Flashcards in Vasculitides Deck (43)
What are the three mechanisms of vasculitides?
By which mechanism do the following disorders cause vasculitides?
(e) EGPA, Churg-Straus
(f) Microscopic Polyangiitis
(h) Henoch-Schonlein Purpura
(i) Giant Cell Artritis
Mechanisms of vasculitides
(a) SLE => immune complex
(b) GPA => granulomatous and ANCA
(c) Cryoglobulinemia = immune complex
(d) Hypersensitivity = immune complex
(e) EGPA (Churg-Straus) = ANCA associated
(f) Microscopic Polyangiitis = MPA = ANCA
(g) Takajasu's = granulomatous
(h) Henoch-Schonlein Purpura = immune complex
(i) Giant cell arteritis = granulomatous
(j) RA = immune complex mediated
Name two large vessel vasculitides?
Giant cell arteritis and Takajasu's
What is the prototypical medium vessel arteritis?
PAN = polyarteritis nodosa
Describe the mechanism of immune complex vasculitis
Immune complexes form when there is an excess of antigens and antibodies (often from presence of autoantibodies => Ag-Ab complexes form in circulation then deposit in tissues, or less commonly may form directly in tissues
-immune complexes then activate complement which generates anaphylatoxins and chemoattracts for platelets and neutrophils
-neutrophils infiltrate and release superoxide anions and lysosomal enzymes that injure tissues
Formation of immune complexes --> ICs deposit in BV wall --> Neutrophils release lysosomal enzymes --> Fibrinoid necrosis of BV wall
What is ANCA?
(a) Two ways to measure presence of ANCA
ANCA = anti-neutrophil cytoplasmic antibodies
(a) ANCA presence can be detected by indirect immunofluorescence or ELISA to specific antibodies (to PR3 or MPO)
C-ANCA vs. P-ANCA
(a) location of fluorescent staining
(b) associated with presence of which autoantibody
(c) associated most strongly w/ which vasculitides
C-ANCA vs. P-ANCA
(b) PR-3 autoantibody
(c) strongly associated w/ GPA (granulomatous vasculitis)
(b) Anti-MPO (myeloperoxidase) enzyme
(c) More strongly seen in EGPA and MPA
Describe the pathogenicity of ANCA
-ANCA binds to neutrophils and monocytes, directly inducing ROS release and degranulation
-ANCA binds to endothelial cells and induces injury
In ANCA vasculitides what titers can be monitored to tract treatment response and predict relapse?
Can monitor anti-MPO (EGPA and MPA) and anti-PR3 (GPA) antibodies to monitor treatment response and predict relapse
Mechanism of granulomatous vasculitis
(b) Main cells involved
(c) Key cytokine and its fxn
(d) Key histological finding
(a) Unknown antigen activates
(b) Th1 cells to secrete
(c) Interferon gamma which activates macrophages to form mononuclear cell infiltrates w/ epithelioid cell transformation and granuloma formation
(d) Multinucleated giant cells
Common presentation of a granulomatous vasculitis
Constitutional symptoms: fever, fatigue, weakness
Ddxs to rule out when considering granulomatous vasculitis
Infection, Tb, malignancies (mets or paraneoplastic syndrome)
Describe the pathology of the large vessel vasculitides
Large vessel vasculitides = Giant cell/temporal arteritis + Takayasu's
Pathologically: giant cells, granulomatous inflammation, obliteration of lumen by intimal hyperplasia
Differ the prototypical patient (age and ethnicity) in the large vessel vasculitides
Giant cell arteritis: pt > 50s, Caucasian
Distinguish the typical distribution of the two large vessel vasculitides
Giant cell arteritis: most commonly seen in the extracranial branches of the carotid artery (ex: temporal artery)
Takayasu's: typically involves the aorta or aortic main branches (abdominal aorta, arch of aorta)
Gold standard test to diagnose giant cell arterities
(a) Other tests used
Gold standard test for giant cell arteritis = temporal artery biopsy
(a) Less invasive alternatives = doppler ultrasound, angiogram
What is polymyalgia rheumatica (PMR)?
(a) Hallmark findings
(b) Closely associated w/ which vasculitides?
PMR = pelvic and shoulder pain, no vasculitis if just PMR alone
(a) Hallmark findings = pelvic and shoulder pain
(b) 40-60% of giant cell arteritis cases at some point have PMR
What symptoms can help you diagnose GCA over PMR?
How to tell pt has giant cell arteritis and not just polymyalgia rheumatica?
