MedSurg Ch 19

What are the three lines of defense in the immune system

Mechanical barriers, inflammation, and acquired or adaptive immunity

Which components of immunity are part of innate immunity?

First-line barriers (mechanical) and the inflammatory response

What characterizes adaptive immunity?

It is a specific immune response to a microbe and creates lasting immune memory (lifelong immunity)

Besides fighting infections, what other roles does the immune system have?

It prevents the proliferation of cancer cells and initiates the healing of damaged tissue

What can result from immune overactivation?

Reactions such as anaphylaxis and autoimmune disorders

What is primary immune dysfunction?

A condition present at birth due to intrinsic, congenital, or genetic causes that impair immune function

they result from defects in T lymphocytes, B lymphocytes, natural killer cells, phagocytes, or the complement system

What is secondary immune dysfunction?

An acquired immune deficiency that occurs after birth due to environmental or extrinsic factors

caused by HIV, irradiation, chemotherapy, malnutrition, burns, or other diseases

What role do B cells play in the immune system?

They produce antibodies as part of the humoral immune response

What are the primary immunoglobulins produced by plasma cells?

IgG, IgA, and IgM

How do B cells contribute to lifelong immunity?

By creating immune memory in response to infections and immunizations

involved in producing a humoral immune response, which is the antibody response

What is an example of a B-cell deficiency?

X-linked agammaglobulinemia (XLA)

Warning Signs of Primary Immune Deficiency

Eight or more new infections within 1 year

Two or more serious sinus infections within 1 year

Two or more months on antibiotics with little or no effect

Two or more pneumonias within 1 year

Failure of an infant to gain weight or grow normally

Recurrent deep skin or organ abscesses

Persistent thrush in the mouth or elsewhere on skin after age 1

Need for IV antibiotics to clear infections

Two or more deep-seated infections

A family history of immune deficiency

X-linked Agammaglobulinemia (XLA)

an X-linked recessive inherited or congenital primary immune deficiency; mainly affects males because of X chromosome

result of a mutation of the BTK gene. The BTK gene is present on the long arm of the X chromosome, and its defect results in a deficiency of Bruton’s tyrosine kinase, which is essential for the development of B lymphocytes

patient will be prone to severe bacterial infections

The nurse is screening patients for X-linked agammaglobulinemia. The nurse should consider which patient most likely to have the disorder?

A.  A 6-year-old female patient without any family history

B.  A 35-year-old female patient with a respiratory infection

C.  A 7-month-old male patient with recurrent infections

D.  A 40-year-old male patient with a family history

A 7-month-old male patient with recurrent infections

What immune component is deficient in XLA?

Antibodies or immunoglobulins (like IgG, IgA, IgM)

Why are patients with XLA vulnerable to infections?

Because they cannot produce antibodies in response to antigen invasion

What types of infections are common in XLA patients?

Infections of the ears, lungs, skin, conjunctiva, and central nervous system

Recurrent bacterial infections of the respiratory tract are the first indicator (chronic sinus infections, pulmonary diseases)

What serious systemic infections can develop in XLA?

Pneumonia, meningitis, and septicemia

What is an important first step in diagnosing XLA?

Obtaining a detailed family history and history of infections

XLA diagnosis

Detailed family history

B-lymphocyte surface marker assays

Western blot test

Genetic testing

Chest or sinus x-ray

What is the purpose of a Western blot in XLA diagnosis?

To determine if the BTK protein is expressed

read as - Present, absent, partial deficiency, or mosaic expression

What does mosaic BTK expression indicate?

The individual is a genetic carrier of XLA

Periodic radiographs in children with XLA are used

to detect early signs of infection in the chest or sinus

What is the main treatment used to provide short-term passive immunity in XLA?

IV immune globulin (IVIG), containing mostly IgG antibodies

IVIG administered every 3-4wks

What is the goal of prophylactic antibiotic therapy in XLA patients?

To prevent infections before they start

Vaccines and XLA

Killed vaccines stimulate T-cell-mediated immune responses and support protection from infections

Live attenuated vaccines can cause vaccine-associated disease in immunodeficient individual and should be avoided

What are some IVIG-related risks in geriatric patients?

Acute renal failure, fluid overload, thrombosis, hemolysis, and hypersensitivity reactions

XLA manifestations

Fever, fatigue, lethargy, irritability, poor appetite, and behavior changes

Increased respiratory rate, labored or shallow breathing, adventitious lung sounds

Rash, lesions, slow-healing wounds

Redness and/or drainage of the eyes (suggesting conjunctivitis)

Ear pain, pulling at ears, muffled sounds, decreased hearing

What protective measures should nurses implement?

