What
are the different blood groups?
The differences in human blood are due to the presence or absence
of certain protein molecules called antigens and antibodies.
The antigens are located on the surface of the red blood cells
and the antibodies are in the blood plasma. Individuals have
different types and combinations of these molecules. The blood
group you belong to depends on what you have inherited from your
parents.
There are more than 20 genetically determined blood group systems
known today, but the AB0 and Rh systems are the most important
ones used for blood transfusions. Not all blood groups are compatible
with each other. Mixing incompatible blood groups leads to blood
clumping or agglutination, which is dangerous for individuals.
Nobel Laureate Karl Landsteiner was involved in the discovery
of both the AB0 and Rh blood groups.
AB0 blood grouping system
According to the AB0 blood typing system there are four different
kinds of blood types: A, B, AB or 0 (null).
Blood group A
If you belong to the blood group A, you have A antigens on
the surface of your red blood cells and B antibodies in your
blood plasma
Blood group B
If you belong to the blood group B, you have B antigens on
the surface of your red blood cells and A antibodies in your
blood plasma
Blood group AB
If you belong to the blood group AB, you have both A and B
antigens on the surface of your red blood cells and no A or
B antibodies at all in your blood plasma
Blood group 0
If you belong to the blood group 0 (null), you have neither
A or B antigens on the surface of your red blood cells but
you have both A and B antibodies in your blood plasma
The Rh factor grouping
Rh factor blood grouping system Many people also have a so
called Rh factor on the red blood cell's surface. This is also
an antigen and those who have it are called Rh+. Those who
haven't are called Rh-. A person with Rh- blood does not have
Rh antibodies naturally in the blood plasma (as one can have
A or B antibodies, for instance). But a person with Rh- blood
can develop Rh antibodies in the blood plasma if he or she
receives blood from a person with Rh+ blood, whose Rh antigens
can trigger the production of Rh antibodies. A person with
Rh+ blood can receive blood from a person with Rh- blood without
any problems. According to above blood grouping systems, you can belong
to either of following 8 blood groups:
| A Rh+ |
B Rh+ |
AB Rh+ |
0 Rh+ |
| A Rh- |
B Rh- |
AB Rh- |
0 Rh- |
Do you know which blood group you belong to?
How do we detect the blood group of a sample?
1.
You mix the blood with three different reagents including
either of the three different antibodies, A, B or Rh antibodies.
2.
Then you take a look at what has happened. In which mixtures
has agglutination occurred? The agglutination indicates
that the blood has reacted with a certain antibody and
therefore
is not compatible with blood containing that kind of antibody.
If the blood does not agglutinate, it indicates that the
blood does not have the antigens binding the special antibody
in the reagent.
3.
If you know which antigens are in the person's blood, it's
easy to figure out which blood group he or she belongs
to!
Blood transfusions – who can receive blood from
whom?
Of course you can always give A blood to persons with blood
group A, B blood to a person with blood group B and so
on. But in some cases you can receive blood with another
type
of blood group, or donate blood to a person with another
kind of blood group.
The transfusion will work if a person who is going to receive
blood has a blood group that doesn't have any antibodies
against the donor blood's antigens. But if a person who is
going to receive blood has antibodies matching the donor
blood's antigens, the red blood cells in the donated blood
will clump.
Blood Group Antigens Antibodies Can give
blood to Can receive blood from
AB A and B None AB AB, A, B, 0
A A B A and AB A and 0
B B A B and AB B and 0
0 None A and B AB, A, B, 0 0
| Blood Group |
Antigens |
Antibodies |
Can give blood to |
Can receive blood from |
| AB |
A and B |
None |
AB |
AB, A, B, 0 |
| A |
A |
B |
A and AB |
A and 0 |
| B |
B |
A |
B and AB |
B and 0 |
| O |
None |
A and B |
AB, A, B, 0 |
O |
Other blood groups
Several other blood group antigens have been identified in
humans. Some examples: MN, Bombay Duffy, Lewis, Kell.
They, too, may sometimes cause
• Transfusion reactions and even
• Hemolytic disease of the newborn
In cases where there is no ABO or Rh incompatibility.
Bleed and be a donor
To save a life in danger
Why Blood Donation Is Imperative
People who lose blood in accidents, premature
babies, major surgeries, patients suffering from dengue,
cancer etc. Need
blood. A proper supply of blood is essential for a person’s
existence. In India, in every two seconds someone is in need
of blood. In a year nearly 41 million units of 250 cc blood
is needed in India and out of which only a meager quantity
of half million is provided by the existing systems of blood
donation. In other countries it is worse than in India. As
blood can be not stored indefinitely someone has to volunteer
to donate blood at the moment in which blood is needed. Delay
will prove fatal to the person who is in need of blood urgently.
So it is essential and vital that people must understand
the importance of blood donation and volunteer themselves
to donate blood. They must consider this as a sacred duty
to their fellows and take it as a social obligation.
Who can be a donor
A donor must fulfil the following conditions.
a) He must be above 18 years of age
b) He must be healthy and weight at least 50 Kgs.
c) He must not be suffering from any disease (Cancer, AIDS,
Contagious diseases etc) high Blood Pressure or any other
disorder ….
d) He must not be a drug addict…..
What he must do and what he must not do
1) A donor must avoid smoking on the day in which he donates
his blood. Of course he can smoke three hours after the donation.
2) He must not consume alcohol for 48 hours before the donation.
(He must abstain from drinks for that day even after the
donation.)
3) He must take a good meal at least 3 hours before the donation.
4) He must take snacks after the donation and take a good
meal later.
5) He must take fluids in plenty. The donor will not feel
drained or tired if he takes fluids.
6) He must refrain from heavy exercises for 12 hours after
the donation
