Biomaterial Database

The complement fixing ability of putative circulating immune complexes in rheumatoid arthritis and its relationship to extra-articular disease. 1982

B E Bourke, and I K Moss, and P Mumford, and A Horsfall, and R N Maini

The hypothesis that the pathogenicity of putative circulating immune complexes (CIC) in rheumatoid arthritis (RA) is related to their ability to fix complement was investigated. Three assays for CIC were employed; (a) the 125I C1q binding assay (C1q BA), (b) the C1q solid phase assay (C1q SP) and (c) the Raji cell assay (RCA). Evidence for hypercatabolism of complement was obtained by using a highly sensitive quantitative assay for C3d (a breakdown product of C3) by rocket immunoelectrophoresis. One hundred and fifty-two patients with classical or definite RA were studied; 54 had clinical evidence of extra-articular disease including vasculitis, nodules, scleritis, neuropathy and lung disease; 98 patients had clinical evidence of joint disease alone. Plasma levels of C3d were significantly elevated in the RA group as a whole 16.7 +/- 4.4 mg/l (mean +/- 1 s.d.) compared with 13.1 +/- 3.25 mg/l in a group of 55 normal controls (P less than 0.01). Elevated levels of C3d were found in 26% of all patients but occurred significantly more often in the extra-articular disease group (P less than 0.05). Fifty-four percent of patients had at least one positive assay for CIC although no individual assay was positive in more than 36% of the group as a whole. The prevalence of positive CIC was significantly greater in those patients with extra-articular disease than in those with joint disease alone (P less than 0.005). Of the total of 82 patients with putative CIC, 30 (37%) had a raised C3d level. The coincident finding of positive tests for CIC and an elevated C3d level was very significantly correlated with the presence of extra-articular disease (chi 2 = 12.7 P = 10(-3)). Whilst putative CIC are frequent in RA (54%) these findings in contrast to previous work, suggest that the majority are not associated with abnormal complement activation and may account for the relative infrequency of clinically detectable active extra-articular disease.

UI	MeSH Term	Description	Entries
D008180	Lupus Erythematosus, Systemic	A chronic, relapsing, inflammatory, and often febrile multisystemic disorder of connective tissue, characterized principally by involvement of the skin, joints, kidneys, and serosal membranes. It is of unknown etiology, but is thought to represent a failure of the regulatory mechanisms of the autoimmune system. The disease is marked by a wide range of system dysfunctions, an elevated erythrocyte sedimentation rate, and the formation of LE cells in the blood or bone marrow.	Libman-Sacks Disease,Lupus Erythematosus Disseminatus,Systemic Lupus Erythematosus,Disease, Libman-Sacks,Libman Sacks Disease
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D010003	Osteoarthritis	A progressive, degenerative joint disease, the most common form of arthritis, especially in older persons. The disease is thought to result not from the aging process but from biochemical changes and biomechanical stresses affecting articular cartilage. In the foreign literature it is often called osteoarthrosis deformans.	Arthritis, Degenerative,Osteoarthrosis,Osteoarthrosis Deformans,Arthroses,Arthrosis,Arthritides, Degenerative,Degenerative Arthritides,Degenerative Arthritis,Osteoarthritides,Osteoarthroses
D003166	Complement Activating Enzymes	Enzymes that activate one or more COMPLEMENT PROTEINS in the complement system leading to the formation of the COMPLEMENT MEMBRANE ATTACK COMPLEX, an important response in host defense. They are enzymes in the various COMPLEMENT ACTIVATION pathways.	Activating Enzymes, Complement,Enzymes, Complement Activating
D003167	Complement Activation	The sequential activation of serum COMPLEMENT PROTEINS to create the COMPLEMENT MEMBRANE ATTACK COMPLEX. Factors initiating complement activation include ANTIGEN-ANTIBODY COMPLEXES, microbial ANTIGENS, or cell surface POLYSACCHARIDES.	Activation, Complement,Activations, Complement,Complement Activations
D003168	Complement Fixation Tests	Serologic tests based on inactivation of complement by the antigen-antibody complex (stage 1). Binding of free complement can be visualized by addition of a second antigen-antibody system such as red cells and appropriate red cell antibody (hemolysin) requiring complement for its completion (stage 2). Failure of the red cells to lyse indicates that a specific antigen-antibody reaction has taken place in stage 1. If red cells lyse, free complement is present indicating no antigen-antibody reaction occurred in stage 1.	Complement Absorption Test, Conglutinating,Conglutination Reaction,Conglutinating Complement Absorption Test,Complement Fixation Test,Conglutination Reactions,Fixation Test, Complement,Fixation Tests, Complement,Reaction, Conglutination,Reactions, Conglutination,Test, Complement Fixation,Tests, Complement Fixation
D003176	Complement C3	A glycoprotein that is central in both the classical and the alternative pathway of COMPLEMENT ACTIVATION. C3 can be cleaved into COMPLEMENT C3A and COMPLEMENT C3B, spontaneously at low level or by C3 CONVERTASE at high level. The smaller fragment C3a is an ANAPHYLATOXIN and mediator of local inflammatory process. The larger fragment C3b binds with C3 convertase to form C5 convertase.	C3 Complement,C3 Precursor,Complement 3,Complement C3 Precursor,Complement Component 3,Precursor-Complement 3,Pro-C3,Pro-Complement 3,C3 Precursor, Complement,C3, Complement,Complement, C3,Component 3, Complement,Precursor Complement 3,Precursor, C3,Precursor, Complement C3,Pro C3,Pro Complement 3
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000293	Adolescent	A person 13 to 18 years of age.	Adolescence,Youth,Adolescents,Adolescents, Female,Adolescents, Male,Teenagers,Teens,Adolescent, Female,Adolescent, Male,Female Adolescent,Female Adolescents,Male Adolescent,Male Adolescents,Teen,Teenager,Youths
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults