Allograft

In the case of an allograft , the transplanted tissue does not come from the recipient , but from a genetically non-identical donor of the same species (with the exception of identical twins ) . The transplanted tissue is called an allograft in such cases .

In order to avoid serious or even fatal rejection of the foreign tissue, a successful allogeneic transplant requires that the characteristics recognized by the immune system match the recipient tissue as completely as possible . A relationship between donor and recipient increases the likelihood of the necessary similarity. Identical twins have the same characteristics, so they do not have a rejection reaction.

Today, the risk of a rejection reaction can be partially or mostly permanently reduced or even completely prevented by administering immunosuppressants .

The characteristics recognized by the immune system to differentiate between self and foreign tissue are called HLA characteristics after their first detection on human white blood cells (English: H uman L eukocyte A ntigen) .

Examples:

• Heart transplant
• Stem cell transplant - e.g. B. in leukemia
• Liver transplant
• Kidney transplant
• Bone graft
• Lung transplant

A special form among the allografts is the so-called composite tissue allograft (English for various tissue allografts ). In contrast to most organ transplants, different tissues are used at once, e.g. B. in the form of a whole hand, transplanted. The tissues have different immunogenities ; Nevertheless, it is usually possible to prevent rejection of the transplanted body part by means of standard immunosuppressions.

literature

• Renate Huch, Klaus D. Jürgens (ed.): Man - body - disease . 6th edition. Elsevier, Urban & Fischer, Munich 2011, ISBN 978-3-437-26792-5 , pp. 60 .

Individual evidence

1. ↑ allografts , The free dicitonary
2. ↑ Entry on human leukocyte antigen in Flexikon , a wiki from DocCheck , accessed on November 26, 2015.
3. ↑ Dr. med. Christian A. Radu (coordination) et al: Research Group Composite Tissue Allotransplantation 2 ( Memento from May 18, 2015 in the Internet Archive )
4. ↑ F. Petit, AB Minns, JM Dubernard, S. Hettiaratchy, WP Lee: Composite tissue allotransplantation and reconstructive surgery: first clinical applications. In: Annals of surgery. Volume 237, number 1, January 2003, pp. 19-25, doi: 10.1097 / 01.SLA.0000041228.23111.30 , PMID 12496526 , PMC 1513974 (free full text) (review).

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