Accuracy of the No-Biopsy Approach for the Diagnosis of Celiac Disease in Adults: A Systematic Review and Meta-Analysis.

BACKGROUND & AIMS: Current international guidelines recommend duodenal biopsies to confirm the diagnosis of celiac disease in adult patients. However, growing evidence suggests that immunoglobulin A (IgA) anti-tissue transglutaminase (tTg) antibody levels ≥10 times the upper limit of normal (ULN) can accurately predict celiac disease, eliminating the need for biopsy. We performed a systematic review and meta-analysis to evaluate the accuracy of the no-biopsy approach to confirm the diagnosis of celiac disease in adults. METHODS: We systematically searched MEDLINE, EMBASE, Cochrane Library, and Web of Science from January 1998 to October 2023 for studies reporting the sensitivity and specificity of IgA-tTG ≥10×ULN against duodenal biopsies (Marsh grade ≥2) in adults with suspected celiac disease. We used a bivariate random effects model to calculate the summary estimates of sensitivity, specificity, and positive and negative likelihood ratios. The positive and negative likelihood ratios were used to calculate the positive predictive value of the no-biopsy approach across different pretest probabilities of celiac disease. The methodological quality of the included studies was evaluated using the QUADAS-2 tool. This study was registered with PROSPERO, number CRD42023398812. RESULTS: A total of 18 studies comprising 12,103 participants from 15 countries were included. The pooled prevalence of biopsy-proven celiac disease in the included studies was 62% (95% confidence interval [CI], 40%-83%). The proportion of patients with IgA-tTG ≥10×ULN was 32% (95% CI, 24%-40%). The summary sensitivity of IgA-tTG ≥10×ULN was 51% (95% CI, 42%-60%), and the summary specificity was 100% (95% CI, 98%-100%). The area under the summary receiver operating characteristic curve was 0.83 (95% CI, 0.77 - 0.89). The positive predictive value of the no-biopsy approach to identify patients with celiac disease was 65%, 88%, 95%, and 99% if celiac disease prevalence was 1%, 4%, 10%, and 40%, respectively. Between-study heterogeneity was moderate (I2 =30.3%), and additional sensitivity analyses did not significantly alter our findings. Only 1 study had a low risk of bias across all domains. CONCLUSION: The results of this meta-analysis suggest that selected adult patients with IgA-tTG ≥10×ULN and a moderate to high pretest probability of celiac disease could be diagnosed without undergoing invasive endoscopy and duodenal biopsy.

Development and validation of a tool for assessing adherence to gluten free diet in patients with Celiac disease (Celiac Disease: Compliance Assessment Test; CD-CAT).

OBJECTIVE: Life-long adherence to gluten-free diet (GFD) and its assessment is essential for celiac disease (CeD) patients. We have developed and validated a tool for assessing adherence to GFD which can be used by both physicians and dietitians. DESIGN: Phase-I: Development, content validation and assessment of reliability of tool. Phase-II: Validation of tool against standard dietary evaluation (SDE) (gold standard), IgA anti-tissue transglutaminase antibody (IgA-anti-tTG Ab) and gluten immunogenic peptides in urine (Urine-GIP). Overall, 380 biopsy-confirmed CeD patients [Derivation-cohort: n=100(Phase:I), n=210(Phase:II) and Independent validation cohort, n=70)were recruited. RESULTS: Of initial 90-point questionnaire, 84-items (CD-CAT.v1) were retained after content validation and pilot testing. In Phase:I, upon administering CD-CAT.v1on 100 patients, a comprehensive 35-items tool (CD-CAT.v2;α=0.86) was obtained after removing items with low test-retest reliability and item-rest correlation values. In Phase:II, upon administering CD-CAT.v2 on 210patients,22 items were removed having low correlation values (R<0.4) with SDE. Finally, a 13-item tool (CD-CAT.v3;α=0.84) was obtained with high criterion validity with SDE (r=0.806, p<0.001), moderate convergent validity with CDAT (r=0.602, p=0.007) and moderate to weak correlation with urine GIP (r=0.46, p=0.001) and IgA anti-tTG Ab (r=0.39, p=0.008), respectively. The final 13-item tool also strongly correlated with SDE (r=0.78, p<0.001) in an independent validation cohort of 70 CeD patients. Principal component analysis identified three relevant sub-scales with a cumulative-variance of 62%. The sensitivity and specificity of CD-CAT.v3 were 80% and 91%, respectively, with an area under curve of 0.905 with SDE. The obtained cut-off score of <19 from ROC-curve was further categorized as: 13=excellent,14-18=very good, 19-28=average and >28=poor adherence to GFD. CONCLUSION: CD-CAT is a new and rapid tool for monitoring dietary adherence to GFD with high sensitivity and specificity which can be administered by both physicians and dietitians.

