TeachableMedicalNews article 05072020

Teachable moment in classrooms:

  1. blood chapter – white blood cell types and their functions
  2. blood chapter – hematopoiesis in red bone marrow
  3. respiratory system chapter – alveoli as the sites of gas exchange
  4. respiratory system chapter – immune defense cells of alveoli
  5. lymphatic and immune system chapter – events of inflammation

How could the anti-proliferative drug Jakafi help us defeat the SARS-CoV-2 coronavirus?

The news item:  Recent articles reported that the anti-proliferative drug will be evaluated as potential treatment of SARS-CoV-2 infected patients:

Incyte drug could be part of COVID-19 treatment

A global biopharmaceutical company based in Delaware is working to get one of its drugs approved to treat the new coronavirus disease. Officials at Incyte…

The news item mentions that the drug may inhibit cytokine storm in coronavirus infected patients.

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 3.7 million people, and caused over 266,000 deaths worldwide (on the date of this article). The virus attacks the respiratory system, and may cause pneumonia and respiratory failure.  The ant-inflammatory drug Jakafi holds promise as a possible treatment to lower the lethality of the virus.

Plain English, Please!!! First, let’s talk about what Jakafi is. This drug is used to fight disorders where too many blood cells are made.  Those hemopoietic (blood forming) cells in the red bone marrow are stimulated by cytokines, and Jakafi can slow the action of cytokines. So, this anti-proliferative drug is not expected to kill the virus itself, but to prevent the lethal consequence of the SARS-CoV-2 infection, the cytokine storm.

Second, let’s talk about the cytokine storm.  Our body reacts to viral infections with the process called inflammation. That defensive process relies on immune system cells such as the white blood cells lymphocytes, neutrophils and monocytes that supposed to remove the virus from the site of infection, in our case, the alveoli of the lungs.  The white blood cells of inflammations are made in large numbers in the red bone marrow.  If we want to give instructions to our friends, we send them a text, call them, or alert them on social media. If we want to tell the red bone marrow to make more white blood cells, the body communicates that with the chemicals called cytokines.  In some virus infected people large amounts of cytokines are made in the lungs, and a lot of white blood cells will be made in the red bone marrow, and then those new white blood cells will release even more cytokines. This growing cloud of cytokines is called the cytokine storm. The large number of white blood cells damage small blood vessels, and fluids leak out and pool in the air sacs.  That is why shortness of breath develops, and ventilator machines are needed for the patients.  The large cloud of cytokines can damage blood vessels in the heart and kidneys as well.

Third, let’s talk about how Jakafi may help SARS-CoV-2 patients.  When a hemopoietic cells are stimulated by cytokines, there are many chemical reactions need to happen inside the cell. Those reactions follow each other just like when a line of dominos is toppled over once you push the first domino.  If you remove one domino piece from the line, the toppling action stops, and never reaches the end.  Jakafi removes a domino piece from the line of chemical reactions. That particular domino piece is called JAK (Janus Kinase). Inhibiting JAK disrupts the line of reactions, and the white blood cells production slows down.  Fewer white blood cells make lower amount of cytokines, and that snuffs out the cytokine storm, and prevents deadly damage to the patient.