Detection of Paracoccidioides brasiliensis gp70 circulating antigen and follow-up of patients undergoing antimycotic therapy.
Paracoccidioidomycosis (PCM), one of the most important systemic mycoses in Central and South America, is caused by the dimorphic fungus Paracoccidioides brasiliensis and has a high prevalence in Brazil. Glycoproteins of 43 and 70 kDa are the main antigenic compounds of P. brasiliensis and are recognized by Western blotting by 100 and 96% of PCM patient sera, respectively. In the present study, an inhibition enzyme-linked immunosorbent assay (ELISA) was used to detect gp70 in different biological samples from patients with PCM. gp70 was detected in 98.76% of 81 serum samples, with an average concentration of 8.19 microg/ml. The test was positive for 100% of the patients with the acute and chronic unifocal forms of PCM and 98.43% of the patients with the multifocal chronic form, with average concentrations of 11.86, 4.83, and 7.87 microg/ml, respectively. Bronchoalveolar lavage fluid from 23 patients with pulmonary unifocal PCM and 14 samples of cerebrospinal fluid from patients with neurological PCM were also tested for gp70 detection, with the test showing 100% sensitivity and 100% specificity, with mean gp70 concentrations of 7.5 and 6.78 microg/ml, respectively. To investigate the potential of gp70 detection by inhibition ELISA for the follow-up of PCM patients during antimycotic therapy with itraconazole (ITZ), the sera of 23 patients presenting with the chronic multifocal form of PCM were monitored at regular intervals of 1 month for 12 months. The results showed a decrease in circulating gp70 levels during treatment which paralleled the reduction in anti-P. brasiliensis antibody levels. The detection of P. brasiliensis gp70 from the biological fluids of patients suspected of having PCM proved to be a promising method for diagnosing infection and evaluating the efficacy of ITZ treatment.
Department of Microbiology, Immunology and Parasitology, Federal University of São Paulo, São Paulo, SP, Brazil.
Silvia Helena Marques
SH
da Silva
Daniela de Mattos
Dde M
Grosso
José Daniel
JD
Lopes
Arnaldo Lopes
AL
Colombo
Maria Heloisa Souza Lima
MH
Blotta
Flávio
F
Queiroz-Telles
Zoilo Pires
ZP
de Camargo
D000293:Adolescent; D000935:Antifungal Agents / Q000627:therapeutic use*; D000946:Antigens, Fungal / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D017964:Itraconazole / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010228:Paracoccidioides / Q000276:immunology / Q000302:isolation & purification*; D010229:Paracoccidioidomycosis / Q000175:diagnosis* / Q000188:drug therapy* / Q000382:microbiology
D000935:Antifungal Agents; D000946:Antigens, Fungal; D017964:Itraconazole