Organ Transplantation Flashcards
Define isoimmune response
- body rejects donor tissue as it is recognized as non-self & destroys
What leads to a successful grafting/transplantation
- HLA protein matching of donor & recipient
- better chance with syngeneic (same genes) or autologous (from yourself) transplants
- recipients immune system does not react to graft
Define autograft
- graft of 1 site to another of same individual
Define isograft
- graft of tissue between 2 individuals who are genetically identical
Define homograft
- tissue graft from a donor of the same species as the recipient, but different genetics
Define histocompatibility
- have same blood group
Define allogenic
- possible family member
Define xenograft
- tissue graft or organ transplant from a donor of a different species from the recipient
Describe the possible needs for a re-transplantation
- due to acute/chronic graft failure, rejection, or return of primary disease
- clinical picture of rejection occurs over time
- as survival following transplantation increases so does the need for re-transplantation
- immunosuppressive medication is no longer able to suppress response
What are the guidelines for donor candidates
- no evidence of malignancy, HIV, hepatitis B virus, or sepsis
- hepatitis C virus if present is considered a precaution
- body weight must be within 20% of the ideal
- fully informed of risks with clear & altruistic intentions
- testing of donor organ
How long can hearts be preserved for outside of the body
- up to 6 hours
How long can livers be preserved for outside of the body
- up to 24 hours
How long can kidneys be preserved for outside of the body
- up to 72 hours
How long can lungs be preserved for outside of the body
- lungs cannot be preserved outside of the body for any extended period of time
What determines preference between organ candidates
- preference is given to candidate in critical status from the same geographical location as time is critical
What can exclude an organ candidate
- problematic behavior or psychosocial risk
How are predictor values for rejection evaluated
- panel reactive antibodies
- epstein-barr virus
- herpes simplex virus
- hepatitis
Why is histocompatibility important
- it can determine if antibodies incompatible with donor have been formed by the candidate (positive cross-match)
- if there is a positive cross-match, the transplant will fail
Define haplotype
- HLA antigens that are inherited
Define HLA proteins
- they are surface cells that signal to the immune system whether a cell is part of the self or an invading organism
What are some complications of transplants
- procurement & surgical procedure
- transplantation
- immunosuppressive agents to prevent rejection
- infections & rejection
What are immunological reasons for graft rejection
- residual blood from transplanted organ enters host general circulation
- host recognizes transplanted tissue as foreign & begins immune response with antibodies
What are non-immunological reasons for graft rejection
- ischemic injury: when normal blood is stopped at time of organ harvest from donor
- repercussion injury: when blood flow is restored after transplantation
Describe hyperacute rejection
- it’s immediate from minutes to 48 hours
- rare due to pre antibody & tissue typing
- recipient has antibodies to donors antigens & the organ must be removed
Describe acute or late rejection
- develops in 3 months
- all recipients have some amount of acute rejection
- sudden onset of organ related symptoms: fever, graft tenderness, fatigue, decreased tolerance, or asymptomatic
Describe chronic rejection
- develops within months to years
- slow progressive organ failure due to aggregate sum or irreversible immunological & non-immunologic injuries to graft over time
Describe graft versus host reaction
- mediated by donor’s T lymphocytes
- most often complication of bone marrow transplantation
- if white blood cell inflammation markers are elevated it signifies rejection
- donor’s transplanted lymphocytes respond to the antigens of recipient’s tissues
Define immunosuppressive therapy
- medications to block transplanted recipient’s reactivity to donor organ while sparing other responses
What are the side effects of immunosuppressive therapy
- organ recipients have increased risk of CA
- accelerated hyperlipidemia
- decreased bone density
- myopathies
- neurotoxic reactions: tremor & paresthesia
- increased time for wound healing
Pre-transplant activity & exercise
- limited activity prior = limited tolerance post transplant
- strengthening proximal muscles to support function & accessory respiratory efficiency
- people who participate in an exercise program before transplantation are like to recover more rapidly afterwards
Post-transplant activity & exercise
- extent of recovery depends on function of transplanted organ
- PT begins post operation day (POD) 1
- exercise can decrease cardiovascular disease (CVD), hypertension (HTN), & diabetes (DM)
- the goal is to mobilize the patient out of bed (OOB) as soon as possible
Activity guidelines
- goal is 30 minutes at moderate intensity 4-5 times a week
- monitor minimal dyspnea, mild fatigue, stable vital signs, O2 saturation >90%, & client response
When should you terminate activity
- respiratory rate (RR) >40 breaths per minute
- 3/10 on Borg scale
- decrease in rate pressure product (RRP)
- O2 saturation <90%
- change in mental status, pallor, or client request
