How xenotransplantation procedure developed?

Interest in xenotransplantation reemerged during the 1960s, when large advances were made in immunology. Chimpanzee kidneys have been transplanted into patients with renal failure.¹In 1984, a baboon heart was transplanted into a newborn infant, Baby Fae, who had hypoplastic left heart syndrome and lived 20 days after heart surgery.² A baboon liver was transplanted to a patient with hepatic failure.³Porcine islet cells of Langerhans have been injected into patients with type 1 diabetes mellitus.⁴Porcine skin has been grafted onto burn patients,⁵and pig neuronal cells have been transplanted into patients with Parkinson (Parkinson's) disease and Huntington (Huntington's) disease.⁶

During these advances, several obstacles to the success of xenotransplantation have been identified. These include, but are not limited to, (1) preventing hyperacute rejection, (2) preventing acute vascular rejection, (3) facilitating immune accommodation, (4) inducing immune tolerance, (5) preventing the transmission of viruses from xenografts into humans, and (6) addressing the ethical issues surrounding animal sources for xenografts and the appropriate selection of recipients (given that xenotransplantation remains experimental). The purpose of this review is to identify the obstacles and recent progress made in the field of xenotransplantation.