Detection and quantitation of immune complexes by polyethylene glycol-laser nephelometer assay. I. Immunological study in chronic serum sickness in rabbits.

Polyethylene glycol (PEG)-laser nephelometer assay for the detection of circulating immune complexes (i.c.) has been developed. The method proved to be useful in the detection of i.c. in sera of rabbits with chronic serum sickness. I.c. were detected in 28 animal experimental sera and in samples with preformed immune complexes, but not in sera of 10 healthy rabbits and 5 rabbits prior to immunization. Laser nephelometer assay is a rapid, simple, quantitative screening test suited for clinical use as a first step in i.c. detection.