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Activation of complement by Mycobacterium leprae requires disruption of the bacilli

Ramanuj Lahiri1, Felipe G Sandoval, James L Krahenbuhl

  • 1Laboratory Research Branch, National Hansen's Disease Programs, Louisiana State University, Baton Rouge, 70803 USA.

Leprosy Review
|November 18, 2008
PubMed
Abstract

Insights

Disrupted Mycobacterium leprae (M. leprae) can activate the complement system, a key part of the immune response. This finding supports the link between M. leprae antigens and erythema nodosum leprosum (ENL).

Area of Science:

  • Immunology
  • Microbiology

Background:

  • Erythema nodosum leprosum (ENL) pathogenesis involves immune-mediated events.
  • Antibody-antigen complexes and complement activation are potential contributors to ENL.

Purpose of the Study:

  • To investigate the complement-activating capacity of Mycobacterium leprae (M. leprae).
  • To assess if disrupted M. leprae can activate the complement system.

Main Methods:

  • Incubation of intact and disrupted M. leprae (crude and purified) with normal serum.
  • Determination of hemolytic titer (CH50) to measure complement fixation.

Main Results:

  • Crude M. leprae consumed complement; disrupted preparations showed higher consumption.
  • Purified M. leprae only consumed complement when disrupted.
  • Intact M. leprae did not significantly consume complement.

Conclusions:

  • Disrupted M. leprae can activate the complement system.
  • This supports the hypothesis linking released M. leprae antigens to ENL.
  • May explain increased ENL incidence post-chemotherapy.

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