Format

Send to:

Choose Destination
See comment in PubMed Commons below
Clin Vaccine Immunol. 2010 Jul;17(7):1094-103. doi: 10.1128/CVI.00049-10. Epub 2010 May 12.

Variation in gamma interferon responses to different infecting strains of Mycobacterium tuberculosis in acid-fast bacillus smear-positive patients and household contacts in Antananarivo, Madagascar.

Author information

  • 1Unité des Mycobactéries, Institut Pasteur de Madagascar, Ambatofotsikely BP 1274, Antananarivo 101, Madagascar.

Abstract

The majority of healthy individuals exposed to Mycobacterium tuberculosis will not develop tuberculosis (TB), though many may become latently infected. More precise measurement of the human immune response to M. tuberculosis infection may help us understand this difference and potentially identify those subjects most at risk of developing active disease. Gamma interferon (IFN-gamma) production has been widely used as a proxy marker to study infection and to examine the human immune response to specific M. tuberculosis antigens. It has been suggested that genetically distinct M. tuberculosis strains may invoke different immune responses, although how these differences influence the immune responses and clinical outcome in human tuberculosis is still poorly understood. We therefore evaluated the antigen-specific IFN-gamma production responses in peripheral blood mononuclear cells from two cohorts of subjects recruited in Antananarivo, Madagascar, from 2004 to 2006 and examined the influence of the infecting M. tuberculosis strains on this response. The cohorts were sputum-positive index cases and their household contacts. Clinical strains isolated from the TB patients were typed by spoligotyping. Comparison of the IFN-gamma responses with the spoligotype of the infecting clinical strains showed that "modern" M. tuberculosis strains, like Beijing and Central Asian (CAS) strains, tended to induce lower IFN-gamma responses than "ancient" strains, like East African-Indian (EAI) strains, in index cases and their household contacts. These results suggest that new strains may have evolved to induce a host response different from that of ancient strains. These findings could have important implications in the development of therapeutic and diagnostic strategies.

PMID:
20463103
[PubMed - indexed for MEDLINE]
PMCID:
PMC2897260
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk