Chapter 24:

The Immune System

"Layered defense" system The skin and chemical barriers The innate and adaptive immune systems

*Nonspecific Defense Mechanisms* Chemical barriers or normal flora of the system

(microorganisms) of the GI system, neutralize or kill microorganisms.

*Nonspecific Defense Mechanisms* Neutrophils, dendritic cells, and monocytes

(microorganisms) of the GI system, neutralize or kill microorganisms.They "patrol" the body for pathogens, or can be called in by cytokines. Macrophages live in tissues and produce enzymes and other chemicals; neutrophils are the most common. They go to the site of inflammation (by chemotaxis) and are the first to arrive. They are antigen-presenting cells and activate the adaptive immune system, as well as clean out debris from the infection.

*Antigens and Antibodies* Know all of this! Ig

*Immunoglobulins* (Ig) IgM,IgG, IgA, IgE, IgD

Special Consideration on spina bifida

A child with spina bifida ( congenital spinal column defect) is at increased risk for latex allergies because the mucous membranes of bladder and rectum are exposed to latex during frequent examinations and procedures, such as urinary catheterization. Non Latex gloves and equipment should be used when possible for all children, particularly those with this disorder. (This would help prevent development of latex allergy in healthcare workers as well.)

Key Concept on vaxxine boost

A vaxxine boost the immune system by offering a weak form of an infection that the body can fight off and can "remember" how to combat when a more virulent form presents itself. Most viral vaccines are given as live attenuated (weakened) viruses. Most bacterial vaccines are based on other components, such as harmless toxins from the organism. Because bacterial vaccines are usually weaker, they often contain other contains other substance designed to induce greater immune responses.

*Antigens and Antibodies* Know all of this! Ab

Antibody (Ab) Protein substance that the body produces in response to an antigen

IgM

Antibody produced on initial exposure to antigen; stimulates complement activity. (E.g., after a first tetanus immunization)

Antigen-Antibody Reaction* 5. Describe the process of antibody-mediated immunity. Explain how the "lock-and-key" concept applies to the antigen-antibody complex.

Antibody-mediated immunity (Pg.287) "Lock-and-key" mechanism Antibody changes an antigen, rendering it harmless to the body. The antibody accomplishes this by binding to the antigen, forming an antigen-antibody complex. This binding can be compared to a "lock- and-key" mechanism; an antibody forms in response to only one specific antigen

The nurse is educating a client about how the immune system functions. What term should the nurse tell the client is used to describe any foreign substance or molecule entering the body that stimulates an immune response? * 1/1 Antibody Antigen Cell-mediated Humoral

Antigen

*Antigens and Antibodies* Know all of this! Ag

Antigen (Ag) Any foreign substance or molecule entering the body that stimulates an immune response

acquired (adaptive) immunity

Attained through natural or artificial sources, both either actively or passively.

A client has scleroderma. Which causes scleroderma? * 1/1 Immunodeficiency Specific immunity Autoimmune reaction Latex allergy

Autoimmune reaction

Which part of the immune system produces antibodies? * 1/1 B cells T cells Natural killer cells Phagocytes

B cells

4. A client arrives in the emergency department after being bitten by a raccoon that wandered into the yard. What nursing action does the nurse anticipate preparing for ? A. Administering a rabies vaccine to provide naturally acquired active immunity B. Administer a rabies vaccine to provide artificially acquired passive immunity C. Administer a rabies vaccine to create an antibody mediated immunity D. Administer a rabies vaccine to provide naturally acquired passive immunity

B. Administer a rabies vaccine to provide artificially acquired passive immunity Artificially acquired passive immunity occurs with the injection of ready-made antibodies into a person's system. These antibodies were produced by another individuals immune system. An example of this immunity is the immunization for rabies. This immunization contains ready-made anti rabies antibodies and is given in the event of a bite by a rabid animal or if the animal cannot be located and tested. Tetanus toxoid can also be given in the passive form if a person has become ill with tetanus.

