Association of insulin-dependent diabetes mellitus and celiac disease: a study based on serologic markers

Validation of a novel single-drop rapid human leukocyte antigen-DQ2/-DQ8 typing method to identify subjects susceptible to celiac disease

Background and Aim

Human leukocyte antigen (HLA)‐DQ2 and/or ‐DQ8 is an essential risk factor for celiac disease (CD). About 90–95% of patients with CD carry HLA‐DQ2/‐DQ8 alleles, and HLA‐DQ typing is considered an additional diagnostic test. Conventional polymerase chain reaction (PCR)‐based HLA‐DQ typing methods are expensive, complex, and a time‐consuming process. We assessed the efficacy of a novel HLA‐DQ typing method, “Celiac Gene Screen,” for the detection of CD‐associated HLA haplotypes.

Methods

To assess the diagnostic performance of the Celiac Gene Screen test, 100 ethylenediaminetetraacetic acid (EDTA) blood samples, already characterized by the conventional HLA‐DQ typing method, that is, PCR sequence‐specific oligonucleotide probes (PCR‐SSOP), a concordance between both the methods were explored. For validity, a further 300 EDTA blood samples with unknown HLA‐DQ status were genotyped using the Celiac Gene Screen test, including 141 samples from CD, 56 first‐degree relatives (FDRs) of CD and 103 samples from controls.

Results

Of the 100 samples with known status of HLA‐DQ alleles, 79 samples were HLA‐DQ2 and/or ‐DQ8 positive, and 21 samples were HLA‐DQ2 and/or ‐DQ8 negative by conventional PCR. These 100 samples were re‐typed using the Celiac Gene screen kit; all 79 positives were typed positive, and 21 negatives were typed negative for HLA‐DQ alleles. Among 300 samples with unknown HLA‐DQ status, 118 of 141 (84%) patients with CD, 48 of 56 (86%) FDRs of CD, and 52 of 103 (50%) controls typed positive for HLA‐DQ alleles.

Conclusions

The Celiac Gene Screen HLA‐DQ typing method showed excellent concordance with the conventional HLA‐DQ typing method and could be a cost‐reducing and effective method for CD‐associated HLA screening.

Prevalence of celiac disease in adult type 1 patients with diabetes

Objectives:

Celiac disease, an autoimmune disease, is related to immune mediated intolerance to gluten. Some studies suggest that Celiac Disease was 20 times more frequent in type 1 patients with diabetes. The objective of our study was to evaluate the prevalence of celiac disease in hospital based type 1 diabetic adults.

Methods:

Our study was carried out retrospectively in Medeniyet University Goztepe Training and Educational Hospital in Istanbul between 2012–2013. The cohort comprised 482 type 1 patients with diabetes attending the diabetes outpatient clinic. The data were analyzed by SPSS 10.5 package program. Student’s t tests is used for comparative analyses. A p-value less than 0.05 was considered statistically significant.

Results:

The cohort included 482 type 1 patients with diabetes. Fifty seven of them were not evaluated for Endomysium antibody positivity. Fifteen of the remaining 425 patients were positive for anti endomysial antibody (3.5%). The prevalence of biopsy proven celiac disease was 2.3% (10/425). There was no significant difference between Endomysial antibody positive and negative groups in regard of age, sex, or duration of the disease.

Conclusion:

This study confirms that the celiac disease is common in type 1 diabetic patients. Since a small proportion of celiac patients are symptomatic this disorder should be screened in all adult type 1 patients with diabetes by antiendomysium antibody.

Antithyroid antibodies and thyroid function in pediatric patients with celiac disease

Objective. Aim of the study was to determine the prevalence of autoimmune thyroid disease, persistence of antithyroid antibodies, effect of gluten-free diet, and long-term outcome of thyroid function in pediatric patients with celiac disease (CD). Methods. 67 patients with CD aged from 1 year to 16 years were screened for thyroid antithyroperoxidase, antithyroglobulin and anti-TSH receptor antibodies, serum free triiodothyronine, free thyroxine, and thyroid-stimulating hormone (TSH) at diagnosis and during follow-up. Results. None of the patients had antithyroid antibodies at diagnosis. Antithyroid antibodies became positive in 16.4% of the patients (11/67) 2 to 3 years after the diagnosis of CD. Clinical hypothyroidism was observed only in 3 of 11 CD patients with positive antithyroid antibodies (27.2%). The antithyroid antibodies positive and negative patients did not differ significantly according to compliance to GFD (P > 0.05). A statistically significant difference was observed only in age, in which the patients with positive antithyroid antibodies were younger than the patients with negative antithyroid antibodies (P = 0.004). None of the patients had any change in their thyroid function and antibody profile during their follow-up. Conclusion. Antithyroid antibodies were detected in younger pediatric patients with CD and the prevalence of antithyroid antibodies did not correlate with the duration of gluten intake.

Systematic review: worldwide variation in the frequency of coeliac disease and changes over time

BACKGROUND

Coeliac disease (CD), originally thought to be largely confined to Northern Europe and Australasia and uncommon in North America and the Middle East, is now recognised to be equally common in all these countries. It is still thought to be rare in the Orient and Sub-Saharan Africa.

AIM

To assess geographical differences and time trends in the frequency of CD.

METHODS

Medline and Embase searches were conducted on 10 November 2012, from 1946 and 1980 respectively, using the key words: coeliac disease or celiac disease + prevalence or incidence or frequency.

RESULTS

There were significant intra- and inter-country differences in the prevalence and incidence of CD. Only 24 ethnic Chinese and Japanese patients have been reported in the English literature. Of CD-associated HLA DQ antigens, DQ2 occurs in 5-10% of Chinese and sub-Saharan Africans, compared to 5-20% in Western Europe. DQ8 occurs in 5-10% of English, Tunisians and Iranians, but in <5% of Eastern Europeans, Americans and Asians. The prevalence and incidence of both clinically and serologically diagnosed CD increased in recent years. These geographical and temporal differences seem genuine, although variable indices of suspicion and availability of diagnostic facilities are confounding factors.

CONCLUSIONS

Coeliac disease is increasing in frequency, with significant geographical differences. Although few cases have been described to date in the Orient and Sub-Saharan Africa, there is a significant prevalence of HLA DQ2 and wheat consumption is of the same order as that in Western Europe. CD may therefore become more common in the future in these countries.

Serum autoimmune gastritis markers, pepsinogen I and parietal cell antibodies, in patients with type 1 diabetes mellitus: a 5-year prospective study

BACKGROUND AND AIM

To determine the temporal evolution of serum markers of autoimmune gastritis, mainly pepsinogen I (PI) and parietal cell antibodies (PCA), in patients with Type 1 diabetes mellitus (DM1).

MATERIALS AND METHODS

A 5-yr prospective follow-up study of 168 DM1 patients (87 men, aged 31 ± 9.3 yr) attending the endocrinology outpatient clinic of a university hospital evaluated in 2001 and 2006. Serum PI, gastrin, hemoglobin, cobalamin concentrations, PCA and antibodies to intrinsic factor were measured.

RESULTS

In 2001, 11 patients had low PI concentrations and positive PCA (group I), 11 had only low PI concentrations (group II), and 33 had only positive PCA (group III). After 5 yr, PI remained low and PCA positive in all patients from group I. In group II, PI remained low in 4 and normalized in 7. In group III, 4 patients presented low PI concentrations after 5 yr, which remained normal in the other 29 subjects. PCA became negative in 17 patients from group III. In 2001, 3 of the 11 patients of group I had low cobalamin concentrations. In 2006, 2 additional patients from this group presented low cobalamin concentrations.

CONCLUSIONS

These results show the importance of determining PI together with PCA, since the presence of abnormal results in both tests, that is low PI and positive PCA, is the association that best identifies patients with a higher risk to decrease cobalamin concentrations during follow-up.

Early pregnancy loss in celiac women: The role of genetic markers of thrombophilia

BACKGROUND

Adverse pregnancy outcomes are more frequent in celiac than in non-celiac women.

AIMS

To investigate a possible role of genetic prothrombotic variants in early pregnancy loss of celiac women.

METHODS

Thirty-nine celiac women who had experienced early pregnancy losses (at least two losses within the first 3 months of pregnancy), and 72 celiac women with a history of one or more normal pregnancies and no pregnancy loss (controls) entered the study, at the moment of diagnosis for celiac disease. A clinical history was obtained from each woman. DNA from leukocytes was tested for: factor V Leiden (mutation G1691A), factor V R2 (H1299R), factor II (G20210A), methylenetetrahydrofolate reductase (MTHFR) (C677T and A1298C), beta-fibrinogen (-455 G>A), PAI-1 alleles 4G/5G, factor XIII (V34L), and HPA-1 (L33P).

