Immune system Flashcards
the immune system (what, involves, ______ & ______ critical to maintaining health and preventing disease)
- the body’s defense mechanism against invasion and allows a rapid response to foreign substances in a specific manner
- involves: inflammation, immunity to work w/ other defenses in providing protection from harmful microorganisms and cells
- inflammation and immunity are critical to maintaining health and preventing ds.
TIP: immune system involves (nervous, GI, endocrine)
immunocompetent
- when all the different parts and functions of inflammation and immunity are working well, giving the individual maximum protection against infection
2 types of immunity
1) natural (innate): non specific immunity, present at birth
- first line of hose defense following antigen exposure, because it protects the host without remembering prior contact with an infectious agent
2) acquired (adaptive): specific immunity, develops after birth
- usually develops as a result of prior exposure to an antigen through immunization (vaccination) or by contracting a disease
natural immunity (innate immunity) (what, immunity, mechanism of action, includes 5)
- AKA inflammation
- provides immediate protection (short term) against the effects of tissue injury and invading foreign proteins
- innate-native immunity: natural protective feature of a person
- barrier to prevent organisms from entering the body OR can be an attacking force that eliminates organisms that have already entered the body
- includes: skin, mucosa, cilia of respiratory tract (cough, sneeze), acidic gastric secretions (enzymes -> destroys invading organisms), antimicrobial chemicals on the skin (barrier)
TIP:
- burn to hand, bacteria middle ear -> inflammation -> how severe/intense depends on level of exposure
acquired (adaptive) immunity (what, responses are, type (2))
- internal protection that results in long-term resistance to the effects of invading microorganisms
- responses are not automatic, body has to learn to generate specific immune responses when it is infected by or exposed to specific organisms (may take wks -> months)
- types:
1) active acquired immunity: immunologic defenses developed by the person’s own body
2) passive acquired immunity: temporary immunity transmitted from a source outside the body that has developed immunity through previous disease or immunization (transfer antibiotics mother -> infant (womb, breastfed, IG injections)
review: IgG (appears, role, etc.)
- appears: serum, tissues (interstitial fluid)
- major role: bloodborne and tissue infections
- activates complement system
- enhances phagocytosis
- crosses PLACENTA
review: IgA (appears, what (3))
- appears: bodily fluids (blood, saliva, tears, breast milk, pulmonary/GI/prostatic/vaginal)
- protects against respiratory, GI, GU infections
- prevents absorption of antigens from food
- passes to neonate in breast milk for protection
review: IgM (appears, what)
- appears: intravascular system
- appears: first immunoglobulin produced in response to bacterial/viral infections
- activates complement system
review: IgD (appears, what)
- appears: small amounts in serum
- possibly influences B-lymphocyte differentiation, role is UNCLEAR
review: IgE (appears, what)
- appears: serum
- takes part in ALLERGIC, some hypersensitivity reactions
- combats PARASITIC infections
autoimmunity (what, _______ directed against ______, mgmt, pharm)
- process whereby person develops an inappropriate immunity
- antibodies/lymphocytes are directed against healthy normal cells and tissues (attack on self)
- mgmt: depends on organ/organs affected, NO CURE
- anti-inflammatory drugs, immunosuppressive drugs: commonly used along with symptomatic treatment to suppress the excess immunity
immunity changes w/ aging: inflammation (3)
- reduces neutrophil function
- leukocytosis does NOT occur during acute infection
- older adults may NOT have a fever during inflammatory or infectious episodes
immunity changes w/ aging: antibody mediated immunity (2)
- total # colony forming B-lymphocytes and ability of these cells to mature into antibody secreting cells are diminished
- decline in natural antibodies, decreased response to antigens, and reduction in the amount of time the antibody response is maintained
immunity changes w/ aging: cell mediated immunity
- number of circulating T-lymphocytes decreases
Human immune deficiency virus (what, patho, high potency)
- retrovirus transmitted through direct contact with HIV infected body fluids, such as blood, semen, genital secretions, or from HIV infected mother -> child during pregnancy, birth, or breastfeeding, and attacks the body’s immune system
- patho: HIV has to enter a cell, take over the cell, force the cell into making more copies of the virus (viral particles), these new viral particles then are shed and look for additional cells to infect, repeating the cycle
- high potency: blood, breast milk, vaginal secretions
physical assessment techniques immune system (neuro, resp, cardio, GI, musck, integument, lymph, V/S)
- neuro: cognitive dysfunction, hearing loss, visual changes, headaches, ataxia, tetany
- resp: changes in RR, cough, abnormal lung sounds, rhinitis, bronchospasm
- cardio: hTN, tachycardia, dysrhythmia, vasculitis, anemia
- GI: hepatosplenomegaly, colitis, vomiting/diarrhea
- musculoskeletal: joints mobility, edema, pain
