Pathophysiology Flashcards
Pancreatitis causes
- ERCP
- Drugs (eg azathioprine, sulfasalazine, furosemide, valproic acid)
- infections (eg mumps, coxsackie, mycoplasma pneumoniae)
- hypertriglyceridemia
- structural abnormalities of the pancreatic duct (strictures, cancer, pancreas divisum) or of the ampullary region (choledochal cyst, stenosis of sphincter of Oddi)
- surgery (particularly of stomach, biliary tract, and cardiac surgery)
- hypercalcemia
Crohn’s Disease labs
inc urine oxalate (from intestinal malabsorption) –> calcium oxalate stones
Pheochromocytoma
- arises from neuroendocrine/chromaffin cells in adrenal medulla
- 25% inherited (VHL, RET, NF1)
- inc catecholamine secretion –> headaches, tachycardia/palpitations, sweater, HTN
- Rule of 10s: b/l, extra-adrenal (paragangliomas), malignant
dx = elevated urinary & plasma catecholamines & metanephrines
Thyroiditis
acute, suppurative, subacute, postpartum
- excessive release of preformed thyroid hormone
- symptoms continuous
exam 1 q13
Carcinoid syndrome
excess 5HT and its metabolite 5HIAA from metastatic mid-gut neuroendocrine tumor
sx = flushing, bronchospasm, diarrhea, HoTN
Schwannoma
peripheral nerve tumor located at cerebellopontine angle
sx = tinnitus and unilateral hearing loss
CN III palsy
unilateral ptosis and gaze palsy (“down and out” gaze)
c/b berry aneurysm or uncal herniation or microvascular ischemia (e.g. due to DM)
Wernicke Syndrome triad
ophthalmoplegia, ataxia, confusion
Wernicke Syndrome cause and pathology
chronic thiamine deficiency –> dec glucose utilization esp in CNS
*erythrocyte transketolase levels increased after thiamine infusion
foci of hemorrhage and necrosis in mamillary bodies and periaqueductal gray matter on autopsy
hemolytic anemia cause
decreased G6PD
vitamin B12 deficiency
elevated methylmalonic acid levels
Erythropoietic protoporphyria (EPP)
increased erythrocyte protoporphyrin concentration, i.e. one of the precursors of heme
cholesterol gallstones risk factors
- high TG
- combo of fibric acid derivates and bile acid-binding resins –> inc cholesterol concentration in bile
- etoh
Sickle cell disease
single amino acid substitution: glutamic acid (negatively charged) –> valine (nonpolar, neutral charge) at 6th position in beta-globin chain of Hb molecule
alteration of a region on beta-globin surface that allows hydrophobic interaction among Hb molecules –> aggregation of Hb molecules –> sickling
sickling promoted by hypoxia, inc acidity, dehydration
Hb C disease
glu is replaced by a basic polar (positive charge) lysine
no hydrophobic interactions among Hb molecules as in SCD, hence less severe condition
Saccular (berry) aneurysms
most common cause of SAH (AVM = 2nd most common cause)
usually occur at Circle of Willis
*Anterior communicating artery = most common site
Associated diseases:
- Ehlers-Danlos
- AD polycystic kidney disease
Cerebral amyloid angiopathy
elderly patients
- asx
- or sx from recurrent intracerebral hemorrhages affecting small areas = HA, focal neuro deficits
Charcot-Bouchard aneurysms
- lenticulostriate vessels of basal ganglia 2/2 HTN
bluish neoplasm under nail bed
Possible origin:
- glomus tumor (glomangioma) - thermoregulation function; tumor of modified smooth muscle cells of glomus body whose task is to shunt blood away from skin surface in cold temperature and direct it toward skin surface in hot environments
- subungual melanoma - pigmentation fxn
nephritic syndrome
HTN, hematuria, moderate proteinuria (can see pitting edema)
- Post-streptococcal glomerulonephritis (happens weeks after)
- Anti-GBM disease
- Rapidly progressive glomerulonephritis
- IgA nephropathy
- Alport syndrome
Post-streptococcal glomerulonephritis
Ab against strep Ag cross-react with GBM
