Tuberculosis and hematopoietic stem cell transplant: Review of a difficult and often underestimated problem

Figure 1 Pathogenesis of tuberculosis in hematopoietic stem cell transplant recipients. AlloHSCT: Allogeneic hematopoietic stem cell transplant; TB: Tuberculosis; PTB: Pulmonary TB; LTBI: Latent TB infection; MTB: Mycobacterium tuberculosis.

Figure 2 Cellular immune response against tuberculosis. Mycobacterium tuberculosis (MTB) recognition by specific receptors and tool like receptors activited signaling pathways that lead to cell activation and cytokine production. The activated macrophages secrete cytokines and chemokines that activate macrophages, T cells and neutrophils, producing inflammation. The T cells and natural killer cells producting gamma interferon with other cytokines that induct activation of macrophages contributing to the elimination of MTB or Latent tuberculosis infection. 1: Complement recepter; 2: Mannose recepter; 3: Scavenger receptor; 4: Phagosome; 5: Toll like receptor. IL: Interleukin; LTBI: Latent tuberculosis infection; NK: Natural killer; TNF-α: Tumor necrosis factor alpha; IFN-γ: Interferon gamma.