Day 3 of #31DaysOfTré – What is cystic fibrosis? An Overview

So I obviously have to do this post. The point of this month is to showcase many different facets of cystic fibrosis from my perspective. Without having a solid overview piece, it wouldn't be a good project. As the project progresses, I'll spend more time explaining some of the actual specifics and intricacies of the biochemistry behind CF – how it is inherited, the actual gene, how different drugs work, etc but for now, a relatively simple overview. Disclaimer: As a scientist and writer, I'm going to try to be careful not to go too in-depth, but I also hate oversimplifications. Bear with me.

To start, the canned spiel: CF is a genetic disease that causes a defective protein called the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The CFTR protein is a chloride ion channel on the surface of epithelial cells. There are nearly two thousand disease-causing mutations of CF. Unfortunately, since CF is such a complex genetic disease, no two patients are the same, even including siblings and among patients with the same mutation. Alyssa and I both have the ∆F508 mutation of CF, which is actually the most common mutation. To put into perspective how two patients with the same mutation and 50% of the same DNA (as siblings do) are affected differently: Alyssa was 24 years old when her lung function was failing to the point of needing a double lung transplant – her lung function dropped below 30%. I just turned 24 a week and a half ago and my lung function has been between 85% and 97% for the last 2 years. (Side note: I'll also write a piece delving into the minutiae of pulmonary function tests and what these numbers actually mean; for now, they are a good enough indicator of how healthy someone with CF is.) It's important to note a couple things here, and I'll try to be concise. Obviously, Alyssa and I were never going to have the same disease progression: we cultured different bacteria at different times, different compliance standards, different work ethics, etc. The point is: the disease significantly affects every patient differently.

The CFTR protein is crucial for chloride ion transport. Incidentally, chloride ion transport is important in mucoid development, which is why people with CF have especially thick mucus. CF is commonly known as a lung disease, though I feel compelled to rail against that traditional simplification of the disease. The thick mucus causes complications in many organs and tissues, including, but not limited to, the gastrointestinal tract, the pancreas, the liver, the kidneys, and the sinuses. It is certainly true that progressive lung disease in CF is one of the biggest causes of mortality, but pancreatic insufficiency, CF-related diabetes, fatty liver disease, and many other issues are common burdens in many of our lives.

The architecture of the lungs of people with CF is significantly altered by infection and inflammation as the years go on. The thick mucus in our lungs offers a fertile breeding ground for bacteria. There are a handful of "CF bugs" that colonize our lungs and wreak havoc and cause exacerbations. People with CF also have altered immune systems which leads to a different inflammatory response. The lungs of people with CF eventually become obstructed and damaged to the extent that they are unable to hold as much air and some air becomes trapped (typically collectively simplified to the term "lung function" – again I'll explain this in a subsequent post). The bacteria in the lungs also become resistant to drugs as time goes on. Combine all of these factors together, as well as the stereotypical cough, and it's easy to see why CF is labeled a lung disease. I'm not completely against that phrasing, but it does discount a lot of other problems.

Along with nebulized treatments and chest physiotherapy, in my specific case, I take pancreatic enzymes to help digest my food, as well as supplementary vitamins, a maintenance antibiotic, an anti-inflammatory, a drug that helps keep my liver levels in check, and a "modulator" (the new class of medications that help to correct and potentiate the defective CFTR protein. These drugs are ground-breaking and exciting. I'll write about these too. It's easy to see how I have 31 days of material for #31DaysOfTré). To further demonstrate how cystic fibrosis affects every aspect of my life, I also dedicate myself to daily exercise, keep track of my electrolyte levels and blood sugar levels, and have had six sinus surgeries. All of this becomes a full-time job for which we have no respite. Taking time off of our treatments can mean a hospitalization which can be hard to recover from. It's easy to see how depression and anxiety can become a huge problem in the life of people with chronic disease.

One of the main reasons I studied biochemistry in college was to have a firmer understanding of the underlying mechanics of CF. To put it honestly, I wanted to feel more powerful and more in control. I wasn't totally wrong. Understanding why my medications, treatments, and exercise are so important forces me to have better compliance and adherence. I've now worked in a CF lab for 2 years, along with a year and a half of CF lab experience in Lexington, to help reinforce the biochemistry I studied in college. 

The future for adults, children, and newborns with cystic fibrosis is bright. There are lots of drugs on the horizon and more people are aware than ever, but we have to keep hammering home all of this progress. With this project, I intend on doing just that.