Transfusion medicine

Blood transfusion medicine started with xenotransfusion. A French physician, Jean-Baptiste Denis initiated xenotransfusion in 1667. He performed the first documented blood transfusion on June 15, 1667 to a 15-year-old boy using blood of a lamb. His treatment choice led to the patient’s recovery from violet fever. This paved way for xenotransfusion until 1900 when Karl Landsteiner discovered the human ABO blood group system; then xenotransfusion was abandoned. Recently, due to advances in rDNA technology, xenotransplantation, biomedical researches and the pressing needs for blood transfusion, xenotransfusion is being considered again in humans and pigs are the best choice species. Studies have shown a very close relationship between the haematological parameters and physiology of pigs and humans. Also, there is increasing ability to genetically-modify pigs to reduce immunogenicity. Three antigens present in pig RBCs (Gal, Neu5Gc and Sda) are the recognised issues with immunogenicity of xenotransfusion using pigs. However, development of gene-knockout technologies has proven effective in overcoming these issues. In animals, xenotransfusion is practiced but only used in emergency cases. Xenotransfusion in humans may resurface as researches and technologies improve.