Towards an individual screening strategy for first-degree relatives of celiac patients

Prevalence of Coagulopathy in Patients with Celiac Disease: A Single-Center Retrospective Case-Control Study

Introduction: Despite being one of the most frequent chronic digestive diseases worldwide, with a prevalence of 1%, celiac disease (CD) remains severely underdiagnosed. Among the instruments used to improve its diagnostic rate, hematologic parameters have been proposed as screening tests to select patients with an increased probability of having CD. Assessment of coagulation is included in routine check-ups, and CD has been reported to be associated with coagulopathy. We aimed to assess if subtle changes in coagulation tests could be used in clinical practice to prompt testing for CD. Methods: We retrospectively recruited all patients with clinical suspicion for CD during a study period of 7 years (between 2015 and 2022), who were tested using IgA tissue transglutaminase (tTG) serology and serum total IgA (IgG tTG in case of IgA deficiency) and who underwent upper gastrointestinal endoscopy with multiple biopsy sampling of the duodenal bulb and distal duodenum. We stratified patients into three groups: newly diagnosed CD, gluten-free diet-treated CD, and non-CD controls. Results: Altogether, there were 133 CD patients (71 newly diagnosed, 62 GFD-treated) and 57 non-CD controls. Mean age and gender distribution were similar among the three groups: 43.3 years for newly diagnosed CD, 41.6 years for non-CD controls, and 44 years for GFD-treated CD patients, with a male gender distribution of 21.1%, 28%, and 24.1%, respectively. Among the included newly diagnosed CD patients, 14% had a prolonged INR. The mean INR was slightly higher in newly diagnosed CD patients, compared to GFD-treated CD patients and non-CD controls: 1.12 ± 0.30, 1.02 ± 0.83, and 1.00 ± 0.08, respectively (p = 0.009). Consequently, prothrombin activity was slightly lower in newly diagnosed CD patients, compared to GFD-treated CD and non-CD controls: 94.9 ± 19.3%, 102.3 ± 12.8%, and 101.9 ± 15.15, respectively. Interestingly, after GFD, the mean INR and prothrombin activity of CD individuals reached a value similar to that of non-CD controls. Conclusions: Subtle changes in INR, defined as a value within the normal range, but closer to the upper limit, could be an indicator of probability for CD.

Celiac Disease Genetics, Pathogenesis, and Standard Therapy for Japanese Patients

Celiac disease is an autoimmune disease primarily affecting the small intestine that is caused by the ingestion of gluten in genetically susceptible individuals. The development of celiac disease is based on a complex immune response to gluten proteins. The global average prevalence in the general population is about 1%. In recent years, it has become clear that celiac disease is not less common in Asian countries than in Western countries but often remains undiagnosed. Although the number of patients with celiac disease in Asia is expected to increase with improving disease recognition and advances in diagnostic techniques, there remain few reports of celiac disease in the Far East region of Asia, especially in Japan. In this paper, we outline the epidemiology, diagnosis, and treatment of celiac disease. In addition, we summarize the reported Japanese cases of celiac disease with an overview in Japan.

Prediction Models for Celiac Disease Development in Children From High-Risk Families: Data From the PreventCD Cohort

BACKGROUND & AIMS

Screening for celiac disease (CD) is recommended in children with affected first-degree relatives (FDR). However, the frequency of screening and at what age remain unknown. The aims of this study were to detect variables influencing the risk of CD development and develop and validate clinical prediction models to provide individualized screening advice.

METHODS

We analyzed prospective data from the 10 years of follow-up of the PreventCD-birth cohort involving 944 genetically predisposed children with CD-FDR. Variables significantly influencing the CD risk were combined to determine a risk score. Landmark analyses were performed at different ages. Prediction models were created using multivariable Cox proportional hazards regression analyses, backward elimination, and Harrell's c-index for discrimination. Validation was done using data from the independent NeoCel cohort.

