TeachableMedicalNews article 06042020

Teachable moment in classrooms:

  1. cell chapter – endocytosis and phagocytosis as transport through cell membranes
  2. blood chapter – white blood cell types and their functions
  3. respiratory system chapter – alveoli as the sites of gas exchange
  4. respiratory system chapter – macrophages of alveoli
  5. lymphatic and immune system chapter – antibody structure
  6. lymphatic and immune system chapter – antibodies are made for specific targets

The news item:  Recently reports appeared where blood plasma taken from recovered patients are given to seriously ill COVID-19 patients:

Blood plasma appears safe for COVID-19 patients in early trial results

Researchers report promising results in early safety trials of convalescent plasma therapy, in which the blood of COVID-19 survivors is used to treat patients.

The article mentions that antibodies in the plasma are the active ingredient, and that 5000 patients were evaluated in this trial to determine the safety of such treatment.

So, Why Do I Care??  Have you been living under a rock in the last few months??? The coronavirus, SARS-CoV-2, responsible for the COVID-19 disease has so far infected over 6 million people, and caused over 377,000 deaths worldwide (on the date of this article). The virus attacks the respiratory system, specifically the alveoli, and may cause pneumonia and death by respiratory failure.  The antibodies from the recovered patients hold promise as a possible treatment to lower the lethality of the virus.

Plain English, Please!!!  First, let’s talk about the process of viral infection. Viruses have a very simple goal, which is to get inside living cells, and then hijack the host cell to make thousands of new viruses. Any way we can stop the entry of a virus into cells, or slow the hijacking process will lead to fewer new viruses, so the spreading through the body would be slower and the harm caused by the virus would be milder.

Second, let’s talk about antibodies. The antibodies are protein molecules made inside of a special type of white blood cells (plasma cells) of our immune system. These antibody producing plasma cells release the antibodies into the tissue fluid and blood. Antibodies generally are shaped as a letter Y, and the forked ends of the Yare sticky like Velcro.  The antibodies are made to order, which means that Sars-CoV-2 virus starts up an antibody factory that makes antibodies that stick only to the Sars-CoV-2 virus.

Third, let’s talk about how antibodies may work against viruses. Those sticky ends of the Y shaped antibody can glue together of hundreds of viruses, and the clumped viruses cannot enter the cells.  On top of that the stem of the Y shape alerts macrophages to ingest and digest the clumps of viruses. Very high virus numbers can be neutralized this way.  The antibodies are made for weeks even after the virus had been eliminated from a patient. So, that is the time when plasma (with the antibodies swimming in it) can be harvested from that recovered patient. Those antibodies are ready to stick to the SARS-CoV-2 virus in the ill patients. When the virus numbers are lowered in the sick patient, then the consequences of the infection (fever, damage from cytokine storm) will go away as well.