Immune Flashcards
There are how many types of leukocytes? Which ones are granulocytes and in what circumstances do they increase? Which are non-granular and their functions?
5
Neutrophils: Increased in bacterial infections (a left shift, or bands)
Eosinophils: Increased in allergic and parasiticconditions
Basophils: Increased in allergies mainly
Monocytes/macrophages: phagocytic cells
Lymphocytes- B and T cells: B-cells produce antibodies and T-cells produce CD4 or CD8 cells
What is natural innate immunity? What kind of defense does it provide?
natural defenses and inflammation
Nonspecific, broad spectrum of defense against infections
physical barriers
cellular (phagocytic cells, neutrophils, platelets), and cytokines for communication
intact skin
mucous membranes
cilia in respiratory tract
IgA in saliva and breast milk
histamine
cytokines
prostaglandins
Inflammatory response causing vasodilation
chemotaxis of cells
phagocytosis of foreign material
What makes up pus?
dead neutrophils
bacteria
tissue
What constitutes the aquired immune system? What is the function of B lymphocytes? T-lymphocytes?
Humoral or antibody response
B lymphocytes start process and can transform into plasma cells that manufacture antibodies orimmunoglobulins which disable invaders
IgA,IgD, IgE, IgG, IgM
2) Cellular immune response are theT-lymphocytesthat can turn into cytotoxic (or killer) T cells that attack pathogens or CD4 cells
What is the difference between active and passive acquired immunity? In what ways are they aquitred?
Active immunity: A result of prior exposure to an antigen either through an immunization or contracting a specific infection
1 exposure to the infection
2 immunizations
3 Humoral antibodies (IgM initially, then IgG is a long-lasting antibody)
4 Memory T-cells to recognize the same infection with future exposure
Passive immunity: not long-term for years
1 antibodies from mother to baby
2 receiving an antibody injection (immunoglobulin shot)
What are the 3 main types of T lymphocyte cells and their functions?
1)Helper T cells (aka CD4 cells)
Attack foreign invaders, initiate and augment inflammatory response, increase activated cytotoxic T cells, increase B-cell antibody production
2)Cytotoxic (killer) T cells (aka CD8 cells)
Lyse cells infected with virus; play a role in graft rejection
3)Memory T cells
Remember contact with an antigen and on subsequent exposures mount an immune response
What are 9 variables that can affect immune system function?
Age and gender
Many autoimmune disorders are more common in women, thought to be related to sex hormones
Immune system gradually declines with the aging process
Nutrition
Iron, vitamins, fatty acids, micronutrients, etc. are needed for a robust immune system
Presence of conditions and disorders
SLE, RA, MS, psoriasis, cancer, DM, COPD, fibromyalgia
Allergies
Environmental, foods, medications, latex, vaccines
History of infection and immunization
Childhood and adult vaccines; TB, hepatitis, HIV, STIs, etc.
Genetic factors
Medications and transfusions-
Lifestyle Factors
Poor nutrition, smoking, ETOH, illicit drug use, STIs, environmental hazards
Psychoneuroimmunologicalfactors: Link between brain and immune system
What lab values indicate neutropenia? Potential causes? What is the ANC? At what level are neutropenic precautions indicated?
Neutrophil count: < 2,000/mm3
bacterial infections
drug-induced bone marrow suppression
Absolute neutrophil count (ANC) helps determine severity of the client’s risk of infection, the lower the neutrophil count, the higher the risk of infection
Neutropenic precautions are essential when ANC is <1,000
Neutropenic clients need to report any fevers or signs of infection
What is a lefft shift in WBCs? What is it also referred as? What does it indicate?
Increase of immature neutrophils (bands or stabs) in bloodstream from the bone marrow, so we call it a “ left shift” of the WBC count
also referred to as increased “bands”
Strongly associated with a serious bacterial infectionsince neutrophils are being mobilized
What are neutropenic precautuons?
Restricting visitors
Protective isolation (reverse isolation)
Prohibiting visits by people who have an infection
Restricting exposure to live plants
Restricting ingestion of fresh fruits and vegetables
Avoid contamination from the client’s own bacterial flora (avoid rectal temps and IM injections)
Immediately report low-grade fever to the provider
What is the neddlestick protocol?
