Consequences of testing for celiac disease

Epidemiology, Presentation, and Diagnosis of Celiac Disease

The incidence of celiac disease is increasing, partly because of improved recognition of, and testing for, the disease. The rise in incidence is also due to a real increase of this immune-based disorder, independent of disease detection. The reasons for this true rise in recent decades are unknown but may be related to environmental factors that may promote loss of tolerance to dietary gluten. Strategies to reduce the development of celiac disease have not been proven successful in randomized trials, but the quantity of early-life gluten exposure has been a major focus of prevention efforts. The criteria for the diagnosis of celiac disease are changing, but in adults, diagnosis still depends on the presence of duodenal villous atrophy while the patient is on a gluten-containing diet, along with findings from serology analysis. Although guidelines in the United States continue to mandate a biopsy at all ages, some children receive a diagnosis of celiac disease without a biopsy. If proven accurate and scalable, assays that detect gluten-HLA tetramer complexes might be used in diagnosis to be made in the context of a gluten-free diet without intestinal biopsy.

Case-finding for coeliac disease in secondary care: a prospective multicentre UK study

BACKGROUND

Coeliac disease affects 1% of the population. Despite this high prevalence, the majority of individuals are undetected. Many patients present with subtle symptoms which may also contribute to under diagnosis. Our aim was to determine the relative importance of different presenting characteristics.

METHODS

Unselected gastroenterology patients referred to 4 hospitals in South Yorkshire were investigated for coeliac disease. Diagnosis was based on positive serology and the presence of villous atrophy. Odds ratios were calculated for presenting characteristics and multivariate analysis performed to identify independent risk factors.

RESULTS

4089 patients were assessed (41.5% male, mean age 55.8 ± 18.2 years); 129 had coeliac disease (3.2%, 95% CI 2.6-3.7%). Multivariate analysis of patients referred to secondary care showed family history of coeliac disease (OR 1.26, p < 0.0001), anaemia (OR 1.03, p < 0.0001) and osteoporosis (OR 1.1, p = 0.006) were independent risk factors for diagnosis of coeliac disease. When compared to population controls, diarrhoea (OR 4.1, p < 0.0001), weight loss (OR 2.7, p = 0.02), irritable bowel syndrome symptoms (OR 3.2, p = 0.005) thyroid disease (OR 4.4, p = 0.01) and diabetes (OR 3.0, p = 0.05) were also associated with increased coeliac disease risk.

CONCLUSIONS

Coeliac disease accounts for 1 in 31 referrals in secondary care to unselected gastroenterology clinics. A low threshold for coeliac disease testing should be adopted.

ACG clinical guidelines: diagnosis and management of celiac disease

This guideline presents recommendations for the diagnosis and management of patients with celiac disease. Celiac disease is an immune-based reaction to dietary gluten (storage protein for wheat, barley, and rye) that primarily affects the small intestine in those with a genetic predisposition and resolves with exclusion of gluten from the diet. There has been a substantial increase in the prevalence of celiac disease over the last 50 years and an increase in the rate of diagnosis in the last 10 years. Celiac disease can present with many symptoms, including typical gastrointestinal symptoms (e.g., diarrhea, steatorrhea, weight loss, bloating, flatulence, abdominal pain) and also non-gastrointestinal abnormalities (e.g., abnormal liver function tests, iron deficiency anemia, bone disease, skin disorders, and many other protean manifestations). Indeed, many individuals with celiac disease may have no symptoms at all. Celiac disease is usually detected by serologic testing of celiac-specific antibodies. The diagnosis is confirmed by duodenal mucosal biopsies. Both serology and biopsy should be performed on a gluten-containing diet. The treatment for celiac disease is primarily a gluten-free diet (GFD), which requires significant patient education, motivation, and follow-up. Non-responsive celiac disease occurs frequently, particularly in those diagnosed in adulthood. Persistent or recurring symptoms should lead to a review of the patient's original diagnosis to exclude alternative diagnoses, a review of the GFD to ensure there is no obvious gluten contamination, and serologic testing to confirm adherence with the GFD. In addition, evaluation for disorders associated with celiac disease that could cause persistent symptoms, such as microscopic colitis, pancreatic exocrine dysfunction, and complications of celiac disease, such as enteropathy-associated lymphoma or refractory celiac disease, should be entertained. Newer therapeutic modalities are being studied in clinical trials, but are not yet approved for use in practice. Given the incomplete response of many patients to a GFD-free diet as well as the difficulty of adherence to the GFD over the long term, development of new effective therapies for symptom control and reversal of inflammation and organ damage are needed. The prevalence of celiac disease is increasing worldwide and many patients with celiac disease remain undiagnosed, highlighting the need for improved strategies in the future for the optimal detection of patients.

