title: Validation of western blot for Histoplasma capsulatum antibody detection assay.
abstract: BACKGROUND
  Histoplasmosis is worldwide systemic mycoses caused by the dimorphic fungus Histoplasma capsulatum. The isolation and identification of H. capsulatum in culture is the reference test for histoplasmosis diagnosis confirmation. However, in the absence of it, serology has been used as a presumptive diagnosis through antibody and antigen detection. The purpose of the present study was to validate an immunoassay method (western blot) for antibodies detection in the diagnosis of histoplasmosis.
  
  
  METHODS
  To validate the western blot (WB) a study was conducted using 118 serum samples from patients with histoplasmosis and 118 serum controls collected from January 2000 to December 2013 in residents of the Rio de Janeiro State, Brazil. Diagnostic validation parameters were calculated based on the categorization of results obtained in a 2 × 2 table and subjected to statistical analysis. In addition, the viability of deglycosylated histoplasmin antigen (ptHMIN) onto nitrocellulose membranes previously sensitized was evaluated during the same period.
  
  
  RESULTS
  The WB test showed sensitivity of 94.9 %, specificity of 94.1 %, positive predictive value of 94.1 %, negative predictive value of 94.9 %, accuracy of 94.5 %, and almost perfect precision. Besides, the strips have proved to be viable for using at least 5 years after ptHMIN antigen sensitization.
  
  
  CONCLUSIONS
  Western blot test using ptHMIN provides sensitive, specific, and faster results. Therefore, could be considered a useful tool in the diagnosis of histoplasmosis being used by public health system, even in situations where laboratory facilities are relatively limited.
authors.affiliation: Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Avenida Brasil, 4365, Manguinhos, Rio de Janeiro, RJ, Brazil. marcos.almeida@ini.fiocruz.br.
authors.forename: Marcos de Abreu
authors.initials: Mde A
authors.lastname: Almeida
authors.affiliation: Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Avenida Brasil, 4365, Manguinhos, Rio de Janeiro, RJ, Brazil. claudia.pizzini@ini.fiocruz.br.
authors.forename: Cláudia Vera
authors.initials: CV
authors.lastname: Pizzini
authors.affiliation: Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Avenida Brasil, 4365, Manguinhos, Rio de Janeiro, RJ, Brazil. lisandraserra@yahoo.com.br.
authors.forename: Lisandra Serra
authors.initials: LS
authors.lastname: Damasceno
authors.affiliation: Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Avenida Brasil, 4365, Manguinhos, Rio de Janeiro, RJ, Brazil. mauro.muniz@ini.fiocruz.br.
authors.forename: Mauro de Medeiros
authors.initials: Mde M
authors.lastname: Muniz
authors.affiliation: Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Avenida Brasil, 4365, Manguinhos, Rio de Janeiro, RJ, Brazil. rodrigo.paes@ini.fiocruz.br.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Almeida-Paes
authors.affiliation: Departamento de Patologia, Universidade Federal Fluminense, Rua Marquês de Paraná, 303, Centro, Niterói, RJ, Brazil. rhperalta@globo.com.
authors.forename: Regina Helena Saramago
authors.initials: RH
authors.lastname: Peralta
authors.affiliation: Instituto de Microbiologia Prof. Paulo de Goes, Universidade Federal do Rio de Janeiro, Avenida Carlos Chagas Filho, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ, 373, Brazil. peralta@micro.ufrj.br.
authors.forename: José Mauro
authors.initials: JM
authors.lastname: Peralta
authors.affiliation: Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Avenida Brasil, 4365, Manguinhos, Rio de Janeiro, RJ, Brazil. raquel.vasconcellos@ini.fiocruz.br.
authors.forename: Raquel de Vasconcelos Carvalhaes
authors.initials: Rde V
authors.lastname: Oliveira
authors.affiliation: Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Avenida Brasil, 4365, Manguinhos, Rio de Janeiro, RJ, Brazil. alexandre.vizzoni@ini.fiocruz.br.
authors.forename: Alexandre Gomes
authors.initials: AG
authors.lastname: Vizzoni
authors.affiliation: Escola Nacional de Saúde Pública, Fundação Oswaldo Cruz, Avenida Brasil, Manguinhos, Rio de Janeiro, RJ, 4365, Brazil. carlamv@ensp.fiocruz.br.
authors.forename: Carla Lourenço Tavares
authors.initials: CL
authors.lastname: de Andrade
authors.affiliation: Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Avenida Brasil, 4365, Manguinhos, Rio de Janeiro, RJ, Brazil. rosely.zancope@ini.fiocruz.br.
authors.forename: Rosely Maria
authors.initials: RM
authors.lastname: Zancopé-Oliveira
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000908:Antibodies, Fungal / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D015153:Blotting, Western; D001938:Brazil; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006658:Histoplasma / Q000276:immunology / Q000302:isolation & purification*; D006660:Histoplasmosis / Q000097:blood / Q000175:diagnosis* / Q000276:immunology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D000908:Antibodies, Fungal; D015415:Biomarkers