RESULTS

Age at diagnosis was significantly higher (p=0.002) in the celiac women with pregnancy losses than in controls. Of the gene variants studied, the allelic frequency of 4G variant of PAI-1, and the frequency of mutant genotypes were significantly more frequent in the group of celiac women with early pregnancy loss (p=0.00003 and 0.028, respectively). Surprisingly, the beta-fibrinogen -455 G>A genotype distribution (but not the allelic frequency of the variant allele) significantly differed between the two groups, since variant genotypes were more frequent in the control group (p=0.009).

CONCLUSION

The 4G variant of the PAI-I gene may predispose to miscarriage a subset of celiac women; these data should be verified on larger populations.

Heterogeneity of vitamin D receptor gene association with celiac disease and type 1 diabetes mellitus

OBJECTIVE

Vitamin D has been shown to exert multiple immunomodulatory effects and is known to suppress T-cell activation by binding to the vitamin D receptor (VDR). To determine whether VDR gene polymorphisms are related to the susceptibility to celiac disease, we investigated its implication as a candidate gene in the Basque population. Because celiac disease and type 1 diabetes share common susceptibility loci, we also analyzed families with type 1 diabetes mellitus.

METHODS

A total of 37 families with celiac disease and 64 type 1 diabetic families of Basque origin with at least one affected offspring were genotyped for four VDR restriction-site polymorphisms (Fok I, Bsm I, Apa I and Taq I). The AFBAC approach was used to test for association.

RESULTS

Comparison of VDR genotypes of the patients with those of 88 healthy individuals identified "ff" as a risk genotype for celiac disease [p = 0.01; OR = 3.45 (1.12-10.79)]. On the other hand, a significantly higher frequency of haplotype "fBAt" was observed in the type 1 diabetic group [p(c) = 0.02; OR = 4.4 (1.5-15.3)].

CONCLUSION

Our findings suggest that polymorphisms within the vitamin D receptor gene are markers of susceptibility to or protection from autoimmune diseases, although, at least in the Basque population, association of VDR variants with celiac disease and type 1 diabetes seems to be heterogeneous.

Autoantibody frequency in celiac disease

AIM

In our study, we investigated the levels of glutamic acid decarboxylase antibody (anti-GAD), islet cell antibody (ICA), thyroperoxidase antibody (anti-TPO), thyroglobulin antibody (anti-TG), antinuclear antibodies (FANA), antibodies to double-stranded DNA (anti-ds DNA), antibody to Sjögren syndrome A antigen (anti-SSA), antibody to Sjögren syndrome B antigen (anti-SSB), Smith antibody (anti-Sm), smooth muscle antibodies (ASMA), and antimitochondrial antibody liver-kidney microsome (AMA-LKM) in patients with celiac disease as compared to healthy controls and autoimmune hypothyroid patients.

MATERIALS AND METHODS

A total of 31 patients with celiac disease, 34 patients with autoimmune hypothyroidism and 29 healthy subjects were included in this study. Anti-SSA, anti-SSB, anti-Sm, anti-ds DNA, anti-GAD, anti-TPO and anti-TG were studied by Enzyme-Linked Immunosorbent Assay (ELISA), and AMA-LKM, ASMA, ANA and ICA were studied by immunofluorescence. Clinical data and the results of free thyroxine-thyroid stimulating hormone (FT4-TSH) were collected from the patients' files by retrospective analysis. SPSS ver 13.0 was used for data analysis, and the chi(2) method was used for comparisons within groups.

RESULTS

The frequency of anti-SSA, anti-SSB, anti-GAD, anti-Sm, anti-ds DNA, AMA-LKM, ASMA, ANA and ICA were not significantly different between the groups. Levels of anti-TPO and anti-TG antibodies were found to be significantly higher (<0.001) in autoimmune hypothyroid patients when compared with other groups.

CONCLUSION

In previous studies, an increased frequency of autoimmune diseases of other systems has been reported in patients with celiac disease. We found that the frequency of autoimmune antibodies specific for other autoimmune diseases was not higher in celiac disease.

