Hi, I was wondering if you could talk more about the "holes in the immune system" which I have seen in a couple different places on this site. (including in Dr. Steve's account of Dr. Bob's death) I was wondering what that means and why it happens. Thank you, susan

Hello Susan and thanks for posting.

When we speak about "holes in the immune system", we are referring to gaps in the repertoire of the immune response. If you think of the universe of things that our immune system is supposed to react to (ie., infections, toxins, cancers) as a slice of American cheese, think of an immune system with holes as a slide of Swiss cheese. Each hole represents that part of the immune system that is responsible to fight a specific target.

Things that fall through the holes are diseases that can occur in persons with immune system problems that might not be as severe in those who have healthy immune systems. It appears that there are sometimes these gaps or holes in the recovered immune systems among persons living with HIV and normal CD4s. One theory is that these holes are created when one's disease state is more advanced (AIDS, with low CD4s), and that while ART improves the numbers and fills many of the holes, for some people, holes can still persist. The risk then is if the right pathogen finds the immune system with the corresponding hole.

I hope that metaphor helps. BY