Update on celiac disease - etiology, differential diagnosis, drug targets, and management advances

Celiac disease (CD) is an immune-mediated enteropathy triggered by exposure to wheat gluten and similar proteins found in rye and barley that affects genetically susceptible persons. This immune-mediated enteropathy is characterized by villous atrophy, intraepithelial lymphocytosis, and crypt hyperplasia. Once thought a disease that largely presented with malnourished children, the wide spectrum of disease activity is now better recognized and this has resulted in a shift in the presenting symptoms of most patients with CD. New advances in testing, both serologic and endoscopic, have dramatically increased the detection and diagnosis of CD. While the gluten-free diet is still the only treatment for CD, recent investigations have explored alternative approaches, including the use of altered nonimmunogenic wheat variants, enzymatic degradation of gluten, tissue transglutaminase inhibitors, induction of tolerance, and peptides to restore integrity to intestinal tight junctions.

[Serological diagnosis of celiac disease]

Screening studies using high-sensitivity and specificity markers indicate a prevalence of celiac disease of up to 1% in European and North-American populations. Celiac disease is a frequent condition that has become an important public health issue. Yet the majority of cases remain undiagnosed due to the polymorphism of its clinical manifestations. The new insight in the pathogenesis of celiac disease has lead to the development of new diagnostic tools. Early screening of symptomatic patients and pre-identified at-risk groups significantly improves the quality of life while reducing morbidity and mortality. However, prophylactic benefits of early diagnosis by assessing the general population have not been shown in any study. French and Northern American scientific societies have introduced serological testing in their newly revised strategies to diagnose celiac disease. Older markers judged insufficiently accurate like anti-gliadin and anti-reticulin antibodies have recently been withdrawn from the list of reimbursed medical expenses in France. Anti-endomysium and tissue transglutaminase IgA antibodies have proven to be at this day the most sensitive and specific markers for the diagnosis and follow-up of patients on gluten-free diet, at the exception of IgA-deficient patients. Assays testing for IgG antibodies are recommended upon IgA-deficiency. Although very accurate, a better standardisation of current assays may enable serological testing to replace in a near future histological confirmation brought by small bowel biopsies which remains today the gold standard test to diagnose celiac disease. Indeed, serological testing represents and attractive alternative as it is less invasive, less expansive, laboursaving and more objective in interpretation.

Celiac disease: an underappreciated issue in women&#x2019;s health

Celiac disease (CD) is an immune-mediated enteropathy that is secondary to gluten ingestion and classically associated with gastrointestinal symptoms. Diagnosis is based on serology and confirmatory duodenal biopsy, and the only treatment is lifelong avoidance of gluten. CD has been increasingly recognized to encompass a wide variety of manifestations that are relevant to women&#x2019;s health, including infertility, adverse pregnancy outcomes and reduced BMD. Currently, CD is underdiagnosed, largely owing to lack of recognition of the diverse manifestations by general practitioners. Increased awareness of the clinical spectrum of this disease, as well as targeted testing in at-risk individuals (including women with unexplained infertility and previous adverse pregnancy outcomes, and in specific populations with reduced BMD) is greatly needed in order to improve rates of diagnosis.

Impact of mass screening for gluten-sensitive enteropathy in working population

AIM: To assess: (1) frequency and clinical relevance of gluten sensitive enteropathy (GSE) detected by serology in a mass screening program; (2) sensitivity of antitransglutaminase (tTGA) and antiendomysium antibodies (EmA); and (3) adherence to gluten-free diet (GFD) and follow-up.

METHODS: One thousand, eight hundred and sixty-eight subjects recruited from an occupational health department underwent analysis for tTGA and EmA and, if positive, duodenal biopsy, DQ2/DQ8 genotyping, clinical feature recording, blood tests, and densitometry were performed. Since > 98% of individuals had tTGA < 2 U/mL, this value was established as the cut-off limit of normality and was considered positive when confirmed twice in the same sample. Adherence to a GFD and follow up were registered.

RESULTS: Twenty-six (1.39%) subjects had positive tTGA and/or EmA, and 21 underwent biopsy: six Marsh III (one IIIa, four IIIb, one IIIc), nine Marsh I and six Marsh 0 (frequency of GSE 1:125). The sensitivity of EmA for GSE was 46.6% (11.1% for Marsh I, 100% for Marsh III), while for tTGA, it was 93.3% (88.8% for Marsh I, 100% for Marsh III). All 15 patients with abnormal histology had clinical features related to GSE. Marsh I and III subjects had more abdominal pain than Marsh 0 (P = 0.029), and a similar trend was observed for distension and diarrhea. No differences in the percentage of osteopenia were found between Marsh I and III (P = 0.608). Adherence to follow-up was 69.2%. Of 15 GSE patients, 66.7% followed a GFD with 80% responding to it.

CONCLUSION: GSE in the general population is frequent and clinically relevant, irrespective of histological severity. tTGA is the marker of choice. Mass screening programs are useful in identifying patients who can benefit from GFD and follow-up.

Bone mineral content deficits of the spine and whole body in children at time of diagnosis with celiac disease

BACKGROUND

The aim of this study was to determine whether children with celiac disease (CD) have deficits in spine (SP) and whole body (WB) bone mineral content (BMC) at time of diagnosis, and whether the deficits are related to altered growth and body composition. The secondary aim was to examine the effect of histological grade on BMC.

PATIENTS AND METHODS

A retrospective study of children who had undergone a dual energy x-ray absorptiometry scan at the time of diagnosis with CD between October 1, 2003, and June 15, 2006, were compared with a healthy reference sample of similar age and race from the same geographic region in the United States. SP and WB BMC were expressed as sex-specific z scores relative to age and relative to height to assess differences in the CD group versus controls. Pearson correlation, t tests, and analysis of variance were performed to determine predictors of BMC.

RESULTS

Forty-four children (mean age 10.6 +/- 3.4 years; 77% female, 96% white) with CD were evaluated and compared with 338 healthy children. Children with CD were shorter than children of similar age and sex. SP and WB BMC for age z scores were significantly lower in the CD group compared with controls. When adjusted for height, significant deficits in WB BMC persisted in patients with CD. Low SP and WB BMC correlated with advanced histological grade in CD. Low body mass index correlated with low WB BMC in CD.

CONCLUSIONS

Newly diagnosed children with CD may benefit from screening for low bone mineral content. Patients with low body mass index and those with advanced histological damage (Marsh grade IIIc) particularly may be at risk for osteopenia.

Systematic review: The evidence base for long-term management of coeliac disease

BACKGROUND

While gluten-free diet is an effective treatment for coeliac disease, the need for and goals of long-term management of patients are poorly defined.

AIM

To review systematically the complications and associations of coeliac disease, to identify potential risk factors, to define ways of assessing risk factors and to provide a strategy for management.

METHODS

Review of medical literature from 1975.

RESULTS

There is an increasing list of potential complications and/or conditions associated with coeliac disease, in particular, autoimmune disease, malignancy and bone disease. Risk factors that may predict or influence long-term outcomes include genetic susceptibility, environmental factors predominantly gluten ingestion, persistent small intestinal inflammation/injury and nutritional deficiencies. Genotyping of patients is yet to have an established clinical role in long-term management. Assessment of adherence to the gluten-free diet largely relies upon skilled dietary history, but the ultimate test is duodenal histopathology, which is the only currently established means of assessing healing. Symptoms, serology or other non-invasive means are poor predictors of healing and the likelihood of complications.

CONCLUSION

Evidence (albeit limited) that adherence to a gluten-free diet and mucosal healing prevent and/or ameliorate complications indicates that a planned long-term strategy for follow-up is essential.

