Symptoms and biomarkers associated with undiagnosed celiac seropositivity

Population-based screening for celiac disease reveals that the majority of patients are undiagnosed and improve on a gluten-free diet

The impact of a gluten-free diet (GFD) on screen-detected celiac disease (CD) is currently ambiguous. We aimed to identify the population-based prevalence of undiagnosed adult CD and examine the impact of a GFD on screen-detected CD. In total, 12,981 adults participated in a population-based health study in Tromsø, Norway. Participants with increased levels of anti-tissue transglutaminase-2 IgA or anti-deamidated gliadin peptide IgG were invited to undergo gastroduodenoscopy with both histological and immunohistochemical examination of small-bowel biopsies. The prevalence of previously diagnosed CD was 0.37%. Additionally, the prevalence of previously undiagnosed CD was 1.10%. Thus, 1.47% of the population had CD, of whom 75% were previously undiagnosed. A GFD resulted in significant improvements in overall gastrointestinal symptoms, diarrhea, and health-related quality of life, with reduced abdominal discomfort (76%) and improved levels of energy (58%). The large majority of patients with adult CD were undiagnosed and benefited from a GFD with reduced gastrointestinal symptoms and improved health-related quality of life. In clinical practice, there should be a low threshold for CD testing even in the absence of abdominal complaints because most adult patients appear to consider their symptoms a part of their normal state and therefore remain untested and undiagnosed.Trial registration: Clinical Trials. Gov Identifier: NCT01695681.

Biochemical abnormalities among patients referred for celiac disease antibody blood testing in a primary health care setting

To investigate possible biochemical abnormalities associated with celiac disease (CD) antibody positivity in a primary health care setting and thereby identify predictors that could potentially reduce diagnostic delay and underdiagnosis of CD. This observational cohort study included measurements of CD antibodies in the Copenhagen Primary Care Laboratory (CopLab) database from 2000 to 2015; CD antibody positivity was defined as tissue transglutaminase antibody IgA or IgG ≥ 7 kU/L and/or deamidated gliadin peptide antibody IgG ≥ 10 kU/L. Individuals with a prior diagnosis of CD were excluded. We examined differences between individuals with positive and negative CD antibody tests regarding the results of biochemical tests performed six months before and one month after the date of the CD antibody test. We identified 76,265 measurements of CD antibodies during 2000–2015, and 57,061 individuals met the inclusion criteria (706 antibody-positive and 56,355 antibody-negative). We found lower ferritin, hemoglobin, cobalamin and folic acid levels and higher levels of transferrin, ALAT (alanine transaminase), and alkaline phosphate among individuals with a positive CD antibody test. Furthermore, we illustrated more measurements below the sex-specific reference intervals for hemoglobin, mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), ferritin, cobalamin and folic acid among individuals with a positive CD antibody test. This study identified several biochemical abnormalities associated with CD antibody positivity among individuals referred to CD antibody testing. The pattern of abnormalities suggested that micronutrient deficiencies were prevalent among CD antibody-positive individuals, confirming malabsorption as a sign of CD. These findings illustrate the possibility of reducing diagnostic delay and underdiagnosis of CD.

Presence of high-risk HLA genotype is the most important individual risk factor for coeliac disease among at-risk relatives

BACKGROUND

Family screening has been advocated as a means to reduce the major underdiagnosis of coeliac disease. However, the precise risk of the disease in relatives and the impact of patient- and relative-related individual factors remain obscure.

AIMS

To investigate the individual risk of coeliac disease among patients' relatives.

METHODS

Altogether 2943 relatives of 624 index patients were assessed for the presence of previous coeliac disease diagnosis, or were screened for the disease. Coeliac disease-associated human leucocyte antigen (HLA) genotype was determined from all participants. The association between individual factors and new screening positivity was assessed by logistic regression.

RESULTS

There were 229 previously diagnosed non-index relatives with coeliac disease and 2714 non-affected (2067 first-degree, 647 more distant) relatives. Of these 2714 relatives, 129 (4.8%) were screening-positive (first-degree 5.1%, second-degree 3.6%, more distant 3.5%). The combined prevalence of the previously diagnosed and now detected cases in relatives was 12.2% (6.3% clinically detected, 5.9% screen-detected). In univariate analysis, age <18 years at diagnosis (odds ratio 1.60, 95% CI 1.04-2.45) in index, and age 41-60 years (1.73, 1.10-2.73), being a sibling (1.65, 1.06-2.59) and having the high-risk genotype (3.22, 2.01-5.15 DQ2.5/2.5 or DQ2.5/2.2 vs other risk alleles) in relatives were associated with screening positivity. Only high-risk HLA remained significant (2.94, 1.80-4.78) in multivariable analysis.

CONCLUSIONS

Unrecognised coeliac disease was common among at-risk relatives even in a country with an active case-finding policy, and also in relatives more distant than first-degree. The presence of a high-risk genotype was the most important predictor for screening positivity. ClinicalTrials.gov identifier NCT03136731.