Wash the area with soap and water
Alert your supervisor
Identify the source client
Report quickly to employee health
Consent for baseline testing
Post-exposure prophylaxis medications
CDC says to start antiretroviral meds ASAP and no more than 72 hours after possible HIV exposure
2-3 drugs prescribed for 28 days
Follow-up testing
Usually baseline, 6 weeks, 12 weeks, and 6 months
Document in chart
What are the 4 stages of HIV and symptoms?
Stage O: primary infection, like a cold
Stage 1: HIM asymptomatic (can be for years)
Stage 2: HIV smptomatic–fever, weight loss, swollen nodes
Stage 3: AIDS–CD4 less than 200 or acquiring an AIDs defining disease
What are the criteria of the primary HIV infection/O stage?
From initial infection to the development of antibodies
Antibodies in blood indicate pt is infected with HIV (ELISA test)
AKA acute HIV infection or window period
Window period can last 2 weeks to 6 months
Virus replicates rapidly in CD4 immune cells
Destruction of CD4 T-cell (declining CD4 counts)
Increase in serum viral load
Usually present with non-specific viral illness symptoms that are similar to influenza
Fever, fatigue, sore throat, chills, anorexia, nausea, weight loss, night sweats, rash lasting 1-2 weeks
Person can test negative for at least 2-3 weeks
May test negative for up to 6 months
What are criteria for asymptomatic/stage 1 of HIV?
8-10 years on average before a major HIV-related complication develops such as infection
The client can remain asymptomatic for 10 years or more, but the immune system (CD4 cells) are being destroyed and declining in body
CD4 count is often in the thousands in a healthy individual
Clients generally feel well and have few, if any, symptoms
CD4 = 500 or greater
High enough to preserve immune defensive responses, and get just regular infections (like healthy individual)
What are criteria for symptomatic/stage 2/category B of HIV?
Over time the virus begins actively replicating using the host’s genetic machinery
CD4+ cells are further destroyed
The viral load increases
CD4 = 200 – 499
The client develops symptoms or conditions related to the HIV infection
Often fatigue, fevers, swollen lymph nodes develop
CD4 <500 will begin to result in the appearance of certain infections fromdestruction of immune system such as tuberculosis
What are criteria for stage 3/AIDS?
Defined as : < 200 CD4 or an AIDS defining illness occurs
There are not enough CD4 T-lymphocytes present to fight off infection
As levels drop below 100 cells/mm3, the immune system is severely impaired
This stage is characterized by life-threatening opportunistic infections
“AIDS defining infection” areopportunistic infections that occur in HIV with low CD4 counts
End stage of HIV
Without treatment, death occurs within 5 years from opportunistic infections or cancers
What are 11 AIDS-defining conditions?
Candidiasis of esophagus, bronchi, trachea, or lungs
Herpes simplex (chronic ulcers more than 1 month of duration)
HIV-related encephalopathy
Disseminated or extrapulmonary histoplasmosis (fungal)
Kaposi sarcoma (a soft tissue cancer)
Burkitt lymphoma
Mycobacterium tuberculosis (any site)
Pneumocystis jirovecii pneumonia
Recurrent pneumonia
Progressive multifocal leukoencephalopathy
Recurrent salmonella septicemia
Wasting syndrome attributed to HIV
What is the sequence of HIV testing?
HIV antibody screening test: enzyme-linked immunosorbent assay (ELISA)
Many false positives, so NOT a definitive test
Takes 2-3 weeks to develop antibodies sorequires repeat testing up to 6 months
Home test kits are available using a drop of blood
HIV antibody confirmation test: Western blot
HIV RNA quantification: HIV viral load test
Used for assessing effectiveness of antiviral medications
If viral load if “undetectable” with antiretroviral therapy,it indicates an excellent response to medications
When is a CD4 count performed? What does a decreasing amount indicate? What is a normal CD4-CD8 ratio inidcate? What can be inferred with a CD4 increase wiith antivirals?
