CV Pathology 1 Flashcards
organization of the vasculature into tunics
- intima:
-endothelium = hemostasis regulation
-internal elastic lamina layer - media:
-smooth muscle, helically arranged
-elastic fibers - aventitia:
-connective tissues (loose/dense irregular)
-+/- vaso vasorum
vasculature classifications
- elastic:
-maintain BP
-aorta, pulmonary artery - muscular:
-distribute blood to/from organs - arterioles/venules:
-control blood into/out of capillary bed - capillaries:
-tissue gas/nutrient exchange
-types: continuous, fenestrated, sinusoidal
inflammatory markers - general
*certain proteins released into the bloodstream during inflammation
*if their concentrations increase or decrease by at least 25%, they can be used as systemic inflammatory markers
*help to identify generalized inflammatory state (NOT diagnostic for any particular condition)
*examples: C-reactive protein, erythrocyte sedimentation rate
C-reactive protein (CRP)
*a general inflammatory marker (reliable early indicator of active systemic inflammation)
*made in liver following IL6 secretion by macrophages/T cells
*helps to activate complement
*normal range: <3-10 mg/L
*infections/inflammatory conditions → several hundred-fold increase
*concentrations change rapidly in first 6-8 hours after injury, peak at 48 hours, then normalize once the issue has resolved
erythrocyte sedimentation rate (ESR; sed rate)
*a general inflammatory marker
*ESR = rate at which RBCs in anticoagulated whole blood descend in a standardized tube over a period of 1 hour
*indirect measurement of plasma protein concentrations
*normal values are specific to age and sex
*increased levels → inflammation, pregnancy, anemia, autoimmune disorders, infections, cancer
anti-neutrophilic cytoplasmic antibodies (ANCAs) - overview
*heterogenous autoantibodies directed against neutrophil primary granules and monocyte lysosomes
*directly ACTIVATE neutrophils, stimulating release of ROS and proteolytic enzymes, which in vascular beds → endothelial cell injury
*useful diagnostic markers
anti-myeloperoxidase (MPO-ANCA)
*specific type of perinuclear-ANCA (p-ANCA)
*elevated levels = EGPA (eosinophilic granulomatosis with polyangiitis)
anti-proteinase-3 (PR3-ANCA)
*specific type of cytoplasmic-ANCA (c-ANCA)
*elevated levels = GPA (granulomatosis with polyangiitis)
vasculitis - overview
*group of disorders defined by presence of vessel wall inflammation & destruction
*highly varied pathophysiology and clinical features
*any vessel in any organ may be affected
*> 20 primary forms, based on:
-vessel diameter
-role of immune complexes
-type of inflammation
-organ specificity
-population demographics
vasculitis - general clinical manifestations
*findings referable to the specific tissue(s) involved
*constitutional s/s associated with systemic inflammation: fever, myalgias, arthralgias, malaise
vasculitis - pathogenesis
- immune-mediated inflammation:
-immune complex deposition
-ANCA antibodies
-anti-endothelial cell antibodies
-autoreactive T cells - direct invasion of vascular walls by infectious pathogens:
-may generate immune complexes indirectly inducing immune-mediated process - direct physical/chemical injury (irradiation, mechanical trauma, toxins)
giant cell arteritis - overview
*chronic granulomatous disorder that principally affects LARGE-SIZED ARTERIES in the head
*most common form of vasculitis among US elderly
*arteries commonly affected: TEMPORAL ARTERY, vertebral arteries, ophthalmic arteries, aorta
note - an example of large vessel arteritides
giant cell arteritis - pathogenesis
*T cell-mediated response to as-yet uncharacterized vessel wall antigen
*pro-inflammatory cytokines (TNF) and anti-endothelial cell antibodies
*granulomatous inflammation
giant cell arteritis - pathology
*GRANULOMATOUS INFLAMMATION IN A PATCHY DISTRIBUTION
-nonnecrotizing
-multinucleated giant cells
-fragmented internal elastic membrane
-involved segments exhibit intimal thickening impinging on lumen, causing distal ischemia
Kawasaki disease - overview
*acute, febrile, self-limited arteritis of infancy/childhood
*usually medium vessels/coronary arteries are affected
note - an example medium vessel arteritides