An algorithm for family screening for coeliac disease

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.

HLA Profile of Celiac Disease among First-Degree Relatives from a Tertiary Care Center in North India

OBJECTIVE

To study the prevalence of Celiac disease (CD) in first-degree relatives (FDR) of CD children.

METHODS

This observational study was performed in FDR (parents and siblings) of consecutive newly diagnosed cases of CD enrolled from January 2011 through March 2012. Screening for CD in FDR was done using IgA tissue transglutaminase (tTG) levels in serum and the seropositive subset underwent upper gastrointestinal (UGI) endoscopy and biopsy to confirm the disease. In addition, HLA analysis for CD was performed in most of the index cases and FDR.

RESULTS

Of 202 FDR of the 64 index cases with CD, 17.3 % (35/202) were seropositive for IgA tTG while confirmed biopsy proven CD was diagnosed in 10.2 % (8/78) of children and 8.1 % (10/124) of adults. HLA DQ2/DQ8 was positive in 96.7 % of the index cases and all FDR with confirmed CD.

CONCLUSIONS

The prevalence of CD among FDR is 9 fold higher than the general population. High prevalence of CD in presence of anemia and short stature in seropositive FDR in index study indicates need of targeted screening of this subgroup for the presence of CD.CD is unlikely in the absence of HLADQ2/DQ8.

Risk of Celiac Disease in the First- and Second-Degree Relatives of Patients With Celiac Disease: A Systematic Review and Meta-Analysis

OBJECTIVES

First-degree relatives (FDRs) of patients with celiac disease (CD) are at high risk for CD and prevalence among them varies from 1.6 to 38%. The risk of having CD among FDRs if the FDR is sister, brother, mother, father, son, or daughter of index patient with CD is not known. We conducted a meta-analysis and calculated pooled prevalence of CD among FDRs, second-degree relatives (SDRs), and specific relations with index patient.

METHODS

On search of literature, 2,259 articles appeared of which 54 articles were included in this meta-analysis. Diagnosis of CD was based on standard criteria.

RESULTS

Pooled prevalence of CD was 7.5% (95% confidence interval (CI) 6.3%, 8.8%) in 10,252 FDRs and 2.3% (95% CI 1.3%, 3.8%) in 642 SDRs. Pooled prevalence of CD was highest in siblings (8.9%), followed by offsprings (7.9%) and parents (3.0%). Female FDRs had higher prevalence than male FDRs (8.4% vs. 5.2%, P=0.047). While sisters and daughters of index patient had the highest risk of having CD (1 in 7 and 1 in 8, respectively), the risk was 1 in 13 in sons, 1 in 16 in brothers, 1 in 32 in mothers, and 1 in 33 in fathers. There were also differences in the pooled prevalence of CD in FDRs according to their geographic location.

CONCLUSIONS

Pooled prevalence of CD among FDRs is 7.5% and varies considerably with their relationship with the index patient. The risk of CD in FDRs also varies according to gender and geographical location.

[Should the whole population be screened for coeliac disease?]

To address the issue of mass screening in coeliac disease strict criteria shall be defined. Principles and practice of screening for disease have been defined 40 years ago by Wilson and Jungner, there are still accurate and applied, specially in France for neonatal screening. Screening the whole population for gluten intolerance is not recommended at this time. Aress with gap in scientific knowledge are identified and further prospective epidemiologic studies are needed. These include the timing of screening, defining the natural history of screening-identified asymptomatic patients, developing tools to predict disease onset and disease remission and the potential risks of screening. At the present time, only identification and testing of high-risks groups is recommended.

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

OBJECTIVES

Celiac disease, an autoimmune enteropathy that affects the proximal small intestine, is characteristically seen in people who have a genetic susceptibility to gluten sensitivity. Celiac patients' first-degree relatives are more at risk of acquiring the disease. The objective of the present study was consequently to determine the prevalence of celiac disease in a group of first-degree relatives of our patients with celiac disease.

METHODS

First-degree relatives of 195 patients with celiac disease attending a gastroenterology unit underwent serologic screening. Antitissue transglutaminase (anti-tTG) immunoglobulin A (IgA) and total serum IgA tests were used for first-level screening. Duodenal biopsy was recommended to subjects showing positive results to anti-tTG IgA testing. Biopsy samples were obtained by endoscopy, and biopsy specimens were evaluated and classified according to Marsh classification.

RESULTS

Positive anti-tTG IgA was found in 46 first-degree relatives (9.5%), whereas serum IgA levels were normal. Of 46 serology-positive relatives, 34 agreed to the endoscopy procedure. Histological changes characteristic of celiac disease were found in 23 subjects. The prevalence of celiac disease among the first-degree relatives was found to be at least 4.8%. Of 34 subjects that underwent biopsy, 11 were evaluated as Marsh 0, 5 as Marsh 1, 4 as Marsh 2, 12 as Marsh 3, and 2 as Marsh 4. Of the biopsy-positive subjects, 3 were mothers, 1 was a father, and 19 were siblings.

