Immunology · NEET PG Preparation Microbiology
A patient is evaluated for hereditary angioedema characterized by recurrent episodes of non-pruritic swelling of the face, extremities, and airway, w…
Practice question from Immunology (NEET PG Preparation Microbiology), with the correct answer and a step-by-step solution.
medium · MCQ · Q-9F58AB
A patient is evaluated for hereditary angioedema characterized by recurrent episodes of non-pruritic swelling of the face, extremities, and airway, without urticaria. Laboratory tests show low levels of C4 and decreased functional activity of C1 esterase inhibitor (C1-INH). Which of the following pathways is directly and constitutively overactivated in this condition?
- A.Alternative complement pathway
- B.Classical complement pathwayCorrect answer
- C.Lectin pathway
- D.Terminal membrane attack pathway
Solution
C1 inhibitor normally inhibits C1r and C1s of the classical complement pathway, as well as kallikrein and factor XII of the contact activation system. Deficiency of C1-INH leads to unregulated activation of the classical pathway (consuming C4 and C2) and overproduction of bradykinin, causing angioedema.
More from Immunology
- A 32-year-old man presents with recurrent sinopulmonary infections and bronchiectasis. Laboratory evaluation reveals profoundly low serum l…
- Which of the following interleukins is the primary growth, survival, and differentiation factor for naive T cells and is essential for the…
- A 4-year-old boy presents with recurrent skin abscesses caused by Staphylococcus aureus and deep-seated fungal infections with Aspergillus.…
- During negative selection in the thymic cortex and medulla, developing thymocytes that recognize self-antigens presented by cortical and me…
Practise more Microbiology
Sign up free for adaptive practice on this chapter, with instant feedback and hints on every question.
Start practising freeFree to start · No credit card needed