ISSN:
1365-3083
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
An extension of the Clq-binding assay for the detection of immune-aggregate-mediated and non-immune-aggregate-mediated Clq binding is reported. The assay involves the use of two different Clq preparations, one radioiodinated by means of lactoperoxidase (LPO-125I-Clq) and the other by means of chloramine-T (CT-125I-Clq). The treatment with CT for 20 min at room temperature before iodination for 1 min led to abolishment of the Clq-binding capacities to complexed IgG: approximately 50% of LPO-125I-Clq but only 2% of CT-125I-Clq bound to 80 μg/ml of IgG forming part of tetanus toxoid/anti-tetanus toxoid complexes or to 200 μg/ml of heat-aggregated human gamma globulin. Similar results were obtained with staphylococcal protein-A-aggregated IgG. CT-treated Clq was haemolytically inactive. In contrast to the results with complexed IgG, CT treatment did not markedly reduce binding capacities of Clq to heparin: approximately 55% of LPO- and CT-125I-Clq were bound by 127 U/ml of commercial heparin in normal human serum. Both Clq preparations bound to a comparable extent to fibronectin, fibrinogen, and various bacterial endotoxins. When the LPO- and CT-125I-Clq-binding patterns obtained on serum samples from patients with systemic lupus erythematosus, rheumatoid arthritis, or essential mixed cryoglobulinaemia were compared with binding patterns observed using laboratory reactants, an immediate detection of non-immune-aggregate-mediated Clq binding became possible.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-3083.1983.tb01803.x
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