Solid-phase radioimmunoassay for IgG antibodies to Staphylococcus epidermidis. Use in serious coagulase-negative staphylococcal infections.
A radioimmunoassay (RIA) for human IgG antibodies to Staphylococcus epidermidis was compared with an agar-gel-diffusion 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-gel-diffusion 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.
D000907:Antibodies, Bacterial / Q000032:analysis; D001769:Blood / Q000382:microbiology; D003030:Coagulase; D003429:Cross Reactions; D004697:Endocarditis, Bacterial / Q000382:microbiology*; D006801:Humans; D005779:Immunodiffusion; D007074:Immunoglobulin G / Q000032:analysis; D011863:Radioimmunoassay / Q000379:methods; D018805:Sepsis / Q000382:microbiology*; D013203:Staphylococcal Infections / Q000382:microbiology*; D013212:Staphylococcus epidermidis / Q000302:isolation & purification*
D000907:Antibodies, Bacterial; D003030:Coagulase; D007074:Immunoglobulin G