Transplant

Question 1

syngeneic transplant

Answer 1

transplant between genetically identical individuals

Question 2

allogenic transplant

Answer 2

transplant between non identical individuals of same species

Question 3

autograft

Answer 3

transplant from self…like skin graft

Question 4

allogeneic hepatopoietic stem cell transplant purpose

Answer 4

to help eradicate a hematologic malignancy through use of immune cells from donor that can target the cancer

Question 5

two types of Stem cell transplants with greater risk of relapse

Answer 5

syngeneic and T cell depleted

both increase risk about 3 fold

Question 6

what are chanced of sibling being a HLA match with a patient?

Answer 6

about 1/4

Question 7

how much do kids match parents in HLA?

Answer 7

1/2 match

Question 8

What is rule of thumb when looking for a match?

Answer 8

want to match 12/12 HLA alleles, but if cannot get that then you get less matching likely 11/12 and will need to use some degree of T cell depletion in therapy

Question 9

can you give SCT across ABO blood types?

Answer 9

yes because can deplete donor plasma or RBCs so nothing to react with

Question 10

GVHD acute symptoms and onset

Answer 10

rash, colon and liver issues

first three months after SCT

Question 11

Chronic GVHD symptoms and onset

Answer 11

skin, eyes GI and liver mainly

6 months after SCT

Question 12

medication treatment for GVHD

Answer 12

inhibitors of T cell activation like tacrolimus, cyclosporin, and sirolimus

inhibitors of T cell proliferation like methotrexate

and T cell depleting antibody like Anti thymocyte globulin

Question 13

reason for problems with matched HLAs in GVHD?

Answer 13

can have many minor mismatches for proteins, especially when donor is homozygous for a protein and recepient is heterozygous…leads to unfamiliar proteins the donor T cells may recognize

Question 14

6 rules for matching for SCT

Answer 14

12/12 HLA match
prefer related matches over unrelated matches…less miHA
male preferred because alloreactivity of mother from pregnancy and Y antigens
stem cell source…bone marrow or blood?
CMV negative with CMV negative and CMV + then not important
ABO match preferred

Question 15

mediator of the graft rejection for solid organ transplant?

Answer 15

will always have some form of HLA/peptide rejection.. immunosupression is needed

Question 16

problem with blood transfusions in organ transplant?

Answer 16

previous transfusions can have allowed patient to make antibodies against specific HLA forms so if they have those antibodies then any organ with that HLA cannot be used

Question 17

hyperacute graft rejection characteristics

Answer 17

from ABO antibodies or circulating anti-HLA antibodies

occurs within hours, leads to immune complexes and complement fixation, vascular damage and thrombosis

Question 18

direct allorecognition characteristics

Answer 18

when T cells of recipient will interact with APCs from donor that are presenting peptides and an unfamiliar HLA complex…this goes down as you lose donor APCs

mainly a CD8 cytotoxic response from recipient against the donor

Question 19

indirect allorecognition characteristics

Answer 19

recipient APC digests donor protein and presents on recipient HLA and this can lead to stimulation of a CD4 cell response

Question 20

acute rejection of graft and type of hyper

Answer 20

1-3 weeks after transplant…cell mediated toxicity and humoral graft rejection

type IV mainly

Question 21

chronic rejection of graft characteristics and type of hyper

Answer 21

more than 3 weeks post transplant…fibrosis of vessels can lead to ischemia of organ

mononuclear cells involved…

CD4 cells secrete cytokines that recruit APCs like macrophages

type II and IV

Question 22

rejection prevention meds with solid organs

Answer 22

steroids

DNA replication inhibitors (azathioprine and mycophenolate)

Inhibitors of T cell activation (cyclosporine, tacrolimus, sirolimus)

lymphocyte depleting antibodies (antithymocyte globulin, rituximab, alemtuzumab (CD52 target))