Welcome to our Skin Grafts and Transplants blog! Here we hope to detail the procedure, recent issues, research, and relevance to health care policy in the field of skin grafts and transplants.

Skin is the largest organ of the human body, represents about 16% of the total body weight, and covers the large majority of the body. As the external covering of the body, skin is the first line of defense against infection from pathogens in the environment. Skin also provides the sensation of touch and pressure, prevents water loss, insulates the body, and regulates body temperature. Therefore, it is an essential barrier and mediator to the outside world that must be maintained. Primary methods to restore irreversibly damaged skin include skin grafts and transplants.

Skin grafting is a step on the reconstructive ladder for wounds that cannot be closed primarily. The "reconstructive ladder" is a generalized term coined to describe complex stepwise procedure to treat physical external injury. Skin grafting is categorized into five distinct types: Autologous (donor and recipient are the same), Isogeneic (donor and recipient are genetically identical), Allogeneic (donor and recipient are same species), xenogeneic (donor and recipient are of different species), and prosthetic (replacement of lost tissue by synthetic materials).

Saturday, November 21, 2009

Graft Rejection


HLA Rejection: http://www.rpi.edu/dept/chem-eng/Biotech-Environ/KIDNEY/graftrej.html
Platelet Rejection: http://www.sciencedaily.com/releases/2009/02/090217173038.htm
Picture: http://www.pennmedicine.org/health_info/images/19192.jpg

These are the current theories on graft rejection.

1) In Humans- Traditional understanding of Graft rejection
Human leukocyte antigens prevent skin graft transplantation from one individual to another. Since five linked genes, each with multiple alleles at each locus, determine the HLA group, it is very difficult to find matches among individuals. T lymphocytes attack the skin transplant and destroy it within a few days.

2) In mice
Recently, Johns Hopkins scientists have found that platelets (the small cells in the bloodstream that help in blood clotting) also play a large role in transplant rejection. They first noticed that increased platelet interactions led to increased and prolonged white blood cell interactions with the inner lining of blood cells. Skin grafts were more effective on platelet-depleted mice, which suggests that limiting the inflammatory response might improve transplanted tissue survival. More studies show that platelets are prevalent both in organ harvest and transplant, which provides a new specific field to target organ transplant rather than the general/traditional HLA theory (t lymphocyres).
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