Face transplant question

[Evil_Joe]

I see a 3rd partial face transplant in the news today and it reminded of a question I had wanted to ask here. If I understand correctly the transplant recipients will have to take anti-rejection drugs in order to sustain their new face. My question is why do skin grafts not require drugs and a face transplant does? Is it because skin grafts are dead cells? Does contant regrowth of skin ever totally replace the old transplanted skin and mitigate or eliminate the need for anti-rejection drugs? Or is new skin growth on the transplant always going to be foreign material?

[Santo_Rugger]

IANAD, but I do know that skin grafts aren’t solely dead cells.

From http://en.wikipedia.org/wiki/Skin_graft

@Wikipedia

For more extensive tissue loss, a full-thickness skin graft, which includes the entire thickness of the skin, may be necessary. This is often performed for defects of the face and hand where contraction of the graft should be minimized. The general rule is that the thicker the graft, the less the contraction and deformity.

Cell cultured epithelial autograft (CEA) procedures take skin cells from the patient to grow new skin cells in sheets in a laboratory. The new sheets are used as grafts, and because the original skin cells came from the patient, the body does not reject them. Because these grafts are very thin (only a few cell layers thick) they do not stand up to trauma, and the “take” is often less than 100%. Newer grafting procedures combine CEA with a dermal matrix for more support. Research is investigating the possibilities of combining CEA and a dermal matrix in one product.

In order to remove the thin and well preserved skin slices and stripes from the donor, surgeons use a special surgical instrument called a dermatome. This usually produces a split-thickness skin graft, which contains the epidermis with only a portion of the dermis. The dermis left behind at the donor site contains hair follicles and sebaceous glands , both of which contain epidermal cells which gradually proliferate out to form a new layer of epidermis.

[Colibri]

As the cite indicates, the basic reason is that skin grafts are normally done using the patient’s own skin. Originally this was skin taken from elsewhere on the body; now it is from the patient’s own cultured cells.

[Evil_Joe]

@Colibri

As the cite indicates, the basic reason is that skin grafts are normally done using the patient’s own skin. Originally this was skin taken from elsewhere on the body; now it is from the patient’s own cultured cells.

Sorry I mean skin grafts not taken from the recipent!

[Evil_Joe]

No one? :dubious:

[Colibri]

@Evil Joe

Sorry I mean skin grafts not taken from the recipent!

Do you have a cite for a recent case of a human skin graft that was not taken from the recipient? They don’t normally do them. Sometimes tissue from other animals is used, but this is merely to protect the surface until the recipient’s own skin can grow back. The foreign tissue dies and sloughs off.

[Evil_Joe]

@Colibri

Do you have a cite for a recent case of a human skin graft that was not taken from the recipient? They don’t normally do them. Sometimes tissue from other animals is used, but this is merely to protect the surface until the recipient’s own skin can grow back. The foreign tissue dies and sloughs off.

http://www.healthatoz.com/healthatoz/Atoz/common/standard/transform.jsp?requestURI=/healthatoz/Atoz/ency/skin_grafting.jsp

This site sorta answered my question. Animal skin and cadaver skin they say is rejected by the immune system in 7 -10 days.

[Colibri]

@Evil Joe

This site sorta answered my question. Animal skin and cadaver skin they say is rejected by the immune system in 7 -10 days.

Yes, unlike other organs, you have enough skin so you can do a transplant to yourself. Also unlike other organs, you regenerate skin so mostly all you need is to have the skinless area covered so that this can occur.

[Evil_Joe]

@Colibri

Yes, unlike other organs, you have enough skin so you can do a transplant to yourself. Also unlike other organs, you regenerate skin so mostly all you need is to have the skinless area covered so that this can occur.

Thats why i was wondering if the the face transplant would eventually be fully regenerated by the patient’s skin ( and have none of the original transplant left ) and then wouldn’t need further anti-rejection drugs. If not when the skin is regenerating is it regenerating the transplant skin and not new recipient tissue?

[Colibri]

@Evil Joe

Thats why i was wondering if the the face transplant would eventually be fully regenerated by the patient’s skin ( and have none of the original transplant left ) and then wouldn’t need further anti-rejection drugs.

A face transplant entails a lot more than just the skin. It may also include in the lips and cheeks, nerves, cartilage in the nose, and so on. Those tissues won’t be replaced by the recipient’s own tissues, hence the continued need for drugs. This donor tissue will alway remain.

If not when the skin is regenerating is it regenerating the transplant skin and not new recipient tissue?

In a non-self skin transplant, the recipient’s own skin regenerates underneath the donor skin. The donor skin eventually dies and sloughs off, leaving the recipient’s own skin beneath it. When that happens, no donor skin is left, so no anti-rejection drugs are needed.