Abstract: An investigation on the demonstration of PGL-I antigens in sixty-seven paraffin embedded skin biopsies taken from leprosy patients who covered the whole spectrum of the disease.The PGL-I antigen was demonstrated in sixty-five leprosy biopsy specimens except two from TT patients,by immunohistochemical staining technique.The antigens were identified as in tracytoplasmic bacillary staining,and M.leprae and re lated soluble antigen staining,were displayed morphologically in five staining patterns.In LL, BL and BB cases, the number of specimens with positive PGL-1 was basically parallel to the positivity of acidfast staining, while in the lesions of TT and BT, the positive rate of PGL-I was higher than that of acidfast staining.The results indicate that the specificity and sensitivity of the immunohistochemical staining technique used in this study are suitable for both the pathologic diagnosis and the study of the pathogenesis of leprosy.

Key words: Leprosy, Antibodies, An,gens,PGL-I