Opsonic and complement-dependent bactericidal activities of various immunoglobulin preparations for intravenous use

Some effector functions of various immunoglobulin (IgG) preparations have been compared. Tests for opsonic activity were performed in vitro with human peripheral blood leukocytes and in vivo with mice. The augmentation effects on luminol-dependent chemiluminescence were investigated with human leukocytes. The complement-dependent bactericidal activities were tested with Escherichia coli. Five IgG preparations: pH 4-treated preparation (IG-100), polyethyleneglycol-treated preparation (PEG-G), sulfonated preparation (S-G), pepsin-treated preparation (Pep-G) and a preparation for intramuscular use (GGN) were studied. The results were as follows: (1) IG-100 and PEG-G exhibited strong activities in all test systems; (2) GGN showed a strong opsonic activity; (3) S-G showed relatively weak activities in all test systems, but the revertant S-G preparation exhibited somewhat stronger activities in all systems, and (4) Pep-G showed weak or no activity in all systems. These results suggest that the IgG molecules in IG-100 and PEG-G preparations have satisfactory effector functions. On the other hand, IgG molecules in S-G and Pep-G preparation may have significant deficiencies in their biological functions.