Quantitative comparison of direct and cold-target competition assay in monocyte- and complement-mediated lysis of sensitized erythrocytes.
Differences in the number of the antigenic determinants of A1 and B erythrocytes were exploited to study the influence of the sensitization on antibody-dependent monocyte- and complement-mediated cytotoxicity. Lysis was compared in direct and cold target competition assays. The findings were: (1) Monocyte mediated lysis of both targets was similar; A1 erythrocytes, however, showed stronger competitive inhibition than B cells; (2) the competitive inhibition was influenced by the antiserum concentration in a range where the direct lysis was not; (3) in the presence of optimal concentrations of hyperimmune antisera and complement, A1 erythrocytes were lysed, while B erythrocytes were not; and (4) A1 cells exposed to suboptimal concentrations of complement consumed complement, while B cells did not. It was concluded that the cold target competition assay is more sensitive than the direct cytotoxicity test to detect differences in the sensitization of erythrocytes.
Bakács
T
T
National Institute of Oncology, Budapest, Hungary.
Tótpál
K
K
Ringwald
G
G
Klein
E
E
D000906:Antibodies; D000911:Antibodies, Monoclonal; D003165:Complement System Proteins / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D004912:Erythrocytes / Q000276:immunology*; D006461:Hemolysis; D006801:Humans; D007700:Kinetics; D009000:Monocytes / Q000276:immunology*
D000906:Antibodies; D000911:Antibodies, Monoclonal; D003165:Complement System Proteins