P63 expression in conjunctival proliferative diseases: Pterygium and laryngo-onycho-cutaneous (LOC) syndrome

Purpose: Compare expression of p63 in pterygium and laryngo-onycho-cutaneous (LOC) syndrome with normal conjunctiva. Methods: P63 immunohistochemical detection was carried out in normal, pterygium, and LOC conjunctival tissue. In vitro, growth of normal conjunctival biopsy specimens, pterygium, and LOC in growth tissue was compared. Results: In normal conjunctiva, p63 was poorly expressed in the infranasal quadrant, with 36% of cells stained vs. 55 to 59% in other quadrants (p < 0.05). In pterygium, p63 was overexpressed (59% cells stained) compared to normal supranasal (55%) and normal infranasal conjunctiva (36%, p < 0.05). In LOC, p63 was only expressed in 39% of cells vs. 58% in normal supratemporal conjunctiva (p < 0.05). Cytokeratin 19 was expressed by all cells cultured from normal conjunctival tissue. Conclusions: This study emphasizes the importance of using control tissue explanted from the correspondent conjunctival quadrant when studying proliferative disorders. Different pathogenesis may account for the differences in p63 expression between pterygium and LOC.