Hyper- and Hypo- Immune Disorders Flashcards
What are the two branches of the immune system?
- Innate
2. Adaptive
What is the innate immune system?
non-specific response that targets many common pathogens;
NOT PATHOGEN SPECIFIC, limited diversity
Does the innate immune system need prior exposure?
NO
How does one develop an innate immune system?
passed on from previous generation;
does NOT need previous exposure to pathogen
What compromises the innate immune system?
- epithelial & mucous membranes
- complement factors
- neutrophils
- macrophages
- monocytes
What is the adaptive immune system?
system that must be developed individually; develops memory & is specific towards antigens
delayed response
Which is faster, the innate or adaptive immunity?
innate,
adaptive is delayed
What types of cells are involved in adaptive immunity?
lymphocytes;
B lymphocytes
T lymphocytes
What are the principle cells of the innate immune system?
myeloid cells
→ macrophages, neutrophils, dendritic cells
What is the innate immune system mediated by?
cells and plasma proteins that are ALWAYS present
Is the adaptive immune system weak or powerful?
powerful; usually “silent” until pathogen is found
What creates the receptors of the adaptive immune system?
rearrangements of antigen-receptor genes that occur during the maturation of the lymphocytes
What are the principle cells of the adaptive immune system?
KNOW!!
B lymphocytes
T lymphocytes
The adaptive immune system is mediated by what TWO mechanisms?
- Humoral Immunity
→ mediated by antibodies produced by B cells - Cell-Mediated
→ T cells activated by protein antigens from antigen presenting cells (APCs)
What type of cell mediates humoral immunity?
of the adaptive immune system
B cells.
antibodies
1. NEUTRALIZE MICROBES 2. opsonize microbes for phagocytosis 3. activate the complement system
What type of cell mediates, cell-mediated adaptive immunity?
T cells. [2 types]
→ activated by protein antigens from antigen presenting cells (APCs)
require repeat antigen stimulation
What are the 2 types of T cells?
CD4+ helper T cells [secrete cytokines to activate macrophages; helps B cells make antibodies; stimulates inflammation]
CD8+ helper T cells [kill infected & transformed cells]
The three dysfunctions of the innate immune system are:
- inadequate response
- excessive response
- misdirected response
What are 4 types of an inadequate innate immune system response?
- neutropenia
- abnormal phagocytosis
- deficient in the complement system
- hyposplenism
What are 3 types of excessive innate immune response?
- neutrophilia
- monocytosis
- asthma
*over-reaction
What is one example of a misdirected innate immune response?
angioedema
*body responds, but edema is sent to the wrong place
What are 6 dysfunctions of the adaptive immune system?
- defects in antibody production
- defects in T lymphocytes
- combined immune system defects (SCIDs)
- allergic reactions
- anaphylaxis
- autoimmune disorders
” -penia”
lack of, poverty, deficiency
” -philia”
affinity, attraction, fondness
allergy
reactions against normally harmless environmental antigens
hypersensitivity
excessive immunologic reactions to microbes or environmental agents dominated by inflammation
atopy
propensity or genetic tendency to develop allergic reactions
[ie. lots of food and/or environmental allergies]
Antibody (Ab) is also known as…
an immunoglobulin (Ig)
What is an antibody?
large, Y-shaped, protein USED by the immune system TO IDENTIFY and NEUTRALIZE FOREIGN OBJECTS such as pathogenic bacteria and viruses
Where do T cells come from?
Thymus
Where do B cells come from?
Immature cells are released from the bone marrow; mature in the circulation
How are neutrophils formed?
by stems cells in the bone marrow
What % of WBCs are neutrophils?
40-70%
What are neutrophils?
phagocytes that are found in the blood stream;
FIRST RESPONDERS TO INFLAMMATION
[especially bacterial]
*predominant cells in pus
What is neutropenia?
neutrophil count <1500/mm3
What are 5 types of neutropenia?
- neonatal sepsis
- Kostmann syndrome (autosomal recessive)
- acquired defects (chemo, antivirals)
- autoimmune (Lupus, RA)
- Infection [rate of production is inadequate for consumption]
What are the treatments for neutropenia?
