Solid phase enzyme immunoassay or radioimmunoassay for the detection of immune complexes based on their recognition by conglutinin: conglutinin binding test. A comparative study with 125I labelled C1q binding and Raji cell RIA tests

P. Casali, A. Bossus, N. A. Carpentier, P. H. Lambert

Research output: Contribution to journalArticle

142 Scopus citations

Abstract

Bovine conglutinin was used in a solid-phase assay for the detection of immune complexes. In a first step, the tested serum sample is incubated in polypropylene tubes coated with conglutinin to allow C3-coated immune complexes to bind to solid-phase conglutinin. In a second step, the conglutinin-bound complexes are detected using an enzyme-conjugated or radiolabelled antiimmunoglobulin antibody. The conglutinin-binding (KgB) test does not suffer from the interference of DNA, heparin or endotoxins. Its limit of sensitivity for aggregated IgG is 3 μg/ml undiluted human serum. Immune complexes prepared in vitro using tetanus toxoid, or DNA, and corresponding antibodies in human sera could be detected at various antigen/antibody ratios and at antibody concentrations lower than 8 μg/ml. The KgB test allowed for the detection of immune complexes in sera from patients with systemic lupus erythematosus, rheumatoid arthritis, idiopathic vasculitis, leprosy and leukemia. These sera were also tested using the 125I-labelled C1q-binding activity (BA) test and the KgB test simultaneously, and a significant rank order correlation was observed. In patients with leukemia, a significant correlation was observed using three tests, KgB, 125I-labelled C1q BA and Raji-cell radioimmunoassay (RIA). Therefore, the KgB test appears as a simple and reproducible method, utilizing a very stable reagent, with a sensitivity and specificity comparable to the other tests studied and allowing for clinical application.

Original languageEnglish (US)
Pages (from-to)342-354
Number of pages13
JournalClinical and Experimental Immunology
Volume29
Issue number2
StatePublished - Dec 1 1977
Externally publishedYes

    Fingerprint

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology

Cite this