in allergic conditions. The objective of the present study was to investigate the association between TGF-β1 gene expression and pterygium in atopic and nonatopic participants. Methods: We used questionnaires to record demographic and clinical information from patients who underwent pterygium excision surgery. Skin prick examination was done to confirm or rule out atopy in 30 patients with atopy (Case Group) and 30 individuals without atopy (Control Group). Additionally, measurement of serum immunoglobulin E, cytokines, including interleukin-4 and interferon-γ, and peripheral blood eosinophil count was performed to confirm atopy in 30 consecutive patients (Case Group). A semiquantitative reverse transcription polymerase chain reaction was performed to determine TGF-β1 gene expression in all individuals. Results: TGF-β1 mRNA gene expression was significantly higher (p = 0.0001) in atopic patients 2.50 ± 1.11 compared to nonatopic individuals 1.40 ± 0.46. Eosinophil count and serum immunoglobulin E were significantly higher (p = 0.031 and p = 0.001, respectively) in atopic patients compared to the Control Group. Serum interleukin-4 was also significantly higher (p = 0.01) in atopic patients compared with nonatopic individuals. Conclusion: Excess expression of TGF-β1 gene in pterygium tissue of atopic individuals suggests that growth factors play a role in the pathogenesis of pterygium