Nursing Assessment of Immunity/Immune Function — Vocabulary Flashcards

Vocabulary flashcards covering key terms related to immunity, immune function, hypersensitivity, vaccines, MRSA, allergies, and related nursing considerations.

Antigen

A molecule or part of a molecule that the immune system recognizes as foreign; may be on pathogens, toxins, or non-living substances.

Antibody

A protein that binds specifically to an antigen and helps inactivate or destroy the antigen.

Immunocompetent

Having a normally functioning immune system capable of mounting an effective response.

Immunocompromised / Immunodeficiency

A weakened or deficient immune system, resulting in reduced ability to fight infections.

Hypersensitivity

An exaggerated or inappropriate immune response to a harmless substance.

Recognition stage

First stage of the immune response: identification of antigens as foreign (non-self).

Proliferation stage

Stage in which lymphocytes enlarge, divide, and proliferate in response to antigen exposure.

Humoral immunity

Antibody-mediated immunity that uses B lymphocytes to fight antigens outside cells and produces antibodies.

Cell-mediated immunity

T lymphocyte–mediated immunity that fights antigens inside host cells.

B lymphocytes (B cells)

Lymphocytes that initiate humoral immunity and produce antibodies.

T lymphocytes (T cells)

Lymphocytes that initiate cell-mediated immunity and attack infected cells.

Plasma cells

Differentiated B cells that synthesize and secrete antibodies.

Memory cells

Long-lived lymphocytes that remember a previously encountered antigen for a faster response on re-exposure.

Helper T cells (CD4+ T cells)

Regulator T cells that aid activation of T and B cells; coordinate immune responses.

Suppressor (Regulatory) T cells

T cells that help limit or suppress the immune response to prevent overreaction.

Cytotoxic (killer) T cells

T cells that destroy virus-infected or abnormal cells.

Natural killer (NK) cells / null cells

Non-specific killer cells that destroy infected cells without prior sensitization.

Leukopenia

Total white blood cell count < 4,000/mm3.

Leukocytosis

Total white blood cell count > 10,000/mm3.

Neutropenia

Neutrophil count < 2,000/mm3 (absolute neutrophil count often <1,000 when severe).

Absolute neutrophil count (ANC)

A calculation of neutrophils in the blood; ANC <1,000/mm3 is neutropenic.

CBC with differential

Complete blood count that breaks down white blood cells into subtypes (neutrophils, eosinophils, etc.).

IgE

Immunoglobulin E, antibody type associated with allergic reactions; measured in allergy testing.

RAST (radioallergosorbent test)

Lab test historically used to detect specific IgE antibodies to allergens.

Prick testing

Skin test to identify specific allergen sensitivities by pricking the skin with small amounts of allergen.

CD4 count

A measure of helper T cells used to assess immune function, notably in HIV/AIDS.

Active immunity

Immunity where exposure to an antigen prompts the body to produce antibodies (natural infection or vaccination).

Passive immunity

Immunity where antibodies are provided from another source and the body does not actively respond to the antigen.

Active natural immunity

Immunity obtained from environmental exposure to an antigen with the body mounting its own response.

Active artificial immunity

Immunity acquired through vaccination, where an immune response is triggered without disease.

Passive natural immunity

Antibodies transferred from mother to baby (in utero or via breast milk).

Passive artificial immunity

Antibodies received after exposure (e.g., immunoglobulin injections) without the body creating its own response.

Shingles vaccine (zoster vaccine)

Vaccine given starting around age 50 to prevent shingles; typically two doses spaced months apart.

Influenza (flu) vaccine

Annual vaccine, generally started for children at 6 months and older; may have mild, transient side effects.

RSV vaccine (adults)

Vaccine option for adults aged >60 to reduce RSV-related illness.

Pneumococcal vaccine

Vaccine recommended for adults >65 to prevent pneumococcal disease.

Td (tetanus-diphtheria) vaccine

Vaccine given every 10 years (start as early as 2 months); booster protects against tetanus and diphtheria.

