The pathogenesis of experimental toxic shock syndrome: the role of interleukin-2 in the induction of hypotension and release of cytokines.

Toxic shock syndrome (TSS) is a multisystem disorder characterized by fever, hypotension, and involvement of three other organ systems. The etiologic agent is a toxigenic strain of Staphylococcus aureus which secretes the exotoxin, TSST-1. The toxin is a superantigen which stimulates the immune system to produce interleukin-1 (IL-1), interleukin-2, and tumor necrosis factor (TNF). We hypothesized that TSST-1 induces the release of IL-2 which in turn is either directly involved or acts via an additional mediator to produce hypotension. We submitted four pairs of normal anesthetized adult female baboons to intravenous boluses of TSST-1. One baboon in each pair received anti-IL-2 intravenously and anti-IL-2 receptor intrathyroidally 15 min prior to TSST-1. The other baboon received the same dose and placement of anti-sheep red blood cell antibody. Systolic and diastolic blood pressure was recorded continuously and mean arterial pressure was calculated and plotted. IL-1, IL-2, IL-6, and TNF were measured in serum at varying times before and after toxin administration. Systolic, diastolic, and mean arterial pressure were significantly lower in the sham-treated group versus the experimental (anti-IL-2/IL-2R) group (p < .05 for all variables). In addition no differences were seen in any of the measurements between experimentally treated baboons and those receiving no TSST-1.(ABSTRACT TRUNCATED AT 250 WORDS)