What are the sensitivity and specificity of serologic tests for celiac disease? Do sensitivity and specificity vary in different populations?

Prevalence of celiac disease among first-degree relatives of Indian celiac disease patients

BACKGROUND

Celiac disease, once thought to be uncommon in Asia, is now recognized in Asian nations as well. We investigated the prevalence of celiac disease in first-degree relatives of celiac disease patients followed in our centre.

METHODS

First-degree relatives were screened prospectively for celiac disease using questionnaire-based interview and anti-tissue transglutaminase antibody. Serology positive first-degree relatives underwent duodenal biopsies. Diagnosis of celiac disease was made based on positive serology and villous abnormality Marsh grade 2 or higher. Human leucocyte antigen DQ2/-DQ8 was also assessed in 127 first-degree relatives.

RESULTS

434 first-degree relatives of 176 celiac disease patients were prospectively recruited; 282 were symptomatic (64.9%), 58 were positive for serology (13.3%). Seroprevalence was higher in female than in males (19% vs 8.5%; p=0.001) and highest in siblings (16.9%) than parents (13.6%) and children (5.9%) of celiac patients (p=0.055); 87.4% first-degree relatives were human leucocyte antigen-DQ2/-DQ8 positive. Overall prevalence of celiac disease was 10.9% amongst first-degree relatives.

CONCLUSIONS

The prevalence of celiac disease in first-degree relatives of celiac disease patients was 10.9% in our cohort, and 87% had human leucocyte antigen-DQ2 or -DQ8 haplotype. All first-degree relatives of celiac disease patients should be screen for celiac disease even if asymptomatic or with atypical manifestations.

Simultaneous detection of IgA and IgG antibodies against tissue transglutaminase: The preferred pre-biopsy test in childhood celiac disease

OBJECTIVES

IgA antibodies against tissue transglutaminase (anti-TG2) is a reliable marker of celiac disease (CD). However, IgA-deficient patients are not identified and young children may lack IgA anti-TG2. Combined detection of IgA and IgG (IgA/IgG) against deamidated gliadin peptides (DGP) has shown a high diagnostic performance for untreated CD. Here we examined the utility of IgA/IgG anti-TG2, IgA/IgG anti-DGP and IgA/IgG against a mix of TG2 and DGP (anti-TG2/DGP) in finding CD among children.

METHODS

Serum antibodies against TG2, DGP, and TG2/DGP were determined with ELISA in 242 children referred to a paediatric gastroenterologist. Fifty had untreated CD verified by an intestinal biopsy and 192/242 children had other diseases than CD.

RESULTS

Forty-eight untreated CD children had increased IgA/IgG anti-TG2, 47/50 had increased IgA/IgG anti-DGP and 46/50 had increased IgA/IgG anti-TG2/DGP. One control subject had increased IgA/IgG anti-TG2 and IgA/IgG anti-TG2/DGP, whereas 7/192 control subjects had increased IgA/IgG anti-DGP. The IgA/IgG anti-TG2 assay had the best performance with a sensitivity of 96%, a specificity of 99.5% and the area under the ROC-curve was 0.996 (95% CI 0.992-1, p < 0.0001).

CONCLUSIONS

Detection of one antibody is not sufficient when screening for untreated CD among children due to cases of IgA deficiency. The inclusion of DGP antigens in the IgA/IgG combination assays seems to affect the sensitivity and specificity negatively, whereas detection of IgA/IgG anti-TG2 has the potential of finding most untreated CD patients, including those with IgA deficiency.

Appropriate clinical use of human leukocyte antigen typing for coeliac disease: an Australasian perspective

The past decade has seen human leukocyte antigen (HLA) typing emerge as a remarkably popular test for the diagnostic work-up of coeliac disease with high patient acceptance. Although limited in its positive predictive value for coeliac disease, the strong disease association with specific HLA genes imparts exceptional negative predictive value to HLA typing, enabling a negative result to exclude coeliac disease confidently. In response to mounting evidence that the clinical use and interpretation of HLA typing often deviates from best practice, this article outlines an evidence-based approach to guide clinically appropriate use of HLA typing, and establishes a reporting template for pathology providers to improve communication of results.

Using functional near-infrared spectroscopy (fNIRS) to detect the prefrontal cortical responses to deception under different motivations

In this study, functional near-infrared spectroscopy (fNIRS) was adopted to investigate the prefrontal cortical responses to deception under different motivations. By using a feigned memory impairment paradigm, 19 healthy adults were asked to deceive under the two different motivations: to obtain rewards and to avoid punishments. Results indicated that when deceiving for obtaining rewards, there was greater neural activation in the right inferior frontal gyrus (IFG) than the control condition. When deceiving for avoiding punishments, there was greater activation in the right inferior frontal gyrus (IFG) and the left middle frontal gyrus (MFG) than the control condition. In addition, deceiving for avoiding punishments led to greater neural activation in the left MFG than when deceiving for obtaining rewards. Furthermore, the results showed a moderate hit rate in detecting deception under either motivation. These results demonstrated that deception with different motivations led to distinct responses in the prefrontal cortex. fNIRS could provide a useful technique for the detection of deception with strategy of feigning memory impairment under different motivations.

Genomic risk prediction of complex human disease and its clinical application

Recent advances in genome-wide association studies have stimulated interest in the genomic prediction of disease risk, potentially enabling individual-level risk estimates for early intervention and improved diagnostic procedures. Here, we review recent findings and approaches to genomic prediction model construction and performance, then contrast the potential benefits of such models in two complex human diseases, aiding diagnosis in celiac disease and prospective risk prediction for cardiovascular disease. Early indications are that optimal application of genomic risk scores will differ substantially for each disease depending on underlying genetic architecture as well as current clinical and public health practice. As costs decline, genomic profiles become common, and popular understanding of risk and its communication improves, genomic risk will become increasingly useful for the individual and the clinician.

Unrecognized Celiac Disease in Children Presenting for Rheumatology Evaluation

BACKGROUND AND OBJECTIVES

Current clinical guidelines do not consider patients with rheumatic conditions to be at high risk for celiac disease (CD) despite numerous reported associations between the two in adults and children. The objective of this study was to evaluate the prevalence of CD among patients presenting for pediatric rheumatology evaluation.

METHODS

A total of 2125 patients presenting for initial evaluation by the Division of Pediatric Rheumatology at the Hospital for Special Surgery between June 2006 and December 2013 were screened for CD as a part of the standard initial serologic evaluation. The charts of these patients were evaluated retrospectively at the end of this period.

RESULTS

36 patients (30 girls, 6 boys, mean age 9.4 ± 4.3 years, range 2-16 years) received a diagnosis of CD after serologic testing and evaluation by pediatric gastroenterology. Eight additional patients with known diagnoses of CD presented during this time period. The total prevalence of CD over this 6.5-year period was 2.0%. The most common presenting complaints among patients diagnosed with CD were myalgias, arthralgias, and rash. Less frequently, patients reported gastrointestinal complaints including abdominal pain, nausea, and diarrhea. All patients reported improvement or complete resolution of their musculoskeletal symptoms after initiation of a gluten-free diet.

CONCLUSIONS

This study identified 36 new cases of CD among children presenting for rheumatology evaluation, for an overall prevalence rate of 2.0%. The majority of patients who ultimately received a diagnosis of CD presented with extraintestinal manifestations. These results underscore the importance of screening children presenting for rheumatology evaluation for CD.

