Types of plasma and the proteins within

Blood consists of red blood cells, white blood cells, platelets, and plasma. Plasma is the liquid that makes up 55% of your blood volume. It serves as one of blood’s most critical components because it carries cells and proteins throughout the body. Doctors often use plasma to treat trauma, burn, or shock patients. Pharmaceutical companies also use it to create plasma-derived therapies that treat a wide variety of chronic, rare diseases like blood clotting disorders and immune system conditions. Plasma-derived therapies replace missing or deficient proteins in individuals, which helps them lead healthier lives.

While blood appears red when it leaves the body, plasma is a light yellow liquid. Plasma is 90% water, but it also contains essential proteins and salt. Because it is so complex, plasma can’t be made synthetically. Instead, people donate their blood plasma to help those in need:

• Source plasma is when plasma donors give through plasmapheresis at plasma donation centers. This source plasma is used to manufacture plasma-derived therapies.
• Recovered plasma is when technicians extract plasma from whole blood donation. Each whole blood donation yields only 250 milliliters of plasma, while source plasma donors can supply up to 800 milliliters of plasma in a single donation.
• Convalescent plasma is an antibody-rich product that comes from plasma donated by someone who has recovered from a disease or virus, such as COVID-19. Convalescent plasma is useful too, as some of the same people who need plasma-derived therapies also need convalescent plasma.

Donation centers collect source plasma from donors to manufacture plasma-derived therapies. Source plasma is the plasma donors give through plasmapheresis. When technicians extract plasma from whole blood donation, they call it recovered plasma. Each whole blood donation yields only 250 milliliters of plasma, while source plasma donors can supply up to 800 milliliters of plasma in a single donation.

Not only does plasma carriy oxygen and nutrients throughout your body, but it also contains proteins each performing a different job. These proteins, like albumin, immunoglobulins, and fibrinogen, float around your plasma and keep you healthy.

Albumin makes up about 60% of all plasma proteins, making it the most common protein in your blood. This protein works like a delivery truck and carries important substances throughout your body. Albumin picks up hormones, vitamins, and medications and delivers them to the cells that need them. It also helps maintain the right amount of water in your blood vessels. Without enough albumin, fluid leaks out and can cause swelling in your tissues. When fluid accumulates outside of your blood, it can impact organ function, reduce blood volume, and potentially lead to shock. Shock is a condition where the body's circulatory system fails to deliver adequate blood flow and oxygen to vital organs and tissues. This can create a cycle where the body tries to compensate by retaining more fluid, which worsens the problem.

Immunoglobulins, also called antibodies, act as your body's security team. These Y-shaped proteins patrol your bloodstream and look for invaders like bacteria, viruses, and other germs. When they find a threat, immunoglobulins grab onto it and mark it for destruction. Your body makes many different types of these proteins, and each type specializes in fighting a specific enemy. Vaccines work by teaching your body to make the right antibodies so when you encounter a germ, you can fight it off before you get sick.

Complement proteins work alongside Ig to support your immune system. These proteins help antibodies destroy germs, particularly bacteria, more effectively.

Fibrinogen, also known as clotting factor I, works like a repair kit for your blood vessels. Your blood contains a whole team of clotting factors, like fibrinogen, that work together. When you get injured, your body activates these proteins in a specific order from factor I to factor X. They work together to make sure your blood clots at exactly the right time and place—not too little (which causes bleeding) and not too much (which causes dangerous clots).

Fibrinogen itself transforms into long, sticky fibers called fibrin that weave together to capture platelets and stop bleeding, acting like a natural bandage. Fibrinogen gives your body time to heal the damaged area. Without fibrinogen, even small cuts could become life-threatening.

Transferrin serves as a specialized transporter for iron in your body. Iron is essential for making healthy red blood cells, but it can become dangerous if it floats around freely in your blood. Transferrin safely picks up iron from your intestines after you eat iron-rich foods and delivers it to your bone marrow, where your body makes new red blood cells. This protein also takes iron to your liver for storage when your body has enough.

Plasma and all of the proteins in it work together like a well-trained team. While albumin and transferrin deliver supplies, immunoglobulins and complement proteins fight infections, and clotting factors like fibrinogen repair damage. This amazing plasma and its crew of proteins help keep your body running smoothly every single day, proving that some of the most important parts of your body are too small to see!