Allergy and Immunity Flashcards
(33 cards)
What is the most common disorder of the immune system?
Allergy (1 in 5 people)
What questions should be asked of patients with allergy complaints?
- How do the symptoms begin?
- What is the pattern (e.g., perennial, paroxysmal, or seasonal) of the episodes?
- What is the response to treatment, if any?
- What are the inducing factors (e.g., inhalants, ingestants, inject ants, exercise, and irritants)?
- What is the change over time of progression to remission?
- How severe are the symptoms?
What should be included in the allergic history for any person?
I DARE U:
- Insect stings
- Drug or food allergies
- Asthma and anaphylaxis
- Rhinitis
- Eczema
- Urticaria
What are the important features of a allergy family history?
- Any atopic disease including asthma, rhinitis, and atopic dermatitis
- History of deaths early in childhood
- Autoimmune diseases
- Angioedema
What are the common causes of dyspnea?
10 Ps:
- Pulmonary bronchoconstriction (asthma)
- Pulmonary embolus
- Pneumonia
- Pneumothorax
- Pump failure (congestive heart failure)
- Pericardial tamponade
- Psychogenic
- Poison (carbon monoxide)
- Peak seekers (high altitude)
- Paroxysmal spasm of the vocal cords (vocal cord dysfunction)
What are important indoor allergens?
Dust mites, cockroaches, cats, dogs, and moulds
What are important outdoor allergens?
Trees, grasses, weeds (ragweed), and moulds
List 4 nonspecific components of the innate immune system.
- Physical barriers (e.g., skin)
- Complement
- Polymorphonuclear leukocytes
- NK cells
(Other innate leukocytes include mast cell, phagocytes, basophils, eosinophils, macrophage)
What is the difference between autoimmunity and an autoimmune disease?
Autoimmunity refers to the presence of T cells directed against self. An autoimmune disease is the pathologic organ injury resulting from autoimmunity.
Where do T cells mature?
T cells mature in the thymus.
Where do B cells mature?
B cells mature in the fetal liver and adult bone marrow.
What are the final migration sites for immature T and B lymphocytes?
Secondary lymphoid organs, e.g. Spleen, lymph nodes, intestine (GALT MALT), and peripheral lymphoid tissue
What percentage of circulating lymphocytes are T cells?
80%. The majority of the rest are B cells.
What is the difference between CD4 and CD8 cells?
T cells bearing CD4 can recognize only those antigens embedded in MHC class II, which is found only on the surface APCs. T cells bearing CD8 can recognize antigens embedded in MHC class I, which is found on all nucleated cells.
(4II = 8 = 8I)
Th1 cell function.
Produces: IL2, TNF-β, IFN-γ
Effects: Cell-mediated immunity via activation of macrophage and cytotoxic T cells
Th2 cell function.
Produces: IL-4, IL-5, IL-9
Effects: IgE production, Mast cell growth, Eosinophilia
B cell function.
- Mature to plasma cell to produce antibody
- Phagocytosis
- Antigen presentation
List 5 major Ig isotypes
A, D, E, G, M
Most abundant immunoglobin:
IgA is produced in the highest quantities, but IgG has higher measurable levels in blood/serum
Where is IgA found?
Most secreted to mucosal surfaces as sIgA.
What is unique about IgA and complement?
IgA is the only antibody to activate alternative complement pathway.
Where is IgD found?
It is coexpressed with IgM on mature B cells, but its function is not known. It is not a secreted protein.
What is the role of IgE?
It is associated with allergy and with immunity to parasites for which it is thought to assist in antibody-dependent cell cytolysis.
What is the role of IgG?
- It undergoes somatic mutation with affinity maturation
- a potent opsonin (except IgG4)
- activates the complement
- crosses the placental barrier (as it is small) and provides passive immunity for the newborn