Development and validation of a biomarker for diarrhea-predominant irritable bowel syndrome in human subjects

Diarrhea-predominant irritable bowel syndrome (IBS) is diagnosed through clinical criteria after excluding “organic” conditions, and can be precipitated by acute gastroenteritis. Cytolethal distending toxin B (CdtB) is produced by bacteria that cause acute gastroenteritis, and a post-infectious animal model demonstrates that host antibodies to CdtB cross-react with vinculin in the host gut, producing an IBS-like phenotype. Therefore, we assessed circulating anti-CdtB and anti-vinculin antibodies as biomarkers for D-IBS in human subjects. Subjects with D-IBS based on Rome criteria (n=2375) were recruited from a large-scale multicenter clinical trial for D-IBS (TARGET 3). Subjects with inflammatory bowel disease (IBD) (n=142), subjects with celiac disease (n=121), and healthy controls (n=43) were obtained for comparison. Subjects with IBD and celiac disease were recruited based on the presence of intestinal complaints and histologic confirmation of chronic inflammatory changes in the colon or small intestine. Subjects with celiac disease were also required to have an elevated tTG and biopsy. All subjects were aged between 18 and 65 years. Plasma levels of anti-CdtB and anti-vinculin antibodies were determined by ELISA, and compared between groups. Anti-CdtB titers were significantly higher in D-IBS subjects compared to IBD, healthy controls and celiac disease (P<0.001). Anti-vinculin titers were also significantly higher in IBS (P<0.001) compared to the other groups. The area-under-the-receiver operating curves (AUCs) were 0.81 and 0.62 for diagnosis of D-IBS against IBD for anti-CdtB and anti-vinculin, respectively. Both tests were less specific in differentiating IBS from celiac disease. Optimization demonstrated that for anti-CdtB (optical density≥2.80) the specificity, sensitivity and likelihood ratio were 91.6%, 43.7 and 5.2, respectively, and for anti-vinculin (OD≥1.68) were 83.8%, 32.6 and 2.0, respectively. These results confirm that anti-CdtB and anti-vinculin antibodies are elevated in D-IBS compared to non-IBS subjects. These biomarkers may be especially helpful in distinguishing D-IBS from IBD in the workup of chronic diarrhea.

Screening for celiac disease in the general population and in high-risk groups

BACKGROUND

Celiac disease (CD) occurs in approximately 1% of the Western population. It is a lifelong disorder that is associated with impaired quality of life (QOL) and an excessive risk of comorbidity and death.

OBJECTIVES

To review the literature on screening for CD in relation to the current World Health Organization (WHO) criteria for mass screening.

METHODS

We performed a PubMed search to identify indexed papers on CD screening with a publication date from 1900 until 1 June 2014. When we deemed an abstract relevant, we read the corresponding paper in detail.

RESULTS

CD fulfills several WHO criteria for mass screening (high prevalence, available treatment and difficult clinical detection), but it has not yet been established that treatment of asymptomatic CD may reduce the excessive risk of severe complications, leading to higher QOL nor that it is cost-effective.

CONCLUSIONS

Current evidence is not sufficient to support mass screening for CD, but active case-finding may be appropriate, as we recognize that most patients with CD will still be missed by this strategy. Although proof of benefit is still lacking, screening for CD may be appropriate in high-risk groups.

Review and practice guidelines for celiac disease in 2014

Celiac disease, or gluten-sensitive enteropathy, is defined as a state of heightened immunologic responsiveness to ingested gluten (from wheat, barley, or rye) in genetically susceptible individuals. Ingestion of the offending proteins leads to inflammation and intestinal mucosal damage, which may result in a spectrum of gastrointestinal symptoms, nutritional abnormalities, and systemic complications ranging from anemia and osteoporosis to secondary autoimmunity and malignancy. The genetic influence in the pathogenesis of celiac disease is indicated by its familial occurrence. Celiac disease does not develop unless a person has alleles that encode for human leukocyte antigen DQ2 or DQ8 proteins. The clinical picture of celiac disease has changed considerably during the past 30 years. Diarrhea, which was the presenting symptom in > 90% of celiac disease patients before 1981, is now the chief complaint in < 40%. In contrast, the increased frequency of atypical celiac disease presentations, including anemia and bone disease, is revealed by the widespread availability of serologic testing. An association between celiac disease and autoimmune disorders, such as type 1 diabetes, autoimmune thyroid disease, and Sjögren's syndrome, has been well documented. The tissue transglutaminase immunoglobulin antibody and the endomysial immunoglobulin antibody are the most sensitive and specific serologic tests, respectively, for identifying individuals who need to undergo an intestinal biopsy. If the suspicion of celiac disease is high, intestinal biopsy should be pursued even if serologic tests are negative. The gold standard for the diagnosis of celiac disease is a small bowel biopsy showing villous atrophy. The treatment for celiac disease is lifelong adherence to a gluten-free diet (GFD). Despite the proven benefits of the GFD, it can be exceedingly difficult to completely avoid gluten-containing foods, and adherence to a GFD is estimated to be only 45% to 80%.

Overview of biomarkers for diagnosis and monitoring of celiac disease

Among the adverse reactions caused by wheat, celiac disease (CD) is the longest studied and best-known pathology. The more recently defined non-celiac gluten sensitivity (NCGS) presents with symptoms which are often indistinguishable from CD. Diagnosis of CD is based on serologic, molecular, and bioptic testing. The IgA anti-transglutaminase (tTG) test is considered highly important, as it shows high sensitivity and specificity and its levels correlate to the degree of intestinal damage. Small bowel biopsy can be avoided in symptomatic patients with IgA anti-tTG levels above 10× the manufacturer's cut-off. Recently, tests of anti-deamidated peptides of gliadin (DGP) have replaced classic anti-native gliadin (AGA) tests. DGP assays have a considerably higher diagnostic accuracy than AGA assays, especially in the IgG class, and can replace anti-tTG tests in patients with selective IgA deficiency. The combination of IgG anti-DGP plus IgA anti-tTG assays show greater sensitivity than a single test, with very high specificity. EMA tests have great diagnostic accuracy but are not recommended by all the latest guidelines because they are observer dependent. Biopsy must still be considered the gold standard for CD diagnosis. HLA-DQ genotyping can be used to screen asymptomatic children and in cases of histology/serology disagreement. About half of NCGS patients are DQ2 positive and have IgG AGA. To diagnose NCGS, first CD and wheat allergy must be excluded; then the wheat dependence of symptoms must be verified by a gluten-free diet and subsequent gluten challenge.

Hepatic hemangioma in celiac patients: data from a large consecutive series

Background and Aims. Hepatic hemangioma (HH) has a widely ranging prevalence. The etiology is unclear; however, associations with autoimmune disorders have been described. We aimed at evaluating the prevalence of HH in celiac disease. Methods. Ninety-seven consecutive patients with celiac disease (18 M, 79 F, median age 41, and range 17-84 years) underwent liver ultrasound between January 2011 and 2012. The findings were compared with those of 1352 nonceliac patients (581 M, 771 F, median age 50, and range 16-94 years), without liver disease or previously detected HH, who underwent US in the same period. Results. Ultrasonographic findings consistent with HH were observed in 14 celiac patients (14.4%), a prevalence significantly higher than in controls (69 cases, 5.1%) (P = 0.0006). Subgroup analysis showed that, among women, the prevalence of HH was 16.4% in the celiac disease group (13/79) compared with 5.9% in controls (46/771) (P = 0.002). In celiac setting, HH had a median diameter of 1.3 cm and presented as a single lesion in 12 cases (86%). Conclusions. Our findings are consistent with a significantly higher prevalence of HH in celiac patients. Although mechanisms underlying this association remain unclear, autoimmune and metabolic processes, as well as alterations of gut-liver axis equilibrium, could play a role.