RESULTS

In March 2019, the median follow-up was 8.3 years (22 days-12.0 years); 135/944 children developed CD (mean age, 4.3 years [range, 1.1-11.4]). CD developed significantly more often in girls (P = .005) and in Human Leukocyte Antigen (HLA)-DQ2 homozygous individuals (8-year cumulative incidence rate of 35.4% vs maximum of the other HLA-risk groups 18.2% [P < .001]). The effect of homozygosity DR3-DQ2/DR7-DQ2 on CD development was only present in girls (interaction P = .04). The prediction models showed good fit in the validation cohort (Cox regression 0.81 [0.54]). To calculate a personalized risk of CD development and provide screening advice, we designed the Prediction application https://hputter.shinyapps.io/preventcd/.

CONCLUSION

Children with CD-FDR develop CD early in life, and their risk depends on gender, age and HLA-DQ, which are all factors that are important for sound screening advice. These children should be screened early in life, including HLA-DQ2/8-typing, and if genetically predisposed to CD, they should get further personalized screening advice using our Prediction application.

TRIAL REGISTRATION NUMBER

ISRCTN74582487 (https://www.isrctn.com/search?q=ISRCTN74582487).

Coeliac disease re-screening among once seronegative at-risk relatives: A long-term follow-up study

BACKGROUND

Serological screening of the relatives of coeliac disease patients is widely endorsed. However, the need for and the optimal timing of possible re-testing of once seronegative at-risk individuals for coeliac disease remain unclear.

OBJECTIVE

We investigated this issue by inviting a large cohort of previously screening-negative relatives of patients with coeliac disease to participate in a follow-up study.

METHODS

Altogether 599 relatives of coeliac disease index patients not diagnosed with coeliac disease in a screening study carried out in 2006-2010 were asked about possible later diagnosis or re-tested with coeliac disease autoantibodies in 2017-2021. Besides incidence, the possible impact of various patient-related clinical factors and HLA haplotype on the later diagnosis or screening positivity was examined.

RESULTS

Fifteen (2.5%) relatives were either diagnosed with a coeliac disease (n = 8) during the follow-up period or were found to be screening-positive in the re-testing (n = 7), giving a combined annual incidence of 221/100,000 person-years in all relatives and 336/100,000 among those carrying coeliac disease-associated HLA DQ2/DQ8. The new cases more often carried the high-risk (DQ2.5/2.5 or DQ2.5/2.2; 35.7% vs. 7.4%, respectively, p < 0.001) HLA and were younger at initial screening (23.3 vs. 40.5 years, p = 0.028) and - in spite of a negative screening outcome - had higher median transglutaminase antibody level in the first study than those not affected. There were no significant differences between the affected and non-affected relatives in other demographic data, degree of kinship with the index, current symptoms or frequency of chronic co-morbidities.

CONCLUSION

The incidence rate for later coeliac disease diagnosis or new seropositivity in relatives who had been tested once was 221/100,000 person-years in all and 336/100,000 among those carrying at-risk HLA genetics after ∼10 years of follow-up. HLA-typing could help to target a subgroup of relatives who would benefit most from re-testing.

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

BACKGROUND

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Clinical Presentation in Children With Coeliac Disease in Central Europe

OBJECTIVES

During the past decades, there has been a shift in the clinical presentation of coeliac disease (CD) to nonclassical, oligosymptomatic, and asymptomatic forms. We assessed clinical presentation of CD in children and adolescents in Central Europe.

METHODS

Paediatric gastroenterologists in 5 countries retrospectively reported data of their patients diagnosed with CD. Clinical presentation was analyzed and the differences among very young (<3 years) and older children and adolescents were studied.

RESULTS

Data from 653 children and adolescents (median age 7 years 2 months; 63.9% girls) from Croatia, Germany, Hungary, Italy, and Slovenia were available for the analysis. One fifth (N = 134) of all children were asymptomatic. In symptomatic children, the most common leading symptom was abdominal pain (33.3%), followed by growth retardation (13.7%) and diarrhoea (13.3%). The majority of symptomatic children (47.6%; N = 247) were polysymptomatic. Abdominal pain was the most common symptom in polysymptomatic (66.4%) as well as in monosymptomatic children (29.7%). Comparing clinical presentation of CD in very young children (younger than 3 years) with older children (3 years or older), we found that symptoms and signs of malabsorption were significantly more common in younger (P < 0.001), whereas abdominal pain and asymptomatic presentation were more common in older children and adolescents (both P < 0.001).

