A 6-year-old boy presents with recurrent bacterial sinusitis (HR 102, BP 108/70, RR 22, Temp 38.2°C). CT sinuses shows opacification of maxillary sinuses with normal neutrophil count (7,200/μL). His physician suspects an inherited complement disorder and explains that one complement fragment normally coats bacteria to promote their uptake by neutrophils and macrophages. Which complement component has this opsonization function?
- A)C5b 9
- B)Factor H
- C)C5a
- D)C3bGABARITO
- E)C3a
Explicação
C3b is the major opsonin of the complement system and binds microbial surfaces to enhance phagocytosis. Recurrent pyogenic infections are common when opsonization is impaired because neutrophils and macrophages clear bacteria less efficiently. Ver explicação completa e trilha adaptativa →