Serum markers in the clinical management of celiac disease

The advent of highly reliable noninvasive celiac diagnostic tests has transformed the field of celiac disease, from diagnosis, to evaluation of epidemiology, to clinical and translational research. Serologic tests in their modern forms are highly sensitive and specific for diagnosis, allowing for consideration of avoidance of diagnostic intestinal biopsy in some settings. On the other hand, as predictors of intestinal damage and for use in monitoring disease activity, currently available noninvasive tests have been disappointing. Serologic tests, while a measure of disease activity, do not correlate well with histology or symptomatology, and it is unclear if they predict long-term risk. Additionally, while the many clinically available tests have improved accessibility, they can have widely different cutoff levels and overall performance, making the comparison of levels in individual patients over time and across populations quite difficult. In the future, we can expect to see improvement in the currently available serologic tests including tissue transglutaminase and deamidated gliadin peptide with expansion of the dynamic range of the tests, and the celiac care community should push for a standardization of assays that would simplify research and patient care. Additionally, current serologic tests are measures of the adaptive immune response in celiac disease but do not directly measure intestinal inflammation. Promising work on intestinal fatty acid-binding protein and other assays which directly measure intestinal damage may complement traditional serologic tests and further improve our ability to noninvasively diagnose and monitor celiac disease. The coming years hold promise for the continuing evolution of serum-based tests in celiac disease with the possibility of substantial improvement of patient care and clinical research.

Prevalence and clinical features of celiac disease in patients with autoimmune thyroiditis: cross-sectional study

CONTEXT AND OBJECTIVE

Celiac disease is an autoimmune disorder with an average prevalence of 1% in Europe and the United States. Because of strong European ancestry in southern Brazil, this study aimed to evaluate the seroprevalence of celiac disease among autoimmune thyroiditis patients.

DESIGN AND SETTING

Cross-sectional study in a public university hospital.

METHODS

This cross-sectional prevalence study included autoimmune thyroiditis patients who were tested for anti-endomysial and anti-transglutaminase antibodies between August 2010 and July 2011.

RESULTS

Fifty-three patients with autoimmune thyroiditis were included; 92.5% were women, with mean age of 49.0 ± 13.5 years. Five patients (9.3%) were serologically positive for celiac disease: three of them (5.6%) were reactive for anti-endomysial antibodies and two (3.7%) for anti-transglutaminase. None of them exhibited anemia and one presented diarrhea. Endoscopy was performed on two patients: one with normal histology and the other with lymphocytic infiltrate and villous atrophy.

CONCLUSION

The prevalence of celiac disease among patients with autoimmune thyroid disease was 9.3%; one patient complained of diarrhea and none presented anemia. Among at-risk populations, like autoimmune thyroiditis patients, the presence of diarrhea or anemia should not be used as a criterion for indicating celiac disease investigation. This must be done for all autoimmune thyroiditis patients because of its high prevalence.

Duodenal bulb histological analysis should be standard of care when evaluating celiac disease in children

We confirmed the added value provided by sampling D1 in the diagnosis of CD in comparison to the diagnosis yield when only the more distal duodenum (D2, D3, and/or D4) was sampled. The severity of CD, as assessed by the Marsh-Oberhuber classification, did not increase distally; on the contrary, in 39/60 (65%) of the cohort, the features of CD were either more severe or only present in D1.

Clinical utility of celiac disease-associated HLA testing

BACKGROUND

Negative predictive value (NPV) of celiac disease (CD)-related human leukocyte antigens (HLA) DQ2 and DQ8 approaches 100 % in individual patients. However, studies evaluating its exclusionary utility in patient groups are lacking.

AIM

We aim to assess the performance of HLA testing when applied to patient groups with varying characteristics and propose evidence-based recommendations for its clinical use.

METHODS

Demographic and clinical information was recorded in patients undergoing HLA testing. Using predetermined criteria, patients were classified as CD, non-CD, or indeterminate. Diagnostic yield of HLA testing was defined as the percentage of patients in whom CD could be excluded based on negative HLA test.

RESULTS

Two hundred and fifty-six patients underwent testing for CD-related HLA DQ2 and DQ8. 102 (100 non-CD, 2 CD) patients tested HLA negative for a 98 % NPV and 39 % diagnostic yield. Diagnostic yield was highest (60 %) in patients with intraepithelial lymphocytosis plus normal IgA tissue transglutaminase antibody (IgA-tTG) and lowest in patients with positive IgA-tTG plus villous atrophy (0 %). CD was diagnosed in two HLA-negative patients, who carried half of DQ2.5 trans genotype.

CONCLUSIONS

Diagnostic yield of CD-related HLA testing varies widely depending on clinical indication. HLA testing is a practical and valuable test for most patients in whom initial evaluation for CD is inconclusive. A negative HLA result usually obviates the need for further celiac testing including endoscopy and gluten challenge. Rarely, in patients reported as HLA negative, half of HLA DQ2.5 (cis or trans) is sufficient for development of CD.

Microbial transglutaminase treatment in pasta-production does not affect the immunoreactivity of gliadin with celiac disease patients' sera

The effect of microbial transglutaminase (MTG)-treatment of pasta-dough on the immunoreactivity with celiac disease patient's sera has been investigated. Modification by MTG has been proven by determination of the MTG reaction product ε-(γ-glutamyl)lysine (3.63 μmol/g protein), which was not detectable in non-MTG-treated pasta. Antigenicity has been analyzed by immunoblotting and ELISA using gliadin-extracts from pasta and MTG-treated pasta. Immunoblotting showed that the antibody-population (antigliadin antibodies and antideamidated gliadin antibodies) of the sera is specific for every individual patient. Immunoblotting and ELISA showed that there is no difference in immunoreactivity of gliadin extracted from pasta and MTG-pasta. Recognition pattern and intensity in Western blot as well as antibody titer has also been identical even for sera with a high antideamidated gliadin antibody titer. These results indicate no difference between pasta-gliadin and MTG-pasta-gliadin and especially no increased deamidation in pasta-gliadin by MTG-treatment.

The involvement of the HLA-DQB1 alleles in the risk and the severity of Iranian coeliac disease patients

Coeliac disease (CD) is a highly prevalent autoimmune disorder that is triggered by the ingestion of wheat gluten and related proteins in genetically susceptible individuals. The CD is associated with human leucocyte antigen (HLA) genes particularly with HLA-DQ alleles encoding HLA-DQ2 and DQ8 proteins. To define risk and severity alleles for CD, a total of 120 definite CD patients and 100 healthy controls were genotyped for HLA-DQB1 gene. HLA-DQB1 genotyping was performed in all patients and controls using PCR-SSP technique, and to evaluate the clinical relevance of testing for HLA-DQB1 and determining absolute risk of disease, prevalence-corrected positive predictive value and prevalence-corrected negative predictive value (PcPPV and PcNPV) were calculated. Our results for a first time show that DQB1*02:00 and DQB1*03:02 alleles and DQB1*02:01/03:02 genotype very significantly associated with increased risk of patients with CD, and DQB1*03:01,4 allele provides protection against CD in Iranian patients. Furthermore, the PcPPV for DQB*02:01 and 03:02 alleles in CD were 0.014 and 0.012, respectively, and the highest absolute risk presented by DQB*0201/0302 genotype (PcPPV = 0.079) and 98% of patients with CD carried DQB1*02:01/x or DQB1*03:02/x genotype. The results also clearly demonstrated that the DQB1*02:01 allele significantly associated with severity of CD, while DQB1*03:02 allele associated with mild form of CD. These results suggest that clinically suspected individuals for CD and first-degree relatives of patients with CD to be screened for HLA-DQB*0201 and DQB*0302 alleles for possible early diagnosis and treatments.

Utility of testing patients, on presentation, for serologic features of celiac disease

BACKGROUND & AIMS

Celiac disease shares features of other disorders. It can be diagnosed conclusively only based on duodenal histology analysis, which is not practical for screening purposes. Serologic analysis might be used to identify candidates for biopsy analysis. We aimed to develop a simple diagnostic approach that all clinicians could follow to increase the percentage of patients accurately diagnosed with celiac disease at initial presentation.