Reproductive functions and pregnancy outcome in female patients with celiac disease.

BACKGROUND AND AIM: Abnormalities in the reproductive functions are often ignored while evaluating a patient with celiac disease (CeD). We evaluated the entire reproductive functions in female patients with CeD. METHODS: In a case control study between 2020 and 2021 using detailed questionnaire, we evaluated reproductive functions (age at menarche, menstrual pattern, fertility, pregnancy outcome and menopause) in biopsy-proven female patients with CeD of age >10 years. The questionnaire was administered either in person or telephonically. Age-matched healthy female controls (twice the number) were also recruited. RESULTS: Of 1086 CeD patients, 470 were females and 288 were included. As compared with controls (n = 586), females with CeD had higher age at menarche (14.6 ± 2.0 vs 13.6 ± 1.5 years; P = 0.001), delayed menarche (30.8% vs 11.4%; P = 0.001), abnormal menstrual pattern (39.7% vs 25.8%; P < 0.001), involuntary delay in conception at > 1 year (33.8% vs 11.8%; P = 0.01), current infertility rate (10.5% vs 5.2%;P = 0.028), and poorer overall pregnancy outcomes (abortion [23.5% vs 12.8%; P = 0.001], pre-term birth [16.3% vs 3.7%; P = 0.001]). CONCLUSIONS: Either one or more aspect of reproductive functions and pregnancy outcome is affected adversely in three-fourth female patients with CeD.

Impact of delay in the diagnosis on the severity of celiac disease.

BACKGROUND AND AIM: Celiac disease (CeD) has now become a global disease with a worldwide prevalence of 0.67%. Despite being a common disease, CeD is often not diagnosed and there is a significant delay in its diagnosis. We reviewed the impact of the delay in the diagnosis on the severity of manifestations of CeD. METHODS: We reviewed clinical records of 726 consecutive patients with CeD from the Celiac Clinic database and the National Celiac Disease Consortium database. We extracted specific data including the demographics, symptoms at presentation, time of onset of symptoms, time to diagnosis from the onset of the symptoms, and relevant clinical data including fold-rise in anti-tissue transglutaminase antibody (IgA anti-tTG Ab) and severity of villous and crypt abnormalities as assessed using modified Marsh classification. RESULTS: The median duration between the onset of symptoms and the diagnosis of CeD was 27 months (interquartile range 12-60 months). A longer delay in the diagnosis of CeD from the onset of symptoms was associated with lower height for age, lower hemoglobin, higher fold rise in IgA Anti tTG titers, and higher severity of villous and crypt abnormalities. About 18% of patients presented with predominantly non-gastrointestinal complaints and had a longer delay in the diagnosis of CeD. CONCLUSIONS: There is a significant delay in the diagnosis of CeD since the onset of its symptoms. The severity of celiac disease increases with increasing delay in its diagnosis. There is a need to keep a low threshold for the diagnosis of CeD in appropriate clinical settings.

