title: Evaluation of four molecular methods for the diagnosis of tuberculosis in pulmonary and blood samples from immunocompromised patients.
abstract: The present study analysed the concordance among four different molecular diagnostic methods for tuberculosis (TB) in pulmonary and blood samples from immunocompromised patients. A total of 165 blood and 194 sputum samples were collected from 181 human immunodeficiency virus (HIV)-infected patients with upper respiratory complaints, regardless of suspicious for TB. The samples were submitted for smear microscopy, culture and molecular tests: a laboratory-developed conventional polymerase chain reaction (PCR) and real-time quantitative PCR (qPCR) and the Gen-Probe and Detect-TB Ampligenix kits. The samples were handled blindly by all the technicians involved, from sample processing to results analysis. For sputum, the sensitivity and specificity were 100% and 96.7% for qPCR, 81.8% and 94.5% for Gen-Probe and 100% and 66.3% for Detect-TB, respectively. qPCR presented the best concordance with sputum culture [kappa (k) = 0.864)], followed by Gen-Probe (k = 0.682). For blood samples, qPCR showed 100% sensitivity and 92.3% specificity, with a substantial correlation with sputum culture (k = 0.754) and with the qPCR results obtained from sputum of the corresponding patient (k = 0.630). Conventional PCR demonstrated the worst results for sputa and blood, with a sensitivity of 100% vs. 88.9% and a specificity of 46.3% vs. 32%, respectively. Commercial or laboratory-developed molecular assays can overcome the difficulties in the diagnosis of TB in paucibacillary patients using conventional methods available in most laboratories.
authors.affiliation: Departamento de Imunologia, Centro de Pesquisas Aggeu Magalhães-Fiocruz, Recife, PE, Brasil.
authors.forename: Juliana Maria Azevedo de
authors.initials: JM
authors.lastname: Lyra
authors.affiliation: Hospital Correia Picanço, Secretaria do Estado de Pernambuco, Recife, PE, Brasil.
authors.forename: Magda
authors.initials: M
authors.lastname: Maruza
authors.affiliation: Fundação Estadual de Produção e Pesquisa em Saúde, Porto Alegre, RS, Brasil.
authors.forename: Mirela
authors.initials: M
authors.lastname: Verza
authors.affiliation: Laboratório Central de Pernambuco, Secretaria do Estado de Pernambuco, Recife, PE, Brasil.
authors.forename: Maria Madileuza
authors.initials: MM
authors.lastname: Carneiro
authors.affiliation: Departamento de Saúde Pública, Centro de Pesquisas Aggeu Magalhães-Fiocruz, Recife, PE, Brasil.
authors.forename: Maria de Fátima Militão de
authors.initials: Mde F
authors.lastname: Albuquerque
authors.affiliation: Fundação Estadual de Produção e Pesquisa em Saúde, Porto Alegre, RS, Brasil.
authors.forename: Maria Lúcia
authors.initials: ML
authors.lastname: Rossetti
authors.affiliation: Departamento de Medicina Tropical, Universidade Federal de Pernambuco, Recife, PE, Brasil.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Ximenes
authors.affiliation: Departamento de Parasitologia, Centro de Pesquisas Aggeu Magalhães-Fiocruz, Recife, PE, Brasil.
authors.forename: Maria Cynthia
authors.initials: MC
authors.lastname: Braga
authors.affiliation: Departamento de Imunologia, Centro de Pesquisas Aggeu Magalhães-Fiocruz, Recife, PE, Brasil.
authors.forename: Norma
authors.initials: N
authors.lastname: Lucena-Silva
mesh_terms: D058491:Bacterial Load; D060085:Coinfection; D017931:DNA Primers; D006678:HIV; D015658:HIV Infections / Q000097:blood*; D006801:Humans; D016867:Immunocompromised Host; D008168:Lung / Q000382:microbiology; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D009169:Mycobacterium tuberculosis / Q000254:growth & development; D011933:Reagent Kits, Diagnostic / Q000592:standards; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology*; D014397:Tuberculosis, Pulmonary / Q000097:blood / Q000175:diagnosis*
chemical_list: D017931:DNA Primers; D011933:Reagent Kits, Diagnostic