METHODS

We performed a retrospective analysis of data from 752 patients (88 with celiac disease, none were IgA deficient) who attended a UK district general hospital from January 2007 through December 2008 and underwent biopsy analysis and serologic tests to measure endomyseal antibodies and IgA antibodies against tissue transglutaminase (tTG). Patients avoiding gluten in their diet were excluded. Patients were assigned to 1 of 4 groups: high-risk (based on presence of anemia, chronic diarrhea, unintentional weight loss, or dermatitis herpetiformis), low-risk (based on such factors as dyspepsia, abnormal liver function, ataxia, or chronic cough), nutrient deficiency (based on levels of iron, vitamins B12 and D, or folate), or screening (because they had type 1 diabetes or a family history of celiac disease). Patients with celiac disease were identified using the modified Marsh criteria (grades 1-3) for interpreting duodenal histology. We compared clinical category, serology profiles, and biopsy results between patients with and without celiac disease.

RESULTS

Celiac disease was diagnosed in 64 of 565 patients in the high-risk group (11%), 14 of 156 patients in the low-risk group (9%; P = .47 compared with high-risk group), 7 of 28 patients in the nutrient-deficiency group, and 3 of 3 patients in the screening group. Among 71 patients who tested positive for both antibodies (tTG and endomyseal antibodies), the positive predictive value for celiac disease was 97%; a negative test result for tTG had a negative predictive value of 98%. Among 708 patients with normal-looking biopsy samples, only 62 had celiac disease (9%). Among 44 patients with abnormal biopsy samples, 26 had celiac disease (59%).

CONCLUSIONS

Based on a retrospective analysis, patients with and without celiac disease cannot be distinguished based on clinical features. Patients who present with symptoms of celiac disease should be tested for tTG, to identify candidates for duodenal biopsy analysis.

Accurate and robust genomic prediction of celiac disease using statistical learning

Practical application of genomic-based risk stratification to clinical diagnosis is appealing yet performance varies widely depending on the disease and genomic risk score (GRS) method. Celiac disease (CD), a common immune-mediated illness, is strongly genetically determined and requires specific HLA haplotypes. HLA testing can exclude diagnosis but has low specificity, providing little information suitable for clinical risk stratification. Using six European cohorts, we provide a proof-of-concept that statistical learning approaches which simultaneously model all SNPs can generate robust and highly accurate predictive models of CD based on genome-wide SNP profiles. The high predictive capacity replicated both in cross-validation within each cohort (AUC of 0.87–0.89) and in independent replication across cohorts (AUC of 0.86–0.9), despite differences in ethnicity. The models explained 30–35% of disease variance and up to ∼43% of heritability. The GRS's utility was assessed in different clinically relevant settings. Comparable to HLA typing, the GRS can be used to identify individuals without CD with ≥99.6% negative predictive value however, unlike HLA typing, fine-scale stratification of individuals into categories of higher-risk for CD can identify those that would benefit from more invasive and costly definitive testing. The GRS is flexible and its performance can be adapted to the clinical situation by adjusting the threshold cut-off. Despite explaining a minority of disease heritability, our findings indicate a genomic risk score provides clinically relevant information to improve upon current diagnostic pathways for CD and support further studies evaluating the clinical utility of this approach in CD and other complex diseases.

Celiac disease (CD) is a common immune-mediated illness, affecting approximately 1% of the population in Western countries but the diagnostic process remains sub-optimal. The development of CD is strongly dependent on specific human leukocyte antigen (HLA) genes, and HLA testing to identify CD susceptibility is now commonly undertaken in clinical practice. The clinical utility of HLA typing is to exclude CD when the CD susceptibility HLA types are absent, but notably, most people who possess HLA types imparting susceptibility for CD never develop CD. Therefore, while genetic testing in CD can overcome several limitations of the current diagnostic tools, the utility of HLA typing to identify those individuals at increased-risk of CD is limited. Using large datasets assaying single nucleotide polymorphisms (SNPs), we have developed genomic risk scores (GRS) based on multiple SNPs that can more accurately predict CD risk across several populations in “real world” clinical settings. The GRS can generate predictions that optimize CD risk stratification and diagnosis, potentially reducing the number of unnecessary follow-up investigations. The medical and economic impact of improving CD diagnosis is likely to be significant, and our findings support further studies into the role of personalized GRS's for other strongly heritable human diseases.

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.

PREVALENCE OF CELIAC DISEASE IN CHILDREN WITH EPILEPSY

ContextNeurological symptoms have been well-documented in patients with celiac disease, nevertheless, the presumption of a greater prevalence of epilepsy in celiac patients remains controversial.ObjectivesTo determine the frequency of celiac disease in children and adolescents with idiopathic or cryptogenic epilepsy.MethodsA cross-sectional study. One hundred pediatric patients with non-symptomatic epilepsy were followed-up at two public pediatric neurology clinics in Salvador, Bahia, Brazil. Screening for celiac disease was performed by serial measurements of IgA anti-transglutaminase and IgA anti-endomysium antibodies, followed by bowel biopsy in positive cases. HLA DQ02 and DQ08 were investigated in seropositive individuals, assessing the type of seizures, the number of antiepileptic drugs used and the presence gastrointestinal symptoms.ResultsThree (3.0%) patients tested anti-tTG-positive, two with normal duodenal mucosa (Marsh 0) and one with intraepithelial infiltrate (Marsh I). No villous atrophy of the duodenal mucosa (Marsh III) celiac disease was found. Two patients tested positive for HLA DQ02; none were DQ08 positive.ConclusionThe present study failed to prove the association between celiac disease and epilepsy.

Symptom positivity is essential for omitting biopsy in children with suspected celiac disease according to the new ESPGHAN guidelines

The aim of this study was to assess the accuracy of serological tests in combination with clinical symptoms for diagnosing celiac disease (CD) according to the new proposed European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) criteria. We retrospectively assessed children and adolescents aged 16 months -19 years who were examined for suspicion of CD (n = 345). Evaluation of clinical symptoms and the presence of tissue transglutaminase (anti-TG-IgA) and endomysial antibodies (EMA-IgA) as well as intestinal biopsies was performed in all patients. Human leukocyte antigens (HLAs) were not included. Among 345 biopsied children, 213 (62 %) children had anti-TG titers >10 times the upper limit of normal (ULN) and positive EMA antibodies. Ninety-nine (29 %) children also had symptoms suggestive of CD in addition to EMA positivity and elevated titers of anti-TG >10 times the ULN. In patients who were asymptomatic, but positive for EMA, and had anti-TG antibodies >10 times the ULN, the specificity of tests for Marsh 2-3 was only 85 %, while in symptomatic patients with the same antibodies levels, the specificity was 99 %. Conclusion: Our results reveal that intestinal biopsies could be omitted in 28 % of patients when the new ESPGHAN guidelines are applied. Due to high accuracy of serological tests in combination with clinical symptoms for diagnosis of CD, the new guideline seems to be applicable even without the use of HLA testing.

Children with celiac disease and high tTGA are genetically and phenotypically different

AIM: To investigate whether celiac disease (CD) patients with tissue-transglutaminase antibody (tTGA) ≥ 100 U/mL are different from patients with lower tTGA levels.

METHODS: Biopsy-proven (Marsh III) pediatric CD patients (n = 116) were prospectively included between March 2009 and October 2012. The biopsies were evaluated by a single pathologist who was blinded to all of the patients’ clinical data. The patients were distributed into 2 groups according to their tTGA level, which was measured using enzyme-linked immunoassay: tTGA ≥ 100 U/mL and tTGA < 100 U/mL. The patients’characteristics, symptoms, human leukocyte antigen (HLA) genotype and degree of histological involvement were compared between the 2 groups.