Box 24-2* Description of the Immune Response Basophils and eosinophils

Basophils and eosinophils secrete chemicals to defend against parasites. They also play a role in allergic reactions in asthma.

Box 24-2* Description of the Immune Response • Attack (killing or eliminating microbes)

By macrophages, neutrophils, and natural killer cells. If invading microbe cannot be eliminated, it can be encapsulated or imprisoned by special cells (granuloma); for example, granuloma (tubercle) encloses the bacteria causing tuberculosis, rendering it unable to make the person ill.

5. The nurse is discussing the benefits of breastfeeding to a pregnant mother. What statement made by the client demonstrates UNDERSTANDING of the benefits? A. The infant will receive artificially acquired active immunity to protect the infant from viruses B. The infant will receive artificially acquired passive immunity to protect them from diseases such as multiple sclerosis C. The infant will receive naturally acquired passive immunity to last approximately 6 months D. The infant will receive antibody-mediated immunity to prevent the child from acquiring respiratory disorders for 1 year

C. The infant will receive naturally acquired passive immunity to last approximately 6 months Naturally acquired passive immunity occurs between mothers and infants. Immunity is transferred from mother to fetus during pregnancy via the placental circulation exchange. If the baby is breastfed , the baby also receives protection after birth through the mothers breast milk. Naturally acquired immunity can last to about 6 months of age, when the infant's own immune system begins to take over. ( The infant does not synthesize antibodies; they are " borrowed" from the mother.)

Box 24-2* Description of the Immune Response Mobilization of the immune system

Cytokines released, other lymphocytes activated, natural killer cells stimulated to secrete interferon. Interleukin-8 acts as signal to guide neutrophils to antigen (chemotaxis).

B cells/B lymphocytes:

Develop into cells that produce antibodies(plasma cells). Exposure to antigen causes them to enlarge, multiply rapidly and produce colonies of clones.

3. Describe nursing implications related to the absence of or a deficiency in antibody production. Pg.282-283

Each antigen (foriegn invader) stimulates the production of its own specific antibody. The body can make about 1 million individual antibodies. Antibodies do not destroy but antigens themselves, but label antigens for destruction by other substances.

B Lymphocytes 2. Differentiate between B cells and T cells (lymphocytes).

Exposure to an antigen in the bloodstream activates B cells to enlarge and multiply rapidly to produce colonies of clones. The clones that do not become plasma remain in the body as "memory cells." Repeated exposure to an antigen, memory cells can immediately produce antibodies. This "immunologic memory" makes a person immune to reinfection after having had a disease, but this is not true for all diseases.

Key Concept on exposure of disease

Exposure to disease-causing organism during one's life stimulates the process of naturally acquired active immunity.

Naturally acquired active immunity

Exposure to disease-causing organisms during one's life stimulates the process of acquired immunity.

Key Concept on immunoglobulins

Functions of immunoglobulins vary, depending on the antigen. Immunoglobulins disable bacteria (antitoxins), opsonize (coat) bacteria so they become targets for phagocytes, and/or link to antigens to create enzymes (complement action).

The nurse is reviewing the organs involved in the body's immune system. What are the functions of T cells? Select all that apply * 1/1 Help protect against viral infections Can detect and destroy some cancer cells Produce antibodies Produce plasma cells Create antigens

Help protect against viral infections Can detect and destroy some cancer cells

Helper T cells and killer T cells

Helper T cells - Help regulate innate and adaptive immune responses by instructing other cells to kill infected cells or pathogens. Killer T cells(cytotoxic T) - Kills cells infected with pathogens, or are otherwise damaged or defective.

Interferon-beta:

Helpful in multiple sclerosis

A client walked on a rusty nail and needs a tetanus booster. Which provides the type of antibody generated by a tetanus booster? * 1/1 IgM IgD IgA IgE

IgM

Naturally acquired passive immunity

Immunity is transferred from mother to fetus. During pregnancy via Placental circulation exchange Mother's breast milk- protection after birth.

inborn immunity:

Immunity that is inherited or genetic.

