THE COMPONENTS OF BLOOD
The four components of blood are:
1. Red blood cells (RBCs)
2. Platelets
3. Plasma
4. White blood cells (WBCs)
Blood donations are separated into three components: RBCs, platelets, and plasma. This is so that the exact products can be given to those who need them, and so none of your blood donations go to waste. In some cases, all three may be needed, but in others, only transfusion of one of these components is required. Therefore, one blood donation can save or improve up to three lives.
To picture how these blood cells move through blood vessels and work in your body, check out the image below:
RED BLOOD CELLS
Red blood cells (RBCs) are important as they transport oxygen from the lungs to tissues and organs around the body. RBCs contain a protein called haemoglobin, which is the essential component of RBCs as this is what binds to oxygen and transports it around the body. Therefore, haemoglobin is essential in helping us maintain our strength and energy.
Iron is important as it makes haemoglobin. We get iron through our diet, which is why it is so important to have a well-balanced diet to maintain normal haemoglobin levels. If your iron levels are low, your haemoglobin levels will also be low, which may result in anaemia.
Anaemia is typically caused by a deficiency in the number and quality of RBCs in your body due to low iron and haemoglobin levels. Iron deficiency anaemia is the most common form of anaemia and is generally managed by changing your diet or taking iron supplements. If you are anaemic, you cannot donate blood. However, there are many different forms of anaemia, some of which can only be managed through regular blood transfusions.
There are a number of reasons why someone might need a RBC transfusion. To learn more, go to the link below.
PLATELETS
Platelets are tiny blood cells that prevent and stop bleeding in the body. If you are injured, either internally or externally, platelets will join together to form blood clots and stop the bleed from getting worse.
However, platelets only have a shelf-life of seven days. After they are collected from a donor, they must be moved constantly so that they don't clot. Due to their short shelf-life, there is more of a demand for this specific blood component. To help with this shortage, people can specifically donate platelets. This process typically takes up to 90 minutes, and donors can donate every four-to-six weeks.
In general, platelet transfusions are needed to prevent or treat bleeding. People with diseases such as cancer and bleeding disorders may also require platelet transfusions as part of their care. To learn more, go to the link below:
PLASMA
Plasma is the clear, yellowish fluid that carries blood cells (and many other cells) around the body to where they are needed. Other cells carried by the plasma include clotting factors, antibodies, and hormones.
Clotting factors are important as they work together in a pathway to produce fibrin, a clot-forming substance. Platelets and clotting factors are very important as they work together to stop bleeding.
Ultimately, plasma transfusions may be needed if someone has experienced a massive bleed to replace the clotting factors they have lost. Clotting factors are produced in the liver; therefore, people suffering from liver disease may also need plasma transfusions if the liver is not producing enough clotting factors.
Antibodies are molecules that are produced in your body in response to infections. Even after you have recovered from an infection, the antibodies you have developed can remain in your plasma for some time after you have recovered. This is why plasma donations were used to treat COVID-19, as people who tested positive had antibodies that could be given to help other people recover. However, it is important to note that not all antibodies are beneficial in a transfusion, and some may cause more harm than good. The presence of multiple antibodies is more likely to make your donation incompatible with those who need a blood transfusion, as your blood may be more likely to cause an adverse reaction.
Several therapies are created from plasma to treat certain conditions/diseases. For example, protein albumin can be extracted and used to treat severely shocked/burned patients. Intravenous immunoglobulin (IVIG) is another therapy that can be created from plasma, and is used to treat a range of autoimmune diseases such as Immune Thrombocytopenia Purpura (ITP) and Guillain Barré Syndrome.
After you donate, your blood is separated into red blood cells, platelets and plasma. Once your plasma has been extracted, it can either be frozen until needed or used to create different therapies. However, you can also just donate plasma through a process called plasmapheresis. The process takes around 90 minutes, where your blood is filtered through a machine, only taking your plasma. This means that the rest of your blood is returned to your body – how cool is that!
WHITE BLOOD CELLS
White blood cells (WBCs) are the cells in our immune system responsible for protecting us against infections. All blood donations go through a process called 'leucodepletion' - this is the removal of WBCs. WBCs are removed as they have no benefit to the recipient of a blood transfusion. They are also more likely to cause harm through passing on different viruses or bacteria that donations might not be tested for.