RESULTS: A total of 34 (29.3%) children had tTGA values < 100 U/mL and 82 (70.7%) tTGA levels of ≥ 100 U/mL. Patients with high tTGA levels had lower average body weight-for-height standard deviation scores (SDS) than did patients with tTGA < 100 U/mL (-0.20 ± 1.19 SDS vs 0.23 ± 1.03 SDS, P = 0.025). In the low tTGA group, gastrointestinal symptoms were more common (97.1% vs 75.6%, P = 0.006). More specifically, abdominal pain (76.5% vs 51.2%; P = 0.012) and nausea (17.6% vs 3.7%, P = 0.018) were more frequent among patients with low tTGA. In contrast, patients with solely extraintestinal manifestations were only present in the high tTGA group (18.3%, P = 0.005). These patients more commonly presented with aphthous stomatitis (15.9% vs 0.0%, P = 0.010) and anemia (32.9% vs 11.8%, P = 0.019). In addition, when evaluating the number of CD-associated HLA-DQ heterodimers (HLA-DQ2.5, HLA-DQ2.2 and HLA-DQ8), patients with low tTGA levels more commonly had only 1 disease-associated heterodimer (61.8% vs 31.7%, P = 0.005), while patients with high tTGA more commonly had multiple heterodimers. Finally, patients with tTGA ≥ 100 U/mL more often had a Marsh IIIc lesion (73.2% vs 20.6%, P < 0.001) while in patients with low tTGA patchy lesions were more common (42.4% vs 6.8%, P < 0.001).

CONCLUSION: Patients with tTGA ≥ 100 U/mL show several signs of more advanced disease. They also carry a larger number of CD associated HLA-DQ heterodimers.

A nationwide study of the association between celiac disease and the risk of autistic spectrum disorders

IMPORTANCE

Most case reports suggest an association between autistic spectrum disorders (ASDs) and celiac disease (CD) or positive CD serologic test results, but larger studies are contradictory.

OBJECTIVE

To examine the association between ASDs and CD according to small intestinal histopathologic findings.

DESIGN AND SETTING

Nationwide case-control study in Sweden.

MAIN OUTCOMES AND MEASURES

Through 28 Swedish biopsy registers, we collected data about 26,995 individuals with CD (equal to villous atrophy, Marsh stage 3), 12,304 individuals with inflammation (Marsh stages 1-2), and 3719 individuals with normal mucosa (Marsh stage 0) but positive CD serologic test results (IgA/IgG gliadin, endomysium, or tissue transglutaminase) and compared them with 213,208 age- and sex-matched controls. Conditional logistic regression estimated odds ratios (ORs) for having a prior diagnosis of an ASD according to the Swedish National Patient Register. In another analysis, we used the Cox proportional hazards regression model to estimate hazard ratios (HRs) for future ASDs in individuals undergoing small intestinal biopsy.

RESULTS

A prior ASD was not associated with CD (OR, 0.93; 95% CI, 0.51-1.68) or inflammation (OR 1.03; 95% CI, 0.40-2.64) but was associated with a markedly increased risk of having a normal mucosa but a positive CD serologic test result (OR, 4.57; 95% CI, 1.58-13.22). Restricting our data to individuals without a diagnosis of an ASD at the time of biopsy, CD (HR, 1.39; 95% CI, 1.13-1.71) and inflammation (HR, 2.01; 95% CI, 1.29-3.13) were both associated with moderate excess risks of later ASDs, whereas the HR for later ASDs in individuals with normal mucosa but positive CD serologic test results was 3.09 (95% CI, 1.99-4.80).

CONCLUSIONS AND RELEVANCE

Although this study found no association between CD or inflammation and earlier ASDs, there was a markedly increased risk of ASDs in individuals with normal mucosa but a positive CD serologic test result.

Diagnostic dilemmas in celiac disease

Celiac disease (CD) is an immune-mediated systemic condition triggered by dietary gluten occurring in genetically susceptible individuals. Our understanding of its numerous and varied clinical presentations has evolved over time, which has contributed to the incidence of CD increasing. In most cases, the diagnosis is readily established and patients promptly improve after commencing a gluten-free diet (GFD). However, in some, the diagnosis is not straightforward and presents a challenge to clinicians. Potential dilemmas include those with positive serology but normal histology, negative serology but abnormal duodenal mucosal histology, failure to respond to a GFD or response to a GFD without evidence of CD. In recent years, development of new assays and modifications to existing diagnostic algorithms for CD has also challenged the traditional role of small-bowel histology as critical in CD diagnosis.

Celiac disease and gluten-free diet

Celiac disease is an autoimmunity inflammatory disorder of the small intestine caused by the ingestion of gluten in genetically predisposed individuals. The prevalence of the disorder is around 1 % of the Western population and is still increasing. The symptoms of celiac disease include chronic abdominal pain, diarrhoea, and growth retardation in children, and chronic fatigue and headache, bowel complaints, reduced fertility, dermatitis herpetiformis, osteoporosis, nerve and brain disorders, increasing risk of intestinal cancer. The clinical diagnosis of the disease is based on the serological tests and bowel biopsy. The treatment is a long-life gluten-free diet. It is necessary exclude from the diet wheat, rye, barley and probably oats and buckwheat and their products. The novel approaches for celiac disease are focused on the genetic manipulation of nontoxic gluten proteins, enzyme therapy, immune modulation, and induction of oral tolerance to gluten.

Antibiotic exposure and the development of coeliac disease: a nationwide case-control study

BACKGROUND

The intestinal microbiota has been proposed to play a pathogenic role in coeliac disease (CD). Although antibiotics are common environmental factors with a profound impact on intestinal microbiota, data on antibiotic use as a risk factor for subsequent CD development are scarce.

METHODS

In this population-based case-control study we linked nationwide histopathology data on 2,933 individuals with CD (Marsh stage 3; villous atrophy) to the Swedish Prescribed Drug Register to examine the association between use of systemic antibiotics and subsequent CD. We also examined the association between antibiotic use in 2,118 individuals with inflammation (Marsh 1-2) and in 620 individuals with normal mucosa (Marsh 0) but positive CD serology. All individuals undergoing biopsy were matched for age and sex with 28,262 controls from the population.

RESULTS

Antibiotic use was associated with CD (Odds ratio [OR] = 1.40; 95% confidence interval [CI] = 1.27-1.53), inflammation (OR = 1.90; 95% CI = 1.72-2.10) and normal mucosa with positive CD serology (OR = 1.58; 95% CI = 1.30-1.92). ORs for prior antibiotic use in CD were similar when we excluded antibiotic use in the last year (OR = 1.30; 95% CI = 1.08-1.56) or restricted to individuals without comorbidity (OR = 1.30; 95% CI = 1.16 - 1.46).

CONCLUSIONS

The positive association between antibiotic use and subsequent CD but also with lesions that may represent early CD suggests that intestinal dysbiosis may play a role in the pathogenesis of CD. However, non-causal explanations for this positive association cannot be excluded.

Villous atrophy and negative celiac serology: a diagnostic and therapeutic dilemma

OBJECTIVES

Patients with villous atrophy (VA) and negative celiac disease (CD) serologies pose a diagnostic and therapeutic dilemma. When a definitive etiology for VA is not determined, patients are characterized as having unclassified sprue (US), the optimal management of which is unknown.

METHODS

We studied adult patients with VA on biopsy and negative celiac serologies, evaluated at our tertiary referral center over a 10-year period. Testing for HLA DQ2/8 alleles, antienterocyte antibodies, giardia stool antigen, bacterial overgrowth, total serum immunoglobulins, and HIV was noted. Treatment, response, and repeat-biopsy findings were recorded.

RESULTS

The most common diagnoses of the 72 patients were seronegative CD, medication-related villous atrophy, and US. Of those with US, the majority reported symptomatic improvement with immunosuppressive therapy. Some patients initially labeled as unclassified were found to have VA associated with olmesartan use.

CONCLUSIONS

The role of medications in the development of VA and the optimal dose and length of immunosuppression for patients with US should be investigated further.

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.

Diagnosis of celiac disease in adults based on serology test results, without small-bowel biopsy

BACKGROUND & AIMS

Celiac disease is underdiagnosed, with nonspecific symptoms and high morbidity. New diagnostic factors are needed. We aimed to estimate the frequency at which adult patients with positive results from serology tests are referred for small-bowel biopsies and to identify factors that improve the diagnosis of celiac disease.