A nurse caring for a client with measles understands which defense mechanism has occurred in the client's immune system? * 1/1 Humoral immunity Complement fixation Immunologic memory Cell-mediated immunity

Immunologic memory

Artificially acquired passive immunity

Injection of ready-made antibodies antibodies were produce by another individuals immune system (e.g. rabies)

Types of cytokines

Interferon-alpha, interferon-beta, interleukin-1, interleukin-2, interleukin-3, interleukin-8, interleukin-12, and granulocyte colony-stimulating factor

immunity:

Is the body's ability to recognize and destroy specific pathogens, such as bacteria, viruses, fungi, and also parasites, and to prevent infectious diseases.

An older adult tells visiting grandchildren about having the chicken pox as a child. Which is the effect of chickenpox on the immune system? * 1/1 It will build naturally acquired passive immunity It will build naturally acquired active immunity It will build artificially acquired passive immunity It will build artificially acquired active immunity

It will build naturally acquired active immunity

Key concept on lymphocytes

Lymphocytes formed in bone marrow and lymphatic tissues can transform into specialized cells, B cells and T cells. B cells provide humoral immunity by reacting to antigens and producing antibodies. (The term, antigen, is an abbreviation for "antibody generator.") Antibodies then target antigens for destruction. T cells, which proliferate at the direction of thymic hormones, attack infected cells and provide cell-mediated (cellular) immunity

Key Concept Lymphocytes and antibodies

Lymphocytes formed in bone marrow and lymphatic tissues can transform into specialized cells, B cells and T cells. B cells provide humoral immunity by reacting to antigens and producing antibodies. (The term, antigen, is an abbreviation for "antibody generator.") Antibodies then target antigens for destruction. T cells, which proliferate at the direction of thymic hormones, attack infected cells and provide cell-mediated (cellular) immunity.

Box 24-2* Description of the Immune Response Autoimmune Reaction

Malfunctioning or misinterpretation by immune system of body's own tissues (e.g., rheumatoid arthritis, scleroderma, myasthenia gravis [MG], pernicious anemia, systemic lupus erythematosis [SLE], type I diabetes mellitus, ankylosing spondylitis, Sjogren's syndrome, multiple sclerosis [MS].) • Mast cells are formed in connective tissue and mucous membranes. They help regulate the inflammatory response (mostly in allergy and anaphylactic reactions). They contain histamine, heparin, and other substances.

An older adult client has a decrease in the number of T cells and B cells. What nursing action is a HIGH PRIORITY for this patient ? A. Monitor for signs of infection B. Give warm blankets and keep the room warm C. Encourage the patient to eat 6 small meals a day D. Obtain strict intake and output

Monitor for signs of infection T lymphocytes can recognize foreign invaders and certain cancer cells. They help protect against viral infections and destroy recognized cancer cells. B lymphocytes develop into cells that produce antibodies ( plasma cells).

A client has a decrease in T cells and B cells . What nursing action is a PRIORITY? A. Monitor for altered kidney function B. Monitor regularly for blood loss C. Monitor for joint swelling and tenderness D. Monitor regularly for signs of infection

Monitor regularly for signs of infection

The nurse is educating a group of students about different types of white blood cells. What types of cells are agranular white blood cells? Select all that apply * 1/1 Neutrophils Basophils Eosinophils Monocytes Lymphocytes

Monocytes Lymphocytes

Humoral immunity (humoral= body fluid)

Most of the clones become plasma cells, which produce specific antibodies to circulate in the blood. Macrophages engulf and destroy antigens after antibodies have identified them for destruction.

A mother passes the necessary immunity on to her infant. What type of immunity does this represent? * 1/1 Artificially acquired passive immunity Naturally acquired active immunity Naturally acquired passive immunity Artificially acquired active immunity

Naturally acquired passive immunity

Effects of Aging on the Immune System

Number of T cells and B cells decrease Slowed immune system reaction Increased incidence of tumors Greater susceptibility to infections Baseline temperature is lowered Absence of febrile response to infection

Special Considerations on nursing care for the elderly

Nursing care for the elderly must adapt to changes related to aging. The aging process can have a significant effect on the hematologic and lymphatic systems.

