Basic of organ transplant.

Organ transplant :

Organ transplant is a blessing of medical science unless the graft is rejected by the host.Generally a graft is given to the host is rejected when the tissue type of the host and donor do not match.The degree of rejection depends on the degree of mismatch of the tissue type between the donor and the host.When the donor and the host are the same individual (If some tissue of an individual's body taken from any part of his body and grafted an another place of his body)then the graft is not rejected.This is called autograft.A classic example of autograft is skin grafting.This is hugely done in the surgery department.The explanation for what an autograft is not rejected is that the HLA typing(Tissue typing) of the donor and the host is same.As the tissue typing is same no immune response occurs in the host's body.And the graft is not rejected.Someone may ask you How the graft is rejected when the tissue type of the host and donor do not match?The answer is the activation of T-cell.Which is activated during the mismatch and causes necrosis of the graft endangering the life of the host.