Allergy/Immunology 2 Flashcards
1
Q
Oral allergy syndrome (age/diagnosis, signs and symptoms, induction)
A
Age/Diagnosis: young adults, associated with allergic rhinitis
Signs and symptoms: tingling, pruritis, erythema, angioedema of the lips and tongue, throat itch, throat tightness, no anaphylaxis*, positive skin prick test, oral food challenge with raw vegetable positive negative with cooked
Induction: immediate on contact with raw fruits and vegetables
Ex: eat a mango and get swelling and tingling around the lips; no anaphylaxis
2
Q
food induced anaphylaxis (age/diagnosis, signs and symptoms, induction)
A
Age/Diagnosis: any age, elevated IgE with positive skin test
Signs and symptoms: minutes to 2 hours –> cutatneous or respiratory manifestations, abd pain, vomiting and diarrhea
Induction: ingestion of milk, soy, egg, wheat outgrown peanut, tree nut and shellfish allergies can persist
3
Q
Allergic disease signs and symptoms (6)
A
- Rhinitis - Nasal with sneezing rhinorrhea, nasal itching, congestions
- Asthma - Lungs with coughing, wheezing, shortness of breath
- Atopic Dermatitis- Skin with itching and rash
- Conjunctivitis - Eye with redness, itching and tearing
* Allergic conjunctivitis = clear watery discharge
* Rub their eyes and make it really red
* Allergic conjunctivitis = really red from rubbing - Anaphylaxis
* Systemic with hypotension, shock and death
* Multiple organ systems; feeling of doom and gloom - Food - GI tract with floating, vomiting, diarrhea and cramping
4
Q
Prevention of Atopy Manifestations (2)
A
- Elimination of the offending substance to prevent IgE development and antigen-antibody interaction
- Breastfeeding
* Benefit of maternal IgA and IgG antibodies
* High level of prevention of allergy if you have an allergic family to encourage to breastfeed
5
Q
What is the natural history of allergic disease in atopic individuals?
A
- Genetic susceptibility
- Environmental factors with allergen exposure
- Presence of other risk factors
- Small family
- Passive smoke exposure
- Western lifestyle
- Early use of antibiotics
- Diet
6
Q
Maternal Transferred Immune Protection (4)
A
- Immune state of infant modified by maternal factors transferred by:
a. Placenta – Maternal IgG
b. Mammary gland – Maternal IgA
c. Provides protection against pathogens to which the mother was immune - Decreased resistance to infection if
a. Degree or duration of placental transfer is decreased
i. Prematurity
ii. Placental insufficiency
b. Infant not breastfed - Maternal transfer wears off
- Babies are at greater risk for infection as are non-breastfed infants
7
Q
Division of the immune system (4)
A
- Non-Specific –> Barriers
i. Skin
ii. Secretions (mucous, tears, saliva)
iii. Mucociliary clearance, peristalsis - Phagocytes
a. Neutrophils –When they first come in are not specific; going to attack the same way
b. Macrophages
c. Complement - Cytokines
- Specific
a. Humoral (antibodies)
i. Much more specific
b. Cellular (lymphocytes)
8
Q
Immune system 3 lines of defense
A
- External barriers
- Inflammatory response
* Innate immunity – first line of immune defense - Adaptive immunity – antigen specific response
9
Q
physical and mechanical external barriers of immune system (4)
A
- Skin
- Epithelial lining of the gastrointestinal tract
- Genitourinary tract
- Respiratory tract
10
Q
Biochemical barriers of immune system (6)
A
- Perspiration
- Tears
- Saliva
- Surfactant
- Hydrochloric acid in the stomach
* Giving PPIs has a host of problems associated well beyond the risk of Alzheimer’s
* Stomach needs acid environment so you don’t get sick - Normal bacterial flora in our body
11
Q
Innate Immunity: General info (6)
A
- Uses special cell pattern recognition to provide a line of defense.
- Responds without prior exposure and is activated when there is direct contact with specific microbial products such as lipopolysaccharides, cell wall components, and microbial nucleotides.
* Reacts to cellular components - Older immune system of host defense–
- Uses specific cells pattern recognition and soluble factors to provide a first line of host defense
- Responds without prior exposure
- Activated by direct contact with specific microbial products
12
Q
Innate immunity mediators (6)
A
- neutrophils
- macrophages
- complement
- cytokines that provide a host defense to ward off infection
- Complement and cytokines signal specific cellular and humeral immunity to add in host defenses.