Ten missteps in the management of inflammatory bowel disease in Asia: An expert report by the Asian Pacific Association of Gastroenterology Working Group on Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is rapidly emerging in the Asia Pacific region. However, there are many challenges in the diagnosis and management of this condition. The Asian Pacific Association of Gastroenterology (APAGE) Working Group on IBD conducted a round table meeting to identify 10 common mistakes in the management of IBD in Asia. To summarize, many physicians still over rely on a definitive histological diagnosis before starting treatment and do not fully establish disease extent such as perianal and proximal gastrointestinal involvement in Crohn's disease (CD) or extent of involvement in ulcerative colitis (UC). It is also essential to actively look for evidence of extra-intestinal manifestations, which may influence choice of therapy. In terms of conventional therapy, underuse of topical 5 aminosalicylates (5-ASAs) in UC and inappropriate dosing of corticosteroids are also important considerations. Acute severe UC remains a life-threatening condition and delay in starting rescue therapy after inadequate response to intravenous steroids is still common. Anti-tumor necrosis factors should be considered first line in all cases of complex perianal fistulizing CD. Most patients with IBD are on potent immunosuppressive therapy and should be screened for latent infections and offered vaccinations according to guidelines. Under-recognition and management of significant complications such as anemia, osteoporosis, malnutrition, and thromboembolism should also be addressed. Colonoscopy is still not properly performed for dysplasia/cancer surveillance and for evaluating post-op recurrence of CD. Another common misstep is inappropriate withdrawal of medications during pregnancy leading to increased complications for the mother and the newborn.

Patients with Celiac Disease Have High Prevalence of Fatty Liver and Metabolic Syndrome.

OBJECTIVE: In recent years, patients with celiac disease (CeD) have been reported to have a high prevalence of fatty liver and metabolic syndrome. We conducted a systematic review and meta-analysis to assess the prevalence of fatty liver and metabolic syndrome in patients with CeD and effect of gluten-free diet in them. METHODS: The PubMed, Embase and the Cochrane Library databases were searched for original studies upto November 18, 2022. We included full-text articles published in the English language after 1990 that used well-defined criteria for CeD, fatty liver and metabolic syndrome. A random effects model was used to calculate pooled prevalence. RESULTS: Of 350 studies identified, 11 studies (n = 2578) were included in the analysis. On analysis of both cross-sectional and longitudinal studies, pooled prevalence of fatty liver and metabolic syndrome in treatment-naïve patients with CeD were 18.2% (95% CI 8.3-30.8%, n = 1237) and 4.3% (95% CI 2.4-6.7, n = 1239) and in those on GFD of varying duration was 28.2% (95% CI 20.7-36.4%, n = 1368) and 21.3% (95% CI 11.7-32.9%, n = 2193), respectively. There was no difference in the prevalence of fatty liver and metabolic syndrome between low- or high-income group countries. CONCLUSIONS: Patients with CeD have a high prevalence of fatty liver and metabolic syndrome which increases further with the initiation of GFD. Patients with CeD should thus be screened and monitored for development of fatty liver and metabolic syndrome. They should be counselled appropriately regarding their diet and inclusion of physical activity in their lifestyle.

Unauthentic Information About Celiac Disease on Social Networking Pages: Is It a Matter of Concern in Celiac Disease Management?

BACKGROUND: Facebook (FB) is the most popular online networking platform. Many celiac disease Facebook (CD-FB) pages spread awareness about celiac disease (CD). To get the latest information, patients with CD frequently follow such pages. However, little is known about whether such pages provide authentic and reliable information. AIMS: This study aims to investigate whether CD-FB pages spread misleading information to patients with CD. METHODS: On the Facebook social networking platform, CD-FB pages created in three celiac-prevalent countries (Italy, the USA, and India) were explored using different combinations of keywords. The type/category of the CD-FB page, country of origin, purpose, page web link, and number of followers/members were documented in a Microsoft spreadsheet. All posts distributed on selected CD-FB pages in the last 3 years were thoroughly screened. RESULTS: From August 2022 to March 2023, a total of 200 CD-FB pages from Italy, the USA, and India were explored. Out of these 200 pages, 155 CD-FB (Italy 70; the USA 46; India 39) were found eligible. Of them, 20 (13%) CD-FB pages (Italy 4; the USA 5; India 11) shared misleading information about CD. Surprisingly, 11 (8%) of these 20 pages (Italy 0; the USA 2; India 9) supported alternative treatment options for CD. CONCLUSIONS: CD-FB pages are useful for disseminating celiac-disease-related information. While most such pages provide useful information, 13% of CD-FB pages allow misleading information. Patients with CD should consult their treating unit before following any uncertain information posted on CD-FB pages.

