Immunity and Stress

Immunity: Chapter 3
Hypersensitivity reactions
*Unusual or harmful immune system responses to normally harmful substances.

Type 1
Common, increasing in incidence, genetic propensity inherited.
Hay fever, vomiting > anaphylaxis
Antigen = allergen
Think about it…name some common allergies…
Shellfish, strawberries, nuts
Penicillin, sulfa, local anesthetics

Exposure to allergen > develops IgE antibodies from B lymphocytes
Antibodies attach to mast cells, connective tissue cells in mucosa of GI/respiratory tracts
Re-exposure allergen attaches to IgE antibody on mast cell > releases histamine
Chemical mediators > inflammatory rx, vasodilation, ^ capillary permeability > swelling
Histamine also irritates nerve endings > itching

Clinical signs and symptoms:
1st exposure formation of antibodies/sensitized mast cells
2nd exposure initiates chain of events
Target area red, swollen, vesicles, pruritic, itchy
Hay fever, allergic rhinitis
Food allergies
Atopic dermatitis or eczema
Anaphylaxis, anaphylactic shock

The immune system

Emergency – inject epinephrine immediately (EpiPen), O2, antihistamine, 911, treat shock, CPR, glucocorticoids
Testing/desensitization – scratching skin with small amount of antigen, observe for rx, inject small amounts of antigen to create a blocking antibody

Type II
Cytotoxic hypersensitivity
Antigen is present on cell membrane, circulating IgG react with causing cell destruction
Can be normal body component (blood types) or foreign
Phagocytosis/hemolysis results
Incompatible blood transfusion

Type III
Immune complex hypersensitivity (key word complex…)
Antigen combines with a antibody to form a complex, then deposited in tissues
Rheumatoid arthritis
Serum sickness

Type IV (think takes longer to get to 4 for delayed!)
Cell mediated or delayed hypersensitivity
Delayed response by sensitized T lymphocytes to antigens, rash 48-96 hours
Causes inflammation and destruction of antigen
Example Mantoux test for TB
Other examples poison ivy, chemical rx cosmetics, dyes, soaps, metals, latex

The immune system

Autoimmune Disorders:
Self antigens usually tolerated, self tolerance is lost so Autoantibodies (antibodies formed against self antigens) trigger an immune rx leading to inflammation, necrosis. Genetic component and aging may lead to loss of tolerance for self antigens.
Hashimoto’s thyroiditis, specific
Rheumatic fever
Myasthenia gravis
Pernicious anemia

Systemic Lupus Erythematosus SLE example of generalized autoimmune disease:
Chronic inflammation of many systems
Facial rash across nose and cheeks like markings of a wolf…’lupus’, butterfly rash
Discoid lupus erythematosus version affects only skin
Some drugs can cause a lupus like rx, which will go away with D/C of med
Women, 20s-40s, genetic, hormonal, environmental

Research Theories focus on:
Complement system,
Genetic defect interfering w/normal apoptosis

Large # of autoantibodies against DNA, platelets, erythrocytes
Immune complexes deposited in connective tissue > inflammation, vasculitis, ischemia
Typically affects kidneys, heart, lungs, brain, skin, joints, GI
So what might be the symptoms?

Multiple system involvement
Presence of Antinuclear Antibodies (ANA)
Lupus Erythematosus (LE) cells
Neutrophils containing nuclear material in the blood
Complement levels low
Erythrocyte sedimentation rate (ESR) high

Prednisone (glucocorticoid) to reduce inflammation (during exacerbations)
Antimalarial drug (hydroxychloroquine)
Avoid sun
Avoid fatigue
Exacerbations: fatigue, rash, fever, pain, headache

Causes of Immunodeficiency:
Failure in system, bone marrow, thymus
Genetic or congenital abnormalities, DiGeorge’s syndrome (hypoplasia of the thymus),
Liver disease
Immunosuppressive drugs
Severe stress
Opportunistic infections, resident flora
Prophylactic antimicrobials (preventive antibiotics) necessary
Increased incidence of cancer due to decreased immune surveillance

Replacement of gamma globulins
Bone marrow, thymus transplants

Stress: Chapter 12

*Stressor any factor that creates change in the body or environment…examples?
*Reaction to stress the same but intensity may vary
*Perceptions are important
*Stress is not necessarily bad…but if extreme can trigger a ‘maladaptive’ response

General Adaptation Syndrome (GAS), Hans Selye 1946
Body constantly adapts to changes in needs or environment – ‘fight or flight’ to maintain homeostasis.

3 stages in GAS
1st - Alarm – defenses mobilized by the hypothalamus, sympathetic nervous system, adrenal glands
2nd - Resistance stage hormones elevated and optimum performance
3rd – Exhaustion body unable to respond further or is damaged

Stress and the immune system

Physiological changes during stress are initiated by the sympathetic nervous system...
Increased BP and heart rate
Bronchodilation and increased respirations
Increased blood glucose level (glycogenolysis, gluconeogenesis
Arousal of CNS, release of endorphins for pain
Decreased inflammatory and immune response
Also… vasodilation of the muscles but vasoconstriction of the skin and viscera (kidneys, GI mucosa)
Stressors marked increase in ACTH and cortisol

So think about it…initially increase in level of function, however, then prolonged stress and increased glucocorticoids impairs memory, healing, decreases inflammation…

What are some conditions we associate manifestation or exacerbation with increased stress?

Herpes simplex sores
Seizure activity
Multiple sclerosis
Rheumatoid arthritis
Ulcerative colitis
Irritable bowel syndrome
Gastric and peptic ulcers

Effects of prolonged stress…what happens…

Acute renal failure so we increase hydration, meds to dilate renal arterioles
GI mucosal breakdown, meds to protect gastric mucosa, reduce acid secretions
PTSD maladaptive coping behaviors

Coping with stress:
Can be a vicious cycle fatigue, age, inadequate nutrition, lack of emotional support,
Measures to decrease stress:
Adequate rest
Healthy diet
Regular exercise
Relaxation – meditation, biofeedback, imagery, therapy, music, art
Distraction – play
Anti-anxiety medications

The effects of stress


Gould, B. E., & Dyer, R. M. (2011). Pathophysiology for the health professions (4 ed.). St. Louis, Missouri: Saunders Elsevier.

Story, L. (2012). Pathophysiology: A practical approach. Sudbury, MA: Jones & Bartlett Learning .



Immune system

Stress and the immune system

Stress effects