Isolation precautions, limit visitors, assign nurse not caring for infectious patients

Poor appetite and decreased fluid intake

can be signs of illness and infection with XLA patients

XLA parent teaching

- Teach parents of at-risk children about the 10 warning signs
-Institute precautions to prevent infection
-Protect the patient from direct contact with anyone with a contagious illness
-Safe food handling and storage practices
-Signs and symptoms of infection and when to seek medical attention
-Good hand washing
-Information regarding genetic disorders and community support groups

How are CVID (Common variable immune deficiency) and XLA similar?

Both involve recurrent bacterial infections due to poor antibody production

How are CVID and XLA different in terms of severity and onset?

CVID infections are usually less severe and often diagnosed in adulthood (and not genetic), unlike XLA which is severe and presents in infancy

Common Variable Immune Deficiency (CVID)

B cell deficiency that is due to a lack of differentiation of B cells into plasma cells

this results in low levels of antibodies; they will have normal levels of B cells but fail to differentiate into antibody secreting cells

With some CVID patients

Formation of granulomas in the lungs and lymph nodes may happen

Skin, lymphoid, and gastrointestinal cancers can occur

CVID treatment

IVIG treatments, similar to XLA

How is SIgAD (Selective Immunoglobulin A) diagnosed?

By measuring low serum IgA levels with normal levels of other immunoglobulins

Usually underdiagnosed because many are asymptomatic

What type of immune deficiency is SIgAD classified as?

A B-cell deficiency affecting proliferation, maturation, and IgA production

What does Immunoglobulin G subclass deficiency affect?

One or more IgG subtypes, but not the total IgG level

treated with IVIG and prophylactic abx

What infections are patients with IgG2 deficiency more vulnerable to?

Sinusitis, otitis media, and pneumonia caused by -

Streptococcus pneumoniae

Haemophilus influenzae type B

Neisseria meningitidi

DiGeorge syndrome is an example of

a T cell deficiency

What types of infections are patients with T-cell deficiencies more susceptible to?

Fungal, protozoan, viral, and intracellular bacterial infections

What causes DiGeorge syndrome?

A submicroscopic deletion on chromosome 22, often spontaneous, inherited in autosomal dominant fashion

What embryologic structures are affected in DiGeorge syndrome?

The pharyngeal pouches, especially the 3rd and 4th, which give rise to the thymus, parathyroid, and parts of the heart

What acronym summarizes the clinical features of DiGeorge syndrome?

Cardiac abnormality (especially tetralogy of Fallot)

Abnormal facies

Thymic aplasia

Cleft palate

Hypocalcemia due to hypoparathyroidism

chromosome 22

What are some hallmark facial features in DiGeorge syndrome?

Low-set ears, wide-set eyes, nasal abnormalities, cleft palate, and hooded eyelids

What organism is commonly seen in infections of T-cell deficient patients?

Candida albicans (fungal infection)

What types of infections are common in DiGeorge syndrome?

Opportunistic infections, including yeast, viral (measles, rubella, varicella), protozoal, and fungal infections

What are signs of hypocalcemia in DiGeorge syndrome?

Tetany, muscle spasms, twitching, and possibly seizures due to hypoparathyroidism

What feeding issues are common in DiGeorge syndrome?

Dysphagia, GERD, vomiting, difficulty sucking/swallowing, and possible need for G-tube feeding

How is DiGeorge syndrome diagnosed?

By genetic testing, specifically detecting chromosome 22

Disgorge syndrome treatment

Calcium supplements to prevent tetanus and seizures

IVIG

Prophylactic abx

Bone marrow transplant in severe cases

Hematopoietic stem cell transplantation (HSCT) or thymus tissue transplantation

What is graft-versus-host disease (GVHD), and why is it a concern in DiGeorge syndrome?

It occurs when donor T cells attack host tissues—a risk in blood transfusions and transplants in T-cell-deficient patients

Nursing interventions for DiGeorge syndrome

-Administer calcium supplements as ordered
-Infection control precautions and standard
precautions
-Strategies for addressing feeding difficulties
-Coordinate care for cardiac, infectious disease specialists and speech pathologists

Therapy induced deficiencies

Medication-induced immunosuppression

Corticosteroids, radiation, and surgical removal of immune organs

HIV, malnutrition, burns

How does chemotherapy cause immunodeficiency?