Joint Asian Pacific Association of Gastroenterology (APAGE)-Asian Pacific Society of Digestive Endoscopy (APSDE) clinical practice guidelines on the use of non-invasive biomarkers for diagnosis of colorectal neoplasia.

Screening for colorectal cancer (CRC) is effective in reducing CRC related mortality. Current screening methods include endoscopy based and biomarker based approaches. This guideline is a joint official statement of the Asian Pacific Association of Gastroenterology (APAGE) and the Asian Pacific Society of Digestive Endoscopy (APSDE), developed in response to the increasing use of, and accumulating supportive evidence for the role of, non-invasive biomarkers for the diagnosis of CRC and its precursor lesions. A systematic review of 678 publications and a two stage Delphi consensus process involving 16 clinicians in various disciplines was undertaken to develop 32 evidence based and expert opinion based recommendations for the use of faecal immunochemical tests, faecal based tumour biomarkers or microbial biomarkers, and blood based tumour biomarkers for the detection of CRC and adenoma. Comprehensive up-to-date guidance is provided on indications, patient selection and strengths and limitations of each screening tool. Future research to inform clinical applications are discussed alongside objective measurement of research priorities. This joint APAGE-APSDE practice guideline is intended to provide an up-to-date guide to assist clinicians worldwide in utilising non-invasive biomarkers for CRC screening; it has particular salience for clinicians in the Asia-Pacific region.

Interleukin-9 rescues class switching of Memory B cells derived from Common variable immunodeficiency patients.

Impaired class switch memory (CSM) B cell formation is the hallmark of common variable immunodeficiency (CVID). Various T cell abnormalities have been observed in CVID patients indicating inadequate T-cell help to B cells. A major setback in understanding its pathogenesis is due to diverse clinical presentation. Therefore, we performed extensive immunological investigation in a cohort of CVID patients with similar clinical findings in order to unravel the T cell dysfunction and its influence on the defective humoral immune response. All recruited CVID patients exhibited B cells in the normal range, but reduced CSM B cells. However, patients showed reduced T cell proliferation, reduced level of serum Interleukin-9 (IL-9) and frequency of IL-9 expressing CD4 (Th-9) cells. IL-9 supplementation along with CD40 engagement was effective in inducing in vitro CSM B cells formation in CVID patients. Thus, IL-9 supplementation has the potential to restore impaired CSM B cell formation in CVID.

Prevalence of Celiac Disease in Patients With Liver Diseases: A Systematic Review and Meta-Analyses.

INTRODUCTION: A subset of patients with celiac disease (CeD) has liver involvement in the form of hypertransaminasemia, liver cirrhosis, and autoimmune hepatitis. We conducted a systematic review with meta-analyses to determine the pooled prevalence of CeD in patients with cryptogenic cirrhosis, all-cause cirrhosis, cryptogenic hypertransaminasemia, and all-cause hypertransaminasemia. METHODS: We searched PubMed and EMBASE up to January 2022. Cross-sectional, case-control, and prospective cohort studies performing serological tests and/or intestinal biopsy for CeD on patients with cryptogenic cirrhosis, all-cause cirrhosis, cryptogenic hypertransaminasemia, and all-cause hypertransaminasemia were included to calculate pooled estimates of seroprevalence and the prevalence of biopsy-confirmed CeD in these 4 groups. RESULTS: Of 6,871 articles screened, 20 articles were included finally in 3 meta-analyses for cryptogenic cirrhosis, all-cause cirrhosis, and cryptogenic hypertransaminasemia. For the all-cause hypertransaminasemia group, a qualitative review of 4 studies was conducted instead of a meta-analysis due to significant differences in studies. The pooled prevalence (95% confidence interval) of biopsy-confirmed CeD in cryptogenic cirrhosis was 4.6% (2.2%-7.5%) while the pooled prevalence of biopsy-confirmed CeD in all-cause cirrhosis was 0.8% (0%-3.4%). The pooled prevalence of biopsy-confirmed CeD in cryptogenic hypertransaminasemia was 5.7% (3.2%-8.8%). DISCUSSION: Nearly 1 in 20 patients each with cryptogenic cirrhosis and cryptogenic hypertransaminasemia have CeD; hence, they should both be considered high-risk groups for CeD. While the prevalence of CeD in those with all-cause cirrhosis is similar to that in general population, it may be worth screening them for CeD because liver pathology has the potential for reversal in them.

