Níveis de citocinas e quimiocinas em pacientes com tuberculose determinados pelo ensaio citométrico de esferas ordenadas

Abstract

One-third of the world's population is currently infected with Mycobacterium tuberculosis. The development of new methods of diagnosis and vaccines against tuberculosis (TB) are necessary for disease control. The immune response against M. tuberculosis involves the production of many cytokines and chemokines, but their interaction during the infection is complex. The objective of this work was to study the production of cytokines and chemokines in pulmonary TB under stimulation of M. tuberculosis antigens. The method of Cytometric Bead Array (CBA) was used to evaluate plasma levels of chemokines MIG, IP-10, IL-8, MCP-1 and RANTES in untreated patients with active TB (ATB), in patients during treatment (DTB) and in treated patients (TTB) and healthy controls individuals (HC). We also evaluated, by CBA, the levels of cytokines IFN-γ, TNF-α, IL-6, IL-2, IL-10 and IL-4, and chemokines MIG, IP-10, IL-8, MCP-1 and RANTES, in culture of peripheral blood mononuclear cells (PBMC) after stimulation with the antigens ESAT-6/CFP-10 and 16kDa, in groups of untreated patients with active TB (ATB), in treated patients (TTB), healthy controls individuals (HC) and in contact individuals of patients with TB (CT). The production of plasma chemokines, the levels of MIG, IP-10 and IL-8 were higher in the group ATB, compared to the other (HC, DTB and TTB), and the levels of chemokines analyzed in plasma decreased after the beginning of the treatment. In assays with human PBMC, the cytokine IFN-γ, TNF-α, IL-6, IL-2 and chemokines MIG, IP-10, IL-8 and RANTES were stimulated at higher levels, by the fusion protein ESAT-6 / CFP-10, in groups ATB and CT in relation to the controls and treated patients. The stimulation with antigen 16kDa did not allow for differentiation of these cytokines and chemokines between the groups. IL-10, IL-4 and MCP-1 showed high levels in the cultures of PBMC from healthy control individuals and contacts when stimulated with the studied M. tuberculosis antigens compared to patients with TB. The antigen ESAT-6/CFP-10 differentiated active TB with regard to the production of cytokines IFN-γ, TNF-α, IL-6 and IL-2 and chemokines MIG, IP-10, IL-8 and RANTES, which can contribute to a protective response in TB. The antigen 16kDa was a strong stimulator of IL-4, IL-10 and MCP-1 molecules that can regulate or inhibit the immune response against M. tuberculosis infection, demonstrating the important role of this antigen in promoting the persistence of the bacillus in the host. The plasma levels of chemokines can be effective in differentiating patients with active TB from the healthy control individuals, and can also be useful in monitoring the effect of anti-TB chemotherapy. The comprehension of the dynamics of the immune response against M. tuberculosis antigens can aid the development of new strategies to combat tuberculosis.