RESUMEN
Current diagnostic standards for Mycobacterium tuberculosis (MTB) infection do not distinguish between active and latent tuberculosis (TB). To identify specific biomarkers characterizing the different forms of TB infection, we investigated in parallel with the QuantiFERON -TB Gold In-Tube (QFT-IT) the use of flow cytometry measuring CD4 and CD8 MTB-specific immune response in 17 active-TB patients, 21 health care workers (HCW), 14 recent contacts of TB patients (RC-TB), and 10 bacille Calmette Guerin (BCG)-vaccinated healthy controls (BCG-HC). A correlation (r = 0.4526, P = 0.0002) was found only between the amount of IFN-γ measured by QFT-IT and the frequency of CD4+/CD69+/IFN-γ+ T cells. The frequency of CD4+/CD69+/IFNγ+ responding T cells was higher in active-TB patients (0.254 ± 0.336%, P < 0.01) compared to the other groups. The response of QFT-IT antigen-specific CD8+/CD69+/IFNγ+ T cells was significantly higher in RC-TB (0.245 ± 0.305%, P < 0.05) compared to the other study groups.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Tuberculosis/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Antígenos CD/metabolismo , Antígenos de Diferenciación de Linfocitos T/metabolismo , Vacuna BCG/administración & dosificación , Biomarcadores/análisis , Recuento de Linfocito CD4 , Linfocitos T CD4-Positivos/microbiología , Linfocitos T CD8-positivos/microbiología , Estudios de Casos y Controles , Estudios Transversales , Femenino , Citometría de Flujo , Personal de Salud , Humanos , Interferón gamma/inmunología , Lectinas Tipo C/metabolismo , Masculino , Persona de Mediana Edad , Mycobacterium tuberculosis , Tuberculosis/inmunología , Adulto JovenRESUMEN
QuantiFERON-TB data from 50 children with tuberculosis were analysed to evaluate age related effects. Significantly higher IFN-? responses to TB-specific antigens were associated with younger age, but no difference was found with Mitogen responses. Extrapolating IGRA responses to a Mitogen does not reflect those induced by an antigen-specific stimulus. QFT-IT responses to TB-specific antigens are not compromised with young age.