- Complement amplifies the innate immune response by providing critical factors to enhance phagocytosis via opsonin and attracts white cells to the site of inflammation, thereby acting as chemoattractives.
* Neutrophils = innate response and ward off infection
13
Q
Innate immunity: lymphoid member (4)
A
- A natural killer cell
- Secretes soluble mediators
- Cytokines
- Chemokines
14
Q
Innate immunity: soluble mediators (3)
A
- complements, cytokines in blood and body surfaces enhance effective of cells, link innate and adaptive immunity
- Direct activation of complement system by microbial products
- Promotes opsonization
15
Q
Innate Immunity: neutrophils (2)
A
- Neutrophils form a first line of defense and ingest the infecting organisms, internalizing the organism into an intracellular compartment and releasing bactericidal products.
- The role of neutrophils in the early inflammation process is primarily phagocytic, resulting in the creation of pus at the site of infection.
16
Q
Innate immunity: monocytes
A
appear at the site of inflammation one to seven days after the initial neutrophil infiltration and turn to macrophages ingesting and disposing of foreign material, including bacteria.
*Macrophages = gobblers
17
Q
Innate immunity: eosinophils
A
Eosinophils have mild phagocytic activity and help in the regulation of vascular mediators released by mast cells
*Play an important role in hypersensitive allergic response seen in anaphylaxis
18
Q
Inflammation: Vascular response (8)
A
- Blood vessel dilation: Increased blood flow and concentration of RBC at site of injury
* Warmth, redness - Increased vascular permeability and leakage of fluid out of the vessel
- WBC - Adhere to inner walls of vessels and migrate through vessel walls to site of injury
- Vascular changes bring leukocytes, plasma proteins, and biochemical mediators to site of injury
- Limit and control inflammatory process to prevent spread of inflammatory response to healthy tissue
a. Plasma protein systems (clotting system)
b. Plasma enzymes
c. Cells (eosinophils) - Prevent infection and further damage
- Interact with components of adaptive immune system
* Elicit more specific response to contaminating pathogen by influx of macrophages and lymphocytes - Prepare area of injury for healing
* Removal of bacterial products, dead cells, etc.
19
Q
Preventing infection and further damage (3)
A
- Phagocytic cells – Neutrophil
- Complement system - Can be activated by 3 pathways:
i. Classic pathway
ii. Lectin pathway
iii. Alternative pathway - Amplifies innate immune response by providing critical factors to
a. Enhance phagocytosis (opsonins)
b. Attract cells to site of inflammation (chemo- attractants)
20
Q
Neutrophil function (5)
A
- Direct migration to source of infection
- Ingest (phagocytosis) infecting organism
- Generate phagolysosome
a. Internalizes organism into an intracellular compartment - Release bactericidal products
- Kill infecting organism
a. First line of defense; need to be in the body and they have a granular appearance
b. Gobblers
c. Important in burn clean up
21
Q
Neutrophil activity (3)
A
- Predominant phagocytes in early inflammatory site
a. Activated by inflammatory mediators
i. Bacterial proteins
ii. Complement
iii. Mast cell
iv. Neutrophil chemotactic factor - Short lived at inflammatory site
a. Component of pus - Primary role
a. Removal of debris (burns)
b. Phagocytosis of bacteria (nonsterile lesions)
22
Q
B cells: humoral immunity (3)
A
- B cell differentiation occurs in bone marrow
* Autoreactive B cells eliminated - Requires intracellular signal
* X linked (Bruton agammaglobulinemia)
* Defect intracellular protein, Bruton tyrosine kinase
* Blocks B-cell differentiation and results in lack of circulating B cells and absent antibody response
* Not making immunoglobulins - Major function is production of immunoglobulins - antibodies
* Host protection against encapsulated bacteria and other microbes
23
Q
Phagocytosis (1,2b,3d)
A
- Process by which cell ingests and disposes of foreign material, including microorganisms
- Monocyte/Macrophage
a. Monocyte precursor of macrophage
b. Macrophage -appear at inflammatory site 1-7 days after initial neutrophil infiltration - Eosinophils
a. Mild phagocytic activity
b. Body’s primary defense against parasites
c. Help regulate vascular mediators released from mast cells
d. Important role in hypersensitive allergic response
24
Q
Relationship between B and T cells (7)
A
- A B-cell is triggered when it encounters its matching antigen
- The B-cell engulfs the antigen and digests it,
- Cytokines secreted by the T-cell help the B-cell to multiply and mature into antibody producing plasma cells.
