02791nas a2200373   4500000000100000008004100001260000900042653001200051653001500063653002300078653002900101653001300130653002600143653002600169653002500195653001100220653002800231653001600259653002000275653002700295653001200322653001400334653002300348653002700371653002200398653001900420100001700439700001400456245004700470300001100517490000700528520186800535022001402403       1980                            d  c198010aAnimals10aAntibodies10aAntibody Formation10aAntigen-Antibody Complex10aAntigens10aArthritis, Rheumatoid10aComplement Activation10aHematologic Diseases10aHumans10aImmune Complex Diseases10aImmune Sera10aImmunoglobulins10aImmunologic Techniques10aleprosy10aNeoplasms10aParasitic Diseases10aReceptors, Immunologic10aRheumatoid Factor10aVirus Diseases1 aNydegger U E1 aDavis J S00aSoluble immune complexes in human disease.  a123-700 v123 a<p>The great variety in biochemical properties of immune complexes occurring in human and animal disease states has made the detection of such complexes a difficult task. Variability in immune complex size, specificity, and interaction with humoral or cellular receptor systems, such as complement and phagocytes, suggests different pathogenic properties. The introduction of radioimmunoassays and the recently improved knowledge of the immune complex-receptor interactions 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. This widespread occurrence of soluble immune complexes has lead many investigators to think that such complexes may occur either as a transient physiological phenomenon, important for fast clearance of the antigen, or as primary pathogenic factors triggering inflammatory reactions. Among the 50 procedures for immune complex detection known today, the article will select some pertinent tests, which will be discussed with respect to their specificity, sensitivity, and reproducibility. Furthermore, it is well known that when applied to the study of a patient group with one particular immune complex disease, various tests will result in different percentages of patients having complexes. This observation is due to differences in the underlying principle on which the various tests are based. Thus immune complexes must be further characterized with respect to their size, to the antibody class or specificity involved and, most difficult, to the antigenic specificity which participates in the complex. Recent advances in such experimental characterization of immune complexes in vitro and in the clinical evaluation of patients with complement activation associated to the presence of immune complexes will be discussed.</p>  a0590-8191