We have previously discussed Crohn’s disease in a brief entry about inflammatory bowel diseases. It’s time for the detailed version.
Crohn’s disease is an inflammatory bowel disease (IBD), usually affecting the area between the end of the small intestine and the beginning of the large intestine. However, it can occur anywhere along the digestive tract.
It is a chronic inflammatory condition characterized by lesions in the inner walls of the digestive tract.
It is the most well-known and common IBD, along with ulcerative colitis. In Spain, in 2019, it was estimated that both diseases had a prevalence of about 0.39% (individuals with the disease at a given time). This data is concerning as it showed a significant increase from previous years.
Other studies have confirmed these results. A 2023 study in a region of northwest Italy found an annual increase in Crohn’s disease diagnoses of 169%, comparing the period 2001-2006 with 2016-2021.
In 2015, in the United States, the two IBDs together accounted for 3.1 million diagnosed cases, representing 1.3% of the country’s adult population. The frequency is not uniform worldwide, being higher in the United States and Western Europe.
The causes behind its frequency
This is undoubtedly due to the causes of the disease, which are complex because they are unknown. Although there are several theories, we are once again faced with a complex disease where genetics and environment converge.
It is known that the immune system behaves abnormally during the disease, being the main responsible for the inflammation.
This atypical activity is often initiated by changes in the intestinal microbiota (bacterial populations that inhabit our digestive tract) and/or damage to the intestinal mucosa.
The problem is that there are many ways to provoke dysbiosis, the term given to the imbalance of normal intestinal microbiota in a person. From a salmonella infection to high consumption of oral antibiotics, any cause of dysbiosis can trigger Crohn’s disease.
Due to the characteristics of the disease, diet is suspected to contribute. There is debate in this area, with some consensus that high-fat diets increase the risk.
Interestingly, the most demonstrated environmental risk factor for this pathology is not exactly dietary: it is smoking. A smoker has twice the risk of developing the disease, even more so if the smoker is a woman.
There is also a correlation between developing Crohn’s and having undergone an appendectomy, although some researchers are critical of these findings and argue that there may be cases where the person already had the disease but was misdiagnosed.
Diagnosing and Treating
Diagnostic errors are not uncommon. The symptoms are obvious but ambiguous and vary depending on the severity of inflammation.
Diarrhea, weight loss, and abdominal pain do not narrow down the possible diseases much. Other symptoms can appear depending on the case: presence of blood in the stool, iron deficiency, mouth ulcers, or fever.
With the symptoms and the patient’s family history if relevant information is available, comes the crucial part of the diagnosis: visualizing the intestine. The options are numerous, from abdominal MRI to endoscopies and colonoscopies. The goal is to differentiate it from other IBDs or colorectal cancer, among others.
Unfortunately, there are no markers specific enough to establish a definitive diagnosis on their own today.
The imaging provides new data and is the conclusive test. In Crohn’s disease, there is a high infiltration of immune system cells. The internal architecture of the intestine is altered. The intestinal crypts, glands lining the colon and rectum, are disorganized and shortened, with clear atrophy.
Paneth cells may appear in areas of the tissue where they are not normal (metaplasia), indicating prolonged damage over time.
It’s not only necessary to detect the disease but also to discover its severity, the aggressiveness with which it progresses, location, and subtype for treatment (as it is incurable).
Yes, Crohn’s disease encompasses several subtypes within it. A classification that changes depending on the reference source used, with differences that imply modifications in treatment.
The goal of treatment is to control it and, if possible, to avoid surgery. About 30% of those affected by this disease have to undergo surgery within 5 years of diagnosis.
Surgery is the last option in treatments and involves the removal of damaged intestinal tissue.
Before reaching that alternative, we have various drugs. Most are immune system modulators, especially anti-TNF medications. In recent years, antibodies against integrins and interleukins, molecules involved in the inflammatory response, have been added.
In specific cases, antibiotics are also used for additional complications arising from the microbiota and its risk of infection (remember that the intestinal walls are damaged and become more permeable to the passage of microorganisms).
Dietary changes are also recommended. There are foods to avoid; for example, it is recommended to decrease fiber intake during disease flares because they promote intestinal transit. At such times, you want to give that part of your body a rest.
Is Crohn’s disease hereditary?
Let’s talk genetics. If someone is going to ask if Crohn’s disease is hereditary, no, it is not. But the risk of developing it is hereditary. The same goes for ulcerative colitis. Ulcerative colitis is not hereditary, but a higher risk of developing it can be transmitted from parents.
Between 10-25% of people with a first-degree relative with an IBD develop it in turn.
There is a higher predisposition to develop Crohn’s in individuals of Ashkenazi Jewish ethnicity, indicating a genetic predisposition in this population.
The NOD2 gene in Crohn’s disease is noteworthy. This gene encodes the information for the NOD2 protein. It’s wonderful when names make sense.
The NOD2 protein is a pattern recognition receptor, part of the immune system’s functioning, detecting molecules that possess a muramyl dipeptide structure. These molecules typically make up bacterial walls.
Individuals with mutations in both copies of the gene have a risk 20 to 40 times greater of developing Crohn’s disease. Even a single abnormal copy of the gene increases the risk by 2 to 4 times.
That’s why this and other genes are detected in the tellmeGen DNA test to assess the genetic predisposition of our users. We even tell you the copies you have mutated!
