IgM binding to injured tissue precedes complement activation during skeletal muscle ischemia-reperfusion

J Surg Res. 2004 Nov;122(1):29-35. doi: 10.1016/j.jss.2004.07.005.


Background: Skeletal muscle reperfusion injury is mediated by IgM natural antibodies and by complement activation, as shown by the attenuation of reperfusion injury seen in mice with no natural IgM [] and in mice deficient in complement C3 and C4 []. We postulate that tissue, when ischemic, expresses neoantigens to which preformed natural IgM antibodies bind, in turn producing harmful complement activation and reperfusion injury.

Materials and methods: C57Bl/6 mice were subjected to 2 h of tourniquet-induced hind limb ischemia followed by variable periods of reperfusion. Two hours of ischemia and 3 h of reperfusion produced severe muscle necrosis and edema. Deposition of IgM and C3 in tissue was assessed using immunohistochemistry on both frozen and Formalin-fixed tissue samples.

Results: IgM binding to the endothelium and muscle bundles of the hind limb began during the ischemic period and continued throughout reperfusion up to 6 h. C3 deposition was not present during ischemia and, in contrast, began to appear at 1 h of reperfusion and increased progressively thereafter.

Conclusions: These data demonstrate that IgM binding to ischemic tissues precedes the damaging complement activation by a significant period of time. This has important therapeutic implications when considering anti-inflammatory therapy for reperfusion injury.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Complement Activation*
  • Complement C3 / metabolism
  • Hindlimb
  • Immunoglobulin M / metabolism*
  • Immunohistochemistry / methods
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Muscle, Skeletal / blood supply*
  • Muscle, Skeletal / metabolism*
  • Muscle, Skeletal / pathology
  • Reperfusion Injury / blood
  • Reperfusion Injury / metabolism*
  • Reperfusion Injury / pathology*
  • Staining and Labeling
  • Time Factors


  • Complement C3
  • Immunoglobulin M