HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Zubler, R. H. Articles by Miescher, P. A. Search for Related Content PubMed Articles by Zubler, R. H. Articles by Miescher, P. A.

Detection of Immune Complexes in Unheated Sera by a Modified ¹²⁵I-C1q Binding Test

Effect of Heating on the Binding of C1q by Immune Complexes and Application of the Test to Systemic Lupus Erythematosus¹

From the World Health Organization Immunology Research and Training Centre, Hôpital Cantonal, 1211 Geneva 4, Switzerland

Abstract

The ¹²⁵I-C1q binding test was modified in order to allow for the detection of immune complexes in native unheated human serum. Indeed, heat-inactivation (56°, 30 min) was found to reduce the C1q-binding activity of immune complexes mixed with native serum. This effect was not observed when EDTA was added to the native serum before mixing with immune complexes. The modified ¹²⁵I-C1q binding test was performed in two steps: first, the tested native serum sample was incubated for 30 min at 37°C with 0.13 M EDTA in order to prevent the integration of ¹²⁵I-C1q into the intrinsic C1qrs complex, second, ¹²⁵I-C1q and polyethylene glycol (final concentration 2.5%) were added to this mixture, and further incubated for 1 hr at 4°C. Under these conditions, free C1q remained soluble whereas C1q bound to macromolecular complexes was precipitated. The competitive effect of intrinsic C1q and the interference of other substances such as DNA or bacterial LPS were very limited. The modified C1q binding test was applied to the clinical investigation of 44 patients with systemic lupus erythematosus; and increased C1q binding activity (C1q-BA) was observed in 91% of the samples. The level of C1q-BA was found to be significantly correlated to the DNA-binding capacity and to the decrease of the level of some complement components.

Footnotes

¹ This work has been supported by Grant 3.260.0.74 from the Swiss National Research Foundation and by the World Health Organization.

This article has been cited by other articles:

				A Familian, A E Voskuyl, G J van Mierlo, H A Heijst, J W R Twisk, B A C Dijkmans, and C E Hack Infliximab treatment reduces complement activation in patients with rheumatoid arthritis Ann Rheum Dis, July 1, 2005; 64(7): 1003 - 1008. [Abstract] [Full Text] [PDF]

				S. Blanchin, V. Estienne, J.-M. Durand-Gorde, P. Carayon, and J. Ruf Complement Activation by Direct C4 Binding to Thyroperoxidase in Hashimoto's Thyroiditis Endocrinology, December 1, 2003; 144(12): 5422 - 5429. [Abstract] [Full Text] [PDF]

				N. Granholm and T. Cavallo Enhancement of renal disease in BXSB lupus prone mice after prior exposure to bacterial lipopolysaccharide Lupus, October 1, 1995; 4(5): 339 - 347. [Abstract] [PDF]

				N.A. Granholm and T. Cavallo Long-Lasting Effects of Bacterial Lipopolysaccharide Promote Progression of Lupus Nephritis in NZB/W Mice Lupus, December 1, 1994; 3(6): 507 - 514. [Abstract] [PDF]

				N. A. Granholm and T. Cavallo Bacterial Lipopolysaccharide Causes Variable of Diverse Immunoglobulin Isotypes in Kidneys of Lupus-Prone Mice Lupus, August 1, 1992; 1(4): 255 - 261. [Abstract] [PDF]

				T. J.M. Cleophas, H. J.J. van Lier, P. Faaber, J. F.M. Fennis, and A. van 't Laar Therapeutic Efficacy of Alpha-Adrenoceptor Blockade in Primary and Secondary Raynaud's Syndrome Angiology, November 1, 1984; 35(11): 719 - 723. [Abstract] [PDF]