How Does Convalescent Plasma Therapy Work?

Thanks to the clinical trials that have been carried out to find a solution for fighting the novel coronavirus, the statistics of recovered patients in the world are slowly rising. Worldwide, we have a 25% recovery rate. Although that is still far beyond our target which is 100%, we should still appreciate the fact that the efforts of our scientists are showing great outcomes. 

There is still no specific treatment that has been proven effective for this infection. You may have heard about different promising treatments of COVID-19 but let us focus now on convalescent plasma and why it has been one of the highlights of the field of clinical trials. 

What is plasma?

The blood is made up of different kinds of cells. There are red blood cells that carry your oxygen and wastes in and out of our bodies. We also have white blood cells that are responsible for our protection or immunity. There are platelets that are involved in the prevention of bleeding. When these three and other cellular particles are separated, you will be left with plasma. This part contains different substances like proteins, salts, enzymes, water, and antibodies.

Antibodies or what we also call immunoglobulins are proteins that are produced by the immune system. This was created to attack a foreign substance, like viruses or bacteria. Upon the entrance of the virus or bacteria (antigens), antibodies are produced to basically attack it. There are different roles of antibodies:

• They circulate the antigen to contain it
• They bind to, attack, and kill the antigen
• They attach to the antigen and prevent it from infecting other cells

Note that these antibodies can identify an antigen that has previously attacked the system. By collaborating with other cells, they can remember the features of their enemy and get triggered to be in a defense mode.

Basically speaking, of your immune system has crossed path with a COVID-19 virus, your immune system can now provide immunity for you on that virus for months.

Convalescent plasma

A number of COVID-19 survivors have expressed the intention to donate their blood samples. What does this mean? It means that laboratories can now extract the plasma with antibodies that were already trained to combat the Novel coronavirus. They will now be fighting the same antigen but within a different individual.

This blood component with these activated antibodies is now called convalescent plasma. This plasma came from recovered COVID-19 positive patients that were properly selected and screened. Their ABO grouping, as well as RhD, have been identified properly. The donated blood has been tested negative for other diseases like human immunodeficiency virus or hepatitis. 

Scientific evidence

Scientific investigations have shown positive results for the use of convalescent plasma therapy in curing infected patients. Clinical symptoms and paraclinical criteria improvement, lung lesions showed degrees of absorption, and viremia disappearances were reported to have improved in one research study.

In another publication, they claim to have identified that transfusion of convalescent plasma can lead to lower mortality and shorter hospitalization. They have also added that there were no adverse effects or complications observed in patients who have received the therapy.

Improvement in clinical status (normalization of body temperature, decreased SOFA score, and viral loads) was noted following a transfusion in a study published last March. 

Risks of convalescent therapy

Although many pieces of literature attest to the effectiveness of plasma convalescent therapy, we should remember that humans have unique biological attributes that can influence the efficacy of certain medical interventions. There are risks associated with this therapy just like the others. 

• Possible circulatory overload
• If the patient receiving has severe damage in their lungs, they could also develop TRALI or transfusion-associated acute lung injury
• Allergic reactions are also common for transfused blood and blood by-products

 With any therapy treatment there are always risks, so speak with your primary care physician before making any decisions.