MCQ Pathology Answer 25

• Immune mediated disorder secondary to pharyngitis caused by GAβHS (Strep. pyogenes)

• Presents 2-3 weeks following infection

• Possibly due to cross reactivity of anti-M capsular Abs

• Slight familial predisposition

• 3% of infections progress to RF

• 70% have mitral valve involvement

• 25% have combined mitral & aortic valve involvement

• Mitral valve involvement > women

• Aortic valve involvement > men

• Stenosis > regurgitation

• Immune complex deposition

• Mixed inflammatory infiltrate of all heart layers with fibrinoid necrosis

• Possible fibrinous pericarditis

• Aschoff bodies, ring of mixed inflammatory cells with central necrosis and large macrophages (Anitschkow cells)

• Line of closure vegetations and leaflet/chordae tendineae fusion

Category: Pathology MCQs