- Possible blood types (estimated global %, 2018)
- O-positive: 38.67%
- O-negative: 2.55%
- A-positive: 27.42%
- A-negative: 1.99%
- B-positive: 22.02%
- B-negative: 1.11%
- AB-positive: 5.88%
- AB-negative: 0.36%
- Possible blood types (estimated global %, 2018)
- Agglutinogen (Ag)
- Glycoprotein on surface of RBC
- “ID tag”
- Agglutinin (An)
- Antibody in plasma
- “Body guard”
- Agglutinogen (Ag)
- Characteristics of each Type:
Type Agglutinogen (Ag) Agglutinin (An) A A b B B a AB A + B none O none a + b
- Clumping of RBCs
- Caused by REACTION between matching Agglutinogen and Agglutinin
- A + a = BAD
- Blood Transfusions
- Transfuse blood from same group when possible
- If another group, must NOT have matching Ag/An
DONOR RECIP A B AB O A 🗹 X – Bb X – Bb 🗹 B X – Aa 🗹 X – Aa 🗹 AB 🗹 🗹 🗹 🗹 O X – Aa X – Bb X – Aa/Bb 🗹
- 🗹 = No agglutination, safe to transfuse
- AB = universal recipient
- O = universal donor
- Rh Factor (D antigen)
- If PRESENT, Rh +
- If NOT present, Rh –
- Best to give + to + and – to –
- But okay to give – to +
- See Erythroblastosis Fetalis and Hyperbilirubinemia lessons
- If mother is Rh- and baby is Rh+, mother can create antibodies against Rh factor
- Affects subsequent pregnancies
All right in this lesson we’re going to talk about blood grouping and blood types.
So I’m sure you’ve all heard of the different types of blood types that are out there and we’re going to get into those in a minute. But the thing that you have to understand about different blood types is how it works.
When we talk about blood types a, b, ab, and o, we’re referring to something called agglutinogen and it’s a glycoprotein found on the surface of the red blood cell. And it gives its red blood cell a particular ID. So a Type A agglutinogen makes the red blood cell type a, Group B agglutinogen would make that blood type a and it goes on and on. If both antigens are present it’s considered a group AB, and if there is no antigen present then it’s considered group O.
We worry about something called agglutinin and what agglutinin is is that it’s an antibody in the plasma and it works to act as a bodyguard for the blood. In our bodies, we have an awesome immune system that goes to protect. But even our efforts to do good like giving blood transfusions, sometimes things don’t work out as planned. As you can see Anna’s chart we have these antibodies called agglutinins and they work to serve as a protecting marker. What happens is in the group a blood group, there is an anti B antibody in the blood. And what happens is anytime Group B blood is introduced, the antibody will tag B red blood cell with the group b antigen attached, and it triggers an immune response. so this is why it’s really important that we understand why blood group and blood typing works.
So as we looked at this chart we see that group a has the type A antigen attached to the red blood cell body, and that the anti B antibody is the plasma. and just the opposite for Group B. There’s a type B antigen attached directly to the red blood cell, and anti a antibodies in the plasma. But if we look at group AB there are no antibodies in the plasma but both the AB antigens are attached to the red blood cell. And vice-versa for group O. There are no antigens attached directly to the red blood cell but there are anti a and anti-b antibodies found in the plasma.
And the reason we need to know about these antibodies and antigens is that there’s a process called agglutination which is a clumping of red blood cells. And the reason this happens is that there’s a reaction between antibody and antigen when they have the same ID. So if you had your group a red blood cells and Group B was introduced, there are a bunch of anti-b antibodies floating around the blood. So the anti-b antibodies would tag those Group B red blood cells, and the red blood cells will start to clump and it would cause a bad reaction.
So now that we have kind of a general idea of what’s going on with these blood types, let’s look it blood transfusions why this all makes sense.
Blood types are really important for those in the medical setting especially when there’s someone who’s involved in maybe a car crash or some sort of other trauma where they need blood. The last thing that anybody wants to do is give somebody the wrong blood type and if they have some sort of major adverse reaction a potentially die for something that what’s meant to be life-saving. So anytime blood transfusions are done the goal is to transfuse blood from the same group when possible.
So if a person needs blood, and they are blood type A, it’s best that they get type A because they have antibodies waiting around to protect themselves. But if you give them type O, there are no antigens on the type O blood type that will cause a reaction. If you look at type B, it’s a real similar thing. You can give them type B blood, or you can get them typos because o lacks both of those antigens. Then you have type AB who has both antigens. That means that they can get type A and type B blood and also type O. But when it comes to typos it’s really particular. And it’s really important that type O blood patients get type O, because they don’t have any antigens on the red blood cells, but they do have the presence of both of those antibodies in the plasma ready for a reaction.
There’s also another really important factor blood grouping, and Rh factor. The Rh factor is a d antigen found in some types of blood types. So if the factor is present, it means that the person is considered an Rh-positive. And it’s a factor is absent, then they’re going to be considered Rh negative. Now when it comes to matching these different blood types for the Rh factor, if you have someone who is RH positive, they can receive Rh negative blood. That’s because there’s no antigen on the red blood cell to initiate an immune response. But if you flip it around, and you give someone who is Rh negative RH positive blood, there’s going to be an immune reaction.
The other important thing about Rh factor is that it’s an additional consideration when you’re talking about blood times. So you can have someone who has the presence of a antigens, and the D antigens, so they would be considered a type A positive blood. Or you can have someone who has no antigens at all which would make them O Negative. There is a fantastic resource attached to this lesson that talks about what types of blood can be given to what types of patients, there’s a big chart that shows it so I want you to go check it out.
Okay so let’s recap.
We talked about blood types there are types a, b, ab, and type O.
Also when you’re talking about blood types remember that there are antibodies and antigens that play a big role in blood transfusions. Antigens are present on the red blood cell, and antibodies are present in the plasma.
Agglutination is that process of the clumping of the red blood cells, and what happens when the antigens and antibodies are the same letter type. So if you have someone what a type A antibody they cannot receive a type A antigen because it will cause a reaction.
Rh factor is that an antigen, and it is either present or not present, so in the presence of the Rh factor, the person will be RH positive. If the factors absent, then they are considered Rh negative.
When someone’s getting a blood transfusion, it’s always best to give the same type and Rh factor when possible. Remember that type AB is the universal recipient, and that type O is the universal donor.
That’s it for a lesson on blood grouping. Make sure you check out all the resources attached to this lesson. Now go out, and be your best self today, and as always, happy nursing!