See “Screening for Celiac Disease” by Hill on page 414, “Epidemiology of Coeliac Disease and Comorbidity in Norwegian Children” by Størdal et al on page 467, and “Transglutaminase IgA Antibodies in a Celiac Disease Mass Screening and the Role of HLA-DQ Genotyping and Endomysial Antibodies in Sequential Testing” by Sandström et al on page 472.
For those who enjoy investigating the changing occurrence of diseases and related risk factors, Scandinavian countries are doubtless heaven on earth. Using the data collected by nationwide in- and outpatient registers, researchers from those countries are often able to draw the variable epidemiology of diseases year by year, and possibly to link the observed variations to changes in environmental factors. Ivarsson et al (1) precisely described “strange” epidemics of celiac disease (CD) affecting young Swedish children between 1984 and 1996, and linked this finding to changes in infant feeding practices occurring during the same period of time. Other Swedish authors are meticulously dissecting the risk of CD comorbidities and/or complications by analyzing information retrieved from the Swedish health register (2).
In Norway, the Norwegian Patient Register (NPR) contains individual-level hospital data from 2008 onward. Small-bowel biopsies for establishing the diagnosis of CD are only performed at public hospitals reporting to the NPR. In this issue of the Journal of Pediatric Gastroenterology and Nutrition (JPGN), Størdal et al report on the proportion of Norwegian children ages 0 to 12 years affected with clinically detected CD by retrieving NPR data on all hospital contacts during 2008–2011, in which a diagnosis of CD was registered for patients born between 1999 and 2011. A total of 3006 individuals (58.2% girls) were recorded as having CD among 797,360 children, corresponding to a proportion of 3.8/1000 (95% confidence interval 3.7–3.9/1000). The proportion was slightly higher in females and in the southwest part of the country. Among patients with CD, 7.1% were registered with coexisting conditions: type 1 diabetes mellitus (4.7%), Down syndrome (1.6%), or thyroid disease (1.4%). Authors conclude that the occurrence of clinically detected CD in Norway is high and comparable with that in Sweden. Comorbidity was common, but routine screening of high-risk groups contributed to a limited number of cases (3).
The prevalence of clinically detected CD was probably underestimated in this study because children with CD diagnosed between 1999 and 2007 without a follow-up visit between 2008 and 2011 were not included and children with CD diagnosed without a small intestinal biopsy could have been missed as well. Nevertheless, the reported frequency of clinically detected CD in Norway is one of the highest in the world. In our opinion, this finding is related to high disease awareness, an efficient health system, and adequate financial support given to patients with CD and their families. Incidentally, it is interesting to note that biopsy confirmation of diagnosis is still required in Norway for granting financial support to patients with CD. This rule is now out of date because the 2012 European Society for Pediatric Gastroenterology, Hepatology, and Nutrition CD diagnostic guidelines clearly stated that a definitive diagnosis can sometimes be made even without this investigation (4).
This survey did not include all cases with CD escaping diagnosis because of atypical or absent complaints. Should the overall prevalence of CD in Norway be the same as in other European countries (1%–2%), these data indicate that this condition remains largely undetected in Norway. This is a recurrent leitmotiv of recent epidemiological research on CD: the proportion of clinically detected CD remains <30% in countries with high disease awareness and may be critically low in developing countries (Fig. 1) (1,5–8). In India, only a few thousand cases of CD have been detected out of the estimated 5 to 10 million affected individuals. Unfortunately, as noted by Størdal et al, screening of at-risk groups, for example, patients with other autoimmune disorders or Down syndrome, minimally contributes to the emergence of the “celiac iceberg” (6).
The poor efficiency of the case-finding policies so far adopted for CD detection requires a critical rethinking. CD is basically “one disease,” no matter whether symptoms are present or not. Even patients with apparently silent CD may develop long-term complications (9). Then why are we leaving so many individuals undiagnosed? After all, screening of silent CD is already performed in at-risk groups, such as first-degree relatives of patients with CD. Interestingly, a Swedish survey of patients with screening-detected CD and their families showed that the most common opinion among both adolescents and parents was that future CD mass screening should be “a right for everyone” and should be offered as early as possible (10); however, the strongest arguments against mass CD screening are the high cost of treatment with the gluten-free diet; the lack of a target screening age (CD may develop at any age); uncertainties about the cutoff level of the screening test (as shown by the data of Sandström et al (11)); and uncertainties about the possible health benefits in some cases of screening-detected CD.
For the above reasons, we agree with Hill that the time of mass CD screening has not come yet (12). There is, however, little doubt that a high diagnostic rate of this lifelong condition is an indicator of an efficient health system. Is it, then, possible to improve the current situation? In many countries, children rarely escape a blood checkup before reaching puberty, for example, because of minor surgery and/or recurrent infections. In these circumstances, a serological CD screening test, for example, IgA class anti-transglutaminase and total IgA determination, could well be offered with the informed consent of the parents. After all, burying one's head in the sand is rarely the best solution to a problem.
1. Ivarsson A, Myléus A, Norström F, et al. Prevalence of childhood celiac disease and changes in infant feeding. Pediatrics
2. Ludvigsson JF, Montgomery SM, Ekbom A, et al. Small-intestinal histopathology and mortality risk in celiac disease. JAMA
3. Størdal K, Bakken IJ, Surén P, et al. Epidemiology of coeliac disease and comorbidity in Norwegian children. J Pediatr Gastroenterol Nutr
4. Husby S, Koletzko S, Korponay-Szabó IR, et al. European Society for Pediatric Gastroenterology, Hepatology, and Nutrition guidelines for the diagnosis of coeliac disease. J Pediatr Gastroenterol Nutr
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6. Nenna R, Tiberti C, Petrarca L, et al. The celiac iceberg: characterization of the disease in primary schoolchildren. J Pediatr Gastroenterol Nutr
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8. Makharia GK, Verma AK, Amarchand R, et al. Prevalence of celiac disease in the northern part of India: a community based study. J Gastroenterol Hepatol
9. Fasano A, Catassi C. Clinical practice. Celiac disease. N Engl J Med
10. Rosén A, Emmelin M, Carlsson A, et al. Mass screening for celiac disease from the perspective of newly diagnosed adolescents and their parents: a mixed-method study. BMC Public Health
11. Sandstrom O, Rosen A, Lagerqvist C, et al. Transglutaminase IgA antibodies in celiac disease mass screening and the role of HLA-DQ genotyping and endomysial antibodies in sequential testing. J Pediatr Gastroenterol Nutr
2013; in press.
12. Hill ID. Screening for celiac disease. J Pediatr Gastroenterol Nutr