I'll try to answer what "works" about ivacaftor. CF is a genetic disease that compromises mucus cell's ability to balance the electrolytes, specifically chlorine or the chloride electrolyte ion in table salt. We are familiar with osmosis, the free transport of water through the cell membrane that equalises electrolyte concentration inside the cell to that outside the cell. Water flows through the cell membranes without any special gates called ion channels. But, most things are controlled by the specialized gates, otherwise cells would most likely die rather quickly. No electrolyte is going to pass into or out through the cell membrane, they need to use a gate.
Ivacafter as close as I can tell, enters into the nucleus of cells and substitutes correct DNA Bases called Guanine (G) for the compatible but worthless (D) or aspartic acid. In the mutation G551D, Ivacaftor fully corrects the CFTR mutation, but you have to take it forever or until a permanent answer is found.
Why is this important? We are essentially bags of water placed in cell sized containers. For the bag of water to be embued with life, electrochemical reactions must be organized and a whole bunch more has to work together. Our blood and fluids are a 0.9% salt solution, at best, whatever salt is in a cell is divided by division. And if our sodium ion channels are missing, defective or in the wrong place, the mucus cells draw in water through unstoppable osmosis until the cell concentration of salt equals 0.9%, an obviously hopeless task. A few million cells drawing water from the surrounding environment can thicken mucus like a dried grape. Try drinking raisin mush, imagine breathing through it?
As an old, feeling pretty worn out CFer I don't have CF lungs. By the same token I constantly aspirate saliva and food. Most CFers have nasal infections and most of the infection drains over the epiglottis into the stomach. A certain amount is aspirated leading to pneumonia. CF lungs are deadly and the best way to tell if you have them is in the mucus. It's sometimes difficult to tell if you are clearing lung phlegm or nasal mucus. The rare occasion when I get pneumonia, my coughing shoots as much past my mouth as I catch. The only way I can tell for sure what is from where is to do a sinus rinse first and make sure that it is clean. It could be the ivacaftor is "working". If even that 0.9% of chloride ions equalize to the blood serum, what could be thick unmovable mucus is now water thin and properly moved by the cilia up the wind pipe and out.
When I was first diagnosed, the CF center went full tilt at aggressive treatment. I never got a vest in fact the only reason I replace my nebulizer is time. I've never worn out a compressor. I blow between 90 and 106 FEV1. There are some who wonder if they got the diagnosis right.
A lot of CFers are so focused on helping the lungs, for good reason. Everyone doesn't have to have typical CF, being atypical is a large group. I personally wonder where the GI dominant CFers are hiding. You speak of 75% percentile for weight and height. How is her tummy?
The pancreas is zapped by CF as are all endocrine glands potentially. Epithelial cells lining the small intestine, the pancreas, liver, bile ducts and gallbladder in addition to the urogenital glands all conspire to make sure that life isn't too easy. I'm as sterile as a mule, my pancreas is 95+% atrophied (not yet diabetic) and I envy those sci-fi movies where a hand full of pills passes for food. Eating makes me sick. I don't know if my single group 2 mutation would qualify me for ivacaftor but if it would eliminate the absurd level of pancreatic pain, I would pay anything.
I don't think this answers your real question, what is my daughter's life going to be like? Not to be cliché but "Que sara, sara", what will be, will be. From what I know of CFers, they are different from other people, not by much but enough to be noticed. As soon as possible she should take ownership of maintenance for CF. Count on her neglecting her maintenance at age appropriate times when her rebellion against everything happens. Nobody enjoys being sick, so don't worry too much, she'll test her boundaries just as a toddler looks back at her human safety net before expanding her experience and domain. The CFer, whether through some offsetting gift or disease is unstoppable.