- Released into the blood, antibodies lock onto matching antigens.
- The antigen-antibody complexes are then cleared by the complement cascade or by the liver and spleen.
- This combination of antigen and MHC attracts the help of a mature matching T-cell.
- The T cell then it displays antigen fragments bound to its unique MHC molecules
a. Trigger and engulf an antigen
b. Complement cascade
c. MHC = in antigen and gulfing/attacking
25
Adaptive immunity (4)
1. Adaptive immune response = specific process of recognition and response in the host defense to a foreign substances
* Specificity directed at the inducing antigen (e. g., microorganism).
2. Central players in this system are T and B lymphocytes
3. Cellular components =
a. T lymphocytes: cellular arm
b. B lymphocytes: specific antibody or immunoglobulins
i. Each express antigen specific receptors
ii. Time lag following initial antigen interaction
iii. Memory cells magnify and hasten immune response
4. Many of the effects in the adaptive response are dependent on secreted mediators
a. Release of cytokines and chemokines
i. B cells are the specific; T cells = cellular arm and each expresses an antigen specific receptor
ii. T suppressor cells coming in and saying slow down
iii. Have T suppressor cells to work
26
Types of adaptive immune response (4)
1. Humoral immunity mediated by antibodies (immunoglobulins) produced by B cells
2. Cellular immunity medicated by the direct action of T cells and via secreted cytokines
3. T cells provide help for the B cell antibody production to protein antigens
4. An initial innate response is often linked to the development of an adaptive response
27
Central (primary) lymphoid tissue (2)
1. Immature lymphocytes
2. Bone marrow
i. B lymphocytes
ii. Thymus – T lymphocytes
28
Peripheral (secondary) lymphoid tissue (6)
Mature lymphocytes:
i. Lymph nodes
ii. Spleen
iii. Adenoid
iv. Tonsils
v. Peyer’s patches (ileum)
vi. Tonsils, adenoids, Ileum, appendix, bone marrow, are all responsible for mature lymphocytes
29
T-cell differentiation (2)
1. The TH1 cells are the arm of cellular immunity and activate microphages, enhance cytotoxic T cell function, produce cytokines, and recognize the infecting agent
2. TH 2 cells enhance antibody formation by B cells by releasing cytokines and increases IgE production and mediating eosinophil recruitment and activation
30
Primary exposure (2)
1. Antigen exposed to B cell
2. B cell
i. Antibodies in 3-7 days (IgM)
ii. Make memory cells to recognize antigen for future exposure
31
Secondary exposure (2)
1. Antigen re-exposure
a. Immunologic memory
2. Antibody production within hours
a. Mainly IgG because it has many memory cells
32
Characteristics of Antibody Based (Humoral) Immunity (2)
1. Antibodies provide protection against bacterial infections—lungs, sinuses, middle ear, GI tract
2. Promote ingestion of bacteria, neutralization of toxins, inactivation of certain viruses
33
Antibodies in humoral immunity (3)
1. IgM and IgG—protects against systemic infections
2. IgA: protections at mucosa surfaces—GI, lung
3. IGE: allergic disorders and protects against
i. Measure IgA with serum
ii. IgE with allergy
34
Antigen specificity in humoral immunity (3)
1. Depends on T-cell antigen receptors and B-cell surface immunoglobulin
2. Diversity generated through random genetic recombination process
3. Specificity for virtually any antigen
35
T-cells: cellular immunity (6)
1. Recognize antigen
a. Bind to antigenic fragment displayed by HLA molecule
2. Release cytokines
a. Immunoregulatory e.g. IL-2
b. Pro-inflammatory e.g. IL-10
3. Generate memory cells following the initial encounter with antigen
4. Underlying foundation for successful immunizations
5. Differentiate in thymus from lymphocytes
6. Mature T cells – produce cytokines
a. Cytokines – hormones that affect the immune response
36
CD4 Helper cells: TH1 cells (5)
1. TH1 cells – cellular immunity
2. Cytokines – Interleukin-1 (IL-1), interferon-gamma
3. Enhance cytotoxic T cells
4. Activate macrophages
5. Recognize antigens from intracellular infecting agents,
* Viruses, mycobacteria, and fungi
37
CD4 Helper cells: TH2 cells (9)
1. enhance antibody formation by B-cells
2. Cytokines – IL-4, IL-6, IL-10
3. Increase IgE production and mediate eosinophil recruitment and activation
