HISTOPATHOLOGY OF THE SKIN TEST USING A POLYSACCHARIDE ANTIGEN OF THE PARACOCCIDIOIDES BRASILIENSIS

[摘要] A histopathological study of the skin test with a polysaccharide extracted from the Paracoccidioides brasiliensis was carried out in humans and in guinea pigs. Patients with South American blastomycosis responded with an initial subacute inflammation for 7 days, after 10-15 days granuloma formation was usually observed. These granulomas were generally located around small blood vessels and skin appendages. A differentiation was established between these granulomas and those located beneath the epithelium, which were usually of the foreign body type and probably arose in response to a primary collagen alteration. Experimental data in guinea pigs have shown an acute inflammation located deep in the dermis in the first 2 days. The inflammation almost totally disappeared 7 days later. Granuloma formation was observed only once. From the foregoing study it appears that, in spite of the fact that granuloma formation has a complex pathogenesis, hyper-sensitivity is one of the factors necessary to its production.