Allergens entry routes

Ways allergens enter the body: inhalants (respiratory), contact allergens (skin), ingestants (swallowed), injectables (ID/IM/IV).

Inhalants

Allergens inhaled through the respiratory tract (pollen, dust, mold, animal dander, fragrances).

Contact allergens

Allergens that contact the skin (poison ivy, cosmetics, metals, latex, dyes).

Ingestants

Allergens ingested (medications, foods, preservatives).

Injectables

Allergens delivered via injection (medications, bites, vaccines, transfusions).

Allergic rhinitis

An allergic reaction characterized by sneezing, congestion, runny nose due to allergen exposure.

Food allergies

Allergic reaction to foods (e.g., peanuts, shellfish) triggered by IgE-mediated responses.

Dermatitis medicamentosa

Drug-induced dermatitis; common offenders include penicillin and sulfonamides.

Latex allergy

Allergic sensitivity to latex proteins; can cause dermatitis or more severe reactions.

Dermatitis (contact dermatitis)

Inflammation of the skin due to contact with irritants or allergens (e.g., soaps, fragrances).

Urticaria (hives)

Raised, itchy welts on the skin; a common symptom of an allergic reaction.

Angioedema

Deep swelling, often around eyes/mouth or throat, sometimes life-threatening if airway is compromised.

Bronchospasm

Constriction of the bronchial muscles causing wheezing and shortness of breath.

Epinephrine (epinephrine autoinjector)

First-line treatment for anaphylaxis to rapidly reverse symptoms.

Antihistamines

Medications (e.g., diphenhydramine) that block histamine receptors to reduce allergy symptoms.

Corticosteroids

Anti-inflammatory drugs (e.g., prednisone) used to reduce severe allergic inflammation.

Hypersensitivity Type I

IgE-mediated reactions with rapid onset, including anaphylaxis and hives.

Hypersensitivity Type II

Cytotoxic antibody-mediated reactions (e.g., transfusion reactions) affecting cells.

Hypersensitivity Type III

Immune complex–mediated reactions (e.g., serum sickness) causing inflammation.

Hypersensitivity Type IV

Delayed-type hypersensitivity (e.g., contact dermatitis) mediated by T cells.

Atopy

A genetic tendency to develop allergic diseases and produce IgE against common substances.

Mast cells / Histamine release

Mast cells release histamine and other mediators during allergic reactions, increasing capillary permeability and bronchoconstriction.

MRSA

Methicillin-resistant Staphylococcus aureus; bacteria resistant to many antibiotics, often in wounds or nares.

Colonized (MRSA)

Carrying MRSA in nasal passages or wounds without active infection.

MRSA risk factors

Illegal IV drug use, contact sports, crowded living conditions, immunosuppression, implants, prolonged hospitalization.

MRSA prevention

Hand hygiene, contact precautions, isolation, and not sharing personal items.

Bactrim (trimethoprim/sulfamethoxazole)

Oral antibiotic used as first-line therapy for MRSA in some cases; watch for adverse effects.

Vancomycin

IV antibiotic often used for MRSA; requires trough level monitoring to ensure therapeutic dose.

Trough level monitoring

Blood test to measure the lowest concentration of a drug before the next dose; used to guide dosing.

MRSA complications

Antibiotic resistance can complicate treatment and increase infection risk.

Cellulitis

Common skin infection with bacteria (Strep/Staph) spreading through skin; redness, warmth, edema, pain.

Causes of cellulitis

Break in the skin (surgical wound, cut, bite, tattoo) enabling infection to enter.

Cellulitis treatment

Antibiotics (PO or IV), elevation, warm/moist compresses, and pain relief.

Haemolysis and fever in transfusion reactions

Common signs of transfusion reactions include fever, chills, flank pain, and itching; stop transfusion if reaction occurs.

Blood transfusion reaction management

Stop transfusion, maintain IV fluids, assess patient, notify provider; treat symptoms (antihistamines, steroids) as ordered.