Porcine endogenous retrovirus in xenotransplantation

Purpose of review To highlight and give perspective to research that defines the impact that porcine endogenous retroviruses may have on clinical xenotransplantation. Recent findings Publications are cited that serve to illustrate the advances within this field of research. Research focused on the progression of xenotransplantation toward clinical utility and on the basic biology of porcine endogenous retroviruses is discussed. Topics such as porcine endogenous retrovirus distribution among donor animals and the potential of donor animals to produce infectious virus via genomic recombination are also discussed. Mechanisms to overcome such de novo events in vivo are presented, as well as the advances in the understanding of porcine endogenous retrovirus infectivity studies in animal models. Summary The ongoing research focused on the biology of porcine endogenous retroviruses serves to add further valuable understanding to what has to date only proven a theoretical concern for public health. Recent advances in the genetic engineering of pigs promise a renascence for xenotransplantation, with hopefully significant increases in transplant survival. Armed with an extensive understanding of porcine endogenous retroviruses biology, one can believe that small-scale trial should not be prevented due to safety concerns. However, the field of xenotransplantation continues to await efficacy studies using organ and cell transplants that support clinical activities.