A 34-year-old man with recent streptococcal pharyngitis develops two weeks of progressive dyspnea, orthopnea, and lower extremity edema. Echocardiography shows a dilated left ventricle with reduced ejection fraction. Serum creatinine is elevated, and urinalysis shows RBC casts and mild proteinuria. Which of the following immune mechanisms best explains the cardiac and renal pathology?
- A)IgE-mediated type 1 hypersensitivity causing systemic anaphylaxis
- B)Massive complement activation from immune complex deposition causing acute myocarditis
- C)Molecular mimicry of streptococcal antigens cross-reacting with myocardial and glomerular basement membrane proteinsGABARITO
- D)Th1-mediated granulomatous inflammation in the myocardium
- E)Persistent streptococcal superantigen activation of all T cells regardless of specificity
Explicação
Acute rheumatic fever (ARF) develops 2-3 weeks post-streptococcal pharyngitis through molecular mimicry. Streptococcal M protein shares epitopes with myosin, tropomyosin, and N-acetyl-β-D-glucosamine (similar to glomerular basement membrane proteins). Autoanti... Ver explicação completa e trilha adaptativa →