Perform when Western blot is positive
Decreasing count indicates increasing risk of opportunistic diseases
Steadily decreasing count also indicates a poor prognosis or medication resistance/non-adherence
CD4-to CD8 ratio normal is 2:1. A ratio less than 1 indicates severe disease
Used for assessing the health of the immune system
An increasing CD4 count with antiviral medications indicates a strengthening of the immune system
What is the goal of antiretroviral therapy? What combination of drug classes are used to achieve this?
suppressHIV replication
Reduce HIV-associatedmorbidity and prolong durationand quality of life
Restore and preserveimmunologic function of client
Maximally and durably suppressplasma HIV viral load
Prevent HIV transmission by reducing serum viral load
Use of combination therapy to prevent resistant HIV infection
Nucleoside reverse transcriptase inhibitors (NRTIs)
Non-nucleoside reverse transcriptase inhibitors (NNRTIs)
Protease inhibitors (PIs)
Fusion inhibitors
What are the MOAs of the 4 HIV drug antiviral classes?
ENTRY/FUSION INHIBITORS
Blocks the entry of HIV into cells
REVERSE TRANSCRIPTASE INHIBITORS
Blocks the conversion of HIV RNA to DNA
INTEGRATION INHIBITORS
Blocks the HIV DNA to enter the cellular DNA in nucleus
PROTEASE INHIBITORS
Blocks proteases from forming the final HIV protein products
What is the prototype fusion inhibitor med? MOA? Nursing considerations? SE?
Prototype: enfuvirtide
A class of antiretroviral drugs that work on the outside of the host CD4 cell to prevent HIV from fusing with and infecting it. Fusion inhibitors act by binding to an envelope protein and blocking the structural changes necessary for the virus to fuse with the host CD4 cell.
Only given by injection
Use is limited due to adverse effects
Side effects
Common injection site reaction (severe pain, erythema, cysts, cellulitis)
Increases the risk of pneumonia
What is the nucleotide reverse transcriptase inhibitor (NRTI) med? For what is it commonly used? SE?
zidovudine
Usedin pregnant women to prevent passing the HIVto unborn child
Also given to newborns to protect from HIV mother
Blocks reverse transcription-stops virus from replicating in cells
Side effects
Bone marrow suppression (aplastic anemia)
Black box warning: associated with myopathy with long-term use
What is Kaposi sarcoma? How does it manifest?
Cutaneous lesions but may involve multiple organ systems, usually brownish pink to deep purple, may be flat or raised and surrounded by ecchymosis and edema
Lesions cause discomfort, disfigurement, ulceration, and potential for infection
What are S/S of B-cell lymphoma or Hodgkin, Non-Hodgkin lymphoma? What does it typically indicate?
Weight loss, night sweats, fever
Poor prognosis due to severe suppression of immune system, and now the need for chemotherapy
What is HIV encepalopathy? Patho? nursing considerations?
Progressive cognitive, behavioral, and motor function decline
Probably directly related to the HIV infection
HIV triggers release of toxins/lymphokines that result in cellular dysfunction, inflammation, and neurotransmitter interference
Maintain client safety and initiate seizure precautions
What is crytococcus neoformans?
Fungal infection that causes fever, headache, malaise, stiff neck, N/V, mental status changes, seizures by invading the brain tissue
-atopy indicates what kind of allergic reactions? Examples?
IgE antibody action and a genetic predisposition
atopic dermatitis, asthma, allergic rhinitis)
What are diagnostic findings when evaluating allergic disorders? WBC? Eosiniphils? IgE? What is a serum specific IgE test? Skin test? Nursing considerations?
WBC
Usually normal except with infection orinflammation
Eosinophil count
Elevated with an allergic reaction (bee sting, spider bite, etc.)
IgE level
High levels support a diagnosis of allergic disease
Serum-specific IgE Test ( radioallergosorbent test- RAST)
Takes blood of client to test if IgE is present to a specific allergen
Skin tests (intradermal or scratch)
Considered most accurate confirmation of allergy
Emergency equipment must be readily available to treat anaphylaxis!!!
Stopall antihistamines/corticosteroids 48 hrs. to 2 weeks prior to thetest
What are medications for anaphylactic allergies and what doe they target? Can other meds replace epinephrine if anaphylaxis is present?
Oxygen: if respiratory assistance needed due to shortness of breath or hypoxemia
Epinephrine IM: for anaphylactic reactions such as swelling, wheezing, hypotension, vomiting combined with an urticarial rash
Antihistamines: for urticarial rash or itching by blocking histamine effect
Corticosteroids: to help reduce systemic inflammation in anaphylaxis
Adjunct therapy of antihistamines and corticosteroids are not in place of epinephrine