Acquired (Adaptive) Immunity (cont.)

Occurs when a person is deliberately exposed to a causative agent and can also be acquired through active or passive

antibody-mediated immunity:

Person deliberately exposed to a causative agent and can also be acquired through active or passive means.

Interleukin-2

Produced by T cells, stimulates production of interferon. Treats many solid cancer. (Malignant melanoma and kidney cancer/also has adverse effects)

Interleukin-1:

Produced by macrophages, mobilizes T lymphocytes

antibody

Protein substance the body produces in response to an antigen.

Cytokines

Proteins that act as messengers to help regulate some of the functions of lymphocytes and macrophages during the immune response

A client has been told that atrophy of the thymus has occurred. Which time in the life cycle is marked by atrophy of the thymus? * 1/1 Early in life Middle age Old age Puberty

Puberty

Box 24-2* Description of the Immune Response Recognition of an antigen

Recognition (of antigen) via antigen processing: Mostly by macrophages. Antigens ingested, broken up, packaged, carried to the surface of cell membrane, and assigned to T-cell receptor.

Immune Response

Recognition of antigen via antigen processing Basophils and eosinophils Mobilization of immune system Attack (killing or eliminating microbes) Autoimmune reaction* Immunodeficiency disorders*

Interleukin-3

Required for differentiation of certain T cells

Natural killer (NK) cells

Secrete some cytokines and kill certain microbes (viruses) and cancer cells. They are ready to target specific cells as soon as they are produced. They are part of the body's natural defense against cancer.

T cells/T lymphocytes:

T cells enable the body to differentiate between "self" and "nonself,". cause tissue or organ rejection after transplantation/ T lymphocytes responsible for fighting cancer cells, viruses, and intracellular parasites.

Key Concept on T cells

T cells recognize a "nonself" target only after antigens have been processed and presented, combined with a "self-receptor" called a major histocompatibility (MHC) molecule, which coats the molecule with an antibody. B cells are involved in humoral immune response. T cells provide cell-mediated (cellular) immune response. Both B cells and T cells have receptor molecules that recognize specific target cells

Explain Lymphocytes*

The "cornerstone" of the immune system Found in blood, lymph, and lymphoid tissues, such as the lymph nodes and tonsils They alone have the ability to recognize foreign substances in the body. B lymphocytes Develop into cells that produce antibodies (plasma cells) T lymphocytes Help protect against viral infections Can detect and destroy some cancer cells Maturation occurs in the thymus

Immunity

The body's ability to recognize and destroy specific pathogens.

Structure and Function of the Immune System

The body's immune system includes The bone marrow (cells in bone marrow can develop into RBCs, WBCs, and platelets), lymphoid organs, and the mononuclear phagocyte system Functions: Defense Homeostasis Surveillance

Complement fixation

The complement combines with the antigen-antibody complex and helps in the attack on invading antigens.

Key Concept on self and nonself

The immune system must distinguish between "self" (normal components of the body) and "nonself" (foreign tissues or substances). In some cases, this mechanism is faulty and the body destroys its own cells.

IgG

The only antibody transferred from mother to fetus across the placenta; protects fetus against antitoxins, viruses, and bacteria and protects the newborn for the first few months. Most common antibody and is produced on second and future exposure to an antigen. (E.g., after a tetanus booster).

Key Concept on antigens

The second exposure to an antigen can cause a quicker and more dramatic response than the first, because of "immunologic memory." (The first exposure causes a more delayed reaction, because it takes time to form antibodies, which are ready for the second exposure and act quickly.) This is an important concept when related to allergic reactions.

