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Cystic fibrosis complications

Created by Amy Fan.

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Video transcript

- [Voiceover] I want to talk about some complications of Cystic Fibrosis that don't seem as intuitive. Everybody thinks of CF as mostly thick mucus in the lungs, and you have GI problems, not having the pancreas enzymes, and those are the very important and poster-child complications of CF, but there's some other things that don't seem as intuitive, just in thinking of the chloride channel not working. I want to talk about three of these, and let's start with the issue of infertility. This actually affects a lot, I would say, most CF patients. Up to 98 percent of the men can be infertile, and men and women have different reasons, but let's look at men first. For men, the reason that they tend to be infertile is because of an absence of these tubes called vas deferens, so, vas deferens. It's a funny word to describe a specific set of tubes in the male reproductive system. If I were to draw it, let's put the testes down here, and sperm begins their life down here, but, after maturing and they have to be transferred up these tubes that are connected to the testes that transfer the sperm and allow them to mature, these are the vas deferens. In CF, up to 98 percent of men don't have this, and this condition's called vas deferens agenesis. Genesis means to generate, and agenesis just means it doesn't develop. When these babies are in the womb, the thick mucus here clogs off these tubes and they don't actually ever develop, so we have vas deferens agenesis. That's the reason for male infertility because the sperm can't go to where they need to go, and they can't mature without the vas deferens, so, basically, we don't have sperm production here. For females, of course, the reason is completely different. If I could just draw the female system really quickly, I'm going to draw it like this, so here is the cervix, and up here is the uterus, and over here are the ovaries. For sperm to get up here, to impregnate this woman, it has to go through the cervix, but we have thick mucus here due to the Cystic Fibrosis, so a lot of sperm doesn't get through. For females to produce eggs and be fertile, nutrition is important, so the actual underlying nutrition problem in CF can lead to female infertility as well. Here they're still producing eggs, they're able to get pregnant but, technically, it is difficult. Keep in mind that even though CF patients can be infertile, meaning it's hard to get pregnant, or they can't get pregnant on their own, they're not sterile. Being sterile would mean that they can't have children, even with infertility treatments, but, in this case, they can. We can artificially put the embryo into this woman's uterus and it can grow there, or for the men we can artificially extract his sperm. People with CF, they can reproduce, but, usually, not without some kind of reproductive therapy. If a woman with CF … Actually, it's difficult to carry a baby sometimes because, again, nutrition, and a lot of those other combinations of CF come into play. That's infertility and, I don't know about you, but I wouldn't have expected this to be part of this spectrum of disease but, obviously, it's a huge part of their life. Now, the next thing I want to talk about, I guess, belongs to the family of GI or gut complications. It's called intussusception, and it's even harder to spell than it is to say, so I'm going to just spell this correctly. Intussusception, and this is in people, without CF, this still occurs, but mostly in babies, and people with Cystic Fibrosis can have this into adulthood, or they can have it, more commonly, as a child. It's a mechanical thing in the gut that, I think the best way to describe it is, if you can imagine a telescope, one of those telescope that come in segments and you can open it, one segment after another, so this is a looking lens, then each segment gets a little smaller, like that, and this is with the telescope fully open, so when you need to close the telescope and take it home, what do you do is that you push the end here, this way, and it folds in on itself, and that's exactly how intussusception happens in the gut, so you have, just going along in the gut, say we're going from the small intestine here to the large intestine, and the gut here can suddenly just collapse this way, folding into the large intestine. This cuts off the blood supply. It's extremely painful. Babies will cry and fuss. Sometimes it reverses itself, sometimes you're using air. You shoot air into here to push it out, but, again, it's extremely rare to see this in people after 12, but, in Cystic Fibrosis, it happens, so just something to watch out for if you're treating somebody with CF and they suddenly have abdominal pain, this should be on the list of things to think about. The third complication I wanted to talk about has to do with bone density. Now, you might think, what does bone have to do with chloride channels and mucus? This is, kind of, a weird one, but most people who have Cystic Fibrosis have osteopenia, osteo-- so osteo means bone, penia means not enough of, or lack of, so osteopenia means low bone density. Now, if this gets really bad, it reaches a criteria of osteoporosis, and this, you've probably heard of as an old people disease. As you get older, your bone density erodes away and you get osteoporosis, but young Cystic Fibrosis patients can have this as well because what's a very important thing for bone to develop is Vitamin D. I think we all know this. If you take calcium for your bones, most of the time it comes with Vitamin D. Now, there are four vitamins, out of all of them, that are fat soluble, so fat soluble means that the vitamin has to be absorbed into the body with fat instead of with water, like the other vitamins, and there are four of them. It's Vitamins A, D, E, and K. Notice how Vitamin D is one of them, so the impaired fat absorption in people with CF makes it hard to get these four vitamins. To absorb fat in our bodies, we need bile from the liver, so I'm drawing a liver right here, and, with the clogged chloride channels and thick mucus, bile or, actually, the bile ducts in the liver gets clogged off. People with CF actually lack bile and they don't produce the right amount of bile salts, so it's hard to absorb these vitamins. They can eat them, but it's hard to get into the bloodstream this way, so the lack of Vitamin D here leads to osteopenia. Since we can't change the fact that this happens, there are other ways to try to maximize the amount of bones that we can have, and one important way is to exercise, especially weight-bearing exercises like resistance training, and, of course, whatever supplements we can give them. So, these are three complications that might not be intuitively associated with CF, but I just want to show you how Cystic Fibrosis is so wide-reaching as a disease. It really affects everywhere in the body. While it should always make you think of lung infections and nutritional deficiencies, don't forget that there are other complications associated with CF as well.