CONCLUSIONS

The present study identified 23 undiagnosed cases of celiac disease among 484 first-degree relatives of 195 patients with celiac disease, confirming the high prevalence (4.8%) of the disease in this specific group. It is suggested that an extensive screening policy be mandatory for these subjects.

Prevalence, human leukocyte antigen typing and strategy for screening among Asian first-degree relatives of children with celiac disease

BACKGROUND AND AIM

Data on prevalence, human leukocyte antigen (HLA) typing and small bowel histology among first-degree relatives of subjects with celiac disease (CD) is scarce. This prospective study evaluated the prevalence and role of HLA DQ2/8 testing in screening of first-degree relatives of children with CD.

METHODS

Thirty confirmed children with CD and 91/94 first-degree relatives (parents and siblings) were enrolled. HLA DQ2/8 testing was carried out in all index CD cases. Clinical evaluation with a questionnaire, total serum immunoglobulin A (IgA), human IgA-tissue transglutaminase (IgA-tTGA) and HLA DQ2/8 testing was carried out in all first-degree relatives. Subjects who were positive for IgA-tTGA were recommended endoscopic duodenal biopsy to document histological changes of CD.

RESULTS

Nine first-degree relatives were positive for IgA-tTGA, seven underwent duodenal biopsy and four subjects had Marsh IIIa changes suggestive of CD. The prevalence of histologically confirmed CD in first-degree relatives was 4.4%. The prevalence of potential CD was 9.8%. IgA-tTGA-positive subjects (4/9) were significantly more often symptomatic than IgA-tTGA-negative first-degree relatives (2/82). Twenty-nine (96.6%) index cases of CD and all IgA-tTGA-positive first-degree relatives were positive for HLA DQ2. None of the index CD cases or first-degree relatives were HLA DQ8-positive. A total of 85% of the first-degree relatives were positive for HLA DQ2 and thus at risk of developing CD.

CONCLUSIONS

In this first Asian study on a limited number of families of children with CD, 4.4% of the first-degree relatives had CD. Only 15% of the first-degree relatives were negative for HLA DQ2/DQ8. Initial evaluation with HLA and serology followed by only serial serology in HLA-positive relatives is recommended.

A rapid and sensitive method to detect specific human lymphocyte antigen (HLA) class II alleles associated with celiac disease

BACKGROUND

Celiac disease (CD) is a complex disorder triggered by gluten affecting genetically predisposed individuals. More than 90% of patients carry human lymphocyte antigen (HLA)-DQ2 (DQA1*05, DQB1*02) and/or HLA-DQ8 (DQA1*03, DQB1*0302). We propose the use of the DQ-CD Typing kit that allows identification of the HLA class II alleles (DQA1*0201,*03,*05, DQB1*02,*0302, DRB1*03,*04,*07) selected to be informative in the CD risk evaluation and of a second kit, namely DQ-CD Zygosis, for DQB1*02 homozygosity determination.

METHODS

The study was performed on a cohort of 100 individuals previously HLA typed with commercial kits. Fresh blood or previously extracted DNA was amplified in a unique PCR program using allele-specific primers and visualized on agarose gel.

RESULTS

DNA amplification yielded strong and clear products without non specific signals or ghost bands. All the samples showed the expected alleles in accordance with the previous HLA typing.

CONCLUSIONS

The DQ-CD Typing and Zygosis kits are fast, simple, economical and accurate tools that can be used to determinate the HLA-DQ2/DQ8 status in laboratory practice addressed for the diagnosis of CD. Molecular HLA testing is considered a valid support in the confirmation/exclusion of CD, especially in high-risk groups, such as CD relatives, or when serological and histological data are ambiguous.

Natural history of antibodies to deamidated gliadin peptides and transglutaminase in early childhood celiac disease

INTRODUCTION

Gliadin proteins play a key role in the pathogenesis of celiac disease; however, as a screen for celiac disease, anti-gliadin antibody testing has been replaced by the more sensitive and specific serological assays for transglutaminase autoantibodies (TGAA). A new generation of anti-gliadin antibody assays has been developed to detect synthetic, deamidated homologous gliadin peptides (DGP) with high sensitivity and specificity.

METHODS

Sera were collected prospectively from children with an increased risk for celiac disease as part of an ongoing study at Denver, and studied for the development of celiac autoimmunity. We investigated the high-performance DGP antibody assay in 50 TGAA-positive children both before the development of celiac autoimmunity and following the institution of a gluten-free diet to determine the relationship of DGP antibodies to TGAA. TGAA were measured by an in-house radioassay.

RESULTS

DGP antibodies and TGAA parallel each other over the period of years children were studied. DGP antibodies resolved sooner than TGAA in subjects on a gluten-free diet. DGP antibodies appeared earlier than TGAA in 9 children.

CONCLUSIONS

Measuring DGP antibodies may be more useful than TGAA in monitoring children on a gluten-free diet. DGP antibodies can precede the appearance of TGAA in some at-risk children.