Immunohistochemical Study of Pi Class of Glutathione S-Transferase in Psoriasis and Eczematous Dermatitis

ABSTRACT

BACKGROUND: Glutathione S-transferase(GST) is a family of isoenzymes that play an important role in protecting cells from cytotoxic and carcinogenic agents. Strong activities of GST-Pi in the epithelial tissues was observed in the upper layer of skin, gastrointestinal tract and placenta which have been exposed to exogenous chemicals. OBJECTIVE: This study was done to observe the distribution pattern of GST-Pi in normal, acute and chronic psoriasis or eczematous dermatitis, using paraffin-embedded human skin tissues. METHODS: Twenty-one psoriatic and twenty-six eczematous dermatitis specimens were observed by immunohistochemical staining using an anti-rabbit GST-Pi polyclonal antibody. RESULTS: Stainining reaction for the GST is weakly to moderately stained in the normal epidermis. In the acute stage, upper layer shows weak and moderate staining in the lower epidermis of the psoriasis and eczematous dermatitis but in the chronic stage GST-Pi are noted strongly expression in upper epidermis. CONCLUSION: Immunohistochemical staining for the GST-Pi reveals a more abundant distribution in the chronic stage rather than in the acute stage of psoriasis and eczema tous dermatitis, showing no disease specificity. Therefore it is suggested that the detoxifying capacity decreases in the acute stage of above dermatosis.