By destroying rapidly dividing cells, including WBCs, lymphocytes, and phagocytes, leading to leukopenia and decreased immune response

Pancytopenia

A decrease in all blood cell types - RBCs, WBCs, and platelets

How do corticosteroids suppress the immune system?

They retain T cells in the bone marrow, reduce IgG production, and suppress inflammation and antibody production, decreases lymphocyte count

Which surgical procedures can cause immune suppression?

Removal of spleen, thymus, or lymph nodes

Three signs of infection nurses should monitor for in immunocompromised patients

Fever (>100°F), chills, cough, or cloudy urine, slow healing wounds

Immunocompromised patients should avoid

Cleaning litter boxes (toxoplasmosis)

Reptiles (salmonella)

Avoid raw fruits/vegetables, undercooked meats, fish, eggs, and sushi

WBC with diff is used

to monitor immune system depression

Therapy induced deficiencies patho

Cytotoxic medications destroy WBCs
‒ Remaining lymphocytes cannot release antibodies and lymphokines
-Corticosteroids interfere with cell-mediated
immunity or production of antibodies
‒ Decreased T cells (keep T cells in bone marrow)
‒ Suppression of cell-mediated immunity and lymphopenia
‒ Decreased IgG production

-Decreased antibody-antigen binding

What autoimmune disease targets the thyroid-stimulating hormone (TSH) receptor?

Graves’ disease

What type of hypersensitivity is a typical allergic reaction (including anaphylaxis)?

Type 1 hypersensitivity

What type of hypersensitivity is systemic lupus erythematosus (SLE)?

Type 3 hypersensitivity

What type of hypersensitivity is Graves’ disease?

Type 5 hypersensitivity

Type 1 sensitivity triggers

Pollen, food (peanuts, tree nuts, seafood), medications (penicillin, sulfa), insect stings, latex, radiocontrast media, blood transfusions

Type 1 hypersensitivity s/s

Local - Sneezing, nasal congestion, itchy/watery eyes, nasal discharge, sinus pressure

Systemic - Dyspnea, wheezing, angioedema, rash, nausea, vomiting, diarrhea, hypotension, anxiety, feeling flushed, stridor, shock

What WBC increases during allergic responses

Eosinophils

What test is used to identify specific allergens in type I hypersensitivity?

Skin (scratch) testing

Epinephrine

First line treatment for anaphylaxis (Bronchodilation and vasoconstriction to open airways and maintain BP)

What medication can be used if a patient on beta blockers doesn’t respond to epinephrine?

Glucagon

What lung sounds may be present in severe allergic reactions?

Wheezes or stridor

What should be done immediately if an IV medication is the offending allergen?

Stop the infusion, change the tubing, hang normal saline

What assessment findings would indicate a severe anaphylactic reaction?

A.  Hypotension

B.  Bradycardia

C.  Diuresis

D.  Hypertension

Hypotension

Which actions of epinephrine help alleviate symptoms of anaphylaxis?

A.  Dilates bronchioles, constricts blood vessels, improves cardiac contraction

B.  Dilates blood vessels, constricts bronchioles, and slows cardiac conduction

C.  Blocks histamine and decreases inflammation

D.  Inhibits mast cells and decreases inflammation

Dilates bronchioles, constricts blood vessels, improves cardiac contraction

What is the priority in the teaching plan about the management of an anaphylactic response to a bee sting?

A.  Avoiding allergens

B.  Wearing a Medic Alert bracelet

C.  The use of an EpiPen

D.  Immunotherapy through allergy shots

The use of an EpiPen

Type 2 Hypersensitivity

Transfusion reaction, goodpastures syndrome, autoimmune thrombocytopenia purpura, Myasthenia Gravis

Type 3 hypersensitivity

Systemic lupus, RA, serum sickness (like abx or antiserum after a snakebite)

Type 4 hypersensitivity

Contact dermatitis, positive TB skin test, latex allergy

delayed reactions

Type 5 hypersensitivity

Graves’ disease, b-cell gammapathies

Why is type AB blood considered the universal recipient?

It has no antibodies against A or B antigens

Why is type O blood the universal donor?

It has no A or B antigens on its RBCs

What complication can occur from hemoglobin release during transfusion reactions?

Acute renal failure

What organs are affected in Goodpasture’s syndrome?

Kidneys (glomerulonephritis) and lungs (pulmonary hemorrhage)

What is the pathophysiology of myasthenia gravis?

Autoantibodies block or destroy acetylcholine receptors, reducing neuromuscular transmission