RESUMEN
Rheumatoid arthritis (RA) is an autoimmune disease characterised by the destruction of articular cartilage and bone damage. The chronic treatment of RA patients causes a higher susceptibility to infectious diseases such as tuberculosis (TB); one-third of the world’s population is latently infected (LTBI) with Mycobacterium tuberculosis (Mtb). The tuberculin skin test is used to identify individuals LTBI, but many studies have shown that this test is not suitable for RA patients. The goal of this work was to test the specific cellular immune responses to the Mtb malate synthase (GlcB) and heat shock protein X (HspX) antigens of RA patients and to correlate those responses with LTBI status. The T-helper (Th)1, Th17 and Treg-specific immune responses to the GlcB and HspX Mtb antigens were analysed in RA patients candidates for tumour necrosis factor-α blocker treatment. Our results demonstrated that LTBI RA patients had Th1-specific immune responses to GlcB and HspX. Patients were followed up over two years and 14.3% developed active TB. After the development of active TB, RA patients had increased numbers of Th17 and Treg cells, similar to TB patients. These results demonstrate that a GlcB and HspX antigen assay can be used as a diagnostic test to identify LTBI RA patients.
Asunto(s)
Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Antígenos Bacterianos/inmunología , Artritis Reumatoide/inmunología , Proteínas Bacterianas/inmunología , Tuberculosis Latente/diagnóstico , Malato Sintasa/inmunología , Mycobacterium tuberculosis/inmunología , Linfocitos T Reguladores/inmunología , Análisis de Varianza , Artritis Reumatoide/complicaciones , Ensayo de Inmunoadsorción Enzimática , Citometría de Flujo , Inmunidad Celular/inmunología , /sangre , Estudios Longitudinales , Tuberculosis Latente/complicaciones , Tuberculosis Latente/inmunología , Leucocitos Mononucleares/inmunología , Células TH1/inmunología , /inmunología , Factor de Crecimiento Transformador beta/análisis , Factor de Necrosis Tumoral alfa/inmunologíaRESUMEN
Tuberculosis (TB) is one of the oldest human infectious diseases and one third of the world's population is latently infected. Brazil is an endemic area for TB. One of the most important challenges in TB control is the identification of latently infected individuals. Health Care Workers (HCW) are at high risk of being infected with Mycobacterium tuberculosis and even to become TB latently infected. The aim of this study was to increase knowledge about humoral immune response in TB latently infected individuals. HCW were classified according to their tuberculin skin test (TST), as positive or negative. The antibody response to GLcB, MPT51 and HSPX from Mycobacterium tuberculosis was evaluated. TST negative HCW constituted the majority of those who showed a humoral immune response. Antibody levels varied according to antigen characteristics, TST and BCG status. We suggest that possibly the presence of those antibodies could have a function in the protective immune response against Mycobacterium tuberculosis.