Antibodies reactive to cleaved sites in complement proteins enable highly specific measurement of soluble markers of complement activation

Mol Immunol. 2015 Aug;66(2):164-70. doi: 10.1016/j.molimm.2015.02.029. Epub 2015 Mar 18.


An emerging number of diseases and therapeutic approaches with defined involvement of the complement system justify a need for specific markers reflecting activation of particular effector arms of the complement cascade. Measurement of such soluble markers in circulation is a challenge since the specificity of antibodies must be limited to activated complement fragments but not predominant and ubiquitous parental molecules. Existing assays for the measurement of soluble, activated complement proteins are based on the detection of conformational neoepitopes. We tested an alternative approach based on detection of short linear neoepitopes exposed at the cleavage sites after activation of the actual complement component. Obtained antibodies reactive to C4d and C5b fragments enabled us to set up highly specific sandwich ELISAs, which ensured trustful measurements without false positive readouts characteristic for some of the widely used assays.

Keywords: Antibodies; C4d; C5b; Complement system; Leukemia; Lymphoma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies / chemistry
  • Antibodies / isolation & purification
  • Antineoplastic Combined Chemotherapy Protocols*
  • Complement Activation
  • Complement C4b / chemistry
  • Complement C4b / immunology
  • Complement C5b / chemistry
  • Complement C5b / immunology
  • Complement C5b / metabolism*
  • Enzyme-Linked Immunosorbent Assay / methods*
  • Hematologic Neoplasms / blood*
  • Hematologic Neoplasms / drug therapy
  • Hematologic Neoplasms / immunology
  • Hematologic Neoplasms / pathology
  • Humans
  • Peptide Fragments / blood*
  • Peptide Fragments / chemistry
  • Peptide Fragments / immunology
  • Proteolysis
  • Rabbits
  • Sensitivity and Specificity


  • Antibodies
  • Peptide Fragments
  • Complement C4b
  • complement C4d
  • Complement C5b