PARACOCCIDIOIDES BRASILIENSIS-GP43 USED AS PARACOCCIDIOIDIN

A purified glycoprotein of 43 000 daltons from Paracoccidioides brasil iensis (gp43) was tested as paracoccidiodin in delayed-type hypersensi tivity (DTH) tests in both experimental animals (guinea pig and mice) and patients with paracoccidioidomycosis (PCM). The gp43 paracoccidioi din was compared with the traditional Fava Netto antigen (AgFN). In gu inea pigs, the intradermal injection of 2 mu g of gp43 showed a simila r response to those obtained with AgFN, showing in histological sectio ns a population of lymphoid cells that participate in DTH. In mice, gp 43 at a dose of 3.75 mu g showed positive DTH response. The use of gp4 3 as paracoccidioidin in humans showed that this molecule can be used to evaluate the DTH response in patients with PCM. Of 25 PCM patients studied, 48% were positive to gp43 while only 28% were positive to AgF N; 12 PCM patients were completely anergic to both antigens. Consideri ng only those 13 PCM patients who were responsive to gp43 and/or to Ag FN, 92.3% reacted against gp43 and 53.8% reacted against AgFN (P < 0.0 5). Gp43 skin test responses (13.67 +/- 9.56 mm) were significantly la rger than those obtained with AgFN (8.43 +/- 3.69 mm). Immunohistochem ical study of the human skin showed a perivascular inflammatory respon se constituted predominantly by T lymphocytes, macrophages and polymor phonuclear leukocytes.