In vitro investigations of human immunoglobulin preparations: Fc-receptor reactivity and complement consumption.

The complement consuming activity and monocyte Fc-receptor (FcR) binding of some commercial IgG-preparations for intravenous (i.v.) and intramuscular (i.m.) use was investigated. A pepsin-treated IgG-preparation for i.v. use exhibited no detectable complement consuming activity and impaired FcR binding, whereas an unmodified IgG preparation had no detectable complement consuming activity, but retained full FcR binding. A preparation prepared by PEG-precipitation and ion-exchange chromatography exhibited low complement consuming activity as well as good FcR binding. Three preparations for i.m. use showed moderate to strong complement consuming activity, whereas only one of these preparations retained full FcR binding.