METHODS

We performed a retrospective analysis of data from 2477 subjects who received serology tests for celiac disease between 2005 and 2007. We analyzed results for total levels of IgA, IgA against human tissue transglutaminase (hTTG), IgA and IgG against gliadin, as well as dilution titers of IgA against endomysial antibodies (EMA). Biopsy samples were analyzed by pathologists experienced in detecting mucosal changes associated with celiac disease and graded according to the Marsh system.

RESULTS

Of the 2477 patients, 610 (25%) had abnormal results from serology tests, and 39% of these patients (240 of 610) underwent small-bowel biopsy analyses. Of these patients, 50 (21%) had biopsy findings consistent with celiac disease (Marsh 3 lesions) and were placed on gluten-free diets. Titers of IgA hTTG greater than 118 U identified patients with celiac disease with a 2% false-positive rate. Titers of 21 to 118 U, in combination with an EMA dilution titer of 1:160 or greater, had a positive predictive value of 83% for celiac disease. IgA hTTG levels less than 20 U, in combination with an EMA dilution titer less than 1:10, had a negative predictive value of 92% for celiac disease.

CONCLUSIONS

Serum levels of IgA hTTG greater than 118 U, or 21 to 118 U in combination with an EMA dilution titer of 1:160 or greater, can be used to identify adult symptomatic patients with celiac disease, in the absence of a small-bowel biopsy.

Molecular diagnosis of celiac disease: are we there yet?

BACKGROUND

Celiac disease (CD) is a complex genetic disorder of the small intestine resulting from aberrant cellular responses to gluten peptides. It may affect as much as 1% of the Western population and the only treatment is a lifelong gluten-free diet. Allelic variants of the HLA-DQ locus, coding for the HLA-DQ2 and HLA-DQ8 molecules, contribute to ∼ 40% of CD etiology, whereas other genes, such as MYO9B, CTLA4, IL2, IL21, PARD3 and MAGI2, have only a modest effect. Most of these genes have shown varied association among different populations and an overlap with other autoimmune or inflammatory disorders, indicating that such disorders may share common pathways.

OBJECTIVES

In this review, a molecular approach into diagnostics of celiac disease is shown.

CONCLUSIONS

Genome-wide association studies will allow more genes to be identified, and knowing how risk variants combine will help to predict better the risk for the individual. HLA typing can already be used to identify high-risk individuals.

Celiac disease: the new proposed ESPGHAN diagnostic criteria do work well in a selected population

BACKGROUND

The need for an early and accurate diagnosis in celiac disease (CD) has focused attention on new diagnostic approaches, based on the efficiency of serological markers and the high negative predictive value of human leukocyte antigen (HLA) non-DQ2/8.

METHODS

We performed a retrospective review of all of the patients suspected of having CD who had undergone a small bowel biopsy in our gastroenterology unit. All symptomatic children with serological marker at time of biopsy (immunoglobulin A-tissue transglutaminase antibody, endomysial antibody, and HLA genotype) were included. The triple test (TT) was positive if immunoglobulin A-tissue transglutaminase antibody was 10 times the upper limit of normal, plus positive endomysial antibody plus human leukocyte antigen-DQ2/DQ8.

RESULTS

A total of 150 patients met the inclusion criteria and were enrolled in the study. One hundred sixteen were positive for the TT; 113 of 116 (97.4%) had a Marsh 2/3 histological lesion and had been considered to have CD. Thus, positive predictive value of the TT was 97.4%. The other 3 cases (2.6%) had Marsh 0/1 lesion, so we consider them to be false-positives for the TT; however, on follow-up, all 3 children developed histological damage after a gluten challenge. Finally, the positive predictive value of the TT was 100%. Thirty-four patients were negative for the TT: 22 patients are celiac, 3 are celiac but challenge gluten diet is pending, and the 9 patients left have other gastrointestinal disorder.

CONCLUSIONS

Our study supports the view that in selected children who are symptomatic and positive for the TT, CD diagnosis could be established independent of histological findings.

Antibody response against gastrointestinal antigens in demyelinating diseases of the central nervous system

BACKGROUND

Antibodies against gastrointestinal antigens may indicate altered microbiota and immune responses in the gut. Recent experimental data suggest a connection between gastrointestinal immune responses and CNS autoimmunity.

METHODS

Antibodies against gliadin, tissue transglutaminase (tTG), intrinsic factor (IF), parietal cells (PC) and Saccharomyces cerevisiae (ASCA) were screened in the sera of 45 patients with AQP4-seropositive neuromyelitis optica (NMO) and NMO spectrum diseases (NMO/NMO-SD), 17 patients with AQP4-seronegative NMO, 85 patients with clinically definite multiple sclerosis (MS), and 48 healthy controls (HC).

RESULTS

Thirty-seven percentages of patients with AQP4-seropositive NMO/NMO-SD and 28% of patients with MS had at least one particular antibody in contrast to 8% of HC (P < 0.01, respectively). Antibodies were most common (46%) in AQP4-seropositive myelitis (P = 0.01 versus HS, P = 0.05 versus MS). Anti-gliadin and ASCA were more frequent in the AQP4-seropositive NMO-spectrum compared to controls (P = 0.01 and P < 0.05, respectively).

CONCLUSION

Antibody responses against gastrointestinal antigens are common in MS and AQP4-seropositive NMO/NMO-SD, especially in longitudinally extensive myelitis.

Celiac disease: prevalence, diagnosis, pathogenesis and treatment

Celiac disease (CD) is one of the most common diseases, resulting from both environmental (gluten) and genetic factors [human leukocyte antigen (HLA) and non-HLA genes]. The prevalence of CD has been estimated to approximate 0.5%-1% in different parts of the world. However, the population with diabetes, autoimmune disorder or relatives of CD individuals have even higher risk for the development of CD, at least in part, because of shared HLA typing. Gliadin gains access to the basal surface of the epithelium, and interact directly with the immune system, via both trans- and para-cellular routes. From a diagnostic perspective, symptoms may be viewed as either "typical" or "atypical". In both positive serological screening results suggestive of CD, should lead to small bowel biopsy followed by a favourable clinical and serological response to the gluten-free diet (GFD) to confirm the diagnosis. Positive anti-tissue transglutaminase antibody or anti-endomysial antibody during the clinical course helps to confirm the diagnosis of CD because of their over 99% specificities when small bowel villous atrophy is present on biopsy. Currently, the only treatment available for CD individuals is a strict life-long GFD. A greater understanding of the pathogenesis of CD allows alternative future CD treatments to hydrolyse toxic gliadin peptide, prevent toxic gliadin peptide absorption, blockage of selective deamidation of specific glutamine residues by tissue, restore immune tolerance towards gluten, modulation of immune response to dietary gliadin, and restoration of intestinal architecture.

Are we diagnosing too many people with coeliac disease?

This review will try to address the question of whether we are diagnosing too many people with coeliac disease. The key reasons for diagnosing coeliac disease may be that it is a common condition affecting up to 1% of the adult population. Delays in diagnosis are common. The average time delay reported by Coeliac UK (National Medical Patient Charity), for patients with symptoms prior to the diagnosis being made is 13 years. For every adult case detected, it is estimated that there are eight cases not detected. Patients with coeliac disease have an associated morbidity and mortality. In addition, quality of life studies suggest that the majority of patients benefit from a gluten-free diet (GFD). Furthermore, the GFD reduces or alleviates the risk of the associated complications. All of these facts could even be used to support the argument for screening! However, conversely the tests for coeliac disease are not 100% sensitive and specific. In addition, we do not know whether patients with milder symptoms will derive less benefit from treatment and are at less risk of complications. Furthermore, evidence presented in this review suggests that actual outcomes for screening studies in an adult population have revealed poor uptake and subsequently difficulties with adherence. What little published data that are available also infers that individuals recognised through screening programmes could have been detected if carefully questioned for symptoms. There is evidence to suggest that diagnosing celiac disease is cost-effective and that the diagnostic costs are offset by reduced medical expenditures, reduced hospital and general practice attendances, but this view depends on the population prevalence of coeliac disease. We believe on the basis of the evidence presented in this review that we are not diagnosing too many adults with coeliac disease. However, the authors consider case-finding with a low threshold for serological testing to be the optimal approach. If you look for coeliac disease you will find it.

