title: Development and evaluation of a latex agglutination test for the serodiagnosis of paracoccidioidomycosis.
abstract: Paracoccidioidomycosis (PCM) is the most prevalent systemic mycosis in Latin America. It is caused by the dimorphic fungus Paracoccidioides brasiliensis. The immunodiffusion (ID) test is one of the most widely used techniques for PCM serologic diagnosis due to the simplicity and low costs of its execution. However, it requires trained and qualified people to execute it. The purpose of this study was to evaluate a latex particle agglutination (LA) test for the detection of anti-P. brasiliensis antibodies by using pooled crude exoantigens from the fungus. Fifty-one serum samples obtained from patients with PCM were tested. Positivity was observed in 84% (43/51) of these patients, and the agglutination patterns varied from small clumps with a cloudy background to large clumps with a clear background. The antibody titer reactivity ranged from 1:2 to 1:64. Cross-reactivity was observed in sera from patients with aspergillosis, histoplasmosis, and nonfungal disease. Serum samples obtained from healthy donors were not reactive. The sensitivity and specificity of the LA test were 84% and 81%, respectively. When comparing the LA test with the double-immunodiffusion test, we found an agreement of 92%. Further work is needed to improve the performance of the LA assay before it can be proposed as a reliable diagnostic tool, mainly in laboratories with little infrastructure.
authors.affiliation: Federal University of Pará, Science Biologic Institute, Belém, Pará, Brazil.
authors.forename: Fabíola
authors.initials: F
authors.lastname: Silveira-Gomes
authors.forename: Dayse Nogueira
authors.initials: DN
authors.lastname: Sarmento
authors.forename: Thifany Mendes
authors.initials: TM
authors.lastname: Pinto
authors.forename: Rosiane Ferreira
authors.initials: RF
authors.lastname: Pimentel
authors.forename: Lívia Barreto
authors.initials: LB
authors.lastname: Nepomuceno
authors.forename: Elaine Patrícia T
authors.initials: EP
authors.lastname: Espírito Santo
authors.forename: Maurimélia
authors.initials: M
authors.lastname: Mesquita-da-Costa
authors.forename: Zoilo Pires
authors.initials: ZP
authors.lastname: Camargo
authors.forename: Silvia Helena
authors.initials: SH
authors.lastname: Marques-da-Silva
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000908:Antibodies, Fungal / Q000097:blood*; D000946:Antigens, Fungal; D019411:Clinical Laboratory Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D007841:Latex Fixation Tests / Q000379:methods; D007843:Latin America; D008297:Male; D008875:Middle Aged; D010228:Paracoccidioides / Q000276:immunology; D010229:Paracoccidioidomycosis / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D000908:Antibodies, Fungal; D000946:Antigens, Fungal