Opsonic activity and composition of five intramuscular gammaglobulin preparations

The opsonic activity of five immunoglobulin preparations for intramuscular and subcutaneous substitution therapy was investigated. Various strains of Staphylococcus aureus, Escherichia coli, Streptococcus pyogenes, group B streptococci, Streptococcus pneumoniae and Haemophilus influenzae were used. In addition, the concentration of unsplit IgG molecules, IgG fragments and IgG aggregates in these preparations was determined. With the exception of H. influenzae, all preparations opsonised the bacteria studied almost as well as inactivated serum. All preparations contained an appreciable amount of aggregates, but IgG fragments were not found.