- stop causative agent
- granulocyte stimulating factor (filgrastim)
- bone marrow transplant
What does the spleen do?
primary creator of RBCs in fetal life (up to 5 months old)
- removes old RBCs
- blood reservoir (250mL)
- recycles iron
- metabolizes hemoglobin
- stores 1/4 circulating lymphocytes
- stores & clears platelets
- synthesizes antibodies in the white pulp
- removes antibody-coated bacteria
How is hemoglobin broken down?
globin is degraded into amino acids
heme is metabolized into bilirubin [which is removed by the liver]
How do the spleen & liver “work together”?
the spleen “eats” bacteria, blood flow goes to the liver where toxins are removed & “cleansed” from the blood
What is the size of the spleen?
healthy adult:
2.8in x 5.5in
between 1oz-8oz
Asplenia
absence of normal spleen function;
type of immuno-dysfunction
** sepsis risk is increased 350-fold d/t inability to clear bacteria from the blood [S.pneumoniae, E.coli, H.flu, malaria]
Hyposplenism
reduced spleen function
How can sickle cell affect the spleen?
sickle cell can cause auto-infarction, resulting in vaso-occlusive disease
What is leukocytosis?
WBC count is above normal range;
normal reaction as an inflammatory response but can be from
- tumors - leukemias - stress - pregnancy - convulsions - medications [corticosteroids, lithium, beta agonists]
What are the 5 types of leukocytosis?
- neutrophilia
- eosinophilia
- basophilia
- monocytosis
- lymphocytosis
What is eosinophilic esophagitis?
chronic immune system disease in which a type of WBC (eosinophil) builds up in the lining of the esophagus
→ reaction to foods, allergens or acid reflux
- inflame or injure esophageal tissue; can lead to difficulty swallowing or food to get stuck
*food aversion or non-specific s/s
Neutrophilia
> 7000/mm3
4 causes of neutrophilia
- pancreatitis
- pyelonephritis
- peritonitis
- pneumonia
Leukostasis; count & blood
> 100,000/mm3;
thick blood flow and WBC clumping, can lead to TIAs & strokes
Myeloproliferative disorder or hematologic malignancy
> 50,000/mm3
What is asthma?
exaggerated bronchoconstrictor response to stimuli
Cause of extrinsic asthma:
IgE production, allergens
Cause of intrinsic asthma:
triggers are unrelated to the immune system:
- ETT placement
- cold
- exercise
- stress
- inhaled irritants
When does extrinsic asthma typically develop?
childhood or early adulthood
When does intrinsic asthma typically develop?
later in adulthood
Having a personal and/or family history of asthma is most related to which kind of asthma?
extrinsic asthma
What type of asthma is considered a hypersensitivity reaction to an allergen?
extrinsic
Increased IgE levels are most often found in what kind of asthma?
extrinsic
Does intrinsic asthma include recognizable allergens? elevated IgE levels?
no recognizable allergens;
normal IgE levels
When do s/s of intrinsic asthma appear?
after respiratory infection, emotional reactions, exercise, handling chemicals, taking aspirin, etc.
What is the hallmark sign of misdirected innate immunity?
angioedema
What are the two types of misdirected innate immunity?
- hereditary
2. acquired
What two types of edema form in misdirected innate immunity?
SQ and submucosal
What structures are involved in misdirected innate immunity angioedema?
face, extremities, GI tract
What is the most important thing to remember about acquired misdirected innate immunity?
it will NOT respond to epinephrine
Deficiency in ___ is the most common form of hereditary angioedema.
C1 esterase inhibitor
[autosomal dominant deficiency/dysfunction]
C1INH deficiency is Type 1.
C1INH dysfunction is Type 2.
How does a lack of C1 esterase inhibitor lead to edema?
absence of C1 esterase inhibitor leads to the RELEASE of VASOACTIVE MEDIATORS that increase vascular PERMEABILITY…… producing edema via bradykinin
How long will edema d/t C1 esterase deficiency last?
24-72 hours
How do ACEi cause bradykinin induced angioedema?
ACEi block bradykinin catabolism leading to elevated levels of bradykinin.
How does a person develop acquired bradykinin mediated angioedema?
Patients with lymphoproliferative disorders can develop antibodies to the C1 inhibitor… giving rise to a syndrome that closely resembles hereditary angioedema.
Angioedema can be caused via two different physiological mechanisms, these two pathways are…
- release of mast cell mediators
2. bradykinin release (no allergy symptoms)
Angioedema caused by the release of mast cell mediators is associated with what other s/s?
urticaria, bronchospasm, flushing, hypotension
What is the treatment of mast cell mediated angioedema?
drugs usually used to treat allergy & anaphylaxis.