[Impact of diagnosis of celiac disease on metabolic control of type 1 diabetes]

OBJECTIVE

To asses the prevalence of celiac disease and to evaluate the clinical effects of a gluten-free diet on metabolic control and growth in children and adolescents with type 1 diabetes mellitus (DM1).

PATIENTS AND METHODS

We performed a retrospective study of 261 patients with DM1. Diagnosis of celiac disease was based on the presence of endomysium and tissue transglutaminase antibodies in serum and was confirmed by intestinal biopsy. The impact of a gluten-free diet on metabolic control (mean annual HbAlc values), growth (height and annual growth velocity) and nutritional status (body mass index) was evaluated. Patients diagnosed with DM1 and subsequently with celiac disease were compared with a control group of patients with DM1 only.

RESULTS

Twenty-one (8%) of the 261 diabetic patients were diagnosed with celiac disease and 19% also had another associated autoimmune disease. No significant differences were found in growth or metabolic control after withdrawal of gluten from the diet.

CONCLUSIONS

We found a high prevalence of celiac disease in our type 1 diabetes population. A gluten-free diet had no effects on metabolic control of diabetes or on height or weight. Nevertheless, given the high prevalence of celiac disease and the possible development of long-term complications, such as lymphoma and osteoporosis, we recommend systematic screening in all diabetic patients, especially in the first 5 years after diagnosis of DM1.

Screening of diabetes, thyroid, and celiac diseases-related autoantibodies in a sample of Turkish children with type 1 diabetes and their siblings

OBJECTIVE

The purpose of this study was to investigate the presence of diabetes, thyroid, and celiac diseases (CD)-related autoantibodies in children with type 1 diabetes (DM1) and their siblings.

MATERIALS AND METHODS

The study population included 57 children with DM1, aged 11.7+/-4.5 years and their 89 healthy siblings, aged 11.0+/-5.4 years. Autoantibodies to glutamic acid decarboxylase (GAD65), islet cell (ICAs), insulin (IAAs), antiendomisial antibody (EMA), thyroid peroxidase, thyroglobulin, and thyrotropin receptor antibodies were studied both in diabetic patients and their siblings.

RESULTS

The frequencies of GAD65, ICAs and IAAs positivity were found to be 63.2, 56.1 and 84.2% in patients with DM1 and 53.9, 24.4 and 3.4% in their siblings, respectively. The frequencies of autoimmune thyroid diseases (ATD) as determined by positive thyroid-related autoantibodies were 38.6 and 21.4% (p=0.024) among patients with DM1 and siblings, respectively. Subclinical hypothyroidism or hyperthyroidism was detected in 5.3% of patients with DM1 but in none of their siblings. EMA was positive in 3.5% of diabetic patients and 1.1% of their siblings.

CONCLUSIONS

Our findings supported the view that children with DM1 should be screened annually for ATD. Relatively lower frequency of CD in the present study indicated that screening for CD-related autoantibodies might be postponed to older ages in asymptomatic patients. The present findings also suggested that the screening for diabetes- (especially GAD65) and thyroid diseases-related autoantibodies in siblings may ensure some useful information about the clinical course.

[Celiac disease diagnosis in 2008]

Since the 1990's, the widespread use of very sensitive and specific serological tests has completely changed the conditions of the diagnosis of celiac disease (CD). The active form of the disease is now only the tip of the iceberg representing it. Currently, CD is evoked either in front of mild digestive symptoms at the usual age or in the course of screening in siblings of an index case or in patients at risk (insulin dependent diabetes for example) at a later age using IgA anti-endomysium or anti-tissue transglutaminase antibodies, the sensitivities and specificities of which exceed 90%. In some cases, HLA typing is helpful in allowing to exclude a patient who is neither DQ2 nor DQ8. The intestinal biopsy remains the "gold standard" of the diagnosis showing villous atrophy; the latter, however, is less and less often severe as the disease is milder and milder. The diagnosis of CD then rests on the confrontation of the clinical, biological and histological data. Once CD has been diagnosed, it can be classified either as active or silent (positive serology with isolated villous atrophy), or latent (positive serology with a normal mucosa) and the appropriate therapeutic decision can be taken.

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.

