Clinical meaning
Toxic shock syndrome (TSS) is a severe, rapidly progressive, life-threatening systemic illness caused by bacterial exotoxins that act as superantigens. There are two distinct types: staphylococcal TSS (caused by Staphylococcus aureus producing toxic shock syndrome toxin-1 [TSST-1] and enterotoxins B and C) and streptococcal TSS (caused by Group A Streptococcus [GAS] producing streptococcal pyrogenic exotoxins [SPEs]). Gynecologic or menstrual TSS is predominantly staphylococcal and is classically associated with prolonged use of high-absorbency tampons, though it can also occur with menstrual cups, diaphragms, vaginal sponges, and postpartum wound infections. The pathogenesis of staphylococcal TSS begins when S. aureus colonizing the vaginal mucosa proliferates in the protein-rich, warm, moist environment created by an absorbent tampon left in place for an extended period. The bacteria produce TSST-1, which is a superantigen. Unlike conventional antigens that activate only 0.01-0.1% of T-cells, superantigens bypass the normal antigen processing pathway and directly cross-link the major histocompatibility complex class II (MHC-II) molecule on antigen-presenting cells with the variable region of the T-cell receptor beta chain (Vbeta), resulting in massive, non-specific activation of up to 20-30% of all...