Some COVID-19 vaccines have been linked to dangerous but incredibly rare blood clots.
Now a small study by researchers’ report in ‘Nature Journal’ is revealing new details on how those clots form.
About
Vaccine-induced antibodies attach to a protein called platelet factor 4, or PF4, spurring platelets to form clots.
The vaccine-induced condition is similar to what happens with heparin, a blood thinner that can also attach to PF4.
When heparin binds to PF4, some people’s immune systems then attack the bound molecules, a condition called heparin-induced thrombocytopenia also characterized by clotting.
This hints that heparin and COVID-19 vaccines cause blood to clot in similar ways.
Components of Blood
Plasma
Plasma constitutes 55% of total blood volume. Composed of 90% water, salts, lipids and hormones, it is especially rich in proteins (including its main protein albumin), immunoglobulins, clotting factors and fibrinogen.
Plasma performs several functions: transporting blood cells and nutrients; regulating the body’s water and mineral salts; irrigating tissues; providing a defence against infections; and coagulating blood.
Red blood cells, white blood cells and platelets are suspended in plasma.
White Blood Cells
There are between 6,000 and 8,000 white cells per cubic millimetre of blood.
White cells, slightly larger than red cells, are also called leukocytes.
They purify and protect the body from infections.
Once an infection is detected in any part of the body, the while cells move in to fight it.
Platelets
Platelets, or thrombocytes, are smaller than the red and white blood cells.
Platelets play a role in blood coagulation and wound healing.
When a blood vessel ruptures, platelets combine with fibrin, derived from fibrinogen, to form a clot.
Red Blood Cells
A drop of blood the size of a pinhead contains approximately 5 million red blood cells (erythrocytes).
They are small biconcave disks without a nucleus and get their red colour from an iron-containing protein called hemoglobin.
Red cells make up between 37% and 43% of blood volume in women and between 43% to 49% in men.
Red blood cells carry oxygen throughout the body.
Antibodies
Antibodies, also referred to as immunoglobulins, are glycoproteins naturally produced in response to invading foreign particles (antigens) such as microorganisms and viruses.
They play a critical role in the immune system’s defense against infection and disease.