Serum mannan-binding lectin levels in patients with celiac disease: an analysis of clinical and autoimmune features

Mannan-binding lectin (MBL) is the central protein in the activation of complement through the lectin pathway. MBL plasma concentration is genetically determined and varies significantly among individuals. Recent findings suggest that MBL is associated with the pathogenesis of celiac disease (CD). In this study, MBL and C-reactive protein (CRP) levels were determined in 101 celiac patients and 120 controls, with the aim to associate with the presence of gluten in the diet, disease severity, and the presence of concomitant autoimmune diseases. MBL concentration was determined by ELISA and CRP by nephelometry, using a high-sensitivity method. EmA-IgA and other autoantibodies were tested by indirect immunofluorescence. Although a significant increase in MBL levels was observed in male patients compared to female (P = 0.024), the absence of any other association suggests that circulating MBL and CRP concentrations are not associated with clinical and autoimmune CD features in Brazilian patients.

Clinical benefit of a gluten-free diet in type 1 diabetic children with screening-detected celiac disease: a population-based screening study with 2 years' follow-up

OBJECTIVE

This study was performed to 1) determine the prevalence of celiac disease in Danish children with type 1 diabetes and 2) estimate the clinical effects of a gluten-free diet (GFD) in patients with diabetes and celiac disease.

RESEARCH DESIGN AND METHODS

In a region comprising 24% of the Danish population, all patients <16 years old with type 1 diabetes were identified and 269 (89%) were included in the study. The diagnosis of celiac disease was suspected in patients with endomysium and tissue transglutaminase antibodies in serum and confirmed by intestinal biopsy. Patients with celiac disease were followed for 2 years while consuming a GFD.

RESULTS

In 28 of 33 patients with celiac antibodies, an intestinal biopsy showed villous atrophy. In 5 patients, celiac disease had been diagnosed previously, giving an overall prevalence of 12.3% (95% CI 8.6-16.9). Patients with celiac disease had a lower SD score (SDS) for height (P < 0.001) and weight (P = 0.002) than patients without celiac disease and were significantly younger at diabetes onset (P = 0.041). A GFD was obtained in 31 of 33 patients. After 2 years of follow-up, there was an increase in weight SDS (P = 0.006) and in children <14 years old an increase in height SDS (P = 0.036). An increase in hemoglobin (P = 0.002) and serum ferritin (P = 0.020) was found, whereas HbA(1c) remained unchanged (P = 0.311) during follow-up.

CONCLUSIONS

This population-based study showed the highest reported prevalence of celiac disease in type 1 diabetes in Europe. Patients with celiac disease showed clinical improvements with a GFD. We recommend screening for celiac disease in all children with type 1 diabetes.

Food habits, energy and nutrient intake in adolescents with Type 1 diabetes mellitus

AIMS

The aims were to describe the food habits of adolescents with Type 1 diabetes (Type 1 DM) and to compare them with healthy control subjects; to describe the distribution of energy-providing nutrients in patients and compare it with current recommendations and previous reports; and finally, to investigate associations between dietary intake and glycaemic control.

METHODS

One hundred and seventy-four adolescents with Type 1 DM and 160 age- and sex-matched healthy control subjects completed a validated food frequency questionnaire, and 38 randomly chosen patients completed a prospective 4-day food record.

RESULTS

Patients ate more regularly, and more often ate fruit and fruit juice, potatoes and root vegetables, meat, fish, egg, offal and sugar-free sweets than control subjects. Control subjects more often ate ordinary sweets and snacks. Patients chose coarse rye bread and dairy products with less fat to a greater extent than control subjects. Patients were heavier than control subjects. The intake of saturated fat was higher in patients compared with recommendations and, for boys with diabetes, the intake of protein was higher than recommended. Patients with poorer glycaemic control ate vegetables, fruit and fish less often than patients with better control.

CONCLUSIONS

The food habits of adolescents with Type 1 DM were healthier than those of control subjects. The intake of energy-providing nutrients was in line with current recommendations and showed improvements compared with previous reports, with the exception of fibre intake. The association between dietary intake and glycaemic control needs further investigation in prospective studies.

Usefulness of duodenal biopsy during routine upper gastrointestinal endoscopy for diagnosis of celiac disease

AIM: To describe the trend in duodenal biopsy performance during routine upper gastrointestinal endoscopy in an adult Spanish population, and to analyze its value for the diagnosis of celiac disease in clinical practice.

METHODS: A 15 year-trend (1990 to 2004) in duo-denal biopsy performed when undertaking upper gastrointestinal endoscopy was studied. We analysed the prevalence of celiac disease in the overall group, and in the subgroups with anaemia and/or chronic diarrhoea.

