Important new information has been gained on the pathogenesis and treatment of life-threatening invasive infections caused by group A streptococci (GAS), i.e. streptococcal toxic shock syndrome (STSS) and necrotizing fasciitis (NF). Both STSS and NF lead to superantigen reactions, with activation of up to 10% of CD4+ lymphocytes and release of large amounts of cytokines, mainly tumour necrosis factor beta, interferon gamma, interleukin-1 and interleukin-6. Streptococcal products known to trigger superantigen reactions are the pyrogenic exotoxins SpeA, SpeB and SpeC, and the M proteins. Therapeutically, clindamycin has been shown to reduce mortality in animal experiments compared with penicillin treatment. A possible mechanism is the effect of clindamycin on protein synthesis, which might decrease the production of superantigens. In humans, the use of intravenous immunoglobulin has been shown to significantly reduce mortality in STSS and NF. The most probable mechanism is neutralisation of superantigens by antibodies in the immunoglobulin preparations used.
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The author(s) declare there are no affiliations with or involvement in any organisation or entity with any financial interest in the subject matter or materials discussed in this manuscript.
