title: Deficiency of complement component C3 is associated with accelerated removal of soluble 123I-labelled aggregates of IgG from the circulation.
abstract: Complement and erythrocyte complement receptors CR1 (CD35) play an important role in the clearance of immune complexes. We studied the elimination of soluble 123I-labelled aggregates of human immunoglobulin G (123I-AIgG), used as a model for immune complexes, in two patients with a congenital and two patients with an acquired deficiency of complement component C3, and compared these with 10 healthy controls. The first disappearance halflife of 123I-AIgG was shorter (3.3 +/- 0.4 versus 7.0 +/- 0.4 min in the controls, P = 0.005) and maximal hepatic uptake of aggregates was increased in the C3 deficient patients (maximal liver/background ratio 3.6 +/- 0.4 versus 2.7 +/- 0.2 in controls, P = 0.04). Apparently, in the absence of C3, removal of circulating immune complexes by the liver is accelerated, probably through Fc receptor-dependent mechanisms.
authors.affiliation: Department of Nephrology, University Hospital Leiden, The Netherlands.
authors.forename: C
authors.initials: C
authors.lastname: Halma
authors.forename: M R
authors.initials: MR
authors.lastname: Daha
authors.forename: J A
authors.initials: JA
authors.lastname: Camps
authors.forename: J H
authors.initials: JH
authors.lastname: Evers-Schouten
authors.forename: E K
authors.initials: EK
authors.lastname: Pauwels
authors.forename: E s
authors.initials: Es
authors.lastname: Van
mesh_terms: D000328:Adult; D000936:Antigen-Antibody Complex; D003176:Complement C3 / Q000172:deficiency*; D004912:Erythrocytes / Q000378:metabolism / Q000648:ultrastructure; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood* / Q000378:metabolism; D007457:Iodine Radioisotopes; D008297:Male; D010100:Oxygen / Q000378:metabolism; D011485:Protein Binding; D017463:Receptors, Complement 3b / Q000276:immunology / Q000502:physiology
chemical_list: D000936:Antigen-Antibody Complex; D003176:Complement C3; D007074:Immunoglobulin G; D007457:Iodine Radioisotopes; D017463:Receptors, Complement 3b; D010100:Oxygen