Effective inhibition of cardiolipin-binding antibodies in gram-negative infections by bacterial lipopolysaccharide.
Anticardiolipin antibodies (ACA) were detected by solid-phase enzyme immunoassay in the majority of sera from patients with Gram-positive and Gram-negative bacterial infections. The response involved all the major immunoglobulin classes IgG, IgM, and IgA. The specificity of the ACA was studied in competitive inhibition experiments with three putative antigens: cardiolipin, lipopolysaccharide (LPS) isolated from Salmonella minnesota, strain Re 595, and synthetic Escherichia coli lipid A. The binding of IgG class ACA from the sera of five patients with Gram-negative infections was effectively inhibited by LPS, whereas 100-fold more cardiolipin was required for comparable inhibition. Pure lipid A was a less effective inhibitor of anticardiolipin activity than LPS. This pattern of reactivity was not seen in sera from patients with Gram-positive infections, syphilis, or systemic lupus erythematosus. Our findings suggest that cardiolipin may not be the inducing antigen for the cardiolipin-binding antibodies that develop in Gram-negative infections.
Vaarala
O
O
National Public Health Institute, Helsinki, Finland.
Vaara
M
M
Palosuo
T
T
D000918:Antibody Specificity; D001323:Autoantibodies / Q000096:biosynthesis*; D001424:Bacterial Infections / Q000276:immunology*; D002308:Cardiolipins / Q000276:immunology*; D005260:Female; D006090:Gram-Negative Bacteria; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male
D001323:Autoantibodies; D002308:Cardiolipins; D008070:Lipopolysaccharides