Today is World Blood Donor Day, and if you haven’t donated lately, I hope you take some time today to set up an appointment at a blood drive near you.
One of the first things people think about or ask when talking about blood donation is "what is your/my blood type?"
At the turn of the last century, an Austrian scientist named Karl Landsteiner noticed why some people had fatal reactions to blood transfusions. He realized that when you mixed the blood of two different people you sometimes get clumping or agglutination. He also discovered that these clumps not only were dangerous, but that the reaction that caused them was immunological. He determined that there were different "blood groups." These became known as the blood types of today.
In the first years of life people develop antibodies to the antigens found on blood different from their own. For example, someone with type B (like me) develops antibodies against the A antigen found on the blood cells of someone with type A. Type O blood has no antigens and so develops antibodies against both A and B, and someone with type AB develops no antibodies because they have A and B antigens.
The type(s) of antigens you have on your blood cells is determined genetically. You inherit it from your parents. However, since both your parents contribute, there is no guarantee that you will end up with either of your parent’s blood types.
When someone receives blood that isn’t compatible with their own, their blood’s antibodies see the new blood as foreign. This triggers an immune reaction that starts fighting off the "invaders." This causes the new blood cells to be forced into clumps that start to die. These dying clumps of cells then release toxins into the blood stream that can cause severe problems up to and including death.
So now, thanks to Landsteiner, we know which people can receive which types of blood (see chart below). Therefore blood transfusions are very successful, which is good for the up to 5 million Americans every year who need life-saving blood from someone else.
If you, like me, are a part of the 38% of the American public eligible to donate blood, I hope you do. I know every time I do I almost pass out. But I keep going back. Why? Because each time you donate blood you can save up to three lives.
Just imagine, if you donated every two months (as often as allowed), you could save up to 18 lives a year. If you did that for 30 years, that’s over 500 lives you could save. You could be quite the superhero. All from one hour and one pint of your blood a few times a year. Can you help? Sign up now!
The University of Utah at http://learn.genetics.utah.edu/content/begin/traits/blood/
The American Red Cross at http://www.redcrossblood.org/learn-about-blood/blood-types