- integumentary: lesions, dermatitis, purpura, urticaria, inflammation, discharge
- lymph: lymph nodes are palpated for location, size, consistency, tenderness
- VS: temp. recorded (MAIN), chills/sweating
recommendations for “standard precautions” to prevent spread HIV
- perform hand hygiene
- wear PPE
- handle soiled patient care equipment appropriately with gloves
- follow procedures for environmental control
- handle textiles and laundry in a manner that prevents transfer
- handle needs and other sharps appropriately
- use devices during patient resuscitation
- prioritize patient placement as needed
- educate on proper respiratory hygiene and cough etiquette
- reduce number of sexual partners + abstain from exchanging sexual fluids
- latex condoms
- avoid unprotected sex with another HIV seropositive person (cross infection with that person’s HIV can increase severity of the infection)
- not donate blood, plasma, body organs, or sperm
s/sx acute HIV infection (7)
- fever
- night sweats
- chills
- headache
- muscle aches
- sore throat
- rash
TIP: 4 wks before infection s/sx
stages of HIV (0-3)
1) stage 0:
- interval between the appearance of detectable HIV RNA and the first detection of antibodies
- about 40-80% of patients develop clinical symptoms of a nonspecific viral illness (eg. fever, fatigue, rash) lasting 1-2 weeks
2) stage 1: CD4+ t-cell count of greater than 500 cells/mm3 with NO AIDS defining
3) stage 2: CD4+ t-cell between 200-499 cells/mm3 with NO AIDS defining
4) stage 3: CD4+ t-cell count less than 200 cells/mm3 with AIDS DEFINING ILLNESS, or a person who has higher CD4+ t-cell counts but as an AIDS defining illness (severe development of immune diseases (3 year prognosis)
-s/sx: fevers, chills, wt. loss, sweats, lymph glands, weakness
- opportunistic infections
acquired immune deficiency syndrome (AIDS) (what, diagnosis)
diagnosis of AIDS requires that the person can be HIV positive and have either:
- CD4 T-cell count of less than 200 cells/mm3
- an opportunistic infection
- once AIDS is diagnosed, even if the patient’s t cell count goes higher than 200 cells/mm3 of the infection is successfully treated, the aids diagnosis remains tand the patient does not revert to being just HIV positive
TIP:
- disease mortality (60% adults)
- beginning (development takes months -> years, depends on how acquired, other health illness, interventions)
s/sx AIDS (5)
1) immunologic manifestations: lymphadenopathy, fatigue
2) integumentary manifestations: dry skin, poor wound healing, skin lesions, night swears
3) respiratory manifestations: cough, SOB
4) GI manifestations: diarrhea, weight loss, N/V
5) CNS manifestations: confusion, dementia, headache, fever, visual changes, memory loss, personality changes, pain, seizures
HIV/AIDS diagnostic labs (5)/tests (0)
1) diagnostic labs:
- antibody tests (detects abx, might miss HIV in stage 0)
- antigen/antibody tests (detect HIV)
- nucleic acid (RNA) tests (detect HIV)
- viral load testing (detects presence of HIV viral genetic material/protein)
- CD4+ t-cell count (800-1000, lymphocytes 30-40% diff) (CD4/CD8 = 2:1 ratio)
2) diagnostic tests: NONE
tip:
- blood (faster detection than oral)
- antibodies increased in blood
HIV/AIDS interventions (8)
1) prevention is KEY (education)
2) pre-exposure prophylaxis: truvada (emtricitabine, tenofovir) for HIV negative sexual partners of known HIV positive people to reduce HIV transmission
3) highly active antiretroviral therapy (HAART):
- reduces viral load to help reduce transmission
- improves CD4+ t-cell counts and restores immunologic function
- slows disease progression and reduces HIV associated morbidity/mortality
4) screening for adherence:
- every health care encounter should be used as an opportunity to briefly review the treatment regimen, identify any new issues, and reinforce successful behaviors
- lab tests evaluate whether ART is effective for a specific patient
- viral load should be measured at baseline and on a regular basis thereafter because viral load is the most important indicator of response to ART
5) pain mgmt: NSAIDs, Lyrica, TCAs, Neurotin (BAGA), dilantin, opioids
6) enhancing nutrition: high calorie/high protein diet, good mouth care, drink 2-3L fluids per day, appetite stimulants
7) monitor and treat opportunistic infections: know s/sx, self mgmt
8) comfort measures and supportive care: hydrotherapy, massage, heat or cold
tip:
- viral load below level detection (optimal protection)
- RNA (decrease 20-85 copies)
- figure 32.8 + 32.10
monitor for AIDS manifestations and opportunistic infections (resp., gi., oncological)
1) respiratory infections:
- pneumocystis jiroveci pneumonia (PCP): SOB, cough, chest pain, fever
- TB: cough, night sweats, wt. loss, hemoptysis
2) GI infections:
- candidasis: oropharyngeal, esophageal painless creamy white plaque like lesions
- HIV wasting syndrome: loss of more than 10% body weight with diarrhea or weakness and fever for more than 30 days
3) oncological:
- kaposi sarcoma: variable course from brownish-pink to deep purple cutaneous lesions to multiple organ system involvement
hypersensitivity/allergy (what, 4 types)
- excessive inflammation occurring in response to the presence of an antigen (foreign protein or allergen) to which the patient usually has been previously exposed (occurs with reexposure)
- 4 types:
1) immediate
2) cytotoxic
3) immune complex mediated
4) delayed