Faecal microbiota transplantation with anti-inflammatory diet (FMT-AID) followed by anti-inflammatory diet alone is effective in inducing and maintaining remission over 1 year in mild to moderate ulcerative colitis: a randomised controlled trial.

OBJECTIVE: Microbiome and dietary manipulation therapies are being explored for treating ulcerative colitis (UC). We aimed to examine the efficacy of multidonor faecal microbiota transplantation (FMT) and anti-inflammatory diet in inducing remission followed by long-term maintenance with anti-inflammatory diet in patients with mild-moderate UC. DESIGN: This open-labelled randomised controlled trial (RCT) randomised patients with mild-moderate (Simple Clinical Colitis Activity Index (SCCAI) 3-9) endoscopically active UC (Ulcerative Colitis Endoscopic Index of Severity (UCEIS)>1) on stable baseline medications in 1:1 ratio to FMT and anti-inflammatory diet (FMT-AID) versus optimised standard medical therapy (SMT). The FMT-AID arm received seven weekly colonoscopic infusions of freshly prepared FMT from multiple rural donors(weeks 0-6) with anti-inflammatory diet. Baseline medications were optimised in the SMT arm. Clinical responders (decline in SCCAI>3) at 8 weeks in both arms were followed until 48 weeks on baseline medications (with anti-inflammatory diet in the FMT-AID arm). Primary outcome measures were clinical response and deep remission (clinical-SCCAI <2; and endoscopic-UCEIS <1) at 8 weeks, and deep remission and steroid-free clinical remission at 48 weeks. RESULTS: Of the 113 patients screened, 73 were randomised, and 66 were included in (35-FMT-AID; 31-SMT) modified intention-to-treat analysis (age-35.7±11.1 years; male-60.1%; disease duration-48 (IQR 24-84) months; pancolitis-34.8%; SCCAI-6 (IQR 5-7); UCEIS-4 (IQR 3-5)). Baseline characteristics were comparable. FMT-AID was superior to SMT in inducing clinical response (23/35 (65.7%) vs 11/31 (35.5%), p=0.01, OR 3.5 (95% CI 1.3 to 9.6)), remission (21/35 (60%) vs 10/31 (32.3%), p=0.02, OR 3.2 (95% CI 1.1 to 8.7)) and deep remission (12/33 (36.4%) vs 2/23 (8.7%), p=0.03, OR 6.0 (95% CI 1.2 to 30.2)) at 8 weeks. Anti-inflammatory diet was superior to SMT in maintaining deep remission until 48 weeks (6/24 (25%) vs 0/27, p=0.007). CONCLUSION: Multidonor FMT with anti-inflammatory diet effectively induced deep remission in mild-moderate UC which was sustained with anti-inflammatory diet over 1 year. TRIAL REGISTRATION NUMBER: ISRCTN15475780.

Third Asia-Pacific consensus recommendations on colorectal cancer screening and postpolypectomy surveillance.

The Asia-Pacific region has the largest number of cases of colorectal cancer (CRC) and one of the highest levels of mortality due to this condition in the world. Since the publishing of two consensus recommendations in 2008 and 2015, significant advancements have been made in our knowledge of epidemiology, pathology and the natural history of the adenoma-carcinoma progression. Based on the most updated epidemiological and clinical studies in this region, considering literature from international studies, and adopting the modified Delphi process, the Asia-Pacific Working Group on Colorectal Cancer Screening has updated and revised their recommendations on (1) screening methods and preferred strategies; (2) age for starting and terminating screening for CRC; (3) screening for individuals with a family history of CRC or advanced adenoma; (4) surveillance for those with adenomas; (5) screening and surveillance for sessile serrated lesions and (6) quality assurance of screening programmes. Thirteen countries/regions in the Asia-Pacific region were represented in this exercise. International advisors from North America and Europe were invited to participate.