CONCLUSION

In children with CD, abdominal pain has become the most common symptom. However, in younger children, symptoms of malabsorption are still seen frequently. This raises a question about the underlying mechanism of observed change in clinical presentation in favour of nonclassical presentation and asymptomatic disease at certain age.

Differences Between Familial and Sporadic Celiac Disease

BACKGROUND

It is not known if genetic background, characteristics at diagnosis, physical and psychological well-being, and adherence to a gluten-free diet are comparable between patients with familial or sporadic celiac disease. These issues were investigated in a follow-up study.

METHODS

Altogether 1064 patients were analyzed for celiac disease-associated serology, predisposing HLA-DQ, and non-HLA genotypes. Medical data were collected from patient records and supplementary interviews. Current symptoms and quality of life were further evaluated with the Gastrointestinal Symptom Rating Scale (GSRS), the Psychological General Well-Being questionnaire (PGWB), and Short Form 36 (SF-36) questionnaires.

RESULTS

Familial and sporadic groups differed (P < 0.001) in the reason for diagnosis and clinical presentation at diagnosis, familial patients being more often screen-detected (26% vs. 2%, P < 0.001) and having less often gastrointestinal (49% vs. 69%) and severe symptoms (47% vs. 65%). The groups were comparable in terms of histological damage, frequency of malabsorption, comorbidities, childhood diagnoses, and short-term treatment response. At the time of the study, familial cases reported fewer symptoms (21% vs. 30%, P = 0.004) and lower prevalence of all (78% vs. 86%, P = 0.007), neurological (10% vs. 15%, P = 0.013), and dermatological (9% vs. 17%, P = 0.001) comorbidities. Dietary adherence and GSRS scores were comparable, but familial cases had better quality of life according to PGWB and SF-36. High-risk genotype HLA-DQ2.5/DQ2.5 was more frequent among familial cases, and four non-HLA SNPs were associated with familial celiac disease.

CONCLUSIONS

Despite the greater proportion of high-risk genotypes, familial cases had milder symptoms at presentation than did sporadic cases. Worse experience of symptoms and poorer quality of life in sporadic disease indicate a need for intensified support.

The HLA complex and coeliac disease

The Human Leukocyte Antigen (HLA) has a crucial role in the development and pathogenesis of coeliac disease (CD). The genes HLA-DQA1 and HLA-DQB1, both lying in this region and encoding the HLA-DQ heterodimer, are the main genetic predisposing factors to CD. Approximately 90% of CD patients carry the heterodimer HLA-DQ2.5, leaving only a small proportion of patients with lower risk heterodimers (HLA-DQ8, HLA-DQ2.2 or HLA-DQ7.5). These HLA-DQ molecules act as receptors present in the surface of antigen presenting cells and show high affinity for deamidated gluten peptides, which bind and present to CD4⁺ T cells. This triggers the immunological reaction that evolves into CD. Since specific HLA genetics is present in almost the totality of CD patients, HLA typing has a very high negative predictive value, and it can be used to support diagnosis in specific scenarios. HLA risk has been associated to different CD-related features, such as age at onset, clinical outcomes, antibody levels and grade of histological lesion; but further research is needed. HLA-DQ genotypes have been also suggested to modulate the composition of the gut microbiota.

Celiac Disease Screening for High-Risk Groups: Are We Doing It Right?