- epinephrine
- antihistamines
- glucocorticoids
What is the treatment of bradykinin mediated angioedema?
C1 inhibitor concentrate (is the preferred treatment).
- kallikrein inhibitor
- bradykinin receptor antagonist
FFP can be administered if the above are unavailable [it contains the deficient enzyme]
What is the treatment of ACEi mediated angioedema?
STOP offending drug & administer supportive care.
→ glucocorticoids have been noted to INCREASE the expression of ACE = accelerate bradykinin METABOLISM
[opposite of the ACEi]
What do kallikrein inhibitors do?
block the conversion of kininogen to bradykinin
What medication blocks the conversion of kininogen to bradykinin?
plasma kallikrein inhibitor
How does FFP treat bradykinin induced angioedema?
provides the deficient enzyme
What two medications are NOT effective in acute episodes of bradykinin-mediated angioedema?
catecholamines & antihistamines
When are catecholamines & antihistamines NOT effective?
in bradykinin mediated angioedema
What are the two types of immunodeficiency disorders?
aka. inadequate adaptive immunity
- Primary (congenital)
2. Secondary
What causes primary (congenital) immunodeficiencies?
gene mutations that are usually inherited
Gene mutation that causes a defect in T lymphocytes is known as ____ syndrome.
DiGeorge syndrome
What are secondary immunodeficiencies encountered in high income countries?
- chemotherapy
- radiation
What are secondary immunodeficiencies encountered in low-income countries?
- malnutrition
- acquired immunodeficiency syndrome (AIDS)
Gene mutations that cause dysfunction in T- B- or NK- cell functions, cause ____ syndromes.
severe combined immunodeficiency syndromes
What is the treatment of severe combined immunodeficiency syndromes?
(SCID)
bone marrow or stem cell transplant
gene therapy
enzyme replacement
What organ causes the immune deficiency in DiGeorge Syndrome?
How does this affect severity?
Thymus hypoplasia
→ degree of immunocompromise correlates with the amount of thymus tissue present
What organs can be affected in DiGeorge Syndrome?
thymus, thyroid, parathyroid
(hypoplasia)
Can also have cardiac defects & facial dysmorphisms
- truncus arteriosus
- TOF
- cleft palate
What gene deletion causes DiGeorge Syndrome?
22q11.2
What cell level is abnormal in DiGeorge Syndrome?
T cells are decreased;
B cells are normal
Complete absence of the thymus results in what sundrome?
severe combined immunodeficiency syndrome (SCID)
Severe combined immunodeficiency syndromes (SCID) affect what cells?
T cells
B cells
NK cells
SCID is linked to what chromosome?
X-linked.
boys are affected
girls are carriers
What is the abnormality in the most common form of severe combined immunodeficiency syndrome?
mutation in the gene that codes for interleukin receptors
lack of interleukin receptors → lack of interleukin signaling → lack of T, B, NK cell differentiation/maturation
What are four categories of excessive adaptive immunity?
- anaphylaxis
- bronchial asthma
- allergic rhinitis, sinusitis
- food allergies
What are the clinical & pathological manifestations of anaphylaxis?
[may be caused by drugs, bee sting, food]
- vascular dilation = fall in blood pressure (shock)
- airway obstruction d/t laryngeal edema
What are the clinical & pathological manifestations of bronchial asthma?
airway obstruction d/t smooth muscle hyperactivity
inflammation & tissue injury caused by late-phase reaction
What are the clinical & pathological manifestations of allergic rhinitis, sinusitis?
increased mucous secretion
inflammation of upper airways & sinuses
What are the clinical & pathological manifestations of food allergies?
increased peristalsis d/t contraction of intestinal muscles = vomiting & diarrhea
What are hypersensitivity disorders?
persistent, misdirected, or inadequately regulated immune reactions against a variety of antigens
“overreaction of the immune system”
What does it mean when an individual is “sensitized”?
they have been exposed to and react against an antigen
What are 3 categories of hypersensitivity disorders?
