Abstract
Abstract: :
Purpose: We reported that Microarray gene expression on conjunctiva from a patient affected by Ocular Cicatricial Pemphigoid (OCP) detected Cytokeratin 14 (K14) expression as one of the most down–regulated gene out of 10'000 genes (ARVO 2003, Abstract 4612). K14 is a major protein of cytoskeleton in proliferating, undifferentiated basal cell of pluri–stratified epithelium of mucosa and skin. It is important for cell stability and has a major function in epithelial adhesion to basement membrane via hemi–and desmosome complexes. K14 ia also found in all cell layers of limbal conjunctiva. The purpose of this study was to compare the presence of K14 in conjunctiva from patients affected by OCP to normal and to clarify if changes are specific for OCP. Methods: Immunoperoxidase staining was performed on ten (perilimbal) conjunctivas obtained from patients with biopsy proven OCP, eleven conjunctivas from patients with Chronic Cicatrizing Conjunctivitis (CCC) of other etiologies and five normal conjunctivas. Skin and sclera served as positive and negative control, respectively. Slides were masked, the staining pattern and intensity were scored by two investigators and compared. Results: Staining in all five [100%] normal conjunctivas was characteristic with an intensive coloration of basal cells in a "string of pearls" like pattern. Staining in OCP was normal in one of ten tissues [10%], diminished in two [20%] and not or almost not recognizable in seven of ten tissues [70%]. In CCC (3 Atopy, 3 Stevens–Johnson Syndrome, 1 Rosacea, 1 medication induced and 3 idiopathic) staining was similar with one of eleven normal [9%, idiopathic CCC], diminished in two [18%] and not or almost not detectable in eight of eleven [73%] tissues. There is a statistically significant different K14 pattern in OCP and CCC compared to normal. No difference was found between OCP and CCC. Conclusions: Compared to normal conjunctiva, Cytokeratin 14 staining was severely deranged in conjunctiva from patients with OCP and CCC. The two groups were similar in appearance indicating that basal cell integrity is affected in cicatrizing conjunctivitis regardless of its etiology. Loss of basal (multiplying) epithelial cells or their function could be an important element in the pathogenesis of cicatrizing conjunctivitis and could explain in part the clinical picture of stem cell insufficiency.
Keywords: conjunctivitis • autoimmune disease • cytoskeleton