Activation of complement by Mycobacterium leprae requires disruption of the bacilli.
OBJECTIVE
The immune-mediated events that precipitate erythema nodosum leprosum (ENL) are not well understood. One component may be the complexing of antibody with antigens released from infected macrophages, the activation of complement and the subsequent local inflammation. We assess here the ability of highly-purified, disrupted M. leprae, to activate complement.


RESULTS
Intact and sonically-disrupted crude and alkali-purified nu/nu mouse-derived M. leprae suspensions were incubated with normal serum and a hemolytic titer (CH50) was determined as a measure of complement fixation. Crude M. leprae consumed complement, and disrupted preparations more than the intact. Purified M. leprae preparations did not consume complement unless disrupted.


CONCLUSIONS
M. leprae, if disrupted, can activate complement. This supports a hypothesis that links released antigens with ENL, and may explain the increased probability of an occurrence of ENL following chemotherapy.
Lahiri
Ramanuj
R
Laboratory Research Branch, National Hansen's Disease Programs, Louisiana State University, Baton Rouge, 70803 USA.
Sandoval
Felipe G
FG
Krahenbuhl
James L
JL
Shannon
Edward J
EJ
D000818:Animals; D003167:Complement Activation; D004893:Erythema Nodosum / Q000276:immunology* / Q000503:physiopathology; D006801:Humans; D015440:Leprosy, Lepromatous / Q000276:immunology*; D051379:Mice; D008819:Mice, Nude; D009166:Mycobacterium leprae / Q000276:immunology* / Q000502:physiology; D013010:Sonication