1. Vascular Endothelial Growth Factor VEGF and p53 Expression in Tunisian Patients with Pterygium: Immunohistochemical Analysis
O Beltaief, Kh Errais, I Ammous, A Meddeb-Ouertani
Charles Nicolle University Hospital- Tunis- Tunisia
Authors have no financial interest

2. INTRODUCTION Pterygium is characterized by
abnormal fibrovascular corneo-conjunctival tissue
Recurrence probability after surgery
incompletely understanding of its pathogenesis
Vascular Endothelial Growth Factor (VEGF) and P53 are known to participate in tumor vascularization
Purpose: to study VEGF and p53 expression in active primary and recurrent pterygium in Tunisian patients.

3. PATIENTS AND METHODS
Prospective case-control study in Charles Nicolle University Hospital- Tunis- Tunisia
15 cases of active primary pterygium (hyperemic vascularized tissue )
5 cases of recurrent pterygium in Tunisia
10 Normal human conjunctiva as control (negative control)
Immunohistochemical study
Antibodies against VEGF and p53 were used to analyze the distribution and expression of these markers in pterygia and normal human conjunctiva
Tissue sections were examined in brightfield microscopy
Positive cells was counted with a monocular grid

4. RESULTS
Active primary and recurrent pterygium have different patterns of expression
Active pterygium:
VEGF and p53 proteins were found in all primary pterygia in epithelial cells, vascular endothelial cells, and fibroblasts
VEGF expression was moderate to strong
P53 expression was strong
Recurrent pterygium:
p53 immunoreactivity was weak to moderate
VEGF immunoreactivity was strong
Normal human conjunctiva:
VEGF and p53 expression was weak to negative.

5. Table 1: Immunohistochemical expression of VEGF and p53 on histological tissue sections of conjunctiva with primary and recurrent pterygia
VEGF
p53
patients
Age (years)
Gender
Type Ep Vx Fb 1 71 F P 4+ 3+ 2+ 2 58 M 3 52 1+ 4 65 5 55 6 30 7 40 8 51 9 39 10 42 11 61 12 63 13 24 14 20 15 16 R 17 36 18 62 19 44
P: primary pterygia ; R: recurrent pterygia ; Ep: Epithelial cells; Vx: Vascular endothelial cells; Fb: Fibroblasts

6. Comparative expression of VEGF and p53 in primary pterygium (scale bar is 30 µm) VEGF and p53 expression in primary pterygium in a 52-year-old patient (patient 3) with stage III pterygium: moderate epithelial (Ep) staining for VEGF (A) and low cytoplasmic and nuclear staining for p53, mainly detected in epithelial cells (Ep), were observed (B) VEGF and p53 expression in primary pterygium in a 58-year-old patient (patient 2) with stage II pterygium: very strong epithelial (Ep) staining and strong staining in fibroblasts (Fb) and vascular endothelial cells (Vx) were observed both for VEGF (C) and p53 (D).

7. Comparative expression of VEGF and p53 in primary pterygium (scale bar 30 µm) Weak immunoreactivity of VEGF was mainly seen in the epithelial cells (Ep) of a 65-year-old patient (patient 4) (A), whereas strong expression was observed in all pterygial cells (particularly in epithelial (Ep) and vascular endothelial cells (Vx)) in a 63-year-old patient (patient 12) (B). Weak p53 immunoreactivity was mainly seen in basal epithelial (Ep) and vascular endothelial cells (Vx) in a 39-year-old woman (patient 9) (C), whereas strong expression was found in all pterygial cells in the 63-year-old man (patient 12) (D).

8. Expression of VEGF and p53 expression in recurrent pterygium
Expression of VEGF and p53 expression in recurrent pterygium Very strong and diffuse expression of VEGF (A) observed in all pterygial cells of a 36-year-old patient (patient 17) and weak expression of p53 (B) in epithelial (Ep) and fibroblast cells (Fb). Very strong and diffuse, and strong expression of VEGF (C) in epithelial cells (Ep) and in fibroblasts (Fb) and vascular endothelial (Vx) cells, respectively, and slight or no expression of p53 (D) in epithelial (Ep) and fibroblast (Fb) cells, in a 62-year-old patient (patient 18).

9. CONCLUSION
We found that VEGF and p53 expression was correlated in primary pterygium, suggesting relationships between angiogenesis triggered by VEGF and the level of p53 overexpression.
different patterns of VEGF and p53 expression in primary and recurrent pterygium not only
contribute identifying etiology of this disease
underline the substantial role played by neovascularization and cellular proliferation in the pathogenesis of pterygia

10. CONCLUSION
Overexpression of VEGF in active primary and recurrent pterygium suggests that angiogenesis may play a role in their pathogenesis
Expression of p53 in primary pterygium supports the hypothesis that actinic radiation may be involved in its genesis.
VEGF and p53 may be useful biomarkers for understanding the physiopathology of pterygium.