lecture 20 ORGAN transplant FINAL

an organ transplant

is a surgical operation in which a failure or damaged organ in human body is removed and replaced with a functioning one. The donated organ may be from a deceased donor, a living donor, or an animal

autograft

graft in the same person from one part of the body to other area

like skin graft, hair transplant, bone

isograft

between identical twins

allograft

this is between different members of the same species like
kidney, heart, lung, liver transplant

xenograft

between two different species like monkey to man

these three factors determine donor - recipient compatability

blood type, hla match, serum cross-matching

blood type A

antibody: anti-b
antigen: a antigen
compatiable types: A, O

blood type B

antibody: anti-a
antigen: b antigen
compatiable types: B, O

blood type AB

antibody: none
antigen: a + b antigen
compatiable types: A, O, B, AB, A  Universal recipent)

blood type O

antibody: anti-a and anti B
antigen: no antigens
compatiable types: O (universal donor)

HLA stands for

human leukocyte antigen

antigens are

proteins on the cells in the body

out of over a 100 antigents that have been identified there are 

6 that have been show to be the most importantfor organ transplantation 

if two people share the same HLA type they are considered a

match. This is much more complicated than blood typing

if a recipent has strong antibodies gainst a donors HLA the risk of rejection is

high and a donor would be declined for that recipient

HLA is also called

tissue matching

plasma cross matching is a

crucial trial for transplantation

the crossmatch test is a very important part of

the living donor work-up and is repeated again just before the transplant surgery

blood from the donor and recpient are mixed

if the recipents cells attack and kill the donor cells the crossmatchis considered postive, this means the recipient has antibodies against the donors cells

if the crossmatch is NEGATIVE

the pair is considered compatiable

factors for organ transplants can be

logistical(distance to hospital) , age (organs are given to children in need first), 

survival benefit

is calcuated as the diffrence between life expectancy with transplatation and life expectancy without transplantation

the United network for organ sharing (UNOS)

non profit orginiiazation that contracts with the federal govement department of health and human services to serven as teh nations organs transplant system

hospital that carry out organ transplants rank patients waiting for organs on a variety of criteria aimed to priortize those with the

greatest survival benefits

Comorbidity

the simulataneous prescnece of two or more diseases or medical conditions in a patient

list of comorbidities

age, time on waiting list, infection, mental status, smoking or substance abuse, weight , dibaetes ( some of these factors reduce chances of surviving surgery)

immunosupresseants

stop your immune system from damaging healthy cells and tissues, they are powerful and require careful monitoring

poeople with organ transplants and stem cell transplants take immunosupressants to

prevent rejections

the devlopment and use of new immunosupressant drugs have reduced organ rejection from

about 30% to 12%

because of immunosupressants one year organ transplant survival rate has improved to

95%

progaf (tarcomillius)

reduces T-Cell profileration

Myoclat (mycophenolate mofetti)

reduces T&B cell profileration

septrin (co-trimoxazole)

prevenets opptruisitc interventions (S)

valcyte (valganciclovir)

prevents opprutunistic interventions (V)

rianitdine

protects the stomach

prendisolone

inhibits specefic glucocortroid signaling

cardiopilega

is a pharacological therapy adminstered during cardiac surgery to intetionally and temporaily aresst the heart

the main ingredient in cardiopilega is

potassium nitrate

bathing the heart in a compound high in K+ increases

extraceulluar K+ concentrations, and disrupts the generation of action potentials + contractions

what tempature is cardiopilega to further reduce cellular metbaolism and places the organ in a resting state

ice COLD

cardiopulomnary bypass machine

a machine that temporailly takes over the function of the heart and lungs during surgery, allowing for circulation of blood and oxygen to the body

over a 100k people are on the

on national transplant waiting list in the United States,

how many people die each day waiting for a transplant

17 that is 1/16 annually

how many people are waiting for a heart

3500

about how many poeple waiting for heart transplant die

1/7 adult and ¼ kids

some organs can be harvested from a recently deceased donor like

cornea, bone, skin, blood vessels, tendons

hearts must be harvested from a

living but brain dead patient because heart tissue dies quickly after death

how many hospitals perform heart transplant surgeries

150/6000

distnace is a limiting factor because

hearts only last 4-6 hours after harvesting. Recpieints have to be close and surgery must be planned far in advnace

xenotransplantation can be traced as far back to

as early as the 1900s

pigs and non human primates have very similar

heart and kidney A&P compared to humans

CRISPR

a simple powerful tool to edit genomes. Allows researches to easy alter DNA and modify gene function

scientits modified 10 genes in the pig for heart being

• 3 pig genes resposible for rejection

• inserted 6 HLA human genes

• 1 gene was inactivated to reduce growth

pig heart transplant failed because

the heart failed to relax but patient was able to live two months