Immune System Flashcards
Difference b/w self vs. Non-self
Self: Proteins, molecules made by body.
Non-self: Foreign bodies (pollen, bacteria, viruses, toxins)
Difference b/w cell-mediated immunity vs humoral immunity
Cell mediated:
- Immunes cells directed at eliminating and destroying pathogens or cells
Humoral:
- Purpose is to provide host defense mechanism
- Anitbodies, complements, proteins that can direct or indirect with cellular immunity to orchestrate cell injury and destruction
What is tolerance?
The non-reactivity of the immune system to self particles
When does the immune system begin to develop?
6 weeks of age
4 Functions of the immune system
- Support
- Protect
- Vitalize Functions
- Maintain homeostasis
Which immune system branch is the primary defense against bacterial invasion?
Innate
4 processes of the Innate system
- Integumentary
- Phagocytosis
- Killer T-cells
- Responses (cough, sneeze, fever, normal flora, etc)
What two humoral immune protein mediators are released initially by inflammatory responses?
- Cytokines
- Chemokines
- Both result in bringing other immune cells to site of inflammation/infection and cause further inflammatory responses and fever
- Also increase capillary permeability IRT allow other immune cells to migrate and relocate to site of injury
- This produces pain, swelling, erythema locally and potentially systemically
What is passive immunity?
- Part of the Innate structure
- Antibodies given from one person to another in order to provide protection (mainly via transfusion to another person, ie. breast milk)
- Immediate acting
- last hours to days
Which immune system uses specific antigens to strategically mount an immune response?
Adaptive (aka Acquired)
Destruction of organisms and toxins by antibodies and specific lymphocytes
Which lymphocyte is mainly located in the humoral branch?
B-Lymphocyte
Originate in bone marrow and plasma cells
Which lymphocyte is mainly located in the cell mediated branch?
- T-lymphocte
- Originate in bone marrow
- Mature in Thymus
How is adaptive immunity different from innate immunity?
Adaptive immunity is activated by exposure to pathogens, learns via memory (viruses, vaccines)
Innate attacks based on general threats that are identified, has no memory (bacteria, parasites, etc)
Innate is fast vs Adaptive which is slow
Viruses and vaccines are examples of ___ immunity
Adaptive (Acquired)
How do B cells work?
- Circulate via lymphatic system
- Encounter an antigen, which starts maturation process
How do T cells work?
- mature in Thymus
- can only recognize antigens that are bound to certain receptor molecules ( MCH1 and MCH2)
Difference b/w active and passive immunity
Active:
- Pathogen deliberately administered for purpose of stimulating immune system
- On repeat exposure, immune system provides quicker, better response
- Ex. vaccines
Passive:
- Person receives another persons antibodies to help fight/prevent infections
- Short lived
- Ex. Fetus receives IgG from mother, IgA via breast milk, RhoGam
Which WBC’s make up effector cells? What do Effector cells do?
- Monocytes, Neutrophils, Eosinophils
- Migrate to inflammation in response to chemotactic factors
- Promote killing of foreign cells via opsonization
What is opsinazation?
- Promote killing of foreign cells by the deposition of antibody or complement fragments on the surface of foreign cells
- Done by effector cells
What is the most numerous WBC?
Neutrophils
- 1st cells to appear in acute inflammatory reaction
What is the least common granulocyte?
basophils
Which granulocyte is involved in hypersensitivity reactions?
basophils and Mast cells
- IgE receptors present on both
- release histamine, leukotrienes, cytokines, and prostaglandins
Where are eosinophils mainly located? What do they do?
- GI, Respiratory, Urinary mucosa
- Recruited by inflammatory cells at sites of parasite infections, tumors, and allergic reactions
Which WBC’s make up granulocytes?
- Neutrophils
- Basophils
- Eosinophils
Which WBC’s make up agranulocytes?
- Monocytes (create macrophages)
- Lymphocytes (T cells and B cells)
Difference B-cells and T-cells
B-Lymphocytes: Humoral immunity (produce antibodies)
T-Lymphocytes: Cell mediated immunity (does not produce antibodies)
Most prevalent immunoglobulin
IgG (75% of antibodies)
Which immunoglobulin is involved in allergic reactions?
IgE
Antibodies are also called ____
immunoglobulin
2 main way antibodies work
- Direct attack on the invader
- By activation of competent system
Is a delayed-reaction allergy caused by antibodies of activated T-cells or B-cells?
T-cells
ex. poison ivy
What is urticaria?
- Hives
- Results from antigen entering specific kin areas and causing localized anaphylactoid reactions
- Histamine release causes swelling, redness
What is hay fever?
- Allergen-reagin reaction that occurs in nose.
