13. Transplantation And Pregnancy Flashcards Preview

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Flashcards in 13. Transplantation And Pregnancy Deck (34)
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1
Q

Why you have Ab against blood group B if you have blood group A f.eks

A

1) Carbohydrate antigens of intestinal microbiome
2) Maternal antigen exposition
3) Contact with foreign blood previously
4) Exposition by plant pollens

2
Q

Autograft

A

Transplant from own body (e.g hair transplant)

3
Q

Isograft

A

Transplant from monozygotic twin

4
Q

Allograft

A

Transplant from same species

5
Q

Xenograft

A

Transplantation from different species (e.g monkey)

6
Q

Primary rejection allograft

A
  • Necrosis
  • Rejection
  • Longer reaction than secondary
  • Ca. 14 days
7
Q

Secondary rejection allograft

A
  • Reintroducing graft
  • Necrosis
  • Shorter time before rejection due to memory cells
  • Ca. 5-6 days
8
Q

Critical point in transplantation

A

1) MHC (HLA-A, HLA-B, HLA-DR)
2) Minor histocompatibility antigens
- H-Y (Y chromosome, male)
- Males preferably get grafts from other males
- HA-1 -> HA-5 (non Y chromosome)
3) Other tissue specific antigens
- ABO, Rh blood groups
- VEC (vascular endothelial cell) antigen system
- SK (Skjebred) antigen

9
Q

Difference organ and bone marrow transplantation

A
Organ:
- No cytoablation
- HLA coordination important
- Major complication: rejection
- Success: acceptance
Bone marrow
- Cytoablation necessary
- HLA coordination crucial
- Major complication: GVHD
- Success: tolerance
10
Q

Types of host versus graft reactions (HVG)

A

1) Hyperacute rejection (minutes-hours)
- Complement activation, endoth. damage, inflammation,
- ABO, HLA, VEC incompatibility
2) Acute rejection (weeks)
- IgG binds to alloantigenic antigen
- No complement activation
- Vasculitis: IgG binds to alloantigenic endothel (Th1, CD8)
3) Chronic rejection (months)
- Fibrosis and vascular sclerosis
- CD4 T cells, macrophages
- Vessel occlusion

11
Q

Hematopoietic chimera

A

After bone marrow transplantation

12
Q

Bone marrow transplantation use

A
  • Cancers
  • Autoimmune disorders
  • Other diseases
13
Q

Apheresis

A

Harvesting stem cells from peripheral blood

14
Q

GVHD (graft vs host disease) mediators

A
  • TNF
  • FasL
  • Perforin-granzyme
  • all from cytotoxic T cells
15
Q

Types of GVHD

A

1) Acute
- Endothel cells damaged in skin, liver, GI system
- Delivered by graft T cells
2) Chronic
- Fibrosis + atrophy in multiple tissues
- Loss of tissue function

16
Q

Biological suppression of rejection

A

1) Donor selection
- Family member
- Cadaver
2) Ex vivo graft manipulation
- Suppression/elimination of immunocompetent cells
- Steroid infusion helps downregulate MHC expression

17
Q

Pharma-suppression of rejection

A

1) Cyclosporin
- Block transcription factor: NFAT (IL-2)
2) Azathioprin, cyclophosphamid
- Lymphocyte proliferation blocking
- Anti-CD3 mAb -> T cell depletion
3) Antiinflammatory agents
4) Corticosteroids
++

18
Q

5 years survival heart transplant

A

80%

19
Q

Bile system

A

Very immunogenic
Attacked before liver
??

20
Q

Fetus

A

Hemiallograft in mother

50% mother, 50% father

21
Q

Immunological changes during pregnancy

A

1) TH2 shift
2) Asymmetric Ab’s (only found in pregnancy)
3) HLA-G
4) CD8+ cells decreased -> PIBF, incr IL-10, decr NK)
5) hCG, IL-6

22
Q

Abort

A

Acute or chronic rejection (depending on time)

23
Q

Birth

A

Timely rejection

24
Q

Primiparae hemiallograft

A
  • First pregnancy

- 20 % production of Ab’s against paternal Ag’s

25
Q

Multiparae hemiallograft

A
  • Several pregnancies

- 40-60 % production of Ab’s against paternal Ag’s

26
Q

Trophoblasts

A

Interphase between mother and fetus

  • No MHC II
  • Monomorphic MHC I-like molecules (HLA-G, HLA-E -> inhibition of CTL and NK cells)
27
Q

Immunosuppression in pregnancy

A

Treg and γδ-cells

and TGF beta and Th2 cytokines

28
Q

Endocrine effects of pregnancy

A

1) Maternal
- Progesterone, estrogen
2) Placental (chorion)
- hCG (human choriogonadotrop hormone)
3) Fetal
- alpha-1 fetoprotein

29
Q

PIBF

A

Progesterone induced blocking factor

  • Inhibit NK cells
  • Th2 cytokine excess
  • Anti-abortive effects
  • Inhibits arachidoic acid metabolism
  • Assymmetric antibodies upregulated
30
Q

Most frequent transplantation

A

Transfusion (blood)

31
Q

Graft vs host alloreaction

A

Transplantation immunocompetent tissues
Defenceless recipient
Bone marrow transplantation
Reconstruction of hematopoietic system after chemo-/radiotherapy

32
Q

Host vs graft alloreaction

A

Transplantation of non-immunocompetent tissues

Traditional organ transplantation

33
Q

Liver transplantation survival

A

1 year: >75%

5 years: 70 %

34
Q

Pancreas transplant survival

A

1 year: 72 %