Murray, J A

Objectives To assess the incidence of biopsy-verified coeliac disease (CD) in Sweden and examine the incidence of duodenal/jejunal biopsies with normal mucosa over time as a proxy for CD awareness and investigation. Design Nationwide population-based cohort study 1990–2015 based on biopsy reports indicating villous atrophy (VA) or normal mucosa in the duodenum/jejunum. Results We identified 44 771 individuals (63% females) with a biopsy report specifying VA and 412 279 (62% females) with a biopsy report indicating normal mucosa (without a prior biopsy indicating VA). The median age at diagnosis of CD was 28 years. The mean age-standardised incidence rate during the study period was 19.0 per 100 000 person-years (95% CI 17.3 to 20.8). The incidence reached a peak in 1994 for both sexes and a second higher peak in 2002–2003 for females and in 2006 for males. The lifetime risk of developing CD was 1.8% (2.3% in females and 1.4% in males). Prior to 2015, there was a parallel rise in rates for biopsies showing normal duodenal/jejunal mucosa. Conclusions In Sweden, the incidence of CD increased until 2002–2003 in females and until 2006 in males. Since then, the incidence of CD has declined despite increasing duodenal/jejunal biopsies, suggesting that increased awareness and investigation are unlikely to elevate the incidence of the disease in Sweden. Across a lifetime, 1 in 44 females and 1 in 72 males are expected to be diagnosed with CD in Sweden, indicating a relatively high societal burden of disease.

SummaryBackgroundCoeliac disease is a substantially underdiagnosed disorder, with clinical testing currently guided by case finding.AimTo determine the presence of indications for diagnostic testing and frequency of clinical testing in undiagnosed coeliac disease.MethodsThis was a case‐control study of adults without prior diagnosis of coeliac disease. Undiagnosed cases were identified through sequential serology, and unaffected age‐ and gender‐matched controls were selected. Medical records were systematically reviewed for indications for and evidence of clinical testing.ResultsOf 47 557 adults, 408 cases of undiagnosed coeliac disease were identified. 408 serology negative matched controls were selected. Eight‐matched pairs were excluded, leading to 800 included individuals (61% female; median age 44.2 years). The odds of any indication for clinical testing were similar among undiagnosed coeliac disease and controls (odds ratio (OR) 1.18; 95% CI: 0.85‐1.63, P = 0.32). Most individual indications were not associated with serologic status. Exceptions to this include hypothyroidism, which was more likely in cases of undiagnosed coeliac disease, and dyspepsia and chronic diarrhoea, which were less likely. Cases of undiagnosed coeliac disease were more likely to develop osteoporosis (P = 0.005), dermatitis herpetiformis (P = 0.006), chronic fatigue (P = 0.033), thyroiditis (P = 0.003), autoimmune diseases (P = 0.008), and have a family member diagnosed with coeliac disease (P = 0.001).ConclusionThis study strongly suggests that current case finding is not effective in detecting undiagnosed coeliac disease. Individuals with undiagnosed coeliac disease were more likely than controls to develop indications for testing overtime. A more effective method for detection of coeliac disease is needed.

This article is linked to Tye‐Din and Fang et al papers. To view these articles visit https://doi.org/10.1111/apt.14287 and https://doi.org/10.1111/apt.14250.

SummaryBackgroundTissue transglutaminase (tTG) immunoglobulin A (IgA) testing is a sensitive adjunct to the diagnosis of coeliac disease. The threshold for positivity was developed for diagnosis, with negative results reported as below the reference value (<4 U/mL).AimTo investigate if an undetectable (tTG IgA<1.2 U/mL) is more predictive of healing compared to patients with negative but detectable serology (1.2‐3.9 U/mL).MethodsWe performed a retrospective study of 402 treated coeliac disease patients seen at the Mayo Clinic with negative tTG IgA values drawn within 1 month of duodenal biopsy between January 2009 and December 2015. The Corazza‐Villanacci score was used to assess mucosal healing. The presence of gastrointestinal symptoms was also collected. Logistic regression was used to assess the relationship of clinical variables with a normal biopsy.ResultsPatients with undetectable titres more frequently had normal duodenal histology compared to patients with detectable tTG IgA levels (117/240 vs. 53/162; OR=1.96; 1.292, 2.961). Asymptomatic patients more frequently had normal duodenum as compared to symptomatic patients (88/163 vs. 82/239; OR=2.25; CI: 1.494, 3.377). Patients with undetectable serology and on a gluten‐free diet for ≥2 years were more likely to have no villous atrophy compared to patients with detectable serology (148/192 vs. 55/88; OR=2.02; CI: 1.17, 3.49).ConclusionIn subjects recovering from coeliac disease with negative tTG IgA serology, an undetectable titre is associated with normal histology on follow‐up biopsy.