- Histamine causes intranasal vascular dilation, increased capillary permeability
Type I hypersensitive reaction
Ex. Anaphylaxis
- Mast cell activation
Type II hypersensitive reaction
- Cytotoxic (antibodies)
- Ex. Hemolytic transfusion reaction
Type III hypersensitivity reaction
- Immune complex diseases (aka autoimmune)
- Antibodies binding to antigens release tissue -damaging enzymes
- Ex. SLE, RA
Type IV hypersensitivity reaction
- Cell mediated (T cells)
- delayed sensitivty
- Ex. Contact dermatitis, Poison Ivy, Graft rejection
What are reagins?
- AKA sensitizing antibodies
- Passed on from Parents
- large quantities of IgE antibodies
1 cause of allergic reactions in OR
NMB’s (Rocuronium mainly)
- most common in females r/t cosmetic usage due to quaternary ammonium
2 cause of allergic reaction in OR
latex
Difference b/w anaphylaxis and anaphylactoid reactions
- Response is identical
- Anaphylaxis is Ig mediated, whereas no Ig is involved with anaphylactoid
- Anaphylactoid can occur on 1st exposure, whereas anaphylaxis requires prior exposure
Which hypnotic is mainly responsible for anaphylactic reactions?
- Propofol (66.7%)
How does the epinephrine help counter anaphylaxis?
- Increases cAMP (restores normal capillary permeability and relaxes smooth muscles)
What can you give to a pt who is on a beta blocker and having anaphylaxis?
Glucagon
What type of shock is anaphylaxis ?
Circulatory shock (people die from circulatory collapse)
What are the effects of histamine?
- systemic vasodilation
- Increased capillary permeabilities -> marked loss of plasma from the circulation
- Final result is circulatory shock
During anaphylaxis, what is released from basophils and mast cells that causes spasm of the bronchiole smooth muscles?
- Slow-reacting substance of anaphylaxis
- basically a mixture of leukotrienes
what is the first drug that should be given for anaphylaxis during general anesthesia?
- Epinephrine
- 100-500mcg SQ or IM, can repeat q 10-15mins
- 5-10mcg IV with hypotension
- 0.1 - 1mg IV with CV collapse
Signs/Symptoms of hemolytic transfusion reaction under general anesthesia?
- CV instability
- Hypotension
- Fever
- Hemoglobinuria
- Bleeding diathesis (hypocoagulopathy)
Foods allergies associated with latex allergy
- bananas
- Kiwi
- mango
Basically tropical/passion fruits
Signs/Symptoms of latex allergy under general anesthesia
- Tachycardia
- Hypertension
- Wheezing
- Bronchospasm
- Cardiorespiratory arrest
- Flushing
- Facial edema
- Laryngeal edema
- Urticaria
What is the classic sign of autoimmune disease?
Chronic inflammation
Populations of highest incidence of autoimmune disease
- Young females
- African American, Native Americans, hispanics
What is the most common autoimmune disease?
Graves disease
What is the most common thyroid disorder in the USA?
Hashimoto thyroiditis
What is autoimmune disease?
- Insufficient or limited response to antigens superseded by a self-reactive state that is inadequate and dysfunctional
- Alterations in response to insult cause body to attack itself
- Can be genetic, acquired, or environmental
6 types of autoimmune diseases
- Graves dx
- Hashimoto thyroiditis
- HIV/AIDS
- SLE
- RA
- DM type 1
Affects of anesthetic agents on immune system
- Depress nonspecific host resistance (includes lymphocyte activation and phagocytosis)
Which anesthetic agents depress the immune system?
- Inhalation agents (N2O)
- Opioids
- Regionals
- Hypnotics (decreases ciliary action which leads to high risk of infection)
definition of surgical site infection
- Occurs at or near a surgical incision within 30 days of the procedure
or
- 1 year from the implant.
Which WBC decreases with procedure duration and blood loss?
T-cells
What type of surgery is associated with decreased immune suppression?
- laprascopic
2 conditions during surgery that lead to surgical site infections
- Hypothermia
- Hyperglycemia
True of False
Blood transfusion is associated with depression of the immune system and an increased risk of surgical site infection (SSI)
True
How does immunosuppression occur from surgery and anesthesia
Stimulation of hypothalamus-pituitary-adrenal axis which leads to:
- Stimulation of pro-inflammatory response (VEGF, MMP)
- Stimulations of anti-inflammatory response (IL-10, IL-4, TGF)
- Down regulation of cell-mediated immunity ( NK cells, cytotoxic T-Cells)
What is the anesthetic concern with HIV/AIDS patients?
- NNRTI’s will induce CYP450
- Infection of patients and staff!!
2 most common CV comorbidities with HIV/AIDS
- Abnormal EKG (50%)
- Pericardial effusions (25%)
Common comordidities with HIV/AIDS
Wasting Syndrome:
- Malabsorption and metabolism changes
- > 10% weight loss
- Evaluate fluid status
Neurological:
- Dementia
- Peripheral neuropathies
- Autonomic abnormalities
Hematologic:
- Platelet impairment
(Steroid therapy or spleenectomy)
Cancer:
- Non-Hodgkin’s lymphoma
- Karposi’s Sarcoma (Endothelial Tissue)
What is the most common opportunitistic pathogen in HIV/AIDS patients?
