Premium
Suppression of Alternative Complement Pathway Activity by Radiographic Contrast Media
Author(s) -
MIKKONEN R.,
LEHTO T.,
KOISTINEN V.,
ARONEN H. J.,
KIVISAARI L.,
MERI S.
Publication year - 1997
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1046/j.1365-3083.1997.d01-414.x
Subject(s) - anaphylatoxin , alternative complement pathway , complement system , chemistry , iohexol , dimer , in vitro , inulin , iodixanol , monomer , biophysics , biochemistry , immunology , antibody , medicine , contrast medium , biology , organic chemistry , renal function , polymer , radiology
The authors examined the effect of four different kinds of contrast media (ionic/non‐ionic, monomer/dimer) on the activation of the complement (C) system (haemolytic activity and anaphylatoxin generation) in vitro . In addition, the authors compared the effect of contrast media on inulin‐mediated generation of the anaphylatoxin derivative C3a des Arg in sera from urticarial reactors and their non‐reacting controls. It was observed that the incubation of commercial iohexol, ioxaglate, iodixanol and meglumin amidotriz solutions in normal human serum (NHS) resulted in a dose‐dependent decrease in the haemolytic activity of the alternative C pathway. Contrary to expectations the contrast media did not activate C in NHS. Instead, inulin‐induced generation of C3a des Arg was inhibited by all the four contrast media. The strongest inhibitor was ioxaglate, an ionic dimer. No significant difference between the urticarial reactors and non‐reactors in the inhibition of C3a des Arg generation was observed. In analyzing the mechanism of C inhibition we found that the contrast media solutions, particularly the ionic ones, prevented formation of the alternative pathway C3 convertase, C3bBb, by inhibiting the binding of factor B to surface‐associated C3b molecules. The results suggest that the previously observed decrease in haemolytic C titres by contrast media is due to direct suppression of C activity rather than activation‐induced consumption.