Use of intravenous immunoglobulin in the treatment of staphylococcal and streptococcal toxic shock syndromes and related illnesses.

Pyrogenic toxin superantigens comprise a large family of exotoxins made by Staphylococcus aureus and group A streptococci. These toxins include toxic shock syndrome toxin-1, the staphylococcal enterotoxins, and the streptococcal pyrogenic exotoxins (synonyms: scarlet fever toxins and erythrogenic toxins), all of which have the ability to cause toxic shock syndromes and related illnesses. These toxins have a similar three-dimensional structure that allows them to interact with relatively invariant regions of major histocompatibility complex class II molecules on the surface of antigen-presenting cells and with certain variable regions of the T-cell receptor-beta chain. The consequence of these interactions (and other immunobiological properties of the toxins) is the exaggerated release of bioactive cytokines. The latter molecules are responsible for the clinical signs of illness associated with these toxins.