Blood transfusion and more...

The history of blood transfusion:

In the begining of 19th century, if your body lacks blood or it is toxicated and you need new blood into your body. You have to do ''blood transfusion''. When doctors tried to remove one person’s blood and put it into someone else, sometimes it works and sometimes the two different blood doesn't mix and clumped together which could result in death.

In the early 1900, an Austrian doctor Karl Landsteiner, developed a system of categorizing blood types — the well known ABO blood groups you’ve probably heard of. 

After getting knowledge about antigens and antibodies, the accuracy of survival of  blood transfusions has increased exponentially. 

Antibodies are proteins produced by our immune system that can identify, investigate and if needed, destroy an antigen, which is anything that triggers an immune response.

Most of the times , antigens are viral or bacterial invaders, which can cause sickness or infections to us. Usually our immune system will identify them and label them as something to attack with antibodies and get rid of it in the future.

But sometimes these antigens are produced by our own bodies,which are known as self-antigens, which are not attacked by our immune system.

Different blood groups:

The whole ABO blood system is built upon on these sugar-based self-antigens and corresponding antibodies.Lets have a look on these blood group types:

Type A means you have A antigens on the outside of the red blood cells and B antibodies in the plasma.

Type B reverses this, B antigens on the outside of the red blood cell with A antibodies floating around.

 AB blood have both A and B antigens, but no antibodies in their plasma 

Type O blood has no antigens, but have A and B antibodies.

For almost all the humans of this planet have one of these four blood types. And it’s these combinations that create blood transfusions so complex.

for example if your blood has A antigens and all of a sudden you get blood with B antigens, your body will see them as foreign invaders and attack them. These attacks can cause clumps of red blood cells and antibodies to form. If these clumps get too large, blood clots can cause severe symptoms and even death.

So, when you receive blood it has to match with your type, or be type O, also known as the universal donor type. Wait, but what about those positive and negative symbols?

That positive or negative symbol that comes after your ABO blood type is based on something called the Rhesus Blood Group System.

Rhesus blood grouping is similar to the ABO system because it too has to do with the presence or absence of an antigen on the outside of the red blood cell — in this case the protein-based Rh antigen.

This is too important because when it comes to blood transfusions, a body with Rh positive blood will reject Rh negative blood.

Evolution and heritability of blood:

Now, the big question is why is our blood consist of so many different types. Well, this question has 2 different answers.

First off, we don’t know why we evolve
to have such different blood types. Many scientists hypothesize that we the humans  developed different blood types to help get rid off disease, but since this all happened millions of years ago, it remains a hypothesis.

But even though we don’t know 100% , why our blood is like this evolutionarily. But thanks to some geneticists, as they figured it out what is the reason behind someone's blood type? 

The genetic information your parents pass upon to you help to determine things like what color your eyes and hairs are or how tall or short you are.

This is the same for blood type and it all comes down to the ABO gene, which has three different versions, or alleles: A, B and O.

Each parent has two of these alleles, because they each got one from their parents and passed one down to their child. This all comes together and gets encoded in our DNA to create the blueprint that our body will use to make our blood.

When new blood is made, our DNA will instruct the enzymes to either build A antigens, B antigens, both or none depending on the inheritedallele combination.

Solution of different blood types

 If there would be no blood types then anyone could give blood to anyone and hence no problem with these blood transfusions.

But here’s what’s so cool!
We’re getting closer to technology that bypasses the need for matching blood types entirely.

Scientists recently discovered some enzymes, which can be found in human gut, when added to blood. It could easily strip away the sugar-based antigens on the cell’s surface. Which  would effectively change type A or B to type O, which is the universal donor type since it can be given to A, B, AB or O patients.

At the University of British Columbia,
Some scientists were working to find new enzymes capable of converting red blood cells. And they have succeeded at finding an enzyme in some human gut bacteria that has been able to convert different blood types into an universal one. 

These bacteria lives on mucins (present in the lining of intestines ). These bacterias are evolved to eat sugars present on the mucins. Coincidentally the same sugar structures you would find on red blood cells.

Researcher isolated the DNA from the bacteria responsible for telling the enzymes to detach the sugars off the mucins and put that DNA into lab bacteria.

Now, this new lab bacteria produces the enzymes that are programmed to detach or cut the sugars off from the red blood cells, which will create O type blood.

Then what we can do is we can take blood, then take the red blood cells out of the blood, mix it with the enzymes, leave it for some time then we can eliminate the enzymes away and then those red blood cells are modified.


Making more O blood will be huge, since more blood can be given to more patients in need with less complications. I'm waiting for the era of synthetic blood, which will bring the end of the ''blood donation''.

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  1. Most easy to understand and very creative and innovative and informative one team. Keep going


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