- reactions against self-antigens
- reactions against environmental antigens
- excessive reactions against microbes
What occurs to cause autoimmunity?
an individual’s self-tolerance breaks down
[normally an individual is tolerant to their own antigens]
What is an environmental allergy?
abnormal reaction against common and normally harmless environmental substance antigens
What happens in a hypersensitivity disorder involving excessive reactions against microbes?
the microbe is unusually persistent. the immune response itself becomes the cause of tissue injury
- example: tuberculosis
How many major types of hypersensitivity reactions are there?
4
What is Type 1 hypersensitivity reaction?
“allergy”
immediate, IgE mediated, mast cells
→ caused by IgE antibodies that recognize environmental antigens & sensitize mast cells leading to the release of mediators
ie. anaphylaxis
What is Type 2 hypersensitivity reaction?
antibody mediated
IgG / IgM
ie. myasthenia gravis, Graves disease
What is Type 3 hypersensitivity reaction?
immune complex mediated
ie. SLE (Lupus), glomerulonephritis
What is Type 4 hypersensitivity reaction?
T-lymphocyte mediated
(CD4+ / CD8+ T cells)
ie. rheumatoid arthritis, multiple sclerosis, contact dermatitis, T1DM
What is most important about the course of Type 1 hypersensitivity reactions?
early (w/n minutes) vascular & smooth muscle response
followed by
slow (hours) late-phase inflammatory response
→ do not let a patient go home right away
What are localized hypersensitivity clinical features?
skin
GI tract
What are systemic hypersensitivity clinical features?
itching, urticaria, skin erythema
profound resp difficulty/bronchoconstriction, mucous production, laryngeal edema
vomiting, abdominal cramps, diarrhea
systemic vasodilation
What are clinical s/s a CRNA might see if a patient has an anaphylactic reaction?
unexplained…
↑ airway pressure, wheezing, increased & shark-fin ETCO2, ↓ BP, flushing, rash, ↑ mucous production, ↑ HR
Anaphylaxis is ___ mediated.
Immune mediated - IgE (60%)
What are life-threatening s/s of anaphylaxis?
CV collapse (tachycardia, hypovolemia)
Interstitial edema, urticaria
bronchospasm, laryngeal edema
After production of antigen-specific IgE antibodies, what causes anaphylaxis?
subsequent exposure to antigen results in marked mast cell and basophil degranulation
What is the difference between “anaphylactoid” reaction vs anaphylaxis?
“anaphylactoid” is NOT immune mediated, does NOT involve IgE
→ less common
→ not as profound
→ direct release of histamine from mast cells or basophils… no IgE involvement
___ is a vasoactive amine.
Histamine
Where is histamine stored?
mast cells
When is histamine released?
upon mast cell degranulation
What does histamine cause?
rapid vasodilation, increased vascular permeability, smooth muscle contraction
____ and ____ are lipid mediators of the immune system.
Prostaglandins & leukotrienes
What is the most abundant immune mediator generated by the cyclooxygenase pathway in mast cells?
Prostaglandin D2 (PGD2)
What mediator causes intense bronchospasm?
prostaglandin D2
What are the most potent vasoactive & spasmogenic mediators?
the leukotrienes
What mediators recruit, activate leukocytes & amplify the response?
cytokines;
→ tumor necrosis factor & chemokines
What are 4 major risk factors to anaphylaxis during anesthesia?
- asthma
- atopy
- multiple past exposures to latex
- hereditary conditions (angioedema)
What lab can be drawn to confirm anaphylactic reaction?
plasma tryptase concentration
What is tryptase?
stored in mast cells & released during immune-mediated reactions
→ indicator of mast cell activation
When do plasma histamine levels return to baseline after an allergic reaction?
30-60 minutes
Why isn’t histamine level used to confirm anaphylactic reaction?
non-specific. histamine can be released from many causes
What is the management of perioperative anaphylaxis?
- remove agent if possible
- reverse hypotension & hypoxemia
- replace intravascular fluid
- inhibit further degranulation by stabilizing the membrane of mast cells [steroids / benadryl
- inhibit release of vasoactive mediators
- treat inflammation
- relieve bronchospasm
What medications are given during management of perioperative anaphylaxis?
- oxygen
- epinephrine
- fluid bolus
- phenylephrine
- hydrocortisone
- diphenhydramine
- ranitidine (zantac)
- B2 agonist
Dose of oxygen to administer during anaphylaxis
ventilate with 100%
Dose of epinephrine to administer during anaphylaxis?
