Imbalanced serum IgG subclass pattern in toxic shock syndrome patients: deficiency of specific IgG1 and IgG4 subclass antibodies to toxic shock syndrome toxin 1.

An imbalanced serum IgG subclass pattern was identified in 10 patients with toxic shock syndrome (TSS) showing remarkably low subclass levels of various combinations. IgG2 levels were significantly reduced as compared to normal controls. The IgG subclass-specificity of antibodies to toxic shock syndrome toxin (TSST-1) was investigated by a solid-phase radioimmunoassay. TSS-patients lacked pre-immunity to TSST-1 in all four IgG subclasses. Normally acquired immunity to the toxin as well as the serological response developing in two patients with TSS was generally restricted to IgG1 and IgG4. A strong booster response of all four IgG subclasses was seen in three patients with S. aureus septicaemia due to TSST-1 producing strains. The lack of specific IgG1 and IgG4 antibodies to TSST-1 and the low serum IgG subclass levels found in the TSS-patients could be of pathogenetic significance and help to explain the susceptibility to TSS in certain individuals.