For example, in the 1918 flu pandemic, research has indicated the the immune response that it provoked was one of the reasons it was so deadly[0].
With SARS-COV-2 one of the treatments that has studies that show reduction in mortality is dexamethasone which is a steroid that reduces the inflammatory response (which is an immune response)[1].
So it is not unreasonable to think that an immune system modulating drug may help with SARS-COV-2. Whether or not hydroxychloroquinine specifically does is a different story, but it would not be surprising for something in this class to have a beneficial effect.
0. https://www.sciencedaily.com/releases/2006/09/060927201707.h...
A) knows how to deal with the pathogen specifically
B) doesn’t go wild and kill the host in its own right whilst trying to figure out how to properly deal with the pathogen
My understanding is that without exposure you body kinda throws a lot of different types of t-cells at the issue. Once it kinda knows how to handle it, it just throws the specific variant of t-cells needed.
SARS-COV-2 is a virus. It is not an autoimmune disease. Your immune system is not reacting to your own tissues. It is reacting to the virus, just like an immune system is supposed to. Immunology is very clear about this, though I admit that the details can be confusing at first. The lines get 'blurry' at the molecular level, Ship of Theseus, all that jazz.
Look, we all want hydroxychloroquine to work with covid-19. It would save a lot of lives, potentially. That's a great thing. If it works.
But we cannot administer it without good proof. Currently, the evidence seems to say that it does not work. It may change over time and with more research, but we can only go off of what we know today.