[Skip to Content]
[Skip to Content Landing]
April 1987

Solid-Phase Radioimmunoassay for IgG Antibodies to Staphylococcus epidermidis: Use in Serious Coagulase-Negative Staphylococcal Infections

Arch Intern Med. 1987;147(4):689-693. doi:10.1001/archinte.1987.00370040071013

• A radioimmunoassay (RIA) for human IgG antibodies to Staphylococcus epidermidis was compared with an agar-geldiffusion assay in patients with a variety of infections. The RIA was sensitive and reproducible and discriminated between endocarditis and uncomplicated bacteremias due to coagulase-negative staphylococci. Anti-S epidermidis antibodies by RIA were elevated in 16 (89%) of 18 patients with coagulase-negative staphylococcal endocarditis but in none of 28 patients with uncomplicated bacteremia (n =18) or with blood culture contaminated with these organisms (n =10). Cross-reacting IgG antibodies to S epidermidis antigens were also detected by RIA in 13 (76%) of 17 patients with Staphylococcus aureus endocarditis but in none of 17 patients with nonvalvular S aureus bacteremias and in none of 25 patients with endocarditis or bacteremia caused by other pathogens. Agar-geldiffusion assay was less sensitive than RIA for detecting coagulase-negative staphylococcal endocarditis, being positive in nine (50%) of 18 such patients. This RIA may be useful in distinguishing patients with endocarditis from those with nonvalvular staphylococcemias or blood culture contamination.

(Arch Intern Med 1987;147:689-693)