Antibody response in Staphylococcus aureus septicaemia--a prospective study.

Formation of serum antibodies against alpha-toxin, teichoic acid and lipase was followed in 63 patients with Staphylococcus aureus septicaemia in 240 consecutive serum samples. Control subjects comprised 23 patients with septicaemia due to other causes and 21 febrile patients without septicaemia. An antibody response against alpha-toxin, measured by ELISA, was most common (40%) in the initial serum, but antibody to teichoic acid was present in the highest number of positive patients (60%) when samples were drawn between 0 and 30 days: 74% of the patients showed a positive antibody response to at least one of the three antigens. When complicated versus uncomplicated septicaemia was compared (samples taken 8-14 days), 14 (45%) of 31 patients had a positive response against alpha-toxin versus 12 (75%) of 16, against teichoic acid 16 (51%) of 31 versus 12 (75%) of 16 and against lipase 15 (48%) of 31 versus 8 (50%) of 16. Patients with low initial antibody levels displayed a poorer antibody response than those with higher initial antibody levels. This phenomenon was observed with all three antigens, but was most pronounced with alpha-toxin. The initial antibody levels may predict the antibody response during the course of the disease. ELISA titres against alpha-toxin correlated (r=0.87) with biological neutralising activity of the antisera. The results may indicate a biological role of serum antibodies in staphylococcal septicaemia.