The U.S Preventive Services Task Force (USPSTF) has released its draft recommendations about screening for celiac disease in people who aren’t showing symptoms—even if they may be at risk.
The draft says that although the gluten intolerance can cause health problems, there are too many areas with insufficient research to warrant broader screening.
Celiac Disease and Gluten: Quick Facts
- Celiac disease is an autoimmune disorder triggered by eating gluten
- The immune response causes inflammation that can lead to various problems like diarrhea, abdominal pain, osteoporosis, ataxia, and impaired height
- About 0.4% to 0.95% of U.S adults have celiac disease, though the rate is distinctly higher among those with things like diabetes, other autoimmune conditions, or a family history of celiac disease
- Most cases of celiac disease manifest later in life, between ages 40 and 60
- The main treatment for celiac disease is a gluten-free diet
With celiac disease, there are two tests that can be done. The first is a serological test (blood test, basically) that has a 40% predictive value (ability to tell if someone will develop celiac) in the general population and up to 70% accuracy in the at-risk population. The second is a biopsy of the small intestine, which is the main way a celiac diagnoses is confirmed but it is an invasive procedure that can have complications.
The Case for Screening
There are cases of what is known as “silent celiac disease”, where someone has the necessary blood and cellular markers for celiac but doesn’t actually show symptoms but may develop celiac later in life. The conversion rate for silent celiac disease is up to 15%, though this is not an area that has gotten much study.
Enhanced screening, particularly in at-risk populations, has the potential to let people know if they have the markers that could lead to developing celiac disease down the line. This would allow them to pre-emptively reduce the gluten in their diet and take other steps to prevent the full emergence of the disease.
The Case Against Screening
One of the issues with any test is that the more you look for something, the more you will find it. This is not an inherently bad thing, but the problem is that any enhanced screening program runs the risk of false positives and overdiagnosis.
A false positive is when someone is told they have a condition they actually do not and overdiagnosis is when someone is diagnosed with a condition that they do have but does not warrant medical intervention.
Risk vs. Reward
According to the USPSTF, the type of high-risk individuals enhanced screening could cover would end up in one of the following categories:
- Serologically negative for celiac disease
- Serologically positive but the biopsy is negative, meaning there are markers but no true celiac disease
- Serologically positive and also with a positive biopsy, but the patient would have never gone on to develop true symptoms anyway
- Serologically positive and also with a positive biopsy and the patient will end up developing celiac symptoms
The second and third categories are undesirable outcomes since they subject a patient to unnecessary stress, anxiety, and an invasive procedure with possible complications. The third category has the additional problem of causing someone to start taking what are ultimately unnecessary dietary restrictions and the associated burdens that come with it. Gluten free is not always easy.
There is no currently available method to tell the difference between the third and fourth categories and there is not enough reliable information available to know how many people could benefit from enhanced screening approaches. As a result of all of this, the USPSTF has concluded there is insufficient evidence to assess the balance of harms and benefits for celiac disease screening in patients who are otherwise not showing symptoms.
- Some people can test positive for celiac disease and take proactive steps to prevent full symptoms from appearing later in life
- Some people can test positive for celiac disease, take no measures, and be fine
- There is currently no reliable way to tell the difference between the two
- Based on this and other factors, the USPSTF has recommended that there isn’t enough evidence on risks and benefits to justify screening in people without symptoms
- The recommendation is still in its draft stage and is accepting public comment until May 30, 2016. You can make your voice known here.
“Draft Recommendation Statement – Celiac Disease: Screening,” U.S Preventive Services Task Force web site, May 3, 2016; http://www.uspreventiveservicestaskforce.org/Page/Document/draft-recommendation-statement150/celiac-disease-screening#citation9, last accessed May 4, 2016.