Are Doctors Missing 90% of Celiac Disease Cases?-From Celiac.com

by Jefferson Adams of Celiac.com

If a new study by Canadian nutrition researchers is any indication, most cases of celiac disease remain undiagnosed.


Celiac.com 10/20/2017 - Are doctors even getting close to diagnosing the actual number of cases of celiac disease? Or are they missing the vast majority?

Researchers have said for some time that there are far more people with celiac disease than are being diagnosed, and that the vast majority of cases go undiagnosed.

So, just how far are we from the actual number? Well, if a new study by Canadian nutrition researchers is any indication, doctors are very far from diagnosing most cases.

The team studied the blood work of nearly 3,000 people, and their conclusions are stunning. They say that ninety percent of celiac cases go undiagnosed.

How could this be? One reason is that even classic celiac disease symptom, such as abdominal pain, bloating, gas, diarrhea, anemia and weight loss can mimic other conditions. Less classic symptoms such as fatigue, low vitamin C, D and calcium levels can be misleading.

Ahmed El-Sohemy, a professor of nutritional science at the University of Toronto, wanted to see whether celiac disease results in subpar nutrition because of poorer absorption of vitamins and minerals. But to find out, he needed Canadian data on the frequency of undiagnosed celiac disease.

To that end, El-Sohemy and his colleagues checked blood samples from more than 2,800 individuals in Toronto. One group had an average age of 23, and the other 45. Among their findings is likely ~1%, with 87% of cases being undiagnosed. These findings suggest the need for better screening in high genetic risk groups.

Source:
BMJOPEN.com

To Your Health

Dr. Barbara (TM)

Celiacbrain.blogspot.com (TM)

Screening for Celiac Disease: the use of HLA First?

The arguments for a step wise genetic screening for celiac disease made by a group of rheumatologists who wrote the following article are solid. If the risk of getting or having celiac disease is virtually zero in someone without the genetics of HLA DQ 2.5 or HLA DQ8 then the person with a medical problem associated with celiac disease (like an autoimmune disease) without these genetic markers doesn't need a small bowel biopsy. 

As the genetics tests become more economical than celiac blood tests, and are more accurate than celiac blood tests, then it makes sense to start with genetic HLA testing.


Read the full article here from International Journal of Celiac Disease, 2017.

Here is an excerpt: My Bold

3. A Step Wise Serology/Genetic Approach

CD patients negative for any of these HLA alleles are very rare. Therefore, the absence of both HLA-DQ2 and HLA-DQ8 heterodimer makes diagnosis of celiac disease very unlikely (sensitivity >96 %). HLA typing of patients has been included as a useful test to exclude celiac disease in the ESPGHAN guidelines for CD diagnosis. [8, 9] HLA typing confers a high negative predictive value: patients with a negative HLA (i.e. neither DQ2 nor DQ8) will not develop CD; and a suggested strategy to avoid repeated CD screening would be to first perform an HLA test. [10]

Targeting the HLA risk first, rather than tracking positive serology, would be a reasonable step-up approach, probably cost effective and time saving: in the past, HLA typing has been expensive and time-consuming, but new single nucleotide polymorphisms techniques [11] and other combined home-made procedures [12] have recently been reported as very cost-effective and work-time saving for HLA-DQ2 and DQ8 genotyping in CD screening................

In general population, the preferred test to screen for CD is the measurement of IgA TTG [Link here to a critique of the IgA TTG test]along with total serum IgA to avoid false-negative results due to selective IgA deficiency. Positive serology would lead to endoscopic small intestinal biopsies [14]. These serological tests, based on TTG associated to endomysial and deamidated gliadin peptides antibodies are recognized as performant screening tools. [15]

However, in asymptomatic members of a high-risk group, like those presenting RA, it seems reasonable to test first for negative result of HLA-DQ2/DQ8 in order to exclude CD, so that further serologic testing would be unnecessary [16]. Performing HLA genetic typing seems cost effective and could avoid subsequent fiberoscopies and biopsies [17].................recent studies emerging from the South Hemisphere confer solid arguments to such strategies [18] as CD is reported to be strongly associated with HLA-DQ2 in these regions [19].

It is my opinion and the opinion of these authors that the genetic tests for HLA provides a flexible, cost-effective methodology that could be applied to protocols to diagnose celiac disease and to obtain accurate estimates of the prevalence of CD in large cohort studies. The ESPGHAN guidelines for CD diagnosis are worth a look if you are interested in clinical matters.

To Your Health

Dr. Barbara (TM)

CeliacBrain (TM)