Review: Gluten and glucose management in type 1 diabetes

The prevalence of coeliac disease in patients with type 1 diabetes is significantly increased when compared to the general population. Ancompared to the general population. An explanation of the association between the development of both diseases may be explained by the inheritance of common major histocompatibility complex immunogenotypes that influence the presentation of auto antigens to CD4+ T-Cells. The subsequent loss of self tolerance results in destruction of the small bowel villi and pancreatic β-cells in coeliac and type 1 diabetes respectively. The diagnosis of coeliac disease in type 1 diabetic patients occurs commonly as a result of screening of individuals with subclinical coeliac disease. Recent studies have demonstrated the clinical benefit of treating subclinical coeliac disease in children with improvement in growth parameters, resolution of anaemia and fewer hypoglycaemic episodes. There is no current clinical evidence supporting routine screening of adult type 1 diabetic patients for coeliac disease. After the diagnosis of coeliac disease, type 1 diabetic patients should be commenced on a gluten-free diet with care co-ordinated between a dietician, gastroenterologist anddiabetologist.

Detection of Celiac disease in primary care: a multicenter case-finding study in North America

BACKGROUND

Celiac disease (CD) is one of the most common lifelong disorders in western countries. However, most cases remain currently undiagnosed in North America, mostly due to poor awareness of CD by primary care physicians.

OBJECTIVES

The aims of this study were (a) to determine whether an active case-finding strategy in primary care could increase the frequency of CD diagnosis and (b) to determine the most common clinical presentations of the condition.

METHODS

This was a multicenter, prospective study involving adult subjects during the years 2002-2004, attending one of the participating practices. All individuals with symptoms or conditions known to be associated with CD were tested for immunoglobulin A anti-transglutaminase (tTG) antibodies, and those with elevated anti-tTG were subsequently tested for IgA antiendomysial antibodies (EMA). All subjects who were positive for EMA were advised to undergo an intestinal biopsy and HLA typing.

RESULTS

The study group included 737 women and 239 men, with a median age of 54.3 yr. A positive anti-tTG test was found in 30 out of 976 investigated subjects (3.07%, 95% CI 1.98-4.16). CD was diagnosed in 22 patients (18 women, 4 men). The most frequent reasons for CD screening in these 22 cases were bloating (12/22), thyroid disease (11/22), irritable bowel syndrome (7/22), unexplained chronic diarrhea (6/22), chronic fatigue (5/22), and constipation (4/22). The prevalence of CD in the serologically screened sample was 2.25% (95% CI 1.32-3.18). The diagnostic rate was low at baseline (0.27 cases per thousand visits, 95% CI 0.13-0.41) and significantly increased to 11.6 per thousand visits (95% CI 6.8-16.4, P < 0.001) following active screening implementation.

CONCLUSIONS

This study demonstrates that an active case-finding strategy in the primary care setting is an effective means to improve the diagnostic rate of CD in North America.

The Canadian Celiac Health Survey

The purpose of this study was to characterize the diagnostic process, frequency of associated disorders, family history, and impact of a gluten-free diet in individuals with celiac disease. All members of the Canadian Celiac Association (n=5240) were surveyed with a questionnaire. Respondents included 2681 adults with biopsy-proven celiac disease. The mean age was 56 years. Most common presenting symptoms included abdominal pain (83%), diarrhea (76%), and weight loss (69%). The mean delay in diagnosis was 11.7 years. Diagnoses made prior to celiac disease included anemia (40%), stress (31%), and irritable bowel syndrome (29%). Osteoporosis was common. Prior to diagnosis, 27% of respondents consulted three or more doctors about their symptoms. Delays in diagnosis of celiac disease remain a problem. Associated medical conditions occur frequently. More accurate food labeling is needed. Improved awareness of celiac disease and greater use of serological screening tests may result in earlier diagnosis and reduced risk of associated conditions.

