Immunology of transplantation
Transplantation
• A procedure in which an organ/s, tissue or
a group of cells are removed from one
organism (the donor) and transplanted
into another organism (the recipient), or
moved from one site to another site in the
same organism.
Types of transplantation
• Autotransplantation –within one organism
• Allotransplantation- between one species
• Xenotransplantation- between two
different species
Success rate of transplantation in humans
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© 2005 Elsevier
Polymorphism of HLA antigens
Co-dominant expression of HLA genes
Investigations before solid
organ transplantation
• ABO blood groups compatibility
• Negativity of cross match test
• HLA „similarity“ (does not play a significant
role in heart and liver transplantation)
Effect of HLA-identity on kidney graft survival
Cross match test
• Used for detection of recipient´s antibodies
against donor´s antigens (mainly HLA
antigens)
• Donor´s leukocytes + patient´s plasma
• Positivite – antibodies bind to leukocytes –
can be detected e.g. by flow cytometry
• Positivity contraindicates transplantation
Types of graft rejection
• Hyperacute - minutes to hours after
transplantation. Caused by pre-formed
recipient antibodies against HLA antigens of
the donor. Irreversible.
• Acute -several days to months after
transplantation. Mainly T-cell mediated.
Usually reversible by aggressive
immunosuppression.
• Chronic - years after transplantation.
Continuous decrease in graft function.
Irreversible. Mechanism unknown.
The most frequent types of organ
transplantation
• Heart
• Kidney
• Liver
• Lungs
• Pancreas
• Cornea
• Many other organs
• Extremities, face…
Hematopoietic stem cells
transplantation
• Indications: malignancies, bone marrow
failure, primary immunodeficiencies.
• “Whole“ bone marrow or separated CD34+
cells can be used.
• The most significant complication: graftversus
host reaction (GVHR).
• Optimal HLA-matched donor is required.
Graft-versus host reaction (GVHR)
• Immunological reaction of transplanted T-cells
against recipients (HLA) antigens.
• Skin, liver, intestine predominantly affected.
• Milder forms can be treated by
immunosuppression, severe forms may be fatal.
• Can be induced by transfusion of non-irradiated
blood to immunodeficient patients (primary
immunodeficiencies, leukemia…).