The unborn baby was in trouble. Her mother’s doctors at a British hospital knew something was wrong with the fetus’ blood, so they decided to perform an emergency caesarean several weeks before the baby was born. But despite this and subsequent blood transfusions, the baby suffered a brain hemorrhage with devastating consequences. He unfortunately passed away.
It was not known why the bleeding had occurred. But there was a clue in the mother’s blood, where doctors had noticed strange antibodies. Some time later, as doctors tried to find out more about them, a sample of the mother’s blood arrived at a Bristol lab run by researchers who study blood types.
They made a startling discovery: the woman’s blood was an ultra-rare type, which could have made her baby’s blood incompatible with hers. It’s possible this prompted her immune system to produce antibodies against her baby’s blood – antibodies that then crossed the placenta and harmed her child, ultimately leading to her undoing. It may seem unlikely that such a thing could happen, but decades ago, before doctors had a better understanding of blood types, it was much more common.
By studying the mother’s blood sample, along with a number of others, scientists were able to determine exactly what made her blood different, and in doing so, confirmed a new set of blood types – the system ” Er”, the 44th to be described.
You are probably familiar with the four main blood types: A, B, O and AB. But it is not the only blood classification system. There are many ways in which red blood cells are grouped together based on differences in the sugars or proteins that coat their surface, called antigens. The grouping systems work simultaneously, so your blood can be classified into each – it can, for example, be type O in the ABO system, positive (rather than negative) in the Rhesus system, etc.
Thanks to the differences in antigens, if someone receives incompatible blood from a donor, for example, the immune system of the recipient can detect these antigens as foreign and react against them. This can be very dangerous, which is why donated blood must be compatible if someone is being transfused.
On average, a new blood classification system has been described by researchers every year for the past decade. These new systems tend to involve blood types that are incredibly rare, but for those affected by them, just knowing they have such blood could be lifesaving. This is the story of how scientists cracked the mystery of the last blood system and why it matters.
It was back in 1982 that researchers first described an unusual antibody in a blood sample that hinted that this mysterious blood type was out there. Scientists couldn’t get much further than that at the time, but they knew the antibody was a clue pointing to an unknown molecule or structure that was tricking the person’s immune system into generating it.
In the years that followed, more people with these unusual antibodies appeared, but only occasionally. Typically, these people have surfaced through blood tests containing the mysterious and rare antibodies. Eventually, Nicole Thornton and her colleagues at NHS Blood and Transplant in the UK decided to look into what might be behind the antibodies. “We work on rare cases,” she says. “It starts with a patient who has a problem that we are trying to solve. »