Pathoma--Chapter 2 Flashcards
what are the key mediators of pain?
PGE2 and bradykinin
what are the four cardinal signs of inflammation?
- redness-rubor & warmth calor
- swelling
- pain
- fever
what is the mechanism behind redness in acute inflammation?
vasodilation and increased blood flow
- mediated by prostaglandins, bradykinin, and histamine*
- lead to vasodilation of the arteriole bed
what is the mechanism behind pain in acute inflammation?
sensitization of nerve endings
-caused by bradykinin and PGE2
what two things mediate pain in the inflammatory response?
PGE2 and bradykinin
what is the mechanism of fever?
macrophages release IL-1 & TNF–> perivascular cells of hypothalmaus ( increase in COX–> PGE2)
-increase in set point
What are the 5 mediators of acute inflammation?
- TLR (toll-like receptors)
- Arachdonic acid metabolites
- Mast cells
- Complement
- Hagemen factor (Factor XII)
What factor is associated with DIC?
Hagemen factor (factor XII)
(inactive proinflammatory protein produced in liver that is activated upon exposure to subendothelial or tissue collagen)
-activates coagulation and fibrinolytic systems
-activates complement
-activates kinin
What is an inactive inflammatory protein produced in the liver?
Hageman factor (factor XII) -associated with DIC
What 3 ways is complement activated?
- classically
- alternative pathway
- mannose binding lectin pathway
What is the classic activation of complement?
C1 binds to IgG or IgM that is bound to antigen
What is the alternative activation of complement?
microbial produces directly activate complement
How does the MBL pathways activate complement?
MBL binds to mannose on microrganisms
What happens once complement is activated?
- C3 convertase (C3–> C3a & C3b)
- C5 convertase ( C5–> C5a & C5b)
- C5b complezes with C6-C9 to form MAC
What is the fxn of C3a & C5a?
trigger mast cell degranulation
What is an additional fxn of C5a?
chemotactic for neutrophils
What is the fxn of C3b?
opsonin for phagocytosis
-protein that tags things that neutrophils need to eat up!
What is the fxn of MAC?
MAC (membrane attack complex)
-lyses microbes by creating holes in the cell membrane
What 3 things activate mast cells?
- tissue trauma
- complement proteins C3a & C5a
- Cross linking of cell surface IgE by antigen
What are the 4 key mediators that attract and activate neutrophils?
- LTB4
- C5a
- IL-8
- bacterial products
How is arachadonic acid released from cell membranes?
phospholipaseA2
-two pathways–> enzymes cyclooxygenase (prostaglandins) OR 5-lipoxygenase (leukotrienes)
What happens when a mast cell is activated?
release of preformed histamine
- immediate response: vasodilation and increased vascular permeability
- maintaince: production of leukotrienes
What do prostaglandins do?
PGI2, PGD2, PGE2 –> mediate vasodilation and increased vascular permeability
-PGE2–also mediates pain and fever
What do leukotrienes do?
mediate vasoconstriction, bronchospasm, increased vascular permeability
(2/2 to smooth muscle contraction)
- LTC4, LTD4, LTE4
- LTB4–attracts neutrophils
how are TLR activated?
PAMP (pathogen asoscated molecular patterns)
What is CD14?
TLR that recognizes LPS (PAMP) on gram - bacteria
What does TLR activation cause?
upregulation of NF-KB (nuclear transcription factor)
-activates immune response genes
Do TLR play a role in acute or chronic inflammation?
both
What chromsome mutation is associated with DiGeorge Syndrome?
22q11 microdeletion
Developmental failure of the 3rd and 4th pharyngeal pouch leads to what immunodeficiency?
DiGeorge Syndrome
What is the presentation of DiGeorge syndrome?
things derived from 3/4 pharyngeal pouch
- lack of thymus–T cell deficiency (problems fighting viruses & fungal infection)
- lack of parathyroid–issues with Ca (hypocalcemia)
- great vessels, lower face, superior aspect of heart
What type of immune deficiency occurs in SCID?
both cell mediated (tcell) & humoral (B cell) immunity
what are the etiologies of SCID?
- cytokine receptor defect
- adenosine deaminase deficiency
- MHC II deficiency
characteristics of SCID
what is the tx–temporary and long term
- increased risk of opportunistic infections, fungal, parasitic, viral, and bacterial infection
- avoid live vaccines
- temporary measure: bubble baby!
- long term tx: stem cell transplant–> now they can develop normal
X linked agammaglobuinemia is characterized by
complete lack of ig in blood
2/2 to defective B cell maturation–> plasma cells
what is the mutation in X linked agammaglobuinemia?
bryton tryosine kinase mutation (BTK)
what is the typical presentation of Xlinked agammaglobuinemia? what are these patients at risk for developing?
bacterial , enterovirus , giardia
IgG allows for opsonination
IgA protective against mucosal infections
typically presents after 6 mths
CVID characterized by?
symptoms?
low immunoglobin
2/2 to B cell or helper T cell defect (both required to produce immunoglobin
-typically asymptomatic
Patients with CVID are at increased risk for what as they get older?
autoimmune disease and lymphoma
what three types of infections are people without immunoglobins (low Ig) at risk for developing?
bacterial, entervirus, giardia
What is the most common cause of Ig deficiency?
IgA deficiency
What does IgA protect you from?
mucosal infections–particuarly viral
Patients with what GI disease commonly have IgA deficiency?
Celiac disease–low IgA
hyper IgM syndrome is characterized by?
mutations in what leads to this disease?
characterized by too much IgM
2/2 to mutations in CD40
Class switching is required to produce what Igs?
