Measurement and characterisation of circulating anti-endothelial cell IgG in connective tissue diseases.
We have detected circulating IgG antibodies that bind with high affinity to human umbilical vein endothelial cells in 74% of patients with systemic lupus erythematosus (SLE), 30% of those with scleroderma and 28% of those with rheumatoid arthritis. IgG binding was F(ab) mediated, and did not involve immune complexes. Anti-endothelial IgG were apparently unrelated to other circulating autoantibodies, including anti-cardiolipin or antiDNA IgG. Bound IgG from SLE or scleroderma patients was displaced by IgG from certain unrelated patients whereas others were ineffective. Anti-endothelial cell IgG from all sera tested were adsorbed by human dermal fibroblasts; erythrocytes and leucocytes each adsorbed a fraction of the activity. Purified IgG did not induce complement-mediated cytotoxicity. We conclude that a discrete group of IgG antibodies is common in connective tissue disease patients, reacts predominantly with endothelial cells and dermal fibroblasts, and may be important in the pathogenesis of vascular damage.
Rosenbaum
J
J
Section of Vascular Biology, MRC Clinical Research Centre, Harrow, UK.
Pottinger
B E
BE
Woo
P
P
Black
C M
CM
Loizou
S
S
Byron
M A
MA
Pearson
J D
JD
D001172:Arthritis, Rheumatoid / Q000276:immunology; D001323:Autoantibodies / Q000032:analysis*; D001327:Autoimmune Diseases / Q000276:immunology*; D003240:Connective Tissue Diseases / Q000276:immunology*; D004730:Endothelium, Vascular / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis* / Q000378:metabolism; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D012595:Scleroderma, Systemic / Q000276:immunology; D014471:Umbilical Veins / Q000276:immunology
D001323:Autoantibodies; D007074:Immunoglobulin G