Birds, babies and blood

This is an autobiographical review describing the author's career in immunology research and summarizing his current understanding of the areas involved. Contributions to autoimmunity, immune deficiency, transfusion immunology, HLA-disease associations, reproductive immunology, cellular therapies, and innate immunity are included; also discussion of medical research ethics and various research-related activities.

A novel algorithm for the diagnosis of celiac disease and a comprehensive review of celiac disease diagnostics

There is an urgent clinical need for a better laboratory celiac disease diagnosis with both less false positive results and minimal underdetection. The aim of the present study was to evaluate the performance and diagnostic accuracy of different assays in an outpatient population setting for the diagnosis for celiac disease (CD) in order to design an optimal algorithm. We used 15 different ELISA assays to assess 47 blood samples of newly diagnosed children (positive biopsy results) and 52 samples from age- and sex-matched children with negative biopsy results for CD. Scoring criteria were established for grading the assays performance and characteristics. The combined gliadin and tTG assays exhibited the best sensitivity (100%). The addition of other assays to the CeliCheck neo-epitopes assay improved specificity so that the final algorithm had 100% sensitivity, 96.2% specificity, and 98.1% accuracy. The clinical demand for both maximal sensitivity and maximal specificity cannot be achieved with a single test. Using a combination of a sensitive assay together with specific assays improved celiac disease detection rates, with an acceptable number of false positive results. This model, however, needs to be confirmed prospectively in both children and adults.

Type 1 diabetes associated and tissue transglutaminase autoantibodies in patients without type 1 diabetes and coeliac disease with confirmed viral infections

Coeliac disease and type 1 diabetes are autoimmune diseases that may share the same initiating environmental factors. In this study, the occurrence of type 1 diabetes associated autoantibodies (GADA and IA-2A) and tissue transglutaminase autoantibodies (TGA) was determined in patients with confirmed viral infections and no signs of type 1 diabetes or coeliac disease. Serum samples from 82 Cuban patients tested positive for PCR and IgG specific to enterovirus (HEV, serotype echovirus 16, 20 samples), Epstein-Barr virus (EBV, 20 samples), cytomegalovirus (CMV, 21 samples), and hepatitis C virus (HCV, 21 samples); and sera from 164 controls negative serologically to EBV, CMV, HCV, and echovirus 16 were enrolled in the study. All subjects were screened for GADA, IA-2A, and TGA. The prevalence of TGA in patients infected with HEV, EBV, CMV, or HCV was 55% (11/20), 25% (5/20), 9.5% (2/21), and 9.5% (2/21), respectively. GADA and IA-2A were found in 15% (3/20) and 25% (5/20) of patients infected with HEV. None of the patients infected by EBV, CMV, and HCV had GADA or IA-2A. All children infected with HEV who were positive for type 1 diabetes-associated autoantibodies were also TGA-positive. None of the sera from uninfected subjects were positive for GADA, IA-2A or TGA. In conclusion, TGA can develop during infection with HEV, EBV, CMV, or HCV, while the emergence of islet cell related autoantibodies is restricted to HEV infections. The findings suggest that HEV may be a shared environmental factor for the development of islet and gut-related autoimmunity.

Prevalence of celiac disease among blood donors in São Paulo: the most populated city in Brazil

OBJECTIVE

Celiac disease is a permanent enteropathy caused by the ingestion of gluten, which leads to an immunemediated inflammation of the small intestine mucosa. The prevalence of celiac disease varies among different nations and ethnic backgrounds, and its diversity is determined by genetic and environmental factors. São Paulo city is one of the largest cities in the world, with a vast population and an important history of internal migratory flow from other Brazilian regions, as well as immigration from other, primarily European, countries, resulting in significant miscegenation. The aim of the present study was to estimate the prevalence of adults with undiagnosed celiac disease among blood donors of São Paulo by collecting information on the ancestry of the population studied.

METHODS

The prevalence of celiac disease was assessed by screening for positive IgA transglutaminase and IgA endomysium antibodies in 4,000 donors (volunteers) in the Fundação Pró-Sangue Blood Center of São Paulo, São Paulo, Brazil. The antibody-positive subjects were asked to undergo a small bowel biopsy.

RESULTS

Of the 4,000 subjects, twenty-four had positive tests, although both antibody tests were not always concordant. For example, ten subjects were positive for IgA tissue transglutaminase only. In twenty-one positive patients, duodenal biopsies were performed, and the diagnosis of celiac disease was confirmed in fourteen patients (Marsh criteria modified by Oberhuber). In this group, 67% claimed to have European ancestry, mainly from Italy, Portugal and Spain.

CONCLUSION

The prevalence of celiac disease is at least 1:286 among supposedly healthy blood bank volunteers in São Paulo, Brazil.

Celiac disease

Celiac disease is common, affecting approximately 1 in 100 people, yet it remains underdiagnosed. This article reviews our current understanding of celiac disease, diagnosis, and common pitfalls. Although the cornerstone of treatment is a gluten-free diet, some patients may still have persisting symptoms and warrant further investigations.

Bone mineral density directly correlates with duodenal Marsh stage in newly diagnosed adult celiac patients

OBJECTIVES

To estimate the prevalence of low bone mineral density (BMD) in a prospective series of adult celiac patients and to identify nutritional and metabolic factors associated with osteoporosis and osteopenia.

METHODS

Patients over 18 years of age who were consecutively and newly diagnosed with celiac disease (CD) were recruited. A bone density scan with dual-energy X-ray absorptiometry was carried out on the left hip and lumbar spine; nutritional parameters were analyzed and a hormone study conducted in order to exclude secondary low BMD.

RESULTS

40 patients (36 females/4 males) between the ages of 18 and 68 (mean 44.25 years) were recruited. Overall, at the moment of diagnosis 45% of patients exhibited low BMD at both demarcations. Risk of hip fracture was generally low, but ascended to mild in patients with villous atrophy (p = 0.011). Differences in major fracture risk were also observed depending on Marsh stage (p = 0.015). Significant differences were observed in nutritional status between patients with and without duodenal villous atrophy, with body mass index and blood levels of prealbumin, iron, vitamin D and folic acid significantly lower in Marsh III stage patients. No differences were found in blood hormone levels between Marsh stages or BMDs. The degree of bone mass loss in the lumbar spine directly correlated to Marsh stage. In the hip, a parallel association between BMD and Marsh stage was also observed, but did not reach statistical significance.

CONCLUSION

Duodenal villous atrophy, through malabsorption, was the main determinant factor for low BMD in adult-onset CD patients.

Are positive serum-IgA-tissue-transglutaminase antibodies enough to diagnose coeliac disease without a small bowel biopsy? Post-test probability of coeliac disease

BACKGROUND

It has been suggested that high titres of tTG are associated with elevated positive predictive values (PPV) for celiac disease. However, the PPV of a strongly positive tTG will depend on the celiac disease prevalence in the different risk groups of the disease

AIMS

To assess the PPV of a strongly positive tTG for celiac disease. In addition, to calculate the post-test probability for celiac disease of a strongly positive tTG in a setting of routine clinical practice.

METHODS

145 consecutive celiac disease patients with positive tTG, and with a small bowel biopsy were included. The PPV for different cut-off points of tTG levels for the diagnosis of celiac disease was assessed. In addition, the cut-offs associated with higher PPV were used to calculate the positive likelihood ratio. A simulation in a setting of routine clinical practice was performed to calculate the post-test probability of celiac disease.