Anti-GBM disease
Ab agains type IV collagen GBM –> C3 and IgG deposition in basement membrane
these Ab can cross-react with collagen type IV in alveolar basement membrane –> pulmonary hemorrhage –> renal failure + pulmonary hemorrhage = Goodpasture syndrome
Rapidly progressive glomerulonephritis
severe immune injury (e.g. anti-GBM Ab, immune complex deposition)
glomerular crescents = proliferating parietal cells with infiltration of monocytes and macrophages seen on LM
IgA nephropathy
deposition of IgA-containing complexes
Alport syndrome
defective type IV collagen in GBM
Goodpasture syndrome
anti-GBM disease patient with pulmonary hemorrhage in addition to renal failure
Familial pulmonary arterial htn
inactivating mx of pro-apoptotic BMPR2 gene –> inc in endothelial and smooth muscle cell proliferation
inc arteriolar smooth muscle thickness (medial hypertrophy), intimal fibrosis, luminal narrowing
progresses to plexiform lesions = tufts of small vascular channels
sx = dyspnea, exercise intolerance in women 20-40 yo
tx = lung transplant, vasodilators (e.g. Bosentan = endothelin receptor antagonist and endothelin’s vasoconstricting action)
Paroxysmal supraventricular tachycardia (PSVT)
c/b re-entrant impulse traveling through slowly and rapidly conducting segment of AV node
tx = slow conduction through AV node in order to abolish re-entrant circuit
atherosclerosis
endothelial cell dysfunction –> macrophage and LDL accumulation –> foam cell formation –> fatty streaks –> smooth muscle cell migration (involves PDGF and FGF) –> proliferation and extracellular matrix deposition –> fibrous plaque –> complex atheromas
*occurs in the intima of elastic and large- and medium-sized arteries
abdominal aorta > coronary artery > popliteal artery > carotid artery
RFs for aortic dissection
HTN
bicuspid aortic valve
cystic medial necrosis (Marfan’s syndrome)
inherited connective tissue d/o
Prinzmetal’s variant (anginga)
2/2 coronary artery spasm and occurs at rest
see ST elevation on EKG
Coronary steal syndrome
vasodilator may aggravate ischemia by shunting blood from area of critical stenosis to an area of higher perfusion
Chronic ischemic heart disease
chronic ischemic myocardial damage –> progressive onset of CHF over many years
findings 0-4 hours after MI
gross: none
LM: none
risk for arrhythmia, CHF exacerbation, cardiogenic shock
findings 4-12 hours after MI
gross: occluded artery, dark mottling but pale with tetrazolium stain in area of infarct
LM: early coagulative necrosis edema hemorrhage wavy fibers
findings 12-24 hours after MI
gross: occluded artery, dark mottling but pale with tetrazolium stain in area of infarct
LM:
contraction bands from reperfusion injury
release of necrotic cell content into blood
beginning of neutrophil migration
risk for arrhythmia
findings 1-3 days after MI
gross: hyperemia
LM:
- extensive coagulative necrosis
- tissue surrounding infarct shows acute inflammation
- neutrophil migration
risk for fibrinous pericarditis with friction rub
findings 3-14 days after MI
gross: hyperemic border; central yellow-brown softening (maximally yellow and soft by 10 days)
LM:
macrophage infiltration followed by granulation tissue at the margins
risk of free wall rupture –> tamponade, papillary muscle rupture, ventricular aneurysm, interventricular septal rupture due to macrophages that have degraded important structural components
findings 2 weeks to several months after MI
gross: recanalized artery, region of infarct is gray-white
LM:
contracted scar is complete
risk for Dressler’s syndrome (AI fibrinous pericarditis 2/2 cardiac injury)
cardiac troponin I
rises after 4 hours, elevated for 7-10 days
most specific protein marker for cardiac injury
CK-MD
