2/6/12
Immune System
Includes: Lymphoid organs, Lymphocytes & WBC, Lymphatic System (vessels, nodes, spleen), Chemicals (antigens)
Antigen = substance capable of inducing a SPECIFIC immune response; (aka chemical markers)
Lymphocytes = Natural Killer Cells
Non – Specific
“if it doesn’t belong, NK cells will destroy it”
are floating everywhere, killing
T-Cells = fight infection
Play a major role
Produced in bone marrow
Mature/develop in thymus (hence T-cells)
Present in blood & lymph nodes
Types of T-Cells: Cell-mediated Immunity
Helper T-Cells
Killer T-Cells (have lyse cells)
Memory T-cells
Suppressor T-Cells (limit immune response)
Cell-Mediated Immunity
Immune response; does NOT involve antibodies
Involves activation of:
macrophages,
natural killer cells,
antigen – specific cytotoxic T-lymphocytes
releases various cytokines
B-Cells: Specific Immune Response
Memory Cells
Activated with infection
Created and matured in bone marrow
Present in blood & lymph nodes
Become plasma cells & produce antibodies
Remember specific antigen for future attacks
Interferon: chemical response to viral attack
Will NOT help cell attacked BUT will protect surround cells by limiting viral growth
Antibodies: label antigens for destruction
Protein produced by plasma cells in response to foreign antigen
5 classes
IgG
Greatest percentage of antibodies = 80% of total Ig
Present in blood
Can pass freely through cell walls and placenta
Protects against bacteria, viruses, toxins
IgA
10 – 15%
Abundant in mucus secretions, including tears, saliva, breast milk
Too large to cross placenta
Prevents attachment of pathogens to mucosa
Protects neonates from NEC (GI D/O; preemies are more prone)
Mechanisms of Immunity:
Humoral Immunity
* recognition of antigen as foreign
* B-cells proliferate and differentiate
* Memory B-cells will aid in destruction if antigen returns
* antibodies label antigen for phagocytosis
Allergic Response: antibodies respond to foreign but harmless antigens
Types of Immunity
Acquired
Active
Natural
Exposure (you sneeze on me)
Artificial
Vaccines/Immunization
Passive
Natural
Mother’s Breast milk
Artificial
Serum (antibodies from another source, not your own)
Aging Immune System
Increase:
Immature T-cells
Autoimmune D/O
Cancer
Decrease:
Thymus gland
Response to antigens
Antibody response
Dx Tests
Blood Test
Radiographic Test
Gene Testing
Skin Testing (PPD or allergen scratch test)
Biopsy of affected organs gives Dx, Prognosis & Tx: do everything in one shot!
Therapeutic Measures:
Allergies
Medication Alert ID band
Anaphylaxis kit : Epi-Pen, Antihistamine, Tourniquet
Immunotherapy
Desensitize patient with small injected amounts of allergen
Medications
Also:
Immunosuppressants
Interferon
Hormone Therapy
Surgical Management (splenectomy)
Food Allergies: abnormal response to food expressed by certain characteristic symptoms
System mistakenly attacks a food protein
May be mild – severe, even fatal
Usually occur within a few minutes to an hour of eating
Not the same as food intolerance!
Top 8 Food Allergies
Milk, egg, peanut, treenut, fish, shellfish, wheat, soy
Symptoms
GI distress: N/V/D, abd pain
Eyes: itchy, watering, swelling
Skin: hives, swelling, atopic dermatitis (eczema)
Respiratory: wheezing, cough, laryngeal edema (swelling of lips/throat)
Generalized: anaphylaxis – above s/s + drop in BP, difficulty breathing
Immune System D/O
Category 1: Hypersensitivity Reactions
Transplant rejections
Measles
Anaphylaxis
Hemolytic transfusion reactions
Category 2: Autoimmune Disorders (see list below)
Hives (Urticaria): The release of histamine in response to meds, food, temperature, stress, etc.
Characteristics: raised, pruritic (itchy), non-tender, erythematous wheals
Tx: epinephrine, corticosteroids, antihistamines, histamine H2 blockers
Nsg Interventions
Monitor s/s
Symptomatic relief
Med administration
In severe cases-> airway management
Angioedema: a form of urticarial that affects the subQ tissue rather than skin
Characteristics: swelling esp lips/eyes, mouth/throat & hands/feet; painless, dermal
Autoimmune D/O: immune system recognizes body’s own cells as foreign
(possibly due to infections, drugs or other factors)
and immune response destroys them
List of Autoimmune D/O:
Hashimoto’s Thyroiditis SLE (systemic lupus erythematous)
Pernicious Anemia Ulcerative colitis
Addison’s Disease Dermatomyositis
Type 1 Diabetes (DM) Lupus erythematous
Rheumatoid Arthritis Sjogren’s syndrome
Reiter’s syndrome Grave’s disease
MS (multiple sclerosis/myasthenia gravis)