1-10mcg/kg IV bolus for ↓BP/bronchospasm
Q1-2min
may start infusion @ 0.05-1mcg/kg/min
Dose of fluid bolus to administer during anaphylaxis?
20mL/kg balanced salt solution; repeat as necessary
Dose of phenylephrine to administer during anaphylaxis?
0.1mcg/kg/min IV
titrate to effect if inadequate response to epinephrine
Dose of hydrocortisone to administer during anaphylaxis?
2-3mg/kg IV
Adults: 250mg IV
Child: 50-100mg IV
Dose of diphenhydramine to administer during anaphylaxis?
1-2mg/kg IV
Dose of ranitidine to administer during anaphylaxis?
1.5mg/kg IV
** don’t forget H2 blocker to protect GI system from histamine!!!!
Why administer antihistamines during anaphylaxis?
to protect from H1/H2 receptors
→ helps decrease pruritus & bronchospasm
What medication is a histamine 1 antagonist?
diphenhydramine; competes with histamine for membrane receptor sites
What medication is a histamine 2 antagonist?
ranitidine
How does epinephrine work?
increases intracellular cAMP → restores/stabilizes membrane permeability → decreases the release of vasoactive mediators
What 3 medications can be given if the patient is unresponsive to epinephrine?
- vasopressin
- glucagon
- norepinephrine
How do corticosteroids benefit during anaphylaxis?
may enhance B-agonist effects of other drugs or inhibition of the release of arachidonic acid responsible for production of leukotrienes and prostaglandins
→ no known effect on degranulation of mast cells or antigen-antibody interactions
** takes several hours for effect
Intolerance of a medication:
inability to tolerate the adverse effects of a medication
ie. muscle pains & statins
Idiosyncratic reaction to medication:
drug reactions not related to the known pharmacological properties of the drug
ie. antiepileptic drugs & dyskinesias
Toxic reaction to medication:
dose dependent, having too much drug in a person’s system at one time
Most drug reactions manifest within how many minutes?
5-10
Reaction to ____ is typically delayed >30 minutes
latex
What are 5 common drugs associated with perioperative anaphylaxis?
- muscle relaxants
- antibiotics
- latex
- chlorhexidine
- dyes
What are the 2 muscle relaxants most commonly associated with reactions?
- rocuronium
- succinylcholine
Cross sensitivity occurs between benzylisoquinoliniums & ____.
(atracurium, Cisatracurium, mivacurium)
aminosteroids
over the counter cosmetics (contain ammonium ions & people can produce IgE antibodies to quarternary & tertiary ammonium ions)
morphine & neostigmine (contain ammonium ions)
Histamine from atracurium administration is immune mediated or nonimmune mediated?
nonimmune mediated
Antibiotic most commonly associated with reactions?
penicillin
IgE antibodies can wane over time… rxn as child may disappear as an adult
What are the two allergenic components found in penicillin?
beta-lactam ring (also found in cephalosporins, carbapenems, monobactams)
R-group side chain (also found in cephalosporins)
Cross sensitivity rate between penicillin & cephalosporins:
~2%
What antibiotic is the second most common for reactions?
sulfonamide;
can cause STEVENS-JOHNSON syndrome
What is stevens-johnson syndrome?
severe cutaneous hypersensitivity reaction; macules spread & coalesce leading to epidermal blistering, necrosis, sloughing
What drugs can cause stevens-johnson syndrome?
sulfonamides, antiseizure drugs, antibiotics
What is the pathology of vancomycin reactions?
direct histamine release r/t rate of infusion.
NOT IgE mediated (has been report, but RARE)
What makes latex an allergen?
several Hevea proteins cause an IgE mediated response
Latex is produced from the rubber tree Hevea brasiliensis
What distinguishes a latex- induced reaction from other drug reactions?
delayed onset, typically longer than 30 minutes.
d/t absorption across skin/mucous membranes
What 4 patient characteristics increase the risk of having/developing a latex allergy?
- spina bifida
- multiple previous surgeries
- Hx fruit allergy
- healthcare workers
What food allergies are associated with a latex allergy?
avocado
kiwi
banana
What piece of equipment/container must be considered when a patient has a latex allergy?
stopper of a drug vial
What are the three ingredients in propofol that may trigger an allergic reaction?