The Prevalence of the Celiac Disease in Patients with Dyspepsia: A Systematic Review and Meta-Analysis.

BACKGROUND: Patients with celiac disease (CeD) can commonly present with symptoms of dyspepsia. We conducted a systematic review and meta-analysis of the present literature to assess the prevalence of CeD in patients diagnosed with dyspepsia. METHODS: We searched MEDLINE and EMBASE databases for the keywords: celiac disease, coeliac disease, anti-gliadin, tissue transglutaminase antibody, anti-endomysial antibody, dyspepsia and functional gastrointestinal disorder. All the studies published from January 1991 till May 2021 were included. Diagnosis of CeD was based on the European Society of Pediatric Gastroenterology, Hepatology and Nutrition guidelines. A random-effects model was used to pool the data. RESULTS: Twenty-one studies screening 10,275 patients with dyspepsia were included. The pooled seroprevalence of CeD based on a positive anti-tissue transglutaminase antibody and/or anti-endomysial antibody was 4.8% (95% CI [2.8, 6.7%], I2 = 87.7%). The pooled biopsy-confirmed CeD prevalence was 1.5% (95% CI [1.0, 1.9%]; I2 = 59.8%) in these patients. Both seroprevalence (Odds ratio: 1.8; 95% CI [0.8, 4.0%]; I2 = 0%) and prevalence of biopsy-confirmed CeD (Odds ratio: 1.4; 95% CI [0.8, 2.4]; I2 = 0%) were not higher in patients with dyspepsia compared to controls. There was a moderate risk of selection bias and significant heterogeneity in the pooled results. CONCLUSIONS: The pooled prevalence of CeD in patients with dyspepsia was 1.5% and it was not significantly higher than the general population. These results do not support screening of patients with dyspepsia for CeD.

Prevalence of celiac disease in patients with short stature: A systematic review and meta-analysis.

BACKGROUND AND AIM: Short stature is a common extraintestinal manifestation of celiac disease (CeD). We conducted a systematic review and meta-analysis to assess the global prevalence of CeD in patients presenting with short stature. METHODS: We searched Medline and EMBASE databases for the keywords "celiac disease, coeliac disease, anti-gliadin, tissue transglutaminase antibody, anti-endomysial antibody, short stature and growth retardation." All the studies published from January 1991 to May 2020 were included. Patients without any prior evaluation for short stature were classified as all-cause short stature, while prior evaluated patients, where no cause was found for short stature, were classified as idiopathic short stature. The diagnosis of CeD was based on the European Society for Paediatric Gastroenterology, Hepatology and Nutrition guidelines. A random-effects model was used to pool the data. RESULTS: Seventeen studies screening 3759 patients (1582 with all-cause short stature and 2177 with idiopathic short stature) were included. The pooled seroprevalence of CeD based on positive anti-tissue transglutaminase antibody and anti-endomysial antibody was 11.2% (95% CI 4.0-21.2%; I2  = 86%) and 9.7% (95% CI 2.7-20.2%; I2  = 95%) for all-cause and idiopathic short stature, respectively. Similarly, pooled prevalence of biopsy-confirmed CeD was 7.4% (95% CI 4.7-10.6%; I2  = 76%) and 11.6% (95% CI 4.1-22.2%; I2  = 97%), for all-cause and idiopathic short stature, respectively. There was an overall severe risk of selection bias and significant heterogeneity in the pooled results. CONCLUSIONS: Approximately one in 14 patients with all-cause short stature and one in nine patients with idiopathic short stature had biopsy-confirmed CeD. Therefore, evaluation for CeD may be prudent in all patients with short stature.

Inter- and Intra-assay Variation in the Diagnostic Performance of Assays for Anti-tissue Transglutaminase in 2 Populations.

