A 62-year-old man with a history of chronic hepatitis C develops jaundice, rash on the lower extremities, and glomerulonephritis with RBC casts in the urine. Serum cryoglobulins are elevated, and complement levels (C3, C4) are low. Which of the following immune mechanisms is responsible for the vasculitis and glomerulonephritis in this patient?
- A)Type IV hypersensitivity: Th1-mediated vasculitis with granuloma formation
- B)Type I hypersensitivity: mast cell degranulation causing vessel permeability
- C)Type II hypersensitivity: antibody binding to viral antigens on vessel walls
- D)Type III hypersensitivity: immune complex deposition with complement activationGABARITO
- E)Antibody-mediated complement-independent destruction of endothelial cells
Explicação
Hepatitis C-associated mixed cryoglobulinemia is a Type III hypersensitivity disorder. Viral antigens form immune complexes with antibodies (including rheumatoid factor); these complexes deposit in vessels and glomeruli, activating complement and causing vascu... Ver explicação completa e trilha adaptativa →