RESULTS

No cut-off level was associated with a PPV of 100%. A cut-off of 80 U/mL (11.4×upper normal limit) was associated with the higher PPV value of 98.6%. In the most frequent clinical situations, which in general have a pre-test probability <10%, the post-test probability after having a strongly positive tTG was 90% or less.

CONCLUSIONS

A strongly positive tTG should not be enough to diagnose celiac disease in the most frequent clinical situations, small bowel biopsy remaining as the gold standard in these cases.

Serology in adults with celiac disease: limited accuracy in patients with mild histological lesions

Celiac disease (CD) is a gluten-triggered enteropathy, presenting with insidious clinical patterns. It can occasionally be diagnosed in asymptomatic subjects. Our aim was to define the relationship among symptoms at diagnosis, serological markers [tissue transglutaminase antibodies (tTGA), anti-endomysium antibodies (EMA) anti-actin antibodies (AAA)] and degree of mucosal damage. A total of 68 consecutive adult patients with CD were enrolled. Intestinal biopsies were scored according to the Marsh classification modified by Oberhuber: I-II minimal lesions or absent villous atrophy; IIIA partial villous atrophy; IIIB-C total villous atrophy (TVA). HLA-typing was done for all patients. No association between clinical presentation and severity of mucosal damage was found. Presence of EMA or tTGA was significantly associated with more severe mucosal damage (P < 0.001). Of 12 patients, 11 with AAA were also positive for TVA. The severity of mucosal damage is the main factor governing the detectability of serological markers of CD. The sensitivity of serological testing is questionable in patients with minimal lesions.

Increased risk of systemic lupus erythematosus in 29,000 patients with biopsy-verified celiac disease

OBJECTIVE

To investigate a possible association between celiac disease (CD) and systemic lupus erythematosus (SLE). Case series have indicated a possible association, but population-based studies are lacking.

METHODS

We compared the risk of SLE in 29,048 individuals with biopsy-verified CD (villous atrophy, Marsh 3) from Sweden's 28 pathology departments with that in 144,352 matched individuals from the general population identified through the Swedish Total Population Register. SLE was defined as having at least 2 records of SLE in the Swedish Patient Register. We used Cox regression to estimate hazard ratios (HR) for SLE.

RESULTS

During followup, 54 individuals with CD had an incident SLE. This corresponded to an HR of 3.49 (95% CI 2.48-4.90), with an absolute risk of 17/100,000 person-years and an excess risk of 12/100,000. Beyond 5 years of followup, the HR for SLE was 2.54 (95% CI 1.57-4.10). While SLE was predominantly female, we found similar risk estimates in men and women. When we restricted our outcome to individuals who also had a dispensation for a medication used in SLE, the HR was 2.43 (95% CI 1.22-4.87). The HR for having 2 records of SLE diagnoses, out of which at least 1 had occurred in a department of rheumatology, nephrology/dialysis, internal medicine, or pediatrics, was 2.87 (95% CI 1.97-4.17).

CONCLUSION

Individuals with CD were at a 3-fold increased risk of SLE compared to the general population. Although this excess risk remained more than 5 years after CD diagnosis, absolute risks were low.

Serological diagnosis of celiac disease: comparative analysis of different strategies

BACKGROUND

Different serologic tests are available for the diagnosis of celiac disease (CD).

AIM

To evaluate the diagnostic performance of anti-tissue transglutaminase (tTG) and anti-deamidated gliadin (DGP) for the serologic diagnosis of CD.

METHODS

The study population consisted of 107 consecutive adult CD and 542 consecutive disease controls who underwent an intestinal biopsy. Samples were tested for total IgA, IgA anti-tTG, and IgG anti-DGP antibodies using assays from 2 manufacturers (INOVA and Thermo Fisher). Samples were also tested by a screening assay that simultaneously detects IgA and IgG antibodies to tTG and DGP (tTG/DGP screen) (INOVA).

RESULTS

Positivity for anti-DGP or anti-tTG had a likelihood ratio for CD that varied between 20 and 115, depending on the assay. Double positivity (positive for anti-tTG and anti-DGP) had the highest likelihood ratio (≥ 215) for CD. The likelihood ratios for single positivity (positivity for one assay combined with negativity for the other) had a likelihood ratio between 0.8 and 10.1. The likelihood ratio for CD was lowest (≤ 0.12) for double negative test results. Decision tree analysis revealed that determining IgA anti-tTG and IgG anti-DGP in all patients performed better than other serologic strategies.

CONCLUSIONS

The use of likelihood ratios improves the clinical interpretation of serologic testing for CD. Double positive test results had the highest likelihood ratio for CD, whereas double negative test results had the lowest likelihood ratio.

Correlation between IgA tissue transglutaminase antibody ratio and histological finding in celiac disease

OBJECTIVES

Positivity of both immunoglobulin A anti-tissue transglutaminase (TTG) and anti-endomysium antibodies (EMA) has a positive predictive value of nearly 100% for celiac disease (CD). The objective of the present study was to evaluate whether patients of any age, with high pretest probability of CD and high titre of anti-TTG and EMA positivity, have a high probability of intestinal damage and may not require the biopsy for final diagnosis.

METHODS

A retrospective analysis of 412 consecutively referred patients, age range 10 months to 72 years, who underwent small-bowel biopsy for suspicion of CD and positivity to both anti-TTG and EMA, was performed at 4 Italian centers. Biopsies were evaluated independently by 2 pathologists using Marsh modified classification; in cases of dissimilar results, a third pathologist examined the biopsy. The final histological finding diagnosis was expressed as the prevalent or highest score assigned by the pathologist board.

RESULTS

Three hundred ninety-six patients (96.1%) had histological findings consistent with CD (grade 2 and 3a, 3b, or 3c of modified Marsh classification). An anti-TTG ratio ≥ 7 was able to identify with the 3 assays used (Celikey, anti-TTG immunoglobulin A, EuTTG) all of the patients with significant mucosal damage (Marsh ≥ 2) independent of age and sex; specificity and positive predictive value were 100%. An anti-TTG ratio >20 was more specific (99.8%) for identification of patients with villous atrophy (Marsh 3 a, b, or c).

CONCLUSIONS

Patients with positivity of anti-TTG ≥ 7-fold cutoff, confirmed by positivity to EMA, have a high-degree probability of duodenal damage. In selected conditions, a duodenal biopsy may be avoided and a confirmed greatly positive anti-TTG result could be the basis to prescribe a gluten-free diet.

Transient elastography in patients with celiac disease: a noninvasive method to detect liver involvement associated with celiac disease

BACKGROUND

Liver involvement in celiac disease (CD) is clinically relevant and could require specific treatment in addition to gluten-free diet (GFD). Transient elastography (TE), a noninvasive tool for assessing liver stiffness (LS), has widely been reported as an accurate surrogate marker of liver fibrosis.

AIMS

To prospectively identify celiac patients with liver involvement by TE and to assess the effect of GFD.

MATERIAL AND METHODS

Ninety-five histologically confirmed CD patients (24 newly diagnosed) were consecutively evaluated by TE and compared with 146 patients with chronic hepatitis C (HCV) and 54 healthy subjects.

RESULTS

LS ranged between 2.8 and 6.7 kPa (median 4.9) in healthy subjects, defining 6.9 kPa as the upper reference limit (2 SD above the mean levels). TE was above 6.9 kPa in 10 (10.5%) CD patients. Median TE values resulted significantly higher in CD patients with hypertransaminasemia than those without [6.1 vs. 4.2 kPa (p < 0.01)]. Among the 24 newly diagnosed patients with CD, median TE values declined from 4.4 to 4 kPa, after 6 months of GFD, resulting below 6.9 kPa in 100% of the patients.

CONCLUSIONS

A subset of CD patients with hypertransaminasemia showed liver involvement by TE. Accordingly, based on its accuracy in predicting liver fibrosis, TE could be used to identify those CD patients suitable for liver biopsy.