The Mononuclear Phagocyte System

The specialized cells in this system begin as monocytes and transform into macrophages after entering other tissues via the bloodstream. Destroys worn-out blood cells, bacteria, cancer cells, and other dangerous foreign substances Kupffer cells in the liver sinusoids Dust cells in the lungs

The nurse is assigned to care for a child with spina bifida that requires routine urinary catheterization. What PRIORITY action by the nurse is important to prevent complications caused by an IgE mediated reaction? A. The use of nonlatex gloves for all procedures B. Administer Epinephrine prior to performing the procedure C. Administer Benadryl every 4 hours to prevent an allergic reaction D. Ensure the child does not receive antibiotics

The use of nonlatex gloves for all procedures

Explain T Lymphocytes*

Thymus-derived lymphocytes produce cell-mediated immunity. Make up approximately 80-90% of total lymphocytes They fight cancer cells, viruses, and intracellular parasites. They kill the host cell and prevent replication. Macrophages combine with T cells to release interleukins, which stimulate T-cell growth.

Interferon-alpha

Treat certain cancers. (Hairy cell leukemia)

Is the following statement true or false? Most viral vaccines are given as live attenuated (weakened) viruses.

True A vaccine boosts the immune system by offering a weak form of an infection that the body can fight off and can "remember" how to combat when a more virulent form presents itself.

Is the following statement true or false? The second exposure to an antigen can cause a quicker and more dramatic response than the first.

True The second exposure to an antigen can cause a quicker and more dramatic response than the first because of "immunologic memory." The first exposure causes a more delayed reaction because it takes time to form antibodies to the antigen. Antibodies are ready for the second exposure and act quickly.

Box 24-2* Description of the Immune Response HYPERSENSITIVITY DISORDERS

Type I: anaphylaxis, hay fever, allergy • Type II: cytotoxic, autoimmune hemolytic anemia, transfusion reactions • Type III: immune complex disease reaction to Hepatitis B, some cancers • Type IV: delayed (cell-mediated) hypersensitivity, PPD reactions, latex allergy, sarcoidosis.

Artificially acquired active immunity

Vaccination, inoculation, or immunization Of causative agent (antigen) into the person's system; diluted to reduce its virulence (strength) so the recipient will form antibodies without becoming ill.

Key Concept on NK cells

When NK cells are incubated with interleukin-2, they are called lymphokine-activated killer T cells. They then function even more effectively than do NK cells as a biologic treatment for cancer.

cell-mediated immunity

When T-cells proliferate(rapid increase) and become sensitized (capable of combining with specific foreign antigens).

complement fixation:

When complement system attacks the surface of an anti-body-coated foreign cell, helping antibodies kill the pathogen.

cytokine

a specific protein involved in cell-to-cell communication that coordinates antibody and T cell immune interactions and/or amplies immune reactions.

antigen:

a substance that stimulates the production of antibodies.

gamma globulin:

a type of immunization given after disease exposure that results in only short-term immunity, not specific for a certain disease; also known as immunoglobulin IgG

*Nonspecific Defense Mechanisms* Interferon

also called nonspecific immunity: fights a variety of foreign invaders. examples of of nonspecific defense mechanism include: a protein made by several types of cells, inhibits virus production and infection.

Specific Defense Mechanisms

also called specific immunity The final line of defense against disease, allows body to recognize and respond to foreign substances. Humoral immunity and cell-mediated immunity

Lymphocytes

are the "cornerstone" of the immune system; they alone have the ability to recognize foreign substances in the body Lymphocytes are found in blood, lymph, and lymphoid tissues, such as lymph nodes and tonsils. They form immune cells and their precursors Differentiation of lymphocytes into special lymphocytes called B cells (B lymphocytes) and T cells (T lymphocytes) must occur before detection of foreign invaders begins.

Which of the following immunoglobulins protects the fetus before birth against antitoxins, viruses, and bacteria? a. IgM b. IgG c. IgA d. IgE e. IgD

b. IgG IgG protects the fetus before birth as it is the only antibody transferred from mother to fetus across the placenta. IgM stimulates complement activity. IgA protects mucosal surfaces. IgE is responsible for immediate-type allergic reactions, including latex allergies. IgD is believed to function as an antigen receptor.

