Prevalence estimation of celiac disease in the general adult population of Latvia using serology and HLA genotyping

Relationship between gluten availability and celiac disease prevalence: A geo-epidemiologic systematic review

Celiac disease is a global disease requiring genetic susceptibility and gluten exposure to trigger immune-mediated enteropathy. The effect of the degree of gluten-containing grain availability on celiac disease prevalence is unknown. Our objective was to compare country-based gluten availability to celiac prevalence using a systematic literature review. We searched MEDLINE, Embase, Cochrane, and Scopus until May 2021. We included population-based serum screening with confirmatory testing (second serological study or small intestine biopsy) and excluded specific, high-risk, or referral populations. We determined country-specific gluten availability using the United Nations food balance for wheat, barley, and rye. Human leukocyte antigen (HLA) frequencies were obtained from allelefrequencies.net. The primary outcome was association between gluten-containing grain availability and celiac disease prevalence. Generalized linear mixed models method with Poisson's link was used for analysis. We identified 5641 articles and included 120 studies on 427 146 subjects from 41 countries. Celiac disease prevalence was 0-3.1%, median 0.75% (interquartile range 0.35, 1.22). Median wheat supply was 246 g/capita/day (interquartile range 214.8, 360.7). The risk ratio (RR) for wheat availability on celiac disease was 1.002 (95% confidence interval [CI]: 1.0001, 1.004, P = 0.036). A protective association was seen with barley, RR 0.973 (95% CI: 0.956, 0.99, P = 0.003), and rye, RR 0.989 (95% CI: 0.982, 0.997, P = 0.006). The RR for gross domestic product on celiac disease prevalence was 1.009 (95% CI: 1.005, 1.014, P < 0.001). The RR for HLA-DQ2 was 0.982 (95% CI: 0.979, 0.986, P < 0.001), and that for HLA-DQ8 was 0.957 (95% CI: 0.950, 0.964, P < 0.001). In this geo-epidemiologic study, gluten-containing grain availability showed mixed associations with celiac disease prevalence.

Mode of presentation and performance of serology assays for diagnosing celiac disease: A single-center study in the United Arab Emirates

Objective

To characterize patients with celiac disease (CD), examines the clinical spectrum of CD, and evaluate the performance of serologic tests used for CD screening, in the United Arab Emirates (UAE).

Methods

Medical charts of patients received at the Digestive Diseases Institute of Cleveland Clinic Abu Dhabi from January 2015 to December 2020 were reviewed. Patients who were screened for four serologic biomarkers (anti-tissue transglutaminase IgA [Anti-tTG-IgA], anti-tissue transglutaminase IgG [Anti-TtG-IgG], anti-deamidated gliadin peptide IgG [Anti-DGP-IgG], and anti-deamidated gliadin peptide IgA [Anti-DGP-IgA]) were included. Histopathology was performed on patients with the seropositive test. Marsh score &gt; 1 considered to confirm CD. Characteristics of the Anti-tTG-IgA seropositive patients were described and that correlated with histopathologically confirmed CD were explored.

Results

Of the 6,239 patients, 1.4, 2.9, 4.7, and 4.9%, were seropositive to Anti-tTG-IgG, Anti-TtG-IgA, Anti-DGP-IgA, and Anti-DGP-IgG, respectively. Overall, 7.7% were seropositive to either of the four biomarkers. Of the biopsy-screened 300 patients, 38.7% (1.9% of the total serologically screened) were confirmed with CD. The mean age of Anti-TtG-IgA seropositive patients was 32.1 ± 10.3 SD years, 72% of them were females, and 93.4% were Emirati. In those patients, overweight (28.7%) and obesity (24.7%) were common while 5.8% of patients were underweight. Anemia prevalence was 46.7%, 21.3% had Gastroesophageal reflux disease (GERD), 7.7% with autoimmune thyroid disease, 5.5% (type 1), and 3.3% (type 2) were diabetic. Vitamin D deficiency was observed in 47.8% of the Anti-TtG IgA seropositive patients. Twelve (10.3%) histopathologically confirmed CD patients were seronegative to Anti-TtG-IgA but seropositive to anti-DGP-IgA and/or Anti-DGP-IgG. Body mass index, GERD, autoimmune thyroid disease, type 1 diabetes, asthma, hemoglobin, and vitamin D concentration, were all correlated with biopsy-confirmed CD (P &lt; 0.05). Compared to the gold-standard biopsy test, Anti-TtG-IgA had the highest sensitivity (89.7%) and specificity (83.7%).

