A 19-year-old woman presents with fever (39.2°C), petechial rash, and meningitis. Vitals show HR 118/min, BP 94/62 mmHg, RR 22/min, SpO2 98% on room air. Blood cultures pending; CSF shows elevated protein and pleocytosis. Skin biopsy reveals acute inflammation with hemorrhage and fibrinoid necrosis of vessel walls. Notably, neutrophil infiltration is minimal. She denies recent drug exposure. Which hypersensitivity reaction mechanism explains the observed vascular injury pattern?
- A)Type I hypersensitivity with direct antibody activation of endothelium
- B)ADCC-mediated antibody-dependent cell-mediated cytotoxicity
- C)Type III hypersensitivity with immune complex-mediated vasculitisGABARITO
- D)Type IV hypersensitivity with cytotoxic T-lymphocyte infiltration
- E)Type II hypersensitivity with complement-dependent cytotoxicity
Explicação
Neisseria meningitidis septicemia causes a Type III hypersensitivity reaction. Bacterial antigens form immune complexes that deposit in vessel walls, activate complement via fibrinoid necrosis, and cause the characteristic petechial rash with hemorrhage and en... Ver explicação completa e trilha adaptativa →