RESULTS: Duodenal biopsy was performed in 1033 of 13 678 upper gastrointestinal endoscopies (7.6%); an increase in the use of such was observed over the study period (1.9% in 1990-1994, 5% in 1995-1999 and 12.8% in 2000-2004). Celiac disease was diagnosed in 22 patients (2.2%), this being more frequent in women than in men (3% and 1% respectively). Fourteen out of 514 (2.7%) patients with anaemia, 12 out of 141 (8.5%) with chronic diarrhoea and 8 out of 42 (19%) with anaemia plus chronic diarrhoea had celiac disease. A classical clinical presentation was observed in 55% of the cases, 23% of the patients had associated dermatitis herpetiformis and 64% presented anaemia; 9% were diagnosed by familial screening and 5% by cryptogenetic hypertransaminasaemia.

CONCLUSION: Duodenal biopsy undertaken during routine upper gastrointestinal endoscopy in adults, has been gradually incorporated into clinical practice, and is a useful tool for the diagnosis of celiac disease in high risk groups such as those with anaemia and/or chronic diarrhoea.

Prevalence of celiac disease in Brazilian children with type 1 diabetes mellitus

OBJECTIVE

Although the relationship between celiac disease and diabetes mellitus type 1 is well recognized, there are no studies of this association in Brazil. This study aims to identify the prevalence of celiac disease in a group of children with diabetes mellitus type 1 undergoing treatment in the pediatric endocrinology division of a university hospital in Minas Gerais, Brazil.

METHODS

Immunoglobulin (Ig)A and IgG antigliadin antibodies (enzyme-linked immunoadsorbent assay) were measured in blood collected from 236 children and adolescents with diabetes mellitus type 1. Patients with antigliadin antibodies then had jejunal biopsy and determination of antiendomysial antibodies by indirect immunofluorescence.

RESULTS

Twenty-one patients had IgA or IgG antigliadin antibodies. Nineteen underwent jejunal biopsy. Six had mucosal alterations compatible with celiac disease; four had nonspecific histologic changes; nine had normal biopsies. Thirteen antigliadin antibody-positive patients were antiendomysial antibody-negative; one antiendomysial antibody-negative patient had celiac disease. The prevalence of celiac disease was 2.6% among 234 patients.

CONCLUSIONS

Measurement of antigliadin antibodies in patients with diabetes mellitus type 1 helped in the selection of patients to undergo jejunal biopsy. Antiendomysial antibodies were highly specific and moderately sensitive in predicting celiac disease. The prevalence of celiac disease was higher in diabetics than in the general population, suggesting the need for regular screening assessment of diabetic children.

Complement factor B allotypes in the susceptibility and severity of coeliac disease in patients and relatives

The alternative pathway of complement plays an important role in the pathogenesis of coeliac disease (CD), where factor B (BF) is central to its activation. CD is a gluten-sensitive enteropathy that results from a complex interplay between genetic, immunologic, and environmental factors. In this study we evaluated the association of BF allotypes with the susceptibility and severity of CD, and with the presence of autoantibodies. Seventy-six non-related patients (56 female; 20 male; 2-77 years) and 150 first-degree relatives (87 female, 63 male; 2-75 years) were investigated. As controls, 97 healthy individuals were included (67 female;, 30 male; 1-71 years). The BF allotypes were determined by high-voltage agarose gel electrophoresis, followed by specific immunofixation. Disease severity was evaluated by anti-endomisial antibody (IgA-EmA) titres and histological findings of intestinal mucosa, which showed a high correlation (r = 0.8; P < 0.00001) in samples collected simultaneously. IgA-EmA was detected in all CD patients ingesting gluten, and in 13.3% of the relatives. The IgA-EmA, smooth muscle, mitochondrial, liver-kidney microsomal, nuclear, gastric parietal cells, and thyroid microsome antibodies were tested by indirect immunofluorescence. A significant decrease in BF S (P = 0.026) and an increasing tendency in BF SF allotype (P = 0.06) were observed in CD patients when compared to their relatives. On the other hand, BF S frequency was increased (P = 0.001 RR = 2.32) and BF SF (P = 0.002) decreased in the relatives when compared to the controls. No differences were observed in the distribution of BF phenotypes amongst the CD patients and the control group, and no association was found with CD severity or with the presence of autoantibodies. These results suggest BF SF as a CD susceptibility marker, and BF S as a protection marker of the disease amongst CD families in the Brazilian population.