- lecithin - egg
- sulfite (preservative)
- soybean oil - soy
peanut allergy?
Is a reaction to the sulfite or 2-isopropyl-group in propofol immune mediated or nonimmune mediated?
thought to be immune (IgE) mediated
Patients with ___, ___, or ___ should not receive ASA or NSAIDs.
asthma, hyperplastic sinusitis, nasal polyps
If ASA/NSAIDs is given to a patient with asthma, hyperplastic sinusitis, or nasal polyps, what three s/s can occur?
and why?
- rhinorrhea
- bronchospasm
- angioedema
NOT IgE mediated inhibiting COX1 (medication blocks the production of cyclooxygenase but pushes arachidonic acid to be formed into leukotrienes instead) =↑ synthesis of leukotrienes = basophil & mast cell degranulation
What type of contrast agents have higher rates of reactions?
ionic, high-osmolar agents
→ the higher the iodine, the greater the risk of a reaction
Nonimmune mediated reactions to contrast can be pre-medicated with what three medications?
- hydrocortisone 1-2mg/kg IV
- diphenhydramine 50mg IV
- ranitidine 50mg IV
Nonimmediate reactions to contrast are mediated by what cells?
t cells
What type of local anesthetics are more likely to produce allergic reactions?
ester-type LA
What medications produce possible but rare allergic reactions?
midazolam ketamine etomidate opioids heparin insulin
What 3 medications cause direct histamine release?
morphine
codeine
meperidine
What reaction is caused by Halothane?
halothane hepatitis
d/t halide metabolites
What is found in cosmetics that might produce prior sensitization particular medications?
Dye
CRNAs will give …
- methylene blue
- indocyanine green (ICG)
Allergy to CHG may be ___ and under or over reported?
delayed;
under-reported
Synthetic volume expanders can cause what type of reactions?
both immune and nonimmune mediated
What are 4 synthetic volume expanders that can cause allergic reactions?
- dextrans
- gelatins
- albumin
- starch
Anaphylaxis to blood products occurs how often?
1: 20,000 - 50,000 transfusions
Type II hypersensitivity reactions occur when:
IgG and IgM antibodies inappropriate mark self-components as foreign; targeting them for phagocytosis or complement-mediated destruction
→ may have genetic predisposition
What are four autoimmune disorders?
Systemic Lupus erythematosus (SLE)
Scleroderma
Rheumatoid arthritis
Autoimmune hepatitis
What are three anesthetic considerations of autoimmune disorders?
- specific vulnerable organs
- consequences of therapy/treatment
- acceleration of other/related disease processes
“marked” or “flagged” elements are destroyed by what?
spleen
→ this is why a splenectomy can be helpful in antibody-mediated diseases marked by low blood counts
Antibodies that are deposited in extracellular tissues can recruit and activate:
neutrophils & macrophages
= acute inflammation
→ antibodies can also activate or inhibit receptors on cell surfaces
What is the target antigen in autoimmune hemolytic anemia?
red cell membrane proteins
What is the target antigen in myasthenia gravis?
acetylcholine receptor
What is the target antigen in Graves disease (hyperthyroidism)?
TSH receptor
What is the target receptor in pernicious anemia?
intrinsic factor of gastric parietal cells
What is the mechanism of autoimmune hemolytic anemia?
opsonization and phagocytosis of red blood cells
What is the mechanism of myasthenia gravis?
antibody inhibits acetylcholine binding, down-modulates receptors
What is the mechanism of Graves disease (hyperthyroidism)?
antibody-mediated stimulation of TSH receptors
What is the mechanism of pernicious anemia?
neutralization of intrinsic factor, decreased absorption of vitamin B12
What are the clinicopathologic manifestations of autoimmune hemolytic anemia?
hemolysis, anemia
What are the clinicopathologic manifestations of myasthenia gravis?
muscle weakness, paralysis
What are the clinicopathologic manifestations of Graves disease (hyperthyroidism)?
hyperthyroidism
What are the clinicopathologic manifestations of pernicious anemia?
abnormal erythropoiesis, anemia
What is the pathology of Type III hypersensitivity? (immune complex-mediated)
complexes formed in the circulation deposit in blood vessels & induce inflammation.
Manifest in acute vasculitis → can lead to fibrinoid necrosis of vessel wall & neutrophilic infiltration
What are three common locations of acute inflammation / sites of antigen-antibody complex deposition in type III hypersensitivity?
