Serological diagnosis of pneumocystosis: production of a synthetic recombinant antigen for immunodetection of Pneumocystis jirovecii.
Diagnosis of Pneumocystis pneumonia (PcP) relies on the detection of P. jirovecii in respiratory specimens obtained by invasive techniques. Thus, the development of a serological test is urgently needed as it will allow the diagnosis of PcP using blood, an inexpensive and non-invasive specimen. This study aims to combine the production of a multi-epitope synthetic recombinant antigen (RSA) and an ELISA test for detection of anti-P. jirovecii antibodies, in order to develop a new approach for PcP diagnosis. The RSA was selected and designed based on the study of the immunogenicity of the carboxyl-terminal domain of the major surface glycoprotein. This antigen was purified and used as an antigenic tool in an ELISA technique for detection of Ig, IgG and IgM antibodies anti-P. jirovecii (patent-pending no. PT109078). Serum specimens from 88 patients previously categorized in distinct clinical subgroups and 17 blood donors, were analysed. The IgM anti-P. jirovecii levels were statistically increased in patients with PcP (p = 0.001) and the ELISA IgM anti-P. jirovecii test presented a sensitivity of 100% and a specificity of 80.8%, when associated with the clinical diagnosis criteria. This innovative approach, provides good insights about what can be done in the future serum testing for PcP diagnosis.
Unidade de Parasitologia Médica, Grupo de Protozoários Oportunistas/VIH e Outros Protozoários, Instituto de Higiene e Medicina Tropical, Global Health and Tropical Medicine, Universidade Nova de Lisboa, Lisboa, Portugal.
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Tomás
Unidade de Parasitologia Médica, Grupo de Protozoários Oportunistas/VIH e Outros Protozoários, Instituto de Higiene e Medicina Tropical, Global Health and Tropical Medicine, Universidade Nova de Lisboa, Lisboa, Portugal.
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Cardoso
Centro de Toxicogenómica e Saúde Humana (ToxOmics), Departamento de Genética, NOVA Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisboa, Portugal.
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Esteves
Unidade de Parasitologia Médica, Grupo de Protozoários Oportunistas/VIH e Outros Protozoários, Instituto de Higiene e Medicina Tropical, Global Health and Tropical Medicine, Universidade Nova de Lisboa, Lisboa, Portugal.
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Matos
D000908:Antibodies, Fungal / Q000378:metabolism; D000946:Antigens, Fungal / Q000737:chemistry / Q000276:immunology; D000939:Epitopes / Q000737:chemistry / Q000276:immunology; D006801:Humans; D007075:Immunoglobulin M / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000276:immunology; D064887:Observational Studies as Topic; D045363:Pneumocystis carinii / Q000276:immunology*; D011020:Pneumonia, Pneumocystis / Q000097:blood / Q000175:diagnosis* / Q000276:immunology; D011994:Recombinant Proteins / Q000378:metabolism*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012698:Serologic Tests
D000908:Antibodies, Fungal; D000946:Antigens, Fungal; D000939:Epitopes; D007075:Immunoglobulin M; D008562:Membrane Glycoproteins; D011994:Recombinant Proteins