Skeletal and muscular status in juveniles with GFD treated clinical and newly diagnosed atypical celiac disease--preliminary data

Undiagnosed and untreated celiac disease (CD) constitutes an increasing skeletal health problem due to its association with low bone density and fractures. Examinations of skeletal status in children using dual-energy X-ray absorptiometry (DXA) are prone to size-related misinterpretation. In contrary, the analysis of muscle-bone relationship seems to limit a possibility of misdiagnosis because skeletal status is evaluated from the functional perspective. The study was aimed to assess skeletal status of children suffering from CD with the use of muscle-bone functional algorithm. The study group comprised 29 celiac patients (13.7yr+/-2.9) on gluten-free diet (GFD), and 24 newly diagnosed atypical celiac patients, including subgroup with normal height (n=14; 12.6yr+/-3.9) and subgroup with short stature (n=10; 12.2yr+/-2.9). Muscular and skeletal status was evaluated by DXA (DPX-L, GE). Anthropometry, total body bone mineral density (TBBMD, g/cm(2)). and total body bone mineral content (TBBMC, g) as well as lean body mass (LBM, g) were evaluated. Muscle-bone interactions were estimated using TBBMC/LBM ratio. Previously established references for healthy controls were used for the calculation of Z-scores (age-matched) and SD-scores (height-matched). GFD treated celiacs and atypical celiacs with normal body height had TBBMD, TBBMC, LBM, and TBBMC/LBM ratio Z-scores and SD-scores within normal range for healthy controls. In contrary, atypical celiacs with short stature had significantly lower Z-scores for TBBMD (-2.3+/-0.4), TBBMC (-2.1+/-0.3), LBM (-1.4+/-0.3). and TBBMC/LBM ratio (-2.3+/-0.6) when compared to respective values observed in GFD treated celiacs (p<0.001, p<0.001, p<0.05, p<0.01) and atypical celiacs with normal height (p<0.01, p<0.01, p<0.05, p<0.01). When body-height matching of DXA data was used to limit the influence of body size, the atypical celiacs with short stature had SD-scores for TBBMD (-1.3+/-0.7), TBBMC (-1.3+/-0.6), and LBM (+0.8+/-0.3) not significantly different from the corresponding SD-scores obtained in the remaining 2 groups. Nevertheless, short stature in atypical celiacs still coincided with significantly lower TBBMC/LBM ratio SD-score of -1.9+/-0.7 when compared to values observed in GFD treated celiacs (+0.04+/-0.2; p<0.05) and atypical celiacs with normal height (-0.4+/-0.2; p<0.05). GFD regime in classic celiacs corresponded with physiological values of DXA assessed indicators of bone and muscle status as well as normal muscle-bone interactions. Untreated atypical celiacs may present a broad spectrum of heterogeneous abnormalities from normal to markedly depressed TBBMC/LBM ratio values pointing on the marked imbalance between TBBMC and LBM.

Population screening for coeliac disease in a low prevalence area in Italy

OBJECTIVE

A screening program was proposed for the village of Carcare (population 5700), located in a region of Italy with an apparently low prevalence of coeliac disease (CD): only 1 patient diagnosed out of 2557 inhabitants. The study group comprised 1002 individuals (568 F, 434 M, age range 13-90 years) recruited from blood donors, secondary school pupils and people referred to the local outpatient facilities for routine blood chemistry.

MATERIAL AND METHODS

Total IgA, IgA anti-tissue transglutaminase (tTG) (ELISA, recombinant human antigen) and IgA antiendomysium (EMA) (IFI, umbilical cord substrate) antibodies were measured in the serum of all participants. All patients with IgA deficiency were investigated for IgG tTG antibodies, and in the case of disagreement between tTG and EMA, they were typed for HLA DQ2-DQ8 haplotypes.

RESULTS

Thirteen subjects were positive and 988 negative for autoantibodies (3/988 had IgA deficiency). One serum sample was positive for tTG antibodies but negative for EMA. Ten out of 13 positive subjects consented to undergo duodenal biopsy, which invariably produced evidence of CD despite the absence of clinical signs/symptoms. A post-diagnostic clinical investigation provided evidence showing mild iron deficiency (4 subjects) and osteoporosis (2 subjects). After counselling, all subjects accepted a gluten-free diet.

CONCLUSIONS

The prevalence of CD in the study group was 1:100 (1.0%; 95% CI: 0.5-1.8%): this indicates that CD is largely underdiagnosed in Carcare. Our results suggest that the low prevalence of CD observed in some regions is likely to be due to underdiagnosis.