predominantly found in myocardium but can also be of skeletal muscle origin
***useful in diagnosing reinfarction after acute MI bc levels return to normal after 48 hours
subendocardial infarcts
due to ischemic necrosis of
EKG anterior wall LAD infarct
V1-4
EKG anteroseptal LAD infarct
V1-2
EKG anterolateral LCX infarct
V4-6
EKG lateral wall LCX infarct
I, aVL
EKG inferior wall RCA infarct
II, III, aVF
Temporal arteritis
Large-vessel vasculitis
- elderly female
- u/l HA, jaw claudication
- assoc. with PMR
- tx w high-dose corticosteroid
Takayasu’s arteritis
large-vessel vasculitis
-asian females
polyarteritis nodosa
medium-vessel vasculitis
- young adults
- HBV in 30% of pts
- p/w fever, weight loss, malaise, HA
- GI sx = abd pain, melena
- HTN, neuro dysfunction, cutaneous eruptions, renal damage
- affects renal and visceral vessels, NOT PULMONARY ARTERIES
- immune-complex mediated
- transmural inflammation of the arterial wall with fibrinoid necrosis –> lesions of different ages
- many aneurysms and constrictions on arteriogram
- tx w/ corticosteroids and cyclophosphamide
Kawasaki disease
medium-vessel vasculitis
asian children MI, rupture
tx - high dose aspirin and IVIG
Buerger’s disease (thromboangiitis obliterans)
medium-vessel vasculitis
heavy smokers, males gangrene –> autoamputation of digits
- superficial nodular phlebitis
- Raynaud’s phenomenon
- segmental thrombosing vasculitis
tx - STOP SMOKING
microscopic polyangiitis
small-vessel vasculitis
necrotizing vasculitis commonly involving lungs, kidneys, skin with pauci-immune glomerulonephritis and palpable purpura
no granulomas
p-ANCA
tx with cyclophosphamide and corticosteroids
Granulomatosis with polyangiitis (Wegener’s)
small-vessel vasculitis
upper respiratory tract: perforation of nasal septum, chronic sinusitis, otitis media, mastoiditis
lower respiratory tract: hemoptysis, cough, dyspnea
renal: hematuria, red cell casts
triad:
- focal necrotizing vasculitis
- necrotizing granulomas in the lung and upper airway
- necrotizing glomerulonephritis
c-ANCA
CXR- large nodular densities
tx with cyclophosphamide, corticosteroids
Churg-Strauss syndrome
small-vessel vasculitis
Asthma, sinusitis, palpable purpura, peripheral neuropathy (wrist/foot drop)
can also involve heart, GI, kidneys (pauci-immune glomerulonephritis)
granulomatous, necrotizing vasculitis with EOSINOPHILIA
p-ANCA, elevated IgE
Henoch-Schonlein purpura
small-vessel vasculitis
most common childhood vasculitis –> often after URI
Triad:
- skin: palpable purpura on buttocks/legs
- arthralgia
- GI: abd pain, melena, multiple lesions of same age
vasculitis 2/2 IgA complex deposition
associated with IgA nephropathy
Bernard-Soulier syndrome
defect in GpIb receptor that binds platelets to vWF (which is attached to endothelium)
Abciximab
blocks GpIIb/IIIa
Glanzmann’s thrombasthenia
deficiency of GpIIb/IIIa
Fibrinogen
links GpIIb/IIIa receptors
causes of increased ESR
infections, AI disease, malignant neoplasms, GI disease, pregnancy
causes of decreased ESR
polycythemia, sickle cell anemia, CHF, microcytosis, hypofibrinogenemia
orotic aciduria
genetic mutation in UMP synthase –> can’t make uridine from orotic acid
p/w metaloblastic anemia not cured by B12 or folate
tx with uridine monophosphate to bypass defective enzyme
causes of nonmegaloblastic macrocytic anemias
basically macrocytic anemia where DNA synthesis is not impaired
- liver disease
- EtOHism
- reticulocytosis
- drugs (5-FU, AZT, hydroxyurea)
aplastic anemia
c/b failure or destruction of myeloid stem cells due to:
- radiation and drugs (benzene, chloramphenicol, alkylating agents, antimetabolites)
- viral agents (parvoB19, EBV, HIV, HCV)
- Fanconi’s anemia (DNA repair defect)
- idiopathic (immune-mediated, primary stem cell defect); may follow acute hepatitis