I have little memory of my youngest years but the memories I have seem to involve a doctor. I recall having my eardrums lanced in the days before ear tubes and I recall my mother teaching me "The Lord's Prayer" when they feared polio. Fooled them for sure, it was encephalitis! On the heels of that fun I contracted meningitis. It was as if a hole through my nasal cavity went to my brain. The encephalitis was courtesy of a mosquito and the vast Wyoming tundra. Thank goodness that memory of pain is transitory, I still hold great sympathy for sufferers of headaches. I had an oxygen tent for a couple years and when I finally reached age 10 the only problem I had was to be alive when EVERYONE smoked! Not a problem for your daughter.
Something about needing to power through the school year sick, and being 7, being the unequivocal winner of the skinniest kid in school conditions a drive. Then again it could just be the excess stress hormones racing around areas that don't require it like the higher functioning brain, but I see something special in all CFers. A fervent love of life is good and common in CFers. Maybe we just face fear with grace. Don't worry too much, your daughter has CF, not the other way around. Aside from having a life shortening disease, she is perfect.
My own life is not the one I imagined, it was closer to my wildest dreams. Fortunately I am hyperactive, CF was just a bunch of annoying health problems for most of my life. I also bore easily and quickly get in over my head. I left a wake of destruction in my haste. All people who move forward leave that wake and I have atoned by clearing the wake left by others as mine was. My wife and I grew an idea into an international company building specialized automation. I became the company's globetrotter. I used to say that I have had more fun than any five people. A more accurate description was living more than any five people. For someone who was constantly sick, I spent half of each year traveling internationally. I've prowled the snake markets in Taipei, climbed the North Face of the Eiger, crossed the Sahara desert by camel and in business treated the international community as if they were in Chicago.
I won't ever complain about being a jet setter and I won't apologize for the adventure of a lifetime that lasted nearly 20 years. Adventure is something that is more fitting in retrospect. During these trips, time is expensive and almost beyond human capacity to keep up with. I worked an average of 18 hours daily, visiting existing customers by day and doing new business by night. A six week trip could cover the entire Asian rim from Japan, Korea, Taiwan, Hong Kong to S. E. Asia including Singapore, Malaysia and Thailand. Then fly through Hong Kong to Munich for a trade show, up to Norway and home. Exhausting was an understatement. It took a full 2 weeks to recover and return to a time zone. Six months of each year was devoted to international travel and I had my full time job developing new products and solutions for new customers. I was far from solo, the entire company mobilized to get a part to Hong Kong in 36 hours or start on the design of other specialized automation. Even with the best support I was dealing with normally happy clients now red faced with anger over a part failing after years of 24/7/360 usage. Fixing phantoms was my forté. The more expensive the equipment, the more frequently a mysterious occurrence. Nobody is going to own up to breaking the manufacturing bottleneck, especially when it's more expensive than the Boss's car. My point is the future, regardless of CF is limited by her ambitions.
My body finally lost to CF on the threshold of a dream. Between 48 and 50 I saw the best doctors from the Mayo Clinic to Boston's enclave of medical science. After a lifetime I had created a new company in Bio-medical automation. I had to walk away from it. Now I piddle around in a house that has three laboratories and a shop.
Undoubtedly my parents worried about me just as they worried about my brother and sister. They did fine and aside from being given the choice of going to school or staying home, when I didn't feel well, meaning that I stayed in bed and all I had to keep me occupied was my school work and book(s). I am forever grateful that my CF wasn't diagnosed when my parents passed away. I never felt sickly, avoided that label, although it was obvious that I was going to need a consistent doctor who would keep me healthy. By age 10 I was making and making it to my own doctor appointments, most times although it usually took the form of my complaint which was discussed with my parents and the "well go see the doctor if you must".
Remember that your daughter can't explain the difference between life with CF and without. It would be like trying to feel like it is to be a boy. She has CF and though I have great confidence in a genetic cure that is 100%, we cannot explain CF because we don't know what being without it is like, except for the àirway clearance and external things we do to maintain. She might not need it now or ever, the experience I had would have me blowing my lungs out daily. No phlegm or very little is a good indication she doesn't. I would run it by the doctor and be prepared to challenge a standard answer.
Good luck and let us know,
LL
