The quantitative relationship between clearance rate constants and number of C1-fixing sites.

The rate equation correlating kinetic data for immune-mediated clearance of RBC in guinea pigs was extended to human studies. Rate constants were evaluated for clearance of IgG, IgM, and cold agglutinin-sensitized RBC in normal human volunteers as well as for clearance of IgM-sensitized cells from a small group of patients with primary biliary cirrhosis. All rate constants evaluated in the clearance of sensitized RBC were found to correlate with the number of C1-fixing sites. These correlations not only provide additional support for the mechanism from which the rate of equation was derived, but also allow a quantitative prediction of rate constants and clearance patterns based on the level of sensitization. In addition, the analysis of data from abnormal clearance studies produced rate constants that provided both identification and quantification of the specific defective reaction(s).