Conclusion

Three and two of every 100 patients were serologically (anti-tTG-IgA positive) and histopathologically diagnosed with CD, respectively. Although Anti-TtG-IgA is the most sensitive, specific, and commonly used test, one of every ten histopathologically confirmed patients and Anti-tTG-IgA seronegative were seropositive to Anti-DGP. To avoid missing patients with CD, a comprehensive serological investigation covering DGP-IgG/IgA is warranted.

Wheat consumption and prevalence of celiac disease: Correlation from a multilevel analysis

Celiac disease (CD) is triggered by both genetic and environmental factors. More than 1% of the world's population is affected by CD. In recent years, studies have confirmed a worldwide rising trend in CD prevalence. "Westernized diet" is one of the main factors of this increasing prevalence. However, the relationship between wheat consumption, its dynamics, and CD has not been adequately investigated on a global scale. This study aimed to perform a multilevel analysis of the association between wheat consumption and CD. Wheat consumption data from countries and continents were obtained from the database. The relative increase/decrease in wheat consumption over a long period (since 1961) and a short period (since 2004) were calculated using various statistical tools. The relationship between wheat consumption and celiac frequency was determined using the R-commander R package version 2.6-2. Pearson's correlation coefficient (r = 0.88) confirmed a high positive correlation between wheat consumption and the prevalence of biopsy-proven CD by estimating continent-wide wheat consumption data, but an insignificant correlation was found when the data were compared country-wide.

HLA Haplotype Association with Celiac Disease in Albanian Pediatric Patients from Kosovo

Genetic predisposition to celiac disease (CD) is strongly associated with the presence of HLA alleles in the individual genotype encoding HLA-DQ2 and/or HLA-DQ8 heterodimers. The main aim of this study was to analyze the HLA-A, -B, -DRB1, and -DQ allele and five-locus haplotype frequencies in 60 Albanian pediatric CD patients and 124 non-CD children from Kosovo. The most prevalent haplotype in patients was the ancestral AH 8.1 haplotype present in 22.5% of the cases compared to 2.8% of the controls (P < 0.0001). Additionally, two other haplotypes were also overrepresented in patients (HLA-A^∗02~B^∗50~DRB1^∗07~DQA1^∗02:01~DQB1^∗02:02 and HLA-A^∗68~B^∗44~DRB1^∗07~DQA1^∗02:01~DQB1^∗02:02). Analysis showed that 95.0% of CD patients and 43.3% of controls were carriers of HLA-DQ2 and/or HLA-DQ8 heterodimers. The most frequent CD-predisposing HLA-DQ haplotypes in patients were HLA-DQ2.5 (46.7%) and HLA-DQ2.2 (11.6%), while the most prevalent genotypes were HLA-DQ2.5/DQX (58.3%) and HLA-DQ2.5/DQ2.2 (20.0%). The frequency of the HLA-DQ8 heterodimer among CD patients (4.2%) compared to the control group (8.1%) was without statistical significance. The given data demonstrate differences in the distribution of HLA haplotypes among Albanian CD patients from Kosovo in comparison to other European and non-European populations, as well as provide additional population data to supplement the thus far undisputed importance of the role of HLA-DQ2 and HLA-DQ8 heterodimers in the development of CD.

Prevalence of autoimmune diseases and clinical significance of autoantibody profile: Data from National Institute of Hygiene in Rabat, Morocco

AIM

The objective of this study was to explore the prevalence of various autoimmune diseases (AIDs) in a large cohort of patients and to characterize the autoantibody profile in the patients with and without AIDs to confirm the diagnosis and to refine the Moroccan databases.

PATIENTS AND METHOD

Retrospective study was conducted in the Laboratory of autoimmunity National Institute of Hygiene (NIH) of Rabat in Morocco. A total of 3182 consecutive Moroccan patients (2183 females and 999 males) whose sera were tested for 14 autoantibody profile between 2010 and 2016.

