Immune complexes: characteristics, clinical correlations, and interpretive approaches in the clinical laboratory.

Abstract

Immune-complex-mediated injury is thought to play a role in diseases such as rheumatoid arthritis, systemic lupus erythematosus, serum sickness, various infectious diseases, and malignancies. With increased appreciation of the biological and pathological significance of circulating immune complexes has come efforts to develop appropriate techniques for identifying and measuring them. Common approaches exploit such phenomena as the attachment of complement components to antigen-antibody complexes, the presence of specialized receptors for immune complexes at the surface of cells, and the ability of rheumatoid factor to bind with immune complexes. This variety of assay systems for immune complexes has yielded abstruse results in numerous human pathological conditions. Unfortunately, these results seldom correlate with one another in a given disease. Thus, use of a panel of immune complex assays has been recommended. Indirect consequences of immune complex disease may still be appraised and evaluated with some confidence in clinical medicine: measurements of C3 and C4, cryoglobulins, serum viscosity, and turbidity of serum samples. Measurement of immune complexes may be useful in diagnosis, prognosis, and therapeutic monitoring, but it is the characterization of immune complexes that holds the greatest potential for better understanding of disease mechanisms.

The Role of Immune Complexes in Atherogenesis

“…More details on these techniques can be found in other reviews. 67,68 In tissues, the presence of ICs can be detected using histological and immunohistochemical methods which include immunofluorescence assays for Ig and complement components.…”

Intravenous immunoglobulin in the treatment of human immunodeficiency virus‐related thrombocytopenia

“…The number of peripheral blood CD4+ lymphocytes was analyzed by flow cytometry . Quantitative IgG, IgA, and IgM were measured at baseline and prior to each treatment cycle, as were circulating immune complexes, determined by the pethyethylene glycol (PEG) method [38].…”

Immune-Complexome Analysis Identifies Immunoglobulin-Bound Biomarkers That Predict the Response to Chemotherapy of Pancreatic Cancer Patients

“…Immune complexes (IC) are those formed between the antibody and its antigen [8]. The self-or non-self-antigens are bound to immunoglobulins by non-covalent interactions.…”

“…Circulating Immune Complexes (CIC) are present in healthy subjects and cooperate in the immune response [9]. In healthy subjects, IC are removed from the bloodstream, while, in pathological conditions, CIC can accumulate in the bloodstream or in different tissues, especially in the kidneys, inducing glomerulonephritis [8]. Pathological CIC were discovered as biomarkers of Raynaud's syndrome [8].…”