findings: hypocellular bone marrow with fatty infiltration
AIP: defect, substrate accumulation, 5Ps, and tx
defective porphobilinogen deaminase
accumulation of porphobilinogen, ALA, uroporphyrin (urine)
- Painful abdomen
- Port wine-colored urine
- Polyneuropathy
- Psychological disturbances
- Precipitated by drugs
Tx: glucose and heme (inhibit ALA synthase)
PT tests…
extrinsic pathway
I, II, V, VII, X
PTT tests…
intrinsic pathway
all factors except VII and XIII
vitamin K cofactors
II, VII, IX, X, protein c, protein S
see inc in PT and PTT
Glanzmann’s thrombasthenia
defect in platelet plug formation
dec GpIIb/IIIa –> defective platelet aggregation
Labs: blood smear shows no platelet clumping
ITP
defect: anti-GpIIb/IIIa Ab —> splenic macrophage consumption of platelet/Ab complex
dec platelet survival –> low platelet count
labs: inc megakaryocytes
TTP
deficiency in ADAMTS 13 (vWF metalloprotease) –> dec degradation of vWF multimers –> inc large vWF multimers –> inc platelet aggregation and thrombosis
dec platelet survival hence low platelets
labs; schistocytes, inc LDH
TTP pentad of sx
neurologic, renal, fever, thrombocytopenia, microangiopathic hemolytic anemia
vWF disease
dec platelet to vWF adhesion 2/2 low vWF
most common inherited bleeding d/o
AD
dx with ristocetin assay
tx: desmopressin (DDAVP) –> releases stored vWF from endothelium
causes of DIC
“STOP Making New Thrombi”
Sepsis (gram-negative) Trauma Ob complications acute Pancreatitis Malignancy Nephrotic syndrome Transfusion
Factor V Leiden mx
mutant factor V resistant to degradation by protein C
most common inherited hypercoagulability in whites
Prothrombin gene mx
mx in 3’ UTR –> inc production of prothrombin –> inc plasma levels and venous clots
Antithrombin deficiency
inherited
inc PTT blunted after give heparin (bc it potentiates action of ATIII)
Protein C or S deficiency
dec ability to inactivate factors V and VIII –> inc risk of thrombotic skin necrosis with hemorrhage following admin of warfarin (bc it inactivates C and S further)
what is in fresh frozen plasma
coagulation factors
what is in cryoprecipitate
fibrinogen, factor VIII, factor XIII, vWF, and fibronectin
Most common Hodgkin’s lymphoma
nodular sclerosing
best prognosis
Burkitt’s lymphoma genetic mutation
t(8;14) - translocation of c-myc on 8 and havey chain Ig (14)
affects adolescents and young adults
Path findings of Burkitt’s, virus it’s associated with, endemic vs sporadic form
NHL
starry sky - sheets of lymphocytes with interspersed macrophages
associated with EBV
jaw lesion in endemic form in Africa; pelvis or abdomen in sporadic form
most common adult non-hodgkin lymphoma
Diffuse large BC lymphoma
20% of mature TC origin
Mantle cell lymphoma genetic mutation
t(11;14)
cyclin D1 (11) and heavy-chain Ig (14)
poor prognosis, CD5+
Follicular lymphoma genetic mx
t(14;18)
heavy chain Ig (14) and bcl-2 (18)
difficult to cure, indolent course
Adult TC lymphoma
c/b HTLV-1
p/w cutaneous lesions, esp affects Japan, West Africa and Caribbean
Aggressive
Mycosis fungoides/Sezary syndrome
mature TC neoplasm
adults p/w cutaneous patches/nodules
CD4+, indolent course
Multiple Myeloma
produces lots of IgG (55%) and IgA (25%)
most common primary tumor of bone in elderly
a/w primary amyloidosis, punched out lytic lesions, Monoclonal M protein spike, Ig light chains in urine (Bence Jones protein), rouleaux formation of RBCs
CRAB: hyperCalcemia, Renal insufficiency, Anemia, Bone lytic lesions/Back pain
Waldenstrom’s macroglobulinemia
M spike = IgM (–>hyperviscosity symptoms); no lytic bone lesions
MGUS
monoglonal gammopathy of undetermined significance
monoclonal expansion of plasma cells with M spike
asx PRECUROSR of MM –> develop MM 1-2% per year