RESULTS

Only 944 (29.7%) patients were diagnosed with AIDs of those suspected. The prevalence of systemic lupus erythematosus (SLE), intestinal malabsorption (IM) and arthritis polyarthralgia (AP) were the highest (4.2, 4.1 and 4%), subsequently followed by rheumatoid arthritis (RA) (2.8%), cholestatic syndrome (CS) (1.8%), interstitial lung disease (ILD) (1.6%).In females IM, AP and SLE also showed the highest prevalence (5.4%, 5.3% and 4.9% respectively), while of male, SLE showed the highest prevalence (1.9%). The prevalence of ANA was increased in most patients with systemic especially in neuropathy (NP), hemolytic anemia (HA), primary Sjogren's syndrome (pSS), dermatomyositis (DM), thrombocytopenia (Tb), systemic sclerosis (SSc), ANCA-associated vasculitis (AAV), AP, Renal impairment (RI), SLE, and mixed connective tissue disease (MCTD). Anti-dsDNA antibodies were higher in SLE and ENA showed the highest titers in MCTD. Others are relatively specific for certain disease, such as anti β2GP1 for thrombosis syndrome, anti ANCA for primary sclerosing cholangitis (PSC), AAV, ILD and RI, anti CCP2 for RA, ILD and AP. the prevalence of anti AMA was higher in primary biliary cirrhosis (PBC), followed in CS, also, ANA have been identified in up to 25% of patients with primary biliary cirrhosis. The prevalence of anti-SMA was higher in PBC, treated patients for Chronic hepatitis C (HCV), and autoimmune hepatitis (AIH) and anti-PCA was higher in biermer anemia patients with vitamin B12 deficiency (BA/Def vit B12). The prevalence of IgA EMA, IgA tTG and IgA AGA were higher in patients IM and celiac disease (CD). The prevalence of anti thyroperoxidase (TPO) was significantly increased in the autoimmune thyroiditis (AIT).

CONCLUSION

Our study shows the diagnostic value of auto antibodies in AIDs. It would be interesting to carry out prospective studies on each pathology separately, in order to fill the classic vagaries of the retrospective study and objectively estimate the prevalence in different AIDs. These data on the prevalence of each autoimmune disease are valuable for the public health system.

Frequency of HLA-DQ, susceptibility genotypes for celiac disease, in Brazilian newborns

Background

The frequency of HLA‐DQ2 and DQ8 predisposing genotypes for celiac disease (CD) has shown significant variation among different world regions and has not been previously determined among the highly interbred Brazilian population. The aim of this study was to investigate the frequency of these genotypes among Brazilian newborns (NB).

Methods

We typed DQA1*05 ‐ DQB1*02 (DQ2.5) and DQA1*03 ‐ DQB1*03:02 (DQ8) alleles in 329 NB using qPCR technique. Subsequently we confirmed our results by PCR‐SSP using a reference kit which further identified DQ2.2 (DQA1*02:01 ‐ DQB1*02).

Results

Among the 329 NB, using qPCR technique: 5 (1.52%) carried both DQ2.5 and DQ8 variants; 58 (17.63%) carried only DQ2.5 (DQA1*05 and DQB1*02) and 47 (14.29%) carried only the DQ8 (DQA1*03 and DQB1*03:02) variant. The use of the PCR‐SSP method yielded further information; among the 329 samples: 34 (10.34%) tested positive for DQ2.2 and among the 47 previously DQ8 positives samples, we found 10 (3.04%) that also tested positives for DQ2.2.

Conclusion

43.7% of the analyzed individual tested positive for at least one of the CD predisposing HLA‐DQ genotypes in our group of Brazilian NB. The highest frequency was found for DQ2.5 positive subjects (17.6%) followed by DQ8 (11.3%); DQ2.2 (10.3%); DQ8 and DQ2.2 (3.0%); DQ2.5 and DQ8 (1.5%). We found no positive sample for DQ2.5 associated with DQ2.2.

Genome Database of the Latvian Population (LGDB): Design, Goals, and Primary Results

BACKGROUND

The Genome Database of the Latvian Population (LGDB) is a national biobank that collects, maintains, and processes health information, data, and biospecimens collected from representatives of the Latvian population. These specimens serve as a foundation for epidemiological research and prophylactic and therapeutic purposes.

