A 24-year-old woman presents to the emergency department with fever (39.2°C), vomiting, and a diffuse erythematous sunburn-like rash. Vital signs show hypotension (88/56 mmHg), tachycardia (118 bpm), and tachypnea (22 bpm). She started her menstrual period yesterday and left a tampon in place overnight. Laboratory studies reveal thrombocytopenia (platelets 85,000/μL) and elevated creatinine (2.1 mg/dL). She denies vaginal pain. Which of the following best explains the mechanism of the toxin causing her illness?
- A)Nonspecific activation of T cells by cross linking MHC II and T cell receptorsGABARITO
- B)Inactivation of elongation factor 2
- C)Cleavage of synaptobrevin at peripheral cholinergic terminals
- D)Inhibition of the 60S ribosomal subunit
- E)Blocking release of inhibitory neurotransmitters from Renshaw cells
Explicação
Toxic shock syndrome toxin is a superantigen that cross links MHC II on antigen presenting cells with the beta chain of the T cell receptor outside the normal antigen binding groove. This triggers massive polyclonal T cell activation and cytokine release, caus... Ver explicação completa e trilha adaptativa →