Quantitation of components of the alternative pathway of complement (APC) by enzyme-linked immunosorbent assays

J Immunol Methods. 1990 Oct 19;133(2):181-90. doi: 10.1016/0022-1759(90)90358-3.


Sensitive enzyme-linked immunosorbent assays (ELISA) using monoclonal antibodies have been developed to specifically detect components of the alternative pathway of complement in human blood plasma. Normal values of the factor B split products Ba (1.01 +/- 0.30 micrograms/ml, mean +/- SD), Bb (0.65 +/- 0.23 micrograms/ml), of the C3-fragments C3b/iC3b/C3dg (17.9 +/- 5.7 micrograms/ml), native factor B (238 +/- 48 micrograms/ml), factor D (1.05 +/- 0.27 micrograms/ml), and factor H (702 +/- 292 micrograms/ml) were determined in the EDTA-plasma of healthy probands (n = 55). The simultaneous quantitation of the main cleavage products and of control proteins in the plasma samples permits precise analysis of the activation of the alternative pathway of complement in various disease states. In addition, we describe a method for the specific depletion of factor B prior to fragment-specific assays utilizing monoclonal antibodies conjugated to paramagnetic beads. The latter should permit the quantitation of other complement split products.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Monoclonal
  • Complement Activation / immunology
  • Complement C3 / analysis
  • Complement C3b Inactivator Proteins / analysis
  • Complement Factor B / analysis
  • Complement Factor D / analysis
  • Complement Factor H
  • Complement Pathway, Alternative*
  • Electrophoresis, Polyacrylamide Gel
  • Enzyme-Linked Immunosorbent Assay / methods*
  • Humans
  • Magnetics
  • Mice
  • Mice, Inbred BALB C
  • Microspheres
  • Nephelometry and Turbidimetry
  • Rabbits
  • Reproducibility of Results
  • Sensitivity and Specificity


  • Antibodies, Monoclonal
  • CFH protein, human
  • Complement C3
  • Complement C3b Inactivator Proteins
  • Complement Factor H
  • CFD protein, human
  • Complement Factor D
  • complement factor D, mouse
  • Complement Factor B