-possible change/loss of vision b/c of ischemic optic neuropathy
-system features: fever, weakness, fatigue, wt loss
-just hip/shoulder pain w/o any of the other symptoms associated w/ PGA
Differentiate the treatment of GCA and PMR
Both giant cell arteritis and polymyalgia rheumatic are responsive to steroids, but need to use very different doses (much higher in giant cell)
GCA: around 60 mg
PMR: around 15 mg
How is Takayasu's arteritis diagnosed?
Not going to biopsy the aorta...=> use imaging
-CT angiogram, MRI angiogram: shows stenosis of aortic arch etc
2 key exam findings of Takayasu's arteritis
Pts frequently present w/ arm claudication
-decreased radial pulses
Treatment for Takayasu's arteritis
(a) Adjuvant therapy
Takayasu's arteritis tx = steroids
Also can use steroid sparing agents: MTX and Azothiporine (IL-6Ra)
(a) Adjuvant therapy = aspirin or anti-platelet drug b/c there's accelerated atherosclerosis in Takayasu's
Why may a patient with polyarteritis nodosa have postprandial abdominal pain?
PAN = medium artery vasculitis w/ predilection for arterial bifurcation => ischemia of the gut => angina of the gut basically
-if arteries to the gut are blocked then can't increase supply when needed after a meal
What type of arteritis is most likely: 50 yo white male w/ left hand numbness and right foot drop?
PAN = polyarteritis nodosa- medium vessel disease
What infectious disease is polyarteritis nodosa associated w/?
Chronic hep B and C
Two consequences of vascular inflammation
Most common = BV occlusion => tissue ischemia
Less common = rupture of vasculature => hemorrhage into affected organ
Differentiate the organs involved in GPA vs. MPA
(a) which one is granulomatous?
(b) Antibodies found
GPA (granulomatosis w/ polyangiitis) and MPA (microscopic polyangiitis)- both ANCA-associated vasculitides
GPA: lungs, kidney, ENT
MPA: just lung and kidney
(a) GPA is granulomatous
(b) GPA: anti-Pr3
Which vasculitides is staph aureus infection associated with?
GPA = granulomatosis w/ polyangiitis
What is classic clinical triad of granulomatosis w/ polyangiitis?
Upper airway involvement (ex: sinuses, epistaxis, ansal congestion, coughing)
Lower respiratory tract (ex: granulomatous disease in lungs)
-often kidney disease is the last one in the triad to present
Lab findings of GPA
C-ANCA, anti-PR3 (+), elevated ESR (sed rate)
What is the pathological triad of granulomatosis w/ polyangiitis?
^see these 3 features when you biopsy a lesion from the sinuses, lungs, or kidney
What is the most common presenting factor of GPA?
GPA (granulomatosis w/ polyangiitis) most common presentation = upper airway disease
-otologic: hearing loss
-nasal: nasal ulcers, congestion
(c) Approved biologic
Treating GPA (granulomatosis w/ polyangiitis)
(a) Induce remission w/ cyclophosphamide and prednisone
(b) Maintain remission w/ MTX and Azathioprine (IL-6Ra)
(c) Approved biologic = Rituximab = anti-CD20 antibody, Rituximab is approved for all ANCA vasculitides
What findings frequently precede a diagnosis of EGPA (eosinophilic granulomatosis w/ polyangiitis)
EGPA = Chugr Struass
Commonly preceded by asthma, allergy, rhinitis, and atopy (heightened immune response, tendency to develop allergic disease)
Physical exam finding of EGPA
Non-blanching palpable purpura
Lab findings of EGPA
Elevated white count w/ eosinophilia
P-ANCA, anti-MPO (+)
What size vessels do the ANCA vasculitides involve?
Diagnose the vasculitides:
-diffuse infiltrates on CXR
= MPA = microscopic polyangiitis
-diffuse infiltrates on CXR = lung involvement
-elevated creatinine = kidney disease
-N/V due to uremia (kidney disease)
MPA = small vessel disease involving renal and pulmonary capillaries
Lab findings of microscopic polyangiitis
MPA: P-ANCA, anti-MPO (+)
-possibly elevated creatinine or BUN indicating renal involvement
What is the clinical triad of Behcet's disease?
Oral ulcers, genital ulcers, anterior uveitis (inflammation of the uvea of the eye)
What is Behcet's disease?
Rare, immune-mediated small vessel systemic vasculitis that presents w/ mucus membrane ulceration and ocular problems
What is Henoch Shonlein purpura?
(a) Most common in what population?
(b) Often preceded by what?
Systemic vasculitis (inflammation of BV) due to deposition of IgA containing immune complexes in BV walls
(a) 90% in children
(b) Often preceded by infection (ex: strep throat)