Antibody response to peptidoglycan during staphylococcal infections.

Levels of antibodies to peptidoglycan were measured by solid-phase radioimmunoassay in 76 patients with Staphylococcus aureus infections and 44 patients with infections caused by other bacteria. Levels of IgM antibodies to peptidoglycan were elevated in 24% of the patients with endocarditis or complicated bacteremia caused by S. aureus, 21% of those with serious infections caused by other gram-positive cocci, none of those with less serious infections caused by S. aureus or gram-negative bacilli, and 5% of the normal controls. Levels of IgG antibodies to peptidoglycan were elevated in 50% of the patients with endocarditis or complicated bacteremia caused by S. aureus, 3% of those with less severe infections caused by S. aureus, 17% of those with infections caused by other gram-positive cocci, 20% of those infections caused by gram-negative bacilli, and 5% of the normal controls.