- kidneys (glomerulonephritis)
- synovium of joints (arthritis)
- blood vessels in any tissue (vasculitis)
What is the prototypic human immune complex disease?
systemic lupus erythematosus (SLE)
Type IV hypersensitivity reaction is ___ mediated.
T cell
What are the 2 types of t cell reactions that cause tissue injury and disease?
- cytokine-mediated inflammation (aka: delayed type hypersensitivity); cytokines produced by CD4+ t cells
- cytotoxicity, mediated by CD8+ t cells
What are the typical manifestations of type IV hypersensitivity reaction?
[typical manifestations of this = chronic inflammation]
- rheumatoid arthritis (synovial inflammation and destruction of articular cartilage)
- multiple sclerosis (demyelination of CNS)
- T1DM (antigens of pancreatic islet beta cells)
- Inflammatory bowel disease
- psoriasis (cutaneous plaques)
What are the 2 categories of autoimmune disorders?
- organ-specific
2. systemic
Systemic autoimmune disease involves what two particles?
and targets what 2 types of tissue?
- immune complexes
- autoantibodies
target: connective tissues & blood vessels of involved organs
What are the 5 systemic autoimmune diseases?
- SLE
- RA
- scleroderma/systemic sclerosis
- Sjogren syndrome
- Inflammatory myopathies
Organ-specific autoimmune diseases are divided into what 3 categories?
- Diseases mediated by antibodies
- Diseases mediated by T cells
- Diseases postulated to be autoimmune
What are 6 autoimmune diseases mediated by antibodies?
- autoimmune hemolytic anemia
- autoimmune thrombocytopenia
- autoimmune atrophic gastritis of pernicious anemia
- myasthenia gravis
- graves disease
- goodpasture syndrome
What are 2 autoimmune diseases mediated by T cells?
- T1DM
2. multiple sclerosis
What are 3 diseases postulated to be autoimmune?
- inflammatory bowel disease (Crohn dz, ulcerative colitis)
- primary biliary cholangitis
- autoimmune (chronic active) hepatitis
What is the pathology of SLE?
antibody & antigen complexes are deposited in kidneys and other organs;
antibodies coat blood cells leading to phagocytosis (Type II hypersensitivity)
What is the etiology hypothesis of SLE?
exposure to insult → apoptosis → improper clearance of fragments → failure of B and T cell tolerance activates lymphocytes specific for self antigens
*can affect any organ
Findings of SLE? (8)
Blood vessels: diffuse necrotizing vasculitis
Kidney: proliferative glomerulonephritis, nephritis
Skin: butterfly/macular rasha long nose/cheeks
CV: pericardial effusions, pericarditis, valvular endocarditis, CHF, HTN
Serosal cavities: effusions & fibrosis, avascular necrosis
CNS: depression, anxiety, psychosis, seizures, stroke
Blood: thrombocytopenia, anemia, anti-phospholipid syndrome (hypercoagulability)
Airway: cricoarytenoid arthritis, RLN palsy
ask the patient!
What are 3 other types of lupus?
- Drug-induced Lupus Erythematosus
- Cutaneous Lupus Erythematosus
- Neonatal Lupus
What are 3 drugs that can trigger drug-induced lupus erythematosus?
- hydralazine
- procainamide
- isoniazid
- s/s will disappear 6 months after drug is stopped
How does cutaneous lupus erythematosus present? What makes it worse?
- rashes & discoid lesions on face, arms, neck, shoulders, trunk
→ pigment change and hair loss
affected by sunlight & fluorescent
What causes neonatal lupus?
fetus in the womb of a mother who has lupus; exposure to mom’s antibodies
How does neonatal lupus present?
infant born with skin rash, liver problems, low blood counts
→ may present with congenital heart block (HR 60s-70s) = will need a pacemaker placed!!
- disappear after some months
Drug categories for the treatment of lupus:
- tylenol
- NSAIDs
- immunosupressants
- corticosteroid: prednisone (Cushing syndrome)
- antimalarial: hydroxychloroquine, chloroquine
- anticoagulants: aspirin, heparin, warfarin
- monoclonal antibodies: Belimumab
- repository corticotropin injections: Acthar
What immunosuppressants are used in the treatment of lupus?
cyclophosphamide
methotrexate
azathioprine
mycophenolate mofetil
Anesthesia implications of lupus:
PRE-OP TESTING/EVALUATION
- PFTs
- ECHO
- EKG
- renal function
- labs
What drugs is the patient taking?