4. T helper cell = good thing and enhances cytotoxic T cells
5. Recognizes antigens
6. T1 cellular immunity - good thing
7. Toxic suppressor = mount cytotoxic response
8. If acting poorly = negative role in suppressing immune response
9. Worry with too many cytotoxic around
38
CD8 – Cytotoxic/Suppressor T cells (4)
1. Recognize antigen from nucleated host cells
2. Mount cytotoxic response in response to viral infection involving any tissue
3. Secrete cytokines that can modulate immune reactions
4. May have a role in negatively regulating (suppressing) immune responses
39
Major Differences between T and B lymphocytes (2)
1. B lymphocyte binds with unprocessed native antigen
2. T lymphocyte only interacts with small peptide fragments of the intact antigen where they are bound to a cell surface human leukocyte antigen (HLA molecule)
40
Immune Response and Immunologic Tolerance (1b,2,3e)
1. Selectivity in immune response
a. + response to foreign antigens
b. No response to self antigens
2. Depends on deletion of autoreactive lymphocytes during T cell development - Immunologic Tolerance
3. Autoimmunity - Immunologic tolerance not effective
a. Type 1 diabetes
b. Hashimoto’s thyroiditis
c. Celiac disease
d. Autoimmunity likes each other
e. T1 diabetes, celiac, and thyroid all related — all have greater risks
41
Differences between CD4 and CD8 cells
1. CD4 T- lymphocytes
a. Interacts with Antigen expressing APCS typically
b. Interaction with APCS displaying antigenic peptides from extracellular sources (bacterial or fungi) that require ingestion and processing
2. CD 8 T lymphocytes
a. Source of Cytotoxic effector T cells
b. Capable of destroying any cell that has undergone change (viral infection with viral antigenic peptides)
i. Cytotoxic and destroy any cell with viral infection
ii. CD4 interact and they will help ingest bacteria
42
Immunity (2)
1. Cytokines, while primarily acting locally, mediate innate and adaptive immunity and stimulate T-lymphocyte formation.
2. T helper cells recognize antigen by binding to the antigenic fragment displayed by the human leukocyte antigen (HLA) molecules.
a. Having certain human leukocyte antigens may predispose you to autoimmunity
43
Cytokines (1,2,3e)
1. Each cytokines has many activities that overlap with each other
2. Primarily act locally
3. General categories
a. Mediating innate immunity
b. Mediating adaptive specific immunity
c. Stimulating blood cell formation
d. Defines the types of response:
e. Th1 vs. Th2 vs. Th17
44
Soluble Protein Components of the Immune System (5)
1. Antibodies IgA, IgG, and IgM
2. Complement
3. Chemokines
a. Also promote leukocyte chemotaxis.
4. Surfaces moles
a. Defensins and cathlicidins
b. Role is not clear
5. Cytokines--Differentiate and mature immune cells
a. Interleukins
b. Interferons
c. Tumor necrosis factor alpha
d. Secreted by mast cells and macrophages and initiate fever by the production of prostaglandins and other inflammatory serum proteins
45
Interleukins (5)
1. Biochemical messengers
a. Produced by macrophages and lymphocytes
b. Produced by and have effects of cells independent of infection
2. Alteration of adhesion molecule expression on many cells
3. Induction of leukocyte chemotaxis
4. Induction of proliferation and maturation of leukocytes in the bone marrow
5. Enhancement or suppression of inflammation
46
Interferons (4)
1. Protect against viral infections
2. Do not kill directly, but prevent against further infection
3. Enhance efficiency of development an acquired immune response
4. No effect on cells already infected
47
Tumor Necrosis Factor Alpha (4)
1. Secreted by Macrophages, mast cells
2. Induces fever
3. Caused increased synthesis of inflammatory serum proteins by liver
4. Causes cachexia (muscle wasting) and intravascular thrombosis
48
Chemokines (2)
1. Induce leukocyte chemotaxis
a. CC chemokines
i. Monocytes
ii. Lymphocytes
iii. Eosinophils
2. CX chemokines
a. Neutrophils
49
Summary components of immune system (1b,2d)
1. Cellular components
a. T cells and B cells mediate adaptive immunity
b. Phagocytic lymphocytes and NK cells mediate innate immunity along with non immune cells
2. Soluble protein components
a. Antibodies IgA, IgA, IgM humoral immunity
b. Cytokines—interleukins, interferons, chemokines
c. Complement: Antibody-non antibody activated
d. Surface moles: defensins, cathelicidins