IgA, IgG, IgE
-pt will have high IgM
Wiskott Aldrich syndrome characterized by triad of
It is caused by a defect in what protein?
thrombocytopenia (petechiae, gum bleeding)
ecezma
recurrent infections
2/2 to defect in Wiskott Aldrich syndrome protein (X linked)
deficiencys in any complement C5-C9 they are at increased risk for developing what infections?
Neisseria
deficiency in C1 inhibitor lead to
herediatry angioedema
-edma of skin and mucosal lining (particularly periorbital)
what are the three types of tissues based on regenerative capabilities?
what are examples of each?
- labile: bowel (SC in crypts), skin (SC in basal layer), bone marrow
- stable: liver or proximal renal tubule
- permanent: myocardium, skeletal muscle, neurons
what is the difference between regeneration and repair?
regeneration: requires SC
repair: scar formation
what is the inital tissue type in scar formation? what are the three things characteristically found in it?
granulation tissue
- myofibroblasts
- fibroblasts
- blood vessels
what type of collagen is granulation tissue compromised of?
type III
which of the four types of collagen is strongest? where can each class of collagen classically be seen?
type I has high tensile strength (bone)
type II-cartiledge
type III-pliable (granulation tissue, embryonic tissue)
type IV-basement membrane
what is the fxn of TGF-alpha?
epithelial and fibroblast growth factor
what is the fxn of TGF-beta?
STOp inflammation and initate repair along with IL-10
-fibroblast growth factor
fxn of PDGF
platlet derived growth factor
GF for endothelium, smooth muscle, and fibroblasts
fxn of FGF
fibrobast growth factor
-angiogenesis
skeletal development
fxn of VEGF
vascular endothelial growth factor
-angiogenesis
what is the difference between primary and secondary intention wound healing?
1- realign the edges–ex) suturing
2- edges not reapproximated (space fills with granulation tissue–big scar, can contract 2/2 to myofibroblasts)
what is the most common cause of delayed wound healing?
infection
Deficiency of what three cofactors can independently cause delayed wound healing?
vitamin C (cofactor in hydroxylation of proline-lysine in procollagen--neccessary for crosslinking) Cu (cofactor for lysyl oxidase enzyme that plays a role in cross linking of collagen) Zinc (cofactor for collagenase--replaces type III--> type I collagen)
Hypertrophic scar is caused be excess of what type of collagen?
Type I
Keloid is caused by excess of what type of collagen? what population is most at risk? where are they most commonly seen?
type III, AA, ear
what population is at greatest risk of AI disease? why?
women of reproductive age
-increased estrogen–>decreased apoptosis
what are the three types of self tolerance that are meant to protect against getting AI disease?
what three markers identify Treg?
- central tolerance (occurs where lymphocytes generated)
- peripheral tolerance
- Treg (CD4, CD25, FOXP3)
Patients with SLE can have damage to what layers of their heart?
ALL THREE
Patients with SLE can develop Libman-Sacks endocarditis–what is this characterized by?
small vegetations on both sides of the mitral valve
SLE is characterized by what type of HSR?
type III–ag/ab deposition in tissues–> complement activation and tissue destruction
Pts with SLE typically have deficiencies in what part of the complement cascade?
early part of the classical complement cascade–helps remove ag/ab complexes and be taken up directly by macrophages or taken by erythrocytes to the spleen where they are then taken up by macrophages
What characterizes a discoid rash?
circular, erythematous, scaling rash that can scar
In SLE diffuse proliferative glomerulonephritis presents with…
nephritic syndrome
In SLE membranous glomerulonephritis presents with
nephrotic syndrome
What types of renal disease can patients with SLE develop?
both nephritis and nephrotic syndrome
What ab are specific for lupus?
anti-dsDNA and anti-Sm
Is antiphospholipid syndrome more commonly seen 2/2 to lupus or on its own?
on its own
what are the three antiphospholipid ab?
cardiolipin (false positive for VLDRL or RPR) anti-B2 glycoprotein I lupus anticoagulant (falsely elevated PTT)
what ab is characteristic of drug induced lupus?
antihistone ab
what drugs commonly cause drug induced lupus?
hydralazine, procainaminde, isoniazaid
what ab are positive in patients with sjogren syndrome?
anti-SSA, anti-SSB (antiribonucletide)
what other AI disease is sjogrens syndrome typically seen with?
RA
which ab in sjogrens or lupus is concerning for the fetus?
anti-SSA
-can lead to neonatal lupus–> congential heart block
what is characteristic of sjogrens on biospy?
lymphocytic sialadenitis
what type of HSR is sjogrens characterized by?
type IV–lymphocyte mediated damage w/ fibrosis
2 of these 3 criteria need to be met for a patient to be diagnosed with sjogrens syndrome
- dry eyes
- ana AND anti-ssa, ssb, OR rheumatoid factor
- lymphocytic sialadentis
patients with sjogrens who present with unilateral enlargement of the parotid gland are at increased risk for developing what?
B-cell (marginal zone) lymphoma
scleroderma is characterized by
perivascular fibrosis!!
limited type of scleroderma is characterized by
CREST
- calcinosis (anticentromere)
- reynods (can present years before any other symptom)
- esophageal dysmotility (2/2 to fibrosis of lower esophagus)
- sclerodactyly
- telangiectasias of skin
diffuse type of scleroderma
skin involvement w/ early visceral involvement
- any organ can be involved
- lung–pulmonary HTN and interstital fibrosis–kills
- kidneys–scleroderma renal crisis–sudden onset ARF and htn tx w/ ACEi
- GI tract
- anti-DNA topoisomerase I
antiDNAtopoisomerase I is assocaited with what disease
diffuse scleroderma
mixed connective tissue disease is characterized by
features of sle, sjogrens, and polymyosititis
-ANA + serum ab U1 ribonucleoprotein
