Immunohistochemical expression of epithelial cell markers in corneas with congenital aniridia and ocular cicatrizing pemphigoid

Acta Ophthalmol. 2011: 89: 47–53 . Purpose: We investigated the immunohistochemical characteristics of corneal specimens in congenital aniridia and pemphigoid using various corneal markers to determine the status of the corneal epithelium. Methods: Conjunctivalization was clinically suspected in all corneas. Ten aniridia and seven pemphigoid paraffin‐embedded corneal specimens were stained with periodic Schiff reagent (PAS) and antibodies against CK3/12, CK12, CK19, breast cancer resistance protein 1 (BCRP) and p63. Results: Aniridia: six cases contained goblet cells, four were negative. Both groups had cases with (three of six; one of four) and without CK19 positivity and cases with (two of six; three of four) and without p63 positivity. All aniridia cases except two in the goblet cell group were CK3/12‐ and CK12‐positive and BCRP‐negative. Pemphigoid: only one of the seven cases contained goblet cells. This case stained positively for CK19, 3/12, 12 and p63 and negatively for BCRP. The other six cases were positive for CK3/12, five of which were positive for CK12; only one case was CK19‐positive. Three cases were p63‐positive and two BCRP‐positive. The CK12 staining was heterogenous in most cases and was often found in the superficial layer. Conclusion: Three different stages of epithelial characteristics were found in congenital aniridia and pemphigoid: (i) CK19‐negative and inhomogenous CK12‐positive cases indicating epithelium mainly from (partly) CK12‐deficient limbal stem cells; (ii) CK19‐ and/or goblet cell‐positive and CK12‐positive cases with their epithelia originating from CK12‐deficient limbal stem cells and from incursing conjunctival cells; and (iii) CK19‐positive and CK12‐negative cases consisting of conjunctival cells alone.