Coeliac disease in children with Type 1 diabetes mellitus: the effect of the gluten-free diet

PATIENTS AND METHODS

We assessed the frequency of coeliac disease in 281 children with Type 1 diabetes and the effect of gluten-free diet (GFD) in newly diagnosed cases. Serological screening was performed using anti-gliadin and anti-endomysium antibodies. Data were obtained about clinical symptoms, height and weight-for-height.

RESULTS

A small intestinal biopsy was recommended to 18 patients (6.4%) with positive serological results and 12 children agreed. Nine of them had coeliac disease. Three out of nine coeliac children complained about gastrointestinal symptoms. On a GFD, the symptoms disappeared in two patients. Iron-deficiency anaemia was present in four subjects and disappeared in the three patients who accepted the GFD. In three patients (33%), coeliac disease was asymptomatic. Height and weight-for-height were in the normal range for all patients. For well-complying patients, there was a significant increase in height standard deviation at diagnosis and on follow-up (-0.28 vs. +0.35) (P = 0.03). Changes in weight-for-height were not significant (-4.0% vs. +1.4%) (P = 0.28). There was a trend to an improvement in HbA(1c) (8.0 vs. 7.3%) (P = 0.05).

CONCLUSIONS

Serological screening is effective. There is a therapeutic benefit for some screening-detected patients, but confirmatory studies are needed.

Prospective screening for biopsy proven coeliac disease, autoimmunity and malabsorption markers in Belgian subjects with Type 1 diabetes

AIMS

To determine prospectively the prevalence of biopsy proven coeliac disease (CD) in an adult Type 1 diabetic population from Belgium with regards to associated auto-immunity and malabsorption.

METHODS AND RESULTS

Determination in 400 Type 1 diabetic patients of serum anti-endomysial and/or anti-transglutaminase auto-antibodies. All subjects with abnormal serology underwent an intestinal biopsy. Ten patients (2.5%) had positive antibodies. Diagnosis of CD was confirmed by an intestinal biopsy. Eight patients were symptom-free, although laboratory findings suggesting malabsorption were prominent in the presence of CD [microcytic anaemia, iron and folate deficiencies, low levels of 25(OH)vitamin D3, calcium and cholesterol]. Other auto-immune conditions, especially vitiligo, were found in patients with CD.

CONCLUSIONS

Asymptomatic coeliac disease occurs frequently in adult Type 1 diabetic patients, and is often associated with subclinical malabsorption. Screening should be part of routine evaluation, to implement life-long dietary gluten avoidance.

The prevalence of celiac disease in average-risk and at-risk Western European populations: a systematic review

Until recently, celiac disease (CD) was felt to be a rare disease in the United States. The aim of this study was to conduct a systematic review of the prevalence of CD in general Western populations and in populations at high risk for CD. Standard systematic review methodology was used. A literature search was conducted in MEDLINE (1966 to October 2003) and EMBASE (1974 to December 2003) databases. Qualitative and quantitative prevalence estimates were produced after assessing study heterogeneity. The prevalence of CD in general Western populations is close to 1% and is somewhat higher in certain Western European populations. The prevalence of CD in populations at risk for CD is as follows: 3%-6% in type 1 diabetic patients, up to 20% in first-degree relatives, 10%-15% in symptomatic iron-deficiency anemia (IDA), 3%-6% in asymptomatic IDA, and 1%-3% in osteoporosis. The prevalence of CD in patients suspected of having CD varied depending on the reasons for suspecting CD and on whether the study was conducted in a referral center. In general, the prevalence ranged from 5% to 15%, but was up to 50% in symptomatic patients evaluated in a tertiary referral center. CD is a common medical condition. The prevalence is higher still in high-risk groups. Clinicians in a variety of specialties should have a high index of suspicion for the diagnosis of CD and in particular need to pay close attention to the identified high-risk groups.

Should all children be screened for celiac disease?

To address the issue of screening children for celiac disease, current evidence has been summarized and placed within the context of 8 established criteria for childhood screening. Screening all children for celiac disease is not recommended at this time. Areas with gaps in knowledge are identified as areas in need of further study. These include the timing of screening, defining the natural history of screening-identified celiac disease, developing tools to predict disease onset and disease remission, and the risks of screening.

