Application of immune-adherence haemagglutination assay to study genetic variability of C3b receptor on human erythrocytes.

Immune-adherence haemagglutination assay with human aggregated IgG (aggIgG) and guinea pig complement was standardized in order to study variability of C3b receptor on human erythrocytes. The results were expressed as the intensity of haemagglutination that corresponded to the density of C3b receptor sites as evidenced by radioimmunoassay results. The expression of C3b receptor was determined in 260 normal individuals. Among studied subjects at least two groups could be clearly distinguished-one with high and another with low expression of C3b receptor. The obtained results showed that despite intensive washing procedures or preincubation at 37 degrees C the low or high expression of C3b receptor did not change, which further supports the notion that the variable expression of C3b receptor on erythrocytes is inherited rather than acquired. It is concluded that standardized haemagglutination technique can be used for semiquantitative determination of erythrocyte C3b receptor and therefore allowing to study genetic variability of this receptor.