Tissue transglutaminse-2 (TG2)-based immunoassays are the cornerstone of diagnosis in celiac disease (CeD), with a reported pooled sensitivity as high as 98%.1 However, a few small, single-center studies have questioned their sensitivity in clinical practice.2-5 Moreover, commercial kits use variable TG2 antigens,6 with cutoffs determined by using small, poorly defined populations. Variation in diagnostic performance of anti-TG2 assays in different racial and geographic populations has not yet been studied. We compared the interassay and intra-assay variations in diagnostic performance of 4 immunoglobulin (Ig)A-anti-TG2 assays in Canadian and Indian populations.

Abnormalities in metabolic pathways in celiac disease investigated by the metabolic profiling of small intestinal mucosa, blood plasma and urine by NMR spectroscopy.

Celiac disease (CeD) is an autoimmune enteropathy caused by gluten intake in genetically predisposed individuals. We investigated the metabolism of CeD by metabolic profiling of intestinal mucosa, blood plasma and urine using NMR spectroscopy and multivariate analysis. The metabolic profile of the small intestinal mucosa was compared between patients with CeD (n = 64) and disease controls (DCs, n = 30). The blood plasma and urinary metabolomes of CeD patients were compared with healthy controls (HCs, n = 39). Twelve metabolites (proline (Pro), arginine (Arg), glycine (Gly), histidine (His), glutamate (Glu), aspartate, tryptophan (Trp), fumarate, formate, succinate (Succ), glycerophosphocholine (GPC) and allantoin (Alln)) of intestinal mucosa differentiated CeD from controls. The metabolome of blood plasma with 18 metabolites (Pro, Arg, Gly, alanine, Glu, glutamine, glucose (Glc), lactate (Lac), acetate (Ace), acetoacetate (AcAc), ß-hydroxybutyrate (ß-OHB), pyruvate (Pyr), Succ, citrate (Cit), choline (Cho), creatine (Cr), phosphocreatine (PCr) and creatinine) and 9 metabolites of urine (Pro, Trp, ß-OHB, Pyr, Succ, N-methylnicotinamide (NMN), aminohippurate (AHA), indoxyl sulfate (IS) and Alln) distinguished CeD from HCs. Our data demonstrated changes in nine metabolic pathways. The altered metabolites were associated with increased oxidative stress (Alln), impaired healing and repair mechanisms (Pro, Arg), compromised anti-inflammatory and cytoprotective processes (Gly, His, NMN), altered energy metabolism (Glc, Lac, ß-OHB, Ace, AcAc, Pyr, Succ, Cit, Cho, Cr and PCr), impaired membrane metabolism (GPC and Cho) and intestinal dysbiosis (AHA and IS). An orthogonal partial least square discriminant analysis model provided clear differentiation between patients with CeD and controls in all three specimens. A classification model built by combining the distinguishing metabolites of blood plasma and urine samples gave an AUC of 0.99 with 97.7% sensitivity, 93.3% specificity and a predictive accuracy of 95.1%, which was higher than for the models built separately using small intestinal mucosa, blood plasma and urine. In conclusion, a panel of metabolic biomarkers in intestinal biopsies, plasma and urine samples has potential to differentiate CeD from controls and may complement traditional tests to improve the diagnosis of CeD.

Non-immunological biomarkers for assessment of villous abnormalities in patients with celiac disease.

BACKGROUND AND AIM: Demonstration of villous abnormalities is an essential component of diagnosis of celiac disease (CeD) that requires duodenal biopsies. There is a need for non-invasive biomarker(s) that can predict the presence of villous abnormalities. METHODS: Levels of plasma citrulline, plasma intestinal fatty acid binding protein (I-FABP), and serum regenerating gene 1α (Reg1α) were estimated in treatment naïve patients with CeD and controls. The levels of these biomarkers and their cyclical pattern were validated in a predicted model of enteropathy. Optimum diagnostic cut-off values were derived, and the results were further validated in a prospective validation cohort. RESULTS: While level of plasma citrulline was significantly lower, the levels of plasma I-FABP and serum Reg1α were significantly higher in patients with CeD (n = 131) in comparison with healthy (n = 216) and disease controls (n = 133), and their levels reversed after a gluten-free diet (GFD). In the model of predicted enteropathy (n = 70), a sequential decrease and then increase in the level of plasma citrulline was observed; such a sequential change was not observed with I-FABP and Reg1α. The diagnostic accuracy for prediction of presence of villous abnormality was 89% and 78% if citrulline level was  ≤ 30 µM/L and I-FABP levels were ≥ 1100 pg/mL, respectively. The results were validated in a prospective validation cohort (n = 104) with a sensitivity and specificity of 79.5% and 83.1%, respectively, for predicting villous abnormalities of modified Marsh grade > 2 at calculated cut-off values of citrulline and I-FABP. CONCLUSIONS: Plasma citrulline  ≤ 30 µM/L is the most consistent, highly reproducible non-invasive biomarker that can predict the presence of villous abnormality and has the potential for avoiding duodenal biopsies in 78% patients suspected to have CeD.

