Review: Immune

 Immune is a layman's introduction to immunology. Written by a German science popularizer, it's written in easily understood vernacular and came with lavish color illustrations that I ignored, given that I was reading it on a Kindle paperwhite.

The book explains all the dry stuff you might have garnered from other immunology books or articles about the immune system. For instance, what's the innate immune system? How does it interact with the adaptive immune system? What's a mast cell? What's a T-cell? What's the difference between a Helper-T cell, and a Killer-T cell? How does the immune system know when to turn on and off? What's special about Immune, however, is that he also explores the implications you might not have known or even thought about:

why does the body of a woman not recognize sperm cells as other and kill them right away? Well, it does! This is one of the reasons you need about 200 million sperm cells to fertilize a single egg! Right after sperm is delivered into the vagina, it is confronted with a hostile environment that it has to deal with. The vagina is a pretty acidic and deadly place for visitors, so sperm cells move on as fast as possible to escape it. Most of them gain access to the cervix and uterus within a few minutes. Although here they are greeted by an onslaught of Macrophages and Neutrophils that kill the majority of the friendly visitors that are only trying to do their job. Sperm cells are at least a bit equipped to deal with the hostile immune system (a little like a specialized pathogen if you think about it). They release a number of molecules and substances aimed at suppressing the angry immune cells around them, to buy them a little bit of time. And it may actually be the case that they are able to communicate with the cells that line the uterus, to let them know that they are friendly visitors, which might turn down inflammation. But there is a surprisingly large number of things that are not completely understood yet, in these interactions. In any case, from the millions of sperm cells that entered, only a few hundred enter the fallopian tubes and get a shot at fertilizing the egg. (Kindle Loc 1277)

The analogies used in the explanations are clear and a lot of fun, and Dettmer does a great job also of reminding you that he's simplifying a lot of issues. The explanation of how T-Cells get selected in the Thymus is great, and once again, there's a willingness to expose the implications of your shrinking Thymus:

 Your Thymus basically begins shrinking and withering away when you are a small child. A process that is sped up once you reach puberty. Every year you are alive more and more Thymus cells turn into fat cells or just worthless tissue. The university closes more and more departments and gets worse as you age, until around the ripe age of eighty-five, your T Cell university closes its gates for good. Which is sort of horrible if you like the concept of being alive and healthy. There are other places in the body where T Cells can be educated, but for the most part from this point forward your immune system is more limited than before. Because once your Thymus is gone, you have to get by with the T Cells you have trained up to this point. The absence of the immune cell university is one of the most important reasons why seniors are much weaker and more susceptible to infectious diseases and cancer than younger people. (Kindle Loc 1756)

I also enjoyed the sections on how "immune boosting" is not a good idea, including a depiction of real life experiments that went horribly wrong and a reminder of how little we still know about immunology, including the so-called hygiene hypothesis:

Even in developed countries, a number of studies found that children who grow up in the countryside and especially on farms, surrounded by animals and with much more exposure to the outside, suffer significantly less from immune disorders. So while it doesn’t seem to make a difference if a house is clean or not, it does make a difference if it is surrounded by cows and trees and bushes and if dogs roam freely. So what can you take away from this chapter? Wash your hands at least every time you use the restroom, clean your apartment but don’t try to sterilize it, and clean the tools you use to prepare food properly. But let your kids play in the forest. (Kindle Loc 4170)

 Finally, there's an exploration of in addition the allergies, a discussion of how your immune system plays an active job in suppressing cancer, as well as why we have such a hard time developing anti-viral drugs, whereas it still at least seems somewhat possible to develop newer antibiotics.

The book taught me a lot, and I think it's well worth reading. Recommended.