Research Article Open Access

Exogenous Re-infection by Multiple Exposures to Mycobacterium tuberculosis Contributes to Subsequent Development of Active Tuberculosis

Diane J. Ordway1, Miguel Viveiros1, Fernando A. Ventura2, Ian M. Orme3, Hazel M. Dockrell4 and Leonard Amaral1
  • 1 Universidade de Lisboa Rua da Junqueira, Portugal
  • 2 Centro de Malária e Outras Doenças Tropicais/Instituto de Higiene e Medicina Tropical/Universidade Nova de Lisboa, Portugal
  • 3 Colorado State University, United States
  • 4 London School of Hygiene & Tropical Medicine, United Kingdom

Abstract

The majority of tuberculosis (TB) exists in the world’s poorest countries, where costly biosafety level three facilities for containment of infectious TB patients and diagnostic facilities are not affordable. Health care workers (HCWs), in countries with high burdens of tuberculosis (TB) are at risk of nosocomially acquired TB, as there are increased numbers of cases of TB on open hospital wards and minimal or absent TB infection control. This setting provides a means to study development of immune profiles associated with human exposure to Mycobacterium tuberculosis (Mtb). Individuals with multiple exposures to Mtb develop a Th1 response, involving IFN-γ. However early expression of a Th2 response, consisting of IL-4, was found to be associated with development of active TB disease. A Th2 response was confined to T cells of the CD8 and γδ T cell phenotype which can result in reduced bactericidal function of mycobacterial infected cells. The facets of the immune response which are responsible for failure of elimination of intracellular Mtb leading to active disease are poorly understood.

American Journal of Immunology
Volume 1 No. 1, 2005, 42-47

DOI: https://doi.org/10.3844/ajisp.2005.42.47

Submitted On: 19 February 2006 Published On: 31 March 2005

How to Cite: Ordway, D. J., Viveiros, M., Ventura, F. A., Orme, I. M., Dockrell, H. M. & Amaral, L. (2005). Exogenous Re-infection by Multiple Exposures to Mycobacterium tuberculosis Contributes to Subsequent Development of Active Tuberculosis. American Journal of Immunology, 1(1), 42-47. https://doi.org/10.3844/ajisp.2005.42.47

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Keywords

  • M. tuberculosis
  • T cells
  • health care workers
  • review