module 16 - immunity

immunity

the body’s ability to resist disease through defense, homeostasis, surveillance

what is innate immunity

a quick immune response that is present at birth and first to defend against pathogens

what are the characteristics of innate immunity?

• broad or nonspecific immune response

• feverishly fast

• no memory

• has chemical (ex. pH) and physical barriers (ex. cilia)

what is passive acquired immunity? provide an example

a type of immunity gained through the transfer of antibodies from another source, such as IgA from breastmilk or injections

what are the side effects of Rx immunoglobulin?

• HA

• injection site rxn

• flu-like s/s (fatigue, fever, chills, myalgias, arthralgia, N/V)

• transfusion-associated cardiovascular overload

• delayed side effects: thrombotic events, skin rxns, renal impairment, hemolysis, neutropenia

what is active acquired immunity

a type of immunity that develops antigen exposure, leading to the production of antibodies by the immune system. reinvasion allows the body to respond faster. this can occur through infection or vaccination, providing long-term protection.

describe three primary protective functions of the immune system

1. protects the body invasion

2. removed dead/damaged tissue/cells

3. recognizes and removes cell mutations

what are the three lines of defense and provide examples?

1. Physical barriers (skin, mucous membranes)

2. Innate immune response (phagocytes, inflammation)

3. Adaptive immune response (T cells, B cells)

what are the primary lymphoid organs?

• thymus gland

• bone marrow

describe the function of the thymus gland

• size of gland shrinks with age

• T cell differentiation and maturation

what are the peripheral lymphoid organs?

• lymph nodes

• tonsils

• spleen

• tissues in gut, genitals, bronchi, skin

B lymphocyte function

makes antibodies

T lymphocyte function

accounts for long term immunity to viruses, tumors, and fungi

natural killer cell function

lymphocytes that phagocytize virus infected cells, tumor cells, and transplanted grafts

T cytotoxic cells (CD8) function

• sensitized by antigen exposure

• attacks antigen cell membranes

• releases cytotoxic substances to destroy pathogens

T helper cells (CD4) function

• cell mediated and humoral immunity

• differentiations into different cytokines

dendritic cell function

captures antigens and transports it until met with a T cell with a specificity for it.

cytokine function

messenger between cells that tell them to proliferate, differentiated, secrete, or change activity. they can cause chronic inflammation, autoimmune disease, and sepsis

cytokine release syndrome (CRS)

aggressive reaction to infection or immunotherapy drugs.

CRS symptoms

• fever

• nausea

• fatigue

• body aches

treat promptly

what does the humoral immune response protect from?

• bacteria

• extracellular viruses

• resp pathogens

• GI pathogens

what does the cell-mediated immune response protect from?

• fungi

• intracellular viruses

• chronic infectious agents

• tumor cells

compare and contrast the characteristics of humoral and cell mediated immunity

humoral

• b cells

• produces antibodies

• has memory cells

cellular

• t cells, macrophages

• produces sensitized t cells and cytokines

• has memory cells

what is a suppressed immune response?

when the immune system isn’t working as well as it should

what is an exaggerated immune response?

body reacts excessively to a harmless substance/antigen

immunocompetence

the ability of the immune system to ID and inactivate/destrou invaders

incompetent immune system

when the immune system is unable to meet the demands from a severe infection, cancer, or immunodeficiency disease

overactive immune system

hypersensitivity disorders

what are the causes of type 1 hypersensitivity reactions?

• anaphylactic reactions

• genetic predisposition

describe systemic anaphylactic reaction manifestations

• happens in minutes

• life threatening d/t bronchial construction

• shock

• bronchial edema

• angioedema

• leading cause: drugs

describe local anaphylactic reaction manifestations

• cutaneous wheal and flare rxn

• in minutes or hours

• not dangerous

what are the causes of allergic rhinitis?

• dust

• mold

• animal dander

• pollen

• dust

allergic rhinitis s/s

• rhinorrhea

• sneezing

• tearing

• mucosal swelling

• airway obstruction

• pruritus around eyes, nose, throat, mouth

asthma s/s

• bronchial constriction

• excess thick mucus secretion

• bronchi mucus membrane edema

• decreased lung compliance

atopic dermatitis

chronic, inherited skin inflammation (eczema)

urticaria (hives) s/s

• wheals varied in size/shape

• can appear all over body

• develops quickly and lasts minutes to hours

angioedema

swelling of eyelids, lips, tongue, larynx, hands, feets, GI, genitalia that occurs suddenly or over hours, lasting 24 hrs

what are the causes of type II hypersensitivity reactions?

• hemolytic transfusion rxns (receiving incompatibile blood)

• goodpasture syndrome (lung and kidney disorder)

describe type III hypersensitivity reactions

• tissue damage in immune complex rxns

• associated with autoimmune disorders (lupus, acute glomerulonephritis, RA)

describe type IV hypersensitivity reactions

delayed cell-mediated immune response that occur in 24-48 hrs and causes tissue damage

what are the causes of type IV hypersensitivity reactions?

• contact dermatitis

• bacterial, fungal, viral infections

• transplant rejection

• drug sensitivity

what is the cause of an exaggerated humoral immune response?

allergies (overproduction of IgE, mast cell activation)

what is the cause of an exaggerated cell-mediated immune response?

poison oak

what are the consequences of an exaggerated immune response?

• cardiovascular disease (graves diseases, SLE)

• renal failure (chronic glomerulonephritis, polycystic kidney disease

• HIV causes more opportunistic diseases

what are the causes of a suppressed immune response

• neutropenia

• organ transplants

primary prevention methods

reducing risk factors such as diet, exercise, substance abuse, sexual behavior

secondary prevention methods

HIV testing, genetic testing

chronic allergies interprofessional care

• allergen recognition and control

• stress management

• drug therapy and immunotherapy will not make the patient completely symptom free

• environmental control (changing occupation, moving to differnt climate, giving up favorite pet)

immunotherapy nursing management

• ensure emergency equipment and drugs are available when injections are given

• describe redness and swelling of injection site reaction

• keep accurate records to prevent adverse reactions

• give allergen extract away from a joint to apply a tourniquet

• rotate injection sites

• observe pt for 20-30 minutes

• delayed rxns can occur 24 hours later

what are the risk factors for a suppressed immune system?

• very young (T cell deficiency)

• older adults

how does aging affect the immune system?

also known as immunosenescence, aging results in a higher incidence of cancer, greater risk for infection, increased autoantibodies, lower cell-mediated immunity, and a shrunken thymus (main cause)

what are the categories of primary immunodeficiency disorders?

• phagocytic defects

• b cell deficiency

• t cell deficiency

• combined b and t cell deficiency

what is the primary cause of secondary immunodeficiency disorders?

drug induced immunosuppression. immunosuppressive therapy treats autoimmune disorders. cancer chemo also results in immunosuppression. leukopenia occurs.

name the relevant diagnostic tests

• RBC count

• WBC w/ differential

• fluorescent antinuclear antibody

• CRP

• ESR

• allergy testing

• genetic testing

• rheumatoid factors

• western blot test

• TORCH antibody panel

• organ fxm test