Today blood transfusion is part of routine clinical practice. Precisely for this reason, it is easy to lose sight of just how recent this level of safety is. Mark Turner, PhD, director of the Scottish National Blood Transfusion Service and professor of cellular therapy at the University of Edinburgh in Edinburgh, Scotland, reminded the audience in a lecture accompanying the exhibition “Rag: A History of Blood” that transfusion requires biological understanding, technical infrastructure, and public trust. Where any one of these pillars is missing, blood therapy can turn from a lifesaver into something dangerous.

Early Hopes, Early Catastrophes

The idea that blood could transfer life, strength, or even personality long predates modern transfusion medicine. Turner cites a commonly told — though likely fictional — account involving Pope Innocent VIII (1432-1492). According to the story, in 1492, he was given blood from three young boys on his deathbed in an effort to restore his vitality. The outcome was tragic: The pope died, and so did the children. Medically, the practice had no real rationale, but culturally it reflects how deeply blood was tied to the idea of life and vitality.

Systematic experimentation began in the 17th century. In Paris, Jean-Baptiste Denys (c. 1643-1704), and in London, Richard Lower (1631-1691), carried out transfusions of animal blood into humans, most often using blood from lambs or calves. These efforts were also driven by the hope that some of the animal’s traits might be passed on to the recipient.

The case of Antoine Mauroy became particularly well known. After several animal blood transfusions, he developed a fever, pallor, delirium, and dark urine. From today’s perspective, these symptoms can be interpreted as signs of a severe reaction. Mauroy died after another transfusion; later, much pointed to additional arsenic poisoning administered by his wife. For the nascent field of transfusion medicine, however, the damage was done: The practice fell into disrepute and was banned in France and England for a long time.

The Step Toward Human Transfusion

It was not until the early 19th century that transfusion gained an experimental basis. John Henry Leacock (1789-1856), who studied medicine in Edinburgh, demonstrated in animal experiments that blood from the same species could save a severely bled animal, while blood from a different species triggered dangerous reactions. From today’s perspective, this was an early preclinical study.

James Blundell (1790-1878), who was also trained in Edinburgh and later worked as an obstetrician at Guy’s Hospital in London, England, put these findings into clinical practice. Around 1818, he began performing human-to-human transfusions, mainly on women with postpartum hemorrhage. In doing so, he identified a clear clinical indication: acute blood loss.

The technique remained rudimentary. There were no blood bags, no preservation methods, and no standardized testing; donors and recipients had to be available at the same time. Nevertheless, this marked the decisive transition: It was no longer the prospect of rejuvenation, changes in character, or other speculative effects that determined the use of blood, but rather a clinical emergency.

Blood Banks Transform Medicine

A further step followed when blood could no longer be merely transferred directly but could be made available in an organized manner. In Edinburgh, dentist Jack Copland (1898-1985) founded the first blood transfusion service in 1930. The impetus was the death of a friend’s wife from hemorrhage during childbirth. Because blood could not yet be reliably stored, Copland organized a “walking donor panel”: volunteer donors who could be called upon by phone as needed.

Turner describes this early phase as a mix of improvisation and public service. Copland initially drove donors to the hospitals himself. Later, his 14-year-old son John took over the driving in his father’s Bugatti without really knowing how to drive. He was too short to see over the steering wheel and looked through the spokes.

The anecdote is funny, but it points to a serious principle: Transfusion medicine requires logistics. Today blood services operate with permanent donation centers and mobile blood drives, as well as centralized processing and distribution of blood products. According to Turner, approximately 175,000 blood component transfusions are administered annually in Scotland and around 120 million worldwide. Each one is part of a chain that extends from donor recruitment to the correct administration at the patient’s bedside.

Safety Is Not a State

Modern transfusion medicine has drastically reduced its risks. Whole blood is separated into red blood cell concentrates, platelets, and plasma; each component has its own indications and risks. At the same time, laboratories screen donations for pathogens such as HIV; hepatitis A, B, C, and E; and parvovirus B19. Depending on travel or exposure history, additional tests are performed, such as for malaria, West Nile virus, or toxoplasmosis.

Even in immunohematology, the ABO blood group classification is far from sufficient. In addition to the known blood groups, there are more than 300 other antigens. Patients who have received multiple transfusions, those with irregular antibodies, or those with a complex medical history therefore require specifically selected preparations. Blood is not an interchangeable commodity but a biological medicinal product that must be individually matched.

This complexity explains why errors carry such grave consequences. The wrong blood unit administered to the wrong patient can trigger an acute hemolytic transfusion reaction. At the same time, blood remains a substance of human origin and reflects the pathogens circulating within a population. New viruses, travel patterns, and global outbreaks keep the risk alive.

The infection scandals of the late 20th century illustrate the magnitude of the issue. Between the early 1970s and the early 1990s, thousands of people in the UK were infected with HIV and hepatitis viruses through blood products or transfusions. The consequences spanned generations. For Turner, this history remains a warning: Safety can only be achieved through constant vigilance.

Why Lab-Grown Blood Cannot Yet Replace Blood Donation

The obvious solution would be to replace donor blood with erythrocytes produced in the laboratory. Technically, this is already possible. Erythroid cells can be obtained from induced pluripotent stem cells by reprogramming somatic cells to a more primitive state and then differentiating them into red blood cells.

The problem lies less in the principle than in the scaling. Turner refers to an experiment in which about 1 mL of blood was obtained from 88 culture flasks. For a quantity relevant to transfusion, approximately 22,000 culture flasks would be needed. For now, lab-grown blood is practically no match for donation, which Turner describes as much simpler and faster.

For routine care, voluntary blood donation remains indispensable. Only a small portion of the population donates regularly, while significantly more people require a transfusion at some point in their lives. Turner puts it bluntly: Even those who are healthy today may suddenly find themselves in need of blood. Transfusion medicine therefore functions as a collective infrastructure: People give blood without ever knowing the recipient, the timing, or the specific benefit.

Richard M. Titmuss (1907-1973) described this relationship in “The Gift Relationship” as a social bond. Turner builds on this: Those who donate blood regularly are highly likely to contribute to saving multiple lives. No technological promise can currently replace this simple gesture. In a high-tech medical landscape that often relies on machines, molecules, and algorithms, transfusion thus remains strikingly human.

This story was translated from Univadis Germany, part of the Medscape Professional Network.