[Conjunctival Fas-FasL expression in chronic Stevens-Johnson syndrome]

To investigate the expression level of Fas-FasL in conjunctiva tissue of chronic Stevens-Johnson syndrome (SJS) patients and to analyze the role of Fas-FasL pathway in the mechanism of ocular damage related to SJS.

Conjunctiva tissue was obtained during symblepharon release operation and cryostat sectioned at 5 µm. The tissue morphology was observed by electron microscopy. The expression of Fas-FasL (CD95/CD178) in conjunctiva was detected by immunohistochemistry (direct immunofluorescence). The conjunctiva tissue of normal people was also observed and tested as contrast group.

The pathogenic changes included incrassation of epithelium and cavity of mucous glands in the sub-epithelium. The expression of Fas in SJS patients focusing in the basal layer of epithelium appeared a lower level compared to that in normal human conjunctiva, which distributed equally in all layers of epithelium. The expressions of FasL in SJS patients and normal people were both weak.

The low level expression of Fas-FasL in conjunctiva of SJS patients has certain effect on the chronic ocular damage.