IMM2022 Study Guide - Final Guide: Hematopoietic Stem Cell, Allotransplantation, Skin Grafting
4 May 2018
School
Department
Course
Professor
Transplantation
Autograft =from one part of the body to
another eg skin graft
Isograft: between genetically identical twins
eg monozygotic twins having kidney
transplant
Allograft: between different members of the
same species eg solid organ transplant
Xenograft: between members of different
species eg procine heart valves
The goals of transplantation are to cure
disease (eg cardiomyopathy), prolong life (eg
cystic fibrosis) and enhance quality of life (eg
thorugh mobility)
Most successful transplants are kidney and
hematopoietic stem cells) least successful is
intestines.
PRE TRANSPLANT ASSESSMENT
Is testing for compatibility.
ABO blood group matching
ABO blood groups react with natural
antibodies cause agglutination. If not
matched can result in hyper-acute rejection.
Note that it is possible to transplant across
the ABO barrier using antiCD20 (Rituximab)
Blood type O do not have antigens
universal donor.
Blood type AB are universal recipient.
HLA (human leukocyte antigen) matching
Histocompatibility antigens stimulate a strong
rejection response – encoded by MHC genes.
Use molecular HLA typing (DNA deep
sequencing) to match
Need the closest match at all six loci for bone
marrow and hematopoietic stem cell
transplantation
Pre-formed HLA antibodies – sensitisation
can come from previous blood transfusion,
transplant, pregnancy. Test for this using
luminex testing.
LUMINEX TESTING
• Uniform size beads, coated with
purified HLA antigens, allows the
presence and specificity of HLA IgG
antibodies to be defined
• HLA antibdoies bind to the bead, and
PE-labelled secondary antibodies
attaches, read on flow cytometry
OR can do pre-transplant cross-matches in a
tube. This uses sample from donor and
sample from patient. Serum (with Ab) of the
patients and lymphocyte from the donor. Add
complement and fluoro-quench alive =
green (no Ab), dead = red (Ab)
T-CELL MEDIATED MECHANISMS OF GRAFT
REJECTION
Allorecognition: allogenic MHC structure
resembles a MHC-antigen complex (but it is
actually only MHC) OR allogenic MHC with a
peptide is recognised
Direct allograft rejection: recognise the MHC
on the donor DC
Indirect allograft rejection: recognises parts
of donor on self-molecules
HYPERACUTE
Thrombosis. Can be due to
• B-cells
• Preformed antibodies
• ABO blood groups
• HLA molecules
ACUTE GRAFT REJECTION
There is initial healing and vascularisation. 1-2
weeks, see tissue necrosis due to lymphocytes
and macrophages (predominant T cells). Can
also be due to HLA molecules.
CHRONIC ALLOGRAFT REJECTION
Memory cells contribute to this. Graft failure
is months to years after transplant.
Progressive narrowing of arteries de to
excessive fibrosis. At time of rejection see lots
of lymphocytes.
Graft vs host disease
Is a common side effect of transplantation for
blood cancers. Mature T cells from graft
recognise the host as foreign inflammation,
vomiting, rash ect
Document Summary
Autograft =from one part of the body to another eg skin graft. Isograft: between genetically identical twins eg monozygotic twins having kidney transplant presence and specificity of hla igg antibodies to be defined: hla antibdoies bind to the bead, and. Pe-labelled secondary antibodies attaches, read on flow cytometry. This uses sample from donor and same species eg solid organ transplant sample from patient. Xenograft: between members of different species eg procine heart valves. The goals of transplantation are to cure disease (eg cardiomyopathy), prolong life (eg cystic fibrosis) and enhance quality of life (eg disease (eg cardiomyopathy), prolong life (eg cystic fibrosis) and enhance quality of life (eg thorugh mobility) Most successful transplants are kidney and hematopoietic stem cells) least successful is intestines. patients and lymphocyte from the donor. Add complement and fluoro-quench alive = green (no ab), dead = red (ab)