METHODS

Participant recruitment and biomaterial and data processing were performed according to specifically designed standard protocols, taking into consideration international quality requirements. Legal and ethical aspects, including broad informed consent and personal data protection, were applied according to legal norms of the Republic of Latvia.

RESULTS

Since its start in 2006, the LGDB is comprised of biosamples and associated phenotypic and clinical information from over 31,504 participants, constituting approximately 1.5% of the Latvian population. The LGDB represents a mixed-design biobank and includes participants from the general population as well as disease-based cohorts. The standard set of biosamples stored in the LGDB consists of DNA, plasma, serum, and white blood cells; in some cohorts, these samples are complemented by cancer biopsies and microbiome and urine samples. The LGDB acts as a core structure for the Latvian Biomedical Research and Study Centre (BMC), representing the national node of Latvia in Biobanking and BioMolecular resources Research Infrastructure - European Research Infrastructure Consortium (BBMRI-ERIC).

CONCLUSIONS

The development of the LGDB has enabled resources for biomedical research and promoted genetic testing in Latvia. Further challenges of the LGDB are the enrichment and harmonization of collected biosamples and data, the follow-up of selected participant groups, and continued networking and participation in collaboration projects.

The distribution of HLA DQ2 and DQ8 haplotypes and their association with health indicators in a general Danish population

Background

Human leukocyte antigen (HLA) DQ2 and DQ8 are important risk factors for some autoimmune diseases such as celiac disease (CD), but their possible role in other diseases and health conditions is not fully explored.

Objectives

The objective of this article is to examine the distribution of HLA DQ2 and HLA DQ8 in an adult general population, and their association with health indicators (diseases, symptoms and biomarkers).

Methods

In this cross-sectional, population-based study, 2293 individuals were screened for HLA DQ2 and DQ8; CD-associated alleles (DQA*0201*03*05/DQB*02*0301/0304*0302/0305) and DQB1*02 homozygosity were determined for screen-positive participants. The National Patient Registry provided diagnosis information.

Results

A total of 47.7% (1093/2293) individuals were positive for DQ2 and/or DQ8: 31.2% (716/2293) only DQ2, 11.9% (273/2293) only DQ8, 4.1% (93/2293) both DQ2 and DQ8. Among nine individuals diagnosed with CD, 89.9% (8/9) had DQ2.5cis, 22.2% (2/9) DQ8 and 22.2% (2/9) DQ2.2 (two both DQ2 and DQ8). HLA DQ2.5 was associated with higher thyroid-stimulating hormone levels, while DQ2/DQ8-positive participants had significantly lower prevalence of irritable bowel syndrome (IBS). DQ2/DQ8 were strongly associated with CD, but no other registry-based diagnoses.

Conclusion

In this general Danish population, 47.7% were HLA DQ2/DQ8 positive and thus potentially at risk for CD. All individuals with CD were DQ2/DQ8 positive; the majority DQ2.5. Surprisingly, DQ2/DQ8-positivity was associated with lower IBS prevalence.

Correlation Between Cut-off Level of Tissue Transglutaminase Antibody and Marsh Classification

BACKGROUND

Duodenal biopsy is required for diagnosis of celiac disease in adults, although some studies have suggested adequate accuracy of serology alone.

Objective: We aimed to assess the correlation between anti-tissue transglutaminase (tTG) titer and pathological findings and to define the specific level of tTG for predicting celiac disease in adults without the need for biopsy sampling.

METHODS

This descriptive study was done on 299 participants. The tTG titer and pathological findings of duodenal biopsy samples were used for this study. Analysis of Receiver operating characteristic (ROC) curve was used to find a cut-off point of anti-tTG antibody for mucosal atrophy.

RESULTS

Mean tTG titers was significantly higher in patients graded as Marsh III≥ 3 (p=0.023). ROC curve analysis showed 89.1% sensitivity for cut-off point≥76.5 IU/mL of anti-tTG. For Marsh≥ II, specificity was 28% and positive predictive value was 91%.CON

CLUSION

There is a linear correlation between increasing tTG level and Marsh I to III. Specificity of tTG titer more than 200 was 100% for Marsh >2.