Celiac disease (CD) is an immune-mediated enteropathy triggered by dietary ingestion of gluten in genetically susceptible patients. CD is often diagnosed by a "case-finding" approach of symptomatic patients. In recent times, the diagnostic paradigm has shifted to investigate patients who may be asymptomatic, but are at high risk of developing CD due to shared genetic susceptibilities. These high-risk groups include first-degree relatives of CD patients and patients with Type 1 diabetes mellitus, autoimmune thyroid disease, Down's syndrome, and Turner syndrome. Moreover, CD is often diagnosed as the cause of iron deficiency anemia or unexplained chronic diarrhea. Although screening for CD with serological tests is not recommended for the general population, it should be considered in these special populations. In this review, we explore screening for CD among high-risk groups in light of recent research and development in the CD arena.

Very Low Birth Weight Preterm Infants have Decreased Celiac Disease Autoimmunity During Childhood and Adolescence

Little is known about the effect of prematurity on later development of celiac disease (CD). We conducted a retrospective analysis of real-world data examining the association between very low birth weight (VLBW) prematurity and later development of CD autoimmunity (CDA) in 3580 infants born between years 2000 and 2012 and their matched controls. At a median of 12 years, VLBW prematurity was negatively associated with later development of CDA with a cumulative prevalence of 5.9 per 1000 versus 10.3 per 1000 (P = 0.02), though more former VLBW premature infants were ever tested for CDA (48.5% vs 37.4%, P < 0.001). The odds ratio for developing CDA among children born preterm at VLBW was 0.57 (95% confidence interval (CI) 0.35-0.92) as compared with matched controls. There was no difference in clinical characteristics of CDA between both groups. In conclusion, VLBW preterm infants present a decreased risk for the development of CDA during childhood and adolescence.

Testing for IgA anti-tissue transglutaminase in routine clinical practice: Requesting behaviour in relation to prevalence of positive results

OBJECTIVE

Due to the high awareness of coeliac disease and improvement of serological tests, the number of requested laboratory tests has increased substantially over the years. In the current study we have evaluated the requesting behaviour of distinct clinical disciplines in relation to the prevalence of positive results and in the context of existing guidelines.

METHODS

Data were retrospectively extracted from the laboratory information system over a time-span of 5 years in a tertiary hospital and compared with the situation in a secondary hospital.

RESULTS

Data reveal that for initial testing (n=18,183) the percentage positive results for IgA anti-TTG is <2%. Paediatricians have a slightly higher percentage of seropositive results (2.4-4.0%). Early confirmation (<2 months) of positive results by IgA anti-endomysium antibodies in an independent sample is only performed in a minority of paediatric patients. The majority of positive patients, however, have follow-up measurements (<14 months) in order to examine compliance to a gluten-free diet. Interestingly, initial requests for paediatric patients reveal an equal distribution between boys and girls, while in adult patients there is a two times preponderance of requests in female patients, similar to the female/male ratio in patients with positive results, being either paediatric or adult patients.

CONCLUSION

Although laboratory testing for coeliac disease may be primarily used to exclude the disease, it is evident that the percentage positive results for IgA anti-TTG is extremely low. This may indicate that the clinical manifestations that warrant testing, should be further specified in order to increase the pre-test probability. As the specific serology is important to bypass a biopsy in the diagnosis of coeliac disease according to the paediatric guideline, the confirmation in an independent sample needs to get more attention.

A Clinician's Guide to Celiac Disease HLA Genetics

Celiac disease is a common inflammatory disease triggered by dietary gluten in genetically susceptible individuals. The strongest and best-characterized genetic susceptibilities in celiac disease are class II human leukocyte antigen (HLA) genes known as HLA-DQ2 and DQ8. HLA genetic testing is available through a number of commercial and academic laboratories and is used in the evaluation of celiac disease and to identify at-risk family members. Importantly, HLA genetic testing has a high negative predictive value for celiac disease, but a low positive predictive value. Therefore, for a practicing clinician, it is important to understand when to order HLA genetic testing, what test to order, and how to interpret the result. This review provides a practical primer on HLA genetics in celiac disease.