- corticosteroids
- immunosuppressants
- anticoagulants
AIRWAY INVOLVEMENT
What type of airway involvement can lupus have?
CRICOARYTENOID ARTHRITIS = hoarseness
laryngeal function (pre- & post-op)
?smaller tube needed
?airway may be “stiff”
?airway may be red/irritated
What is scleroderma?
“Hard Skin”
injury to vascular endothelium results in leakage of proteins into interstitial space
inflammation → fibrosis of skin, small blood vessels, and viscera
**COLLAGEN production is not slowed down and gets deposited throughout the body
Etiology of scleroderma:
Unknown:
collagen vascular disease & autoimmune characteristics
onset is 20-40 years old; women; accelerated in pregnancy
What is CREST syndrome?
know
presents in scleroderma:
Calcinoses: Ca deposits
Raynaud’s phenomenon: [evaluate ulnar perfusion before radial a-line placement!]
Esophageal hypomotility
Sclerodactyly: thickened, tight skin [affects mouth opening]
Telangiectasia: dilated capillaries
Skin & musculoskeletal manifestations of scleroderma:
thick skin, diffuse edema (can involve airway), contractures, skeletal muscle myopathy, arthritis & limited joint mobility, avascular necrosis
Nervous system manifestations of scleroderma:
PNS & CNS neuropathies d/t nerve compression by thickened connective tissue
trigeminal neuralgia (pain to forehead, mid, & lower face) dry eyes
Cardiovascular manifestations of scleroderma: (7)
- sclerosis of coronary arteries & conduction system
- cardiac tissue replaced with fibrous tissue
- systemic & pulm HTN
- pericarditis
- pericardial effusion
- intermittent peripheral vasospasm
- RAYNAUD’S PHENOMENON
Respiratory manifestations of scleroderma:
- diffuse interstitial pulmonary fibrosis (up to 80% of patients)
- arterial hypoxemia secondary to decreased diffusion capacity
- decreased pulmonary compliance
Renal manifestations of scleroderma:
- renal artery stenosis d/t arteriolar intimal proliferation → decreased renal blood flow → HTN
GI manifestations of scleroderma:
- dry oral mucosa
- progressive fibrosis of GI tract
- dysphagia
- hypomotility
- ↓ lower esophageal sphincter tone
- malabsorption; vitamin K deficiency (GI tract cannot absorb nutrients)
Anesthetic implications of scleroderma: (9)
- difficult intubation d/t limited mouth opening
- difficult IV access d/t dermal thickening
- pulmonary HTN
- ↓ pulm compliance & ↓ O2 diffusion
- systemic HTN
- aspiration risk d/t hypotonia of LES
- SENSITVE TO RESPIRATORY DEPRESSANTS
- protect eyes from corneal abrasion
- renal dysfunction with altered drug elimination
*regional anesthesia may be challenging d/t contractures and ↓ joint mobility
Sjogren Syndrome
chronic inflammation & destruction of lacrimal & salivary glands
→ dense infiltrates of CD4+ t cells
- dry eyes & mouth; may also involve other exocrine glands lining the respiratory & GI tracts, vagina
Clinical features of Sjogren syndrome:
- dryness of the eyes
- risk for corneal abrasions
- dry mouth (xerostomia0
- nasal dryness causing risk of bleeding/perforation with instrumentation
**patient’s need eye drops every couple of hours
Rheumatoid Arthritis:
chronic, systemic inflammatory autoimmune disease; exaggerated immune response [interleukins, B cells, cytokines, collagenase, leukocyte infiltration]
particularly affects joints; genetic & environmental risk factors
Raynaud phenomenon common
→ inflammation, swelling, destruction of cartilage
Anesthetic implications of rheumatoid arthritis:
atlantoaxial INSTABILITY
SUBLUXATION of the joint.
→ can impair blood flow through vertebral arteries
Pathophysiology of RA:
inflammatory cytokines convert the synovium into a thick ABNORMAL LAYER OF GRANULATION TISSUE “pannus”
→→ Macrophages stimulate the release of platelet-rich growth factor and other enzymes that result in proliferation of cartilage fibrosis & joint destruction