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

Abstract

Recipients of solid organ transplants (SOT) and stem cell transplants (SCT) constitute a group of patients at risk for tuberculosis (TB) development. The prevalence of active TB in patients undergoing SOT is higher than in patients undergoing SCT, probably due to the shorter period of immunosuppression in the latter. We reviewed the importance of SCT in individuals with hematological malignancies. Most TB cases occur in transplant patients by reactivation of latent infection after immunosuppression, most often within the first year after transplant, leading to graft loss and in some cases, death. Relevant variables to assess the risk of TB infection in a transplant recipient include the donor’s and recipient’s medical histories, imaging results, microbiology and tuberculin skin test (TST) and interferon-gamma release assays (IGRA). TST is routinely performed in the donor and recipient before transplantation. If TST is > 5 mm in the recipient or > 10 mm in the donor, it is necessary to exclude active TB (pulmonary and renal). Chemoprophylaxis is recommended in TST (+) recipients and in recipients with recent seroconversion, in donors with a history of untreated TB or in contact with an individual with active TB, if radiological images are suspicious and the IGRA is (+). The drug of choice is isoniazid. These topics are herewith reviewed.

Keywords: Tuberculosis; Prophylaxis; Transplant; Solid organ transplantation; Hematopoietic stem cell transplantation

Core tip: This review highlights the importance of stem cells transplant (SCT) in individuals with cancer and hematological malignancies. However, the risk of acquiring tuberculosis (TB) in this way, has received little attention, especially in developing countries. SCT candidates should be screened for TB with a careful medical history and chart review to ascertain any history of prior TB exposure, since immunocompromised individuals are at higher risk of latent TB progression to active disease. Finally, we mention the importance of the immune response, particularly in allogeneic stem cell transplants, because infection by intracellular microorganisms such as Mycobacterium TB, could be inhibited by the process named cell reprogramming.