Comparison of two immunoassays for the complement protein C4b-binding protein in health and disease.
An enzyme-linked immunoassay for human C4b-binding protein (concentration range 25-400 ng/ml) was developed using two monoclonal antibodies; the intra- and interassay coefficients of variation were less than 7.2%. In 50 normal subjects, 20 patients with liver cirrhosis and 34 full-term newborns, the plasma levels of C4b-binding protein were very similar to those measured by Laurell electroimmunoassay; in 24 patients with elevated erythrocyte sedimentation rates, levels measured by enzyme-linked immunoassay were higher then those measured by the Laurell method (270 +/- 70% vs. 223 +/- 67%). In these patients crossed immunoelectrophoresis showed a pattern different from that of normal individuals, which may explain the lower values found with the Laurell method.
Coppola
R
R
Angelo Bianchi Bonomi Haemophilia and Thrombosis Centre, IRCCS Maggiore Hospital, Milan, Italy.
Tombesi
S
S
Cristilli
P
P
Bergamaschini
L
L
Mannucci
P M
PM
D000328:Adult; D000818:Animals; D000911:Antibodies, Monoclonal; D001667:Binding, Competitive; D001799:Blood Sedimentation; D002352:Carrier Proteins / Q000097:blood* / Q000276:immunology; D015935:Complement C4b / Q000378:metabolism*; D003169:Complement Inactivator Proteins; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000706:statistics & numerical data; D005069:Evaluation Studies as Topic; D005260:Female; D006023:Glycoproteins; D006801:Humans; D007118:Immunoassay / Q000379:methods* / Q000706:statistics & numerical data; D007123:Immunoelectrophoresis, Two-Dimensional / Q000379:methods / Q000706:statistics & numerical data; D007124:Immunoenzyme Techniques; D066298:In Vitro Techniques; D007231:Infant, Newborn; D007249:Inflammation / Q000097:blood; D008103:Liver Cirrhosis / Q000097:blood; D008297:Male; D051379:Mice; D017293:Protein S / Q000378:metabolism; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D000911:Antibodies, Monoclonal; D002352:Carrier Proteins; D003169:Complement Inactivator Proteins; D006023:Glycoproteins; D017293:Protein S; D015935:Complement C4b