- Pneumocystic carinii
- PNA responsible for most HIV/AIDS deaths
Risk of exposure to HIV/AIDS is highest with ____
- Open bore needles
- Risk is 0.3% with percutaneous exposure
- Risk is 0.09% with mucous membrane exposure
- DO NOT RECAP THESE NEEDLES
Treatment for HIV/AIDS exposure
- 2 or more antivirals w/i 1-2 hrs for 1-2 wks
- Testing for 6 months after exposure
Presentation of SLE
- Polyarthritis and dermatitis
- malar rash in 1/3 of patients
Most common cause of death from SLE
- Renal dx
Anesthetic concerns of SLE
- 1/3 patients have cricoarytenoid arthritis and RLN palsy
- Prone to PE, restricitive airway dx, pneumonitis, pulmonary HTN, alveolar hemorrhage
- Cyclophoshamide can inhibit plasma cholinesterase (ester LA’s and succinylcholine)
- Treat with corticosteroids
What is scleroderma?
- Collagen vascular disease
- inflammation, vascular sclerosis, fibrosis of organs/skin
Dx progression of scleroderma
- Injury to the vascular endothelium
- Vascular obliteration and leakage of proteins into the interstitial space
- Tissue edema and lymphatic obstruction due to the protein leakage
- Tissue fibrosis
Is chest wall compliance affected significantly by scleroderma?
No
Why should corticosteroids be avoided in patients with scleroderma?
Can precipitate a renal crisis
CV changes seen with scleroderma
- systemic and pulmonary HTN
- cardiac conduction abnormalities
- myocardial fibrosis
- Raynauds (95% of scleroderma patients)
Anesthetic concerns with scleroderma
- May need fiberoptic intubation
- airway manipulation can cause bleeding
- Pulmonary HTN (avoid acidosis and hypoxemia)
- chronic HTN
- GERD
- Corneal abrasions (prone to dry eyes)
-
What is safe alternative for scleroderma patients?
- Regional
What is RA?
Cellular hyperplasia in synovium
- Infiltration by lymphocytes, plasma cells, and fibroblasts
- Articular cartilage eventually completely destroyed
Anesthetic drug considerations for RA pateints
- May need stress dose of steroids for surgical response
- Cyclophoshamide can inhibit plasma cholinesterase (ester LA’s and succinylcholine)
- NSAIDS (inhibit PLT function)
Anesthesia concerns with RA patients
- Mainly airway!!!!
- cervical extension restriction
- Can cause C1,C2 subluxations
- TMJ opening restricted
- Laryngeal joint swelling/edema
What may you consider in your induction plan for RA patients?
- Glidescope or fiberoptic intubation
Most effective/crucial component of infection prevention
- Hand hygiene
When must you use hand washing as opposed to hand sanitizer?
- Cdiff
- Visibly soiled hands
Which lymphocyte produces antibodies, T-cells or B-cells?
B-cells
T-cells do not produce antibodies
What are complements?
- Immune response that marks pathogens for destruction and makes holes in the cell membrane of the pathogen.
What is more specific, innate or adaptive system?
Adaptive
Delayed-reaction is caused by ______
activated T-cells
NOT BY ANTIBODIES
Latex allergy is type I if ___ occurs
Latex allergy is type IV if _____ occurs
- Anaphylaxis
- dermatitis
Who is most at risk of latex allergies?
- HC workers
- Neural tube defects
- Spina bifida
- GU tract defects
What is the immune response to inflammation?
- Local vasodilation
- Increased blood flow
- Increased capillary permeability
- Extravasation of plasma proteins
- Chemotactic movement of leukocytes to site of injury/infection (alter pH at tissue site)
What tissue products cause inflammation?
- Histamine
- Bradykinen
- Serotonin
- Prostaglandins
- Complement system and clotting system byproducts
- Lymphokines (released by T-cells)
Immunological memory of Innate vs Adaptive
- Innate has none memory
- Adaptive has memory, learning leads to faster responses with subsequent infections
Key component of Innate is ____
Key component of Adaptive is ____
Innate - antimicrobial peptides, proteins, toxic granules
Adaptive - Antibodies
Innate immunity is based on ____
self vs non-self discrimination
How does the inflammatory response bring immune cells to site of infection/infection?
- By increasing blood flow to that area, along with increasing capillary permeability which allows other immune cells to go to site of infection/injury
Which WBC synthesizes mediators to facilitates both B-cell and T-cell responses?
Macrophages
- Arise from monocytes
- Ingest antigens
Which WBC produces hydroxyl radicals, superoxide, and hydrogen peroxide to aid microbe killing?
- Neutrophils (Polymorphonuclear Leukocytes)
What causes SLE exacerbations?
- Infection
- Surgical stress
- Pregnancy
- Drugs
Drugs that exacerbate SLE
- Procainamide
- Hydralyzine
- Captopril
- Enalapril
- Isoniazid
- Methyldopa
- d-penicllamine