IgD:

believed to function as an antigen receptor, it is present in the blood in very small amounts.

vaccine:

boosts the immune system by offering a weak form of an infection that the body can fight off and can "remember" how to combat when a more virulent form presents itself.

*Nonspecific Defense Mechanisms* Vomiting, defecation, and urination

expel microbes from the body, along with normal waste products.

nonspecific immunity:

fight a variety of foreign invaders. Examples: coughing or sneezing, help remove pathogenic material, Fever and inflammation

specific immunity:

final line of defense against disease, allows the body to recognize and respond to foreign substances.

thymus:

gland is considered a central or primary lymphoid organ.It is most active early in life and begins to shrink at puberty.

Interleukin-8

guides neutrophils to the source of an antigen.

*Nonspecific Defense Mechanisms* Mechanical reactions such as coughing or sneezing

help remove pathogenic material.

Granulocyte colony-stimulating factor

helps increase neutrophils in clients who are undergoing chemotherapy

humoral immunity

immunity created by the B lymphocytes and is the body's resistance to circulating disease-producing antigens and bacteria.

*Nonspecific Defense Mechanisms* Hydrochloric acid in the stomach

in the stomach destroys pathogens taken in with foods.

*Nonspecific Defense Mechanisms* Fever and inflammation

intensify the effects of interferons, inhibit the growth of some microbes, and speed up body reactions, aiding in tissue repair.

*Nonspecific Defense Mechanisms* Cilia and macrophages of the respiratory tract

intensify the effects of interferons, inhibit the growth of some microbes, and speed up body reactions, aiding in tissue repair. Tiny hairs in the nose and the turbulent air flow there also serve as mechanical barriers to dust and other foreign particles.

Acquired (adaptive) immunity:

is attained through natural or artificial source

Inborn immunity

is inherited or genetic This inherited, natural, or innate immunity may be common to all members of specific species; may be common to a specific population, sex, or ethnic group, or to an individual person

IgA:

it is important in defense against invasion of microbes via the nose, eyes, ears, lungs and intestines. The major component of secretions such as saliva, tears, and bronchial fluids.

Naturally acquired immunity

occurs when a person is not deliberately exposed to a causative agent.

naturally acquired immunity:

occurs when a person is not deliberately exposed to a causative agent. This immunity can occur both actively and passively.

*Nonspecific Defense Mechanisms* Earwax, mucus, vaginal secretions, and semen

prostatic fluid, and semen, provide protection against pathogens.

*Nonspecific Defense Mechanisms* Skin, tears, interferon

provides a physical barrier and secretes enzymes that kill or reduce virulence of bacteria.

IgE:

responsible for immediate type of allergic reactions, including latex allergies, which can cause many problems for healthcare personnel. (Ranging from hives to Anaphylaxis and death).

Lymphokines

secreted by lymphocytes.

Interleukin-12:

stimulates natural killer cells

Box 24-2* Description of the Immune Response IMMUNODEFICIENCY DISORDERS (ABNORMAL RESPONSE TO ONE'S OWN TISSUES)

• Immune system is compromised and does not function adequately to prevent infections. Some immune disorders, such as HIV and AIDS, take advantage of the immune system's weaknesses and make themselves appear to be a normal part of the body. • The innate (biologic) immune system (immediate nonspecific reactions), such as phagocytosis and the normal flora (microbes) of the GI system—does not require previous exposure to the antigen—closely related to the nervous and sensory systems. • The adaptive (acquired) immune system adapts to specific infection and improves the recognition of the invader (immunologic memory, humoral and cell-mediated immunity), producing a faster and stronger reaction—requires prior exposure to the antigen—develops to recognize specific pathogens ("immunologic memory"), due to T cells and B cells. • "Herd immunity," the phenomenon of organisms living closely together and sharing minor infections all the time.