I’ve posted previously about donating blood, and on 14th November 1666 Samuel Pepys wrote in his diary about a blood transfusion between dogs, performed by the British physician Richard Lower.
The first recorded blood transfusion to a human was performed in 1667 by French physician Jean-Baptiste Denys, the court physician to King Louis XIV. At the time, blood transfusion was an extremely experimental concept, and scientists were only beginning to explore the circulatory system’s function.
Denys transfused blood from a sheep to a 15-year-old boy suffering from a severe fever. Sheep blood was chosen because it was thought that the “calm” temperament of the animal might have a beneficial effect on the patient. Remarkably, the young boy survived the procedure, showing an improvement in his condition, which led Denys to believe in the procedure’s therapeutic value. Encouraged, Denys went on to perform several similar transfusions, although the results were mixed, as some patients suffered serious reactions.
The science of blood transfusion faced significant challenges, primarily because early practitioners did not yet understand blood types or immune reactions. As a result, many patients experienced what we now know to be transfusion reactions due to incompatible blood, leading to severe complications or death in some cases.
The practice was eventually banned in France and England due to these dangers, and transfusion research was largely abandoned until the early 20th century. It wasn’t until Karl Landsteiner discovered human blood types (A, B, AB, and O) in 1901 that blood transfusion became safe and reliable, marking a true turning point for modern medicine. Landsteiner’s work enabled doctors to match donor blood types with recipients, vastly reducing complications and transforming transfusion into a life-saving medical practice.
The early history of transfusion, marked by bold experimentation and setbacks, laid crucial groundwork for the safe, routine blood transfusions we rely on today.