[The detection of soluble immune complexes (author's transl)]. 
The detection and characterization of soluble immune complexes is complicated by the broad spectrum of complexes occurring in human pathology.  Thus, differences in immune complex size, specificity and ability to interact with immunologic effector systems such as complement or cells, suggest variable pathogenic potential.  Therefore, a variety of techniques for detection should be available.  The introduction of radioimmunoassays and the recently improved knowledge of immune complex biochemistry have lead to the description of a large number of detection procedures, which in turn has widened the catalogue of diseases associated with immune complexes.  Among 50 procedures known today, this article selects some pertinent tests which are critically discussed with respect to their specificity, sensitivity and possible interest in clinical medicine.