Pesquisa de IgA contra o antígeno recombinante HspX de Mycobacterium tuberculosis no diagnóstico de tuberculose pleural

Abstract

Objective: To evaluate the accuracy of determining specific IgA to HspX recombinant antigen in pleural fluid and serum samples for the diagnosis of pleural tuberculosis in patients with pleural effusion. Methods: This was a cross-sectional study. Serum and pleural fluid samples of patients with pleural effusion and suspected of having pleural tuberculosis were tested with indirect ELISA in order to determine the optical density of specific IgA to HspX. Results: We evaluated serum and pleural fluid samples from 132 patients: 97 diagnosed with pleural tuberculosis (study group) and 35 diagnosed with pleural effusion due to other causes (control group). The determination of IgA in pleural fluid satisfactorily discriminated between pleural tuberculosis patients and control patients. The sensitivity of the test in pleural fluid and in serum was 69% and 30%, respectively, whereas the specificity was 83% and 84%, respectively. Conclusions: Our data suggest that this test can be used in the diagnosis of pleural tuberculosis. Further studies, involving larger patient samples and different epidemiological scenarios, are warranted.Keywords: Pleural effusion; Tuberculosis/diagnosis; Enzyme-linked immunosorbent assay. ResumoObjetivo: Avaliar a acurácia da dosagem de IgA contra o antígeno recombinante HspX no líquido pleural e no soro de pacientes com derrame pleural para o diagnóstico de tuberculose pleural. Métodos: Estudo transversal de teste diagnóstico. Amostras de líquido pleural e de soro de pacientes com derrame pleural e suspeita de tuberculose pleural foram avaliadas para a determinação da densidade óptica de IgA contra HspX utilizando ELISA indireto. Resultados: Foram avaliadas amostras de líquido pleural e de soro de 132 pacientes: 97 com tuberculose pleural (grupo de estudo) e 35 com derrame pleural por outras causas (grupo controle). A dosagem de IgA em líquido pleural foi capaz de discriminar os pacientes com tuberculose pleural dos controles. A sensibilidade do teste em líquido pleural e em soro foi, respectivamente, de 69% e 30%, enquanto a especificidade foi de 83% e 84%, respectivamente. Conclusões: Os dados sugerem o potencial da utilização deste teste no diagnóstico de tuberculose pleural. Estudos com amostras maiores e em diferentes cenários epidemiológicos são necessários.Descritores: Derrame pleural; Tuberculose/diagnóstico; ELISA. We sequentially included individuals who met the following inclusion criteria: being ≥ 12 years of age; presenting with free pleural fluid or pleural effusion, as demonstrated on lateral decubitus chest X-rays; and presenting with a Karnofsky performance status ≥ 60%. We excluded patients presenting with clinical or biochemical evidence of kidney, heart, or liver failure, those with a history of anticoagulant use or acetylsalicylic acid use in the 10 days preceding the procedure, those in whom the diagnosis was not confirmed, and those who did not complete all of the study procedures.All of the patients were submitted to the following: standardized interview; physica...

Prime–Boost with Mycobacterium smegmatis Recombinant Vaccine Improves Protection in Mice Infected with Mycobacterium tuberculosis

“…Patients that present with active pulmonary TB, for instance, preferentially recognize and respond to other Mtb antigens, i.e., the GLc-B, MPT51, Ag85 complex [8] – [12] . Some responses in patients with extrapulmonary forms of TB are the same as those seen with the active pulmonary TB form [12] , [13] . These features support the hypothesis that a good candidate vaccine should induce immune responses to antigens common to more than one form of TB and should include more than one protein in a single formulation.…”

Detection of anti-HspX antibodies and HspX protein in patient sera for the identification of recent latent infection by Mycobacterium tuberculosis

“…The use of a serodiagnostic test for TB was analyzed by Limongi et al [ 14 ], who reported that specific anti-HspX IgA in pleural fluid samples was useful to discriminate between pleural effusion due to TB and other pulmonary disease. Similarly, detection of IgG, IgA, and IgM antibodies against the M .…”