Diagnostic Accuracy of Point of Care Tests for Diagnosing Celiac Disease: A Systematic Review and Meta-Analysis.

GOALS: To perform a systematic review and meta-analysis to estimate the overall diagnostic accuracy of point of care tests (POCTs) for diagnosing celiac disease (CD). BACKGROUND: Recently, POCTs for CD have been developed and are commercially available. Studies have reported significant variability in their sensitivity (70% to 100%) and specificity (85% to 100%). STUDY: We searched MEDLINE, EMBASE databases, and the Cochrane library through June 2017. Positive reference test was defined as villous atrophy along with positive celiac-specific serology and/or clinical improvement after gluten-free diet. Normal duodenal biopsy was defined as negative reference test. Bivariate random-effect model was used to present the summary estimates of sensitivities and specificities along with 95% confidence regions We assessed methodologic quality using the quality assessment of diagnostic accuracy studies-2 tool. RESULTS: The pooled sensitivity and specificity of all POCTs (based on tTG or DGP or tTG+Anti-gliadin antibodies) for diagnosing CD were 94.0% [95% confidence interval (CI), 89.9-96.5] and 94.4% (95% CI, 90.9-96.5), respectively. The pooled positive and negative likelihood ratios for POCTs were 16.7 and 0.06, respectively. The pooled sensitivity and specificity for IgA-tTG-based POCTs were 90.5% (95% CI, 82.3-95.1) and 94.8% (95% CI, 92.5-96.4), respectively. CONCLUSIONS: The pooled sensitivity and specificity of POCTs in diagnosing CD are high. POCTs may be used to screen for CD, especially in areas with limited access to laboratory-based testing. Further research assessing the diagnostic accuracy of individual POCTs and comparing it with other available POCTs is needed.

Clinical, endoscopic, and histological differentiation between celiac disease and tropical sprue: A systematic review.

BACKGROUND AND AIM: While the prevalence of celiac disease (CD) is increasing globally, the prevalence of tropical sprue (TS) is declining. Still, there are certain regions in the world where both patients with CD and TS exist and differentiation between them is a challenging task. We conducted a systematic review of the literature to find out differentiating clinical, endoscopic, and histological characteristics between CD and TS. METHODS: Medline, PubMed, and EMBASE databases were searched for keywords: celiac disease, coeliac, celiac, tropical sprue, sprue, clinical presentation, endoscopy, and histology. Studies published between August 1960 and January 2018 were reviewed. Out of 1063 articles available, 12 articles were included in the final analysis. RESULTS: Between the patients with CD and TS, there was no difference in the prevalence and duration of chronic diarrhea, abdominal distension, weight loss, extent of abnormal fecal fat content, and density of intestinal inflammation. The following features were more common in CD: short stature, vomiting/dyspepsia, endoscopic scalloping/attenuation of duodenal folds, histological high modified Marsh changes, crescendo type of IELosis, surface epithelial denudation, surface mucosal flattening, thickening of subepithelial basement membrane and celiac seropositivity; while those in TS include anemia, abnormal urinary D-xylose test, endoscopic either normal duodenal folds or mild attenuation, histologically decrescendo type of IELosis, low modified Marsh changes, patchy mucosal changes, and mucosal eosinophilia. CONCLUSIONS: Both patients with CD and TS have overlapping clinical, endoscopic, and histological characteristics, and there is no single diagnostic feature for differentiating CD from TS except for celiac specific serological tests.