CVS Path

Question 1

Rheumatic fever definition

Answer 1

Acute , immunologically mediated, multisystim inflammatory disease after weeks of GROUP A streptococcal pharyngitis.

Rheumatic fever (common manifestation-Acute rheumatic carditis ) progress to rheumatic heart disease (common manifestation- valvular abnormalities mainly mitral value stenosis as mitral valve fibrosis )

Question 2

Pathogensis of rheumatic fevers

Answer 2

Host immune response to streptococcal antigens cross react with host proteins.

CD4+ T cells against. Strep M proteins cross react with cardiac self antigens.

Antibodies binding can activate complement and recruit fc receptor bearing macrophages & neutrophils

Cytokine sproduced by activated T cells can also activate macrophages in Aschoff body

Question 3

Morphology of rheumatic fevers

Answer 3

Lesions in acute RF are Aschoff bodies.

Aschoff bodies: has T cells, plasmacells & plump activated macrophages called antischow cells

Antischow cells- macrophages with round to oval nucleus, abundant cytoplasm, slender, central, wavy ribbon like chromatin ( caterpillar cells)

Pan carditis-lesions & inflammation in all 3 layers of heart

Verrucae- Inflammation of endocardium and left sided valves result in fibrinoid necrosis within cusps, overlying these necrotic foci are small vegetation’s along the lines of closure called verrucae

Mc-callum plaques: In left atrium, irregular thickenings induced by subendocardial lesions exacerbated by recurrent jets

Important anatomic changes of mitral valve- leaflet thickening, commisural fusion, thickening fusion of tendinous cords.