Detection of Staphylococcus aureus antibodies in patients with S. aureus infections and in normal persons, using solid phase radioimmunoassay.

One hundred and thirteen patients with S. aureus infections, eight patients with non-S. aureus septicemia and 167 normal controls were investigated by solid-phase radioimmunoassay for staphylococcal antibodies. All serum samples tested had measurable antibodies, including the normal controls. The test could differentiate the patients group with S. aureus endocarditis from patients with other S. aureus septicemia, as well as from normal controls, as the endocarditis group had significantly higher antibody levels. Patients with non-bacteremic S. aureus infections, such as osteomyelitis and recurrent furunculosis, showed a wide range of antibody levels, 1/3 and 1/4 of the patients, respectively, showing high levels comparable to the endocarditis patients. Among normal controls, high antibody levels were found in 13 per cent.