HLA-DQB1*02 allele in children with celiac disease: Potential usefulness for screening strategies

Through a retrospective analysis of a real-life cohort of children with celiac disease (CD), who underwent HLA-DQ genotyping, we supported our previous findings indicating the presence of HLA-DQB1*02 allele in at least 90%-95% of pediatric patients. In the present study, reporting the HLA-DQ analysis from 184 children (age range: 1-16 years) diagnosed with CD in a single centre, we found that 97.29% of all these CD children (n = 179 out of 184 genotyped patients) resulted to be carriers of at least one copy of HLA-DQB1*02 allele. If a widened screening for CD should result to be appropriate in the pediatric population after further clinical research, this observation might be potentially exploited to consider a two-step screening strategy, starting with the HLA-DQB1*02 targeted analysis followed by the specific serology for CD in these predisposed patients only. However, additional and larger studies are needed to support our findings.

Relevance of HLA-DQB1*02 Allele in the Genetic Predisposition of Children with Celiac Disease: Additional Cues from a Meta-Analysis

Background and Objectives: Celiac disease (CD) is a multifactorial immune-mediated disorder, triggered by the ingestion of gluten in genetically-predisposed subjects carrying MHC-DQ2 and -DQ8 heterodimers, which are encoded by four HLA-DQ allelic variants, overall. This meta-analysis aims at providing further epidemiological support to the predominant relevance of one specific allele, namely HLA-DQB1*02, in the predisposition and genetic risk of CD. Materials and Methods: We performed a search of MEDLINE/PubMed, Embase, Web of Science, and Scopus, retrieving all publications (case-control study, cross-sectional, and retrospective cohort study) on the association between HLA class II polymorphisms and first-degree relatives (FDRs) of children with CD. After a critical reading of the articles, two investigators independently performed data extraction according to the following inclusion criteria: HLA class II genes, any DQ and DR molecules, and CD diagnosed following the current clinical guidelines. A third participant was consulted for discussion to reach an agreement concerning discrepancies. Results: Our search strategy selected 14 studies as being eligible for inclusion, and those were submitted for data extraction and analysis. These studies were published between 1999 and 2016 and, collectively, enrolled 3063 FDRs. Positive and negative likelihood ratios (LR+ and LR-, respectively) for CD diagnosis, according to the presence of the HLA-DQ genotype coding a complete MHC-DQ2 and/or MHC-DQ8 molecules, were 1.449 (CI 1.279-1.642) and 0.187 (CI 0.096-0.362), respectively. If only the isolated presence of HLA-DQB1*02 allele is considered, the pooled estimation of LR+ was 1.659 (CI 1.302-2.155) and, importantly, the LR- still showed a very good discriminatory power of 0.195 (CI 0.068-0.558). Conclusions: Through our differential meta-analysis, comparing the presence of the genotype coding the full MHC-DQ2 and/or DQ8 molecules with the isolated presence of HLA-DQB1*02 allelic variant, we found that the LR- of the latter analysis maintained the same value. This observation, along with previous evidences, might be useful to consider potential cost-effective widened screening strategies for CD in children.

Pediatric Celiac Disease in Central and East Asia: Current Knowledge and Prevalence

The current prevalence of pediatric Celiac Disease (CD) is estimated to be around 1% in the general population, worldwide. However, according to the geographic area, a great variability of CD prevalence has been described. Whereas a number of studies are available from Europe, North and South America, Australia, South-West Asia, and North Africa, the knowledge and awareness of CD in large parts of the remaining world areas is definitively poor. In several countries of Central and East Asia, the consumption of wheat is consistent and/or has significantly increased in recent decades, and CD is supposed to be underdiagnosed in children. In this mini-review, we aimed to summarize the current knowledge about the prevalence of pediatric CD in Central and East Asia, paying attention to the HLA-DQ immunogenetic background as well. Indeed, CD is likely not to be as uncommon as previously or currently thought in countries like Russia, Kazakhstan, and China, in addition to India, where pediatric CD has been clearly showed to be quite prevalent. Therefore, there is an urgent need for population-based studies on the prevalence of CD in those countries, especially in children, in order to increase the awareness of this disease and to improve the diagnostic strategy in these areas.