[Celiac disease in a group of children and adolescents with type 1 diabetes mellitus]

To know the prevalence of celiac disease (CD) in a group of children and adolescents with type I diabetes mellitus. A cross sectional study was conducted at the Instituto Materno Infantil de Pernambuco (IMIP) in March 2000. The sample consisted of 19 children and adolescents with type I diabetes mellitus that had the human anti-tissue transglutaminase antibodies assessed using kits from the Eurospital Laboratory. In case of positive results it was realized small intestine biopsy to confirm the diagnosis. For the calculation of the prevalence of CD it was considered the number of patients with serum positive histological alterations of the mucous membrane of the small intestine compatible with CD. Four patients presented serum positivity for human anti-tissue transglutaminase antibodies with a serum prevalence of 21% (4/19). Out of these four subjects, three who accomplished small intestine biopsy presented histological alterations compatible with CD. The prevalence of CD in this group was 15.8% (3/19). The prevalence of CD in this study group was high, suggesting that those with type I diabetes mellitus should be led as a group of high risk to develop this disease.

Prospective population screening for celiac disease: high prevalence in the first 3 years of life

BACKGROUND

Celiac disease (CD) is an autoimmune enteropathy that develops in genetically susceptible individuals exposed to gliadin. Early diagnosis of CD may reduce the risk of complications, and several studies have related the duration of gluten exposure to the risk of other autoimmune diseases. It has been proposed that silent CD be diagnosed as soon as possible to avoid potential complications.

OBJECTIVES

The purpose of this study was to determine the prevalence of CD among children less than 3 years and to provide treatment to those patients diagnosed with CD.

PATIENTS AND METHODS

Parents of 1100 healthy children born between October 1998 and December 1999 were asked at the time of delivery to enroll their children in a program for the early diagnosis of CD. The parents of 830 children agreed to participate. Patients in the study were examined and anti-tissue transglutaminase antibody was first measured at about 1.5 years of age. A second antibody titer was obtained at about 2.5 years of age. Patients with detectable autoantibodies underwent intestinal biopsy for confirmation of CD.

RESULTS

Of the 830 children initially enrolled, 613 and 484 returned for the first and second visits, respectively. None had anti-tissue transglutaminase antibodies at the first visit, but 9 had anti-tissue transglutaminase immunoglobulins at the second visit. In 7 of these 9, intestinal biopsy confirmed the diagnosis of CD which suggests a minimum prevalence of CD of 1 per 118 healthy newborns.

CONCLUSIONS

The authors observed a very high prevalence of CD, comparable to that observed in other European populations, which might even be higher if all of the children initially examined had returned for their second visit. If general screening for CD were accepted, the authors would recommend age 2-3 years as the best time for measuring tissue transglutaminase antibodies.

Prévalence des marqueurs biologiques de la maladie cœliaque dans une cohorte d’enfants et d’adolescents diabétiques de type I

The aim of this study was to determine the prevalence of celiac disease (CD) markers in a French cohort of 84 children type 1 diabetics. Detection of antitransglutaminase (AtTG), antiendomysium (AEA) and antigliadin (AGA) antibodies was performed. Group 1 included 81 (96.4%) diabetic patients with negative antibodies. Group 2 included 3 patients (3.6%) with positive serological markers: 1 AGA-AEA-AtTG and 1 AEA-AtTG with proved histological diagnosis and 1 AGA positive with negative histology. No statistically significant difference was observed between the groups with regard to age, duration of diabetes, familial target stature, and ratios Height/Age and Weight/Height. Presence of CD serological markers was related to a lower level of HbA1c. Prevalence of CD serological markers is important in this French cohort but lower than other countries.

Coeliac disease in Iranian type I diabetic patients

BACKGROUND

The association between coeliac disease and type I diabetes mellitus has been evaluated in some previous studies, but its prevalence in Iranian diabetic patients remains unknown.

AIM

To evaluate the prevalence of coeliac disease in patients with type I diabetes mellitus in Iran.

PATIENTS

A total of 250 consecutive patients (102 male and 148 female) with type I diabetes mellitus.

METHODS

Total serum immunoglobulin A level and immunoglobulin A endomysial antibody was measured for all patients. Endoscopy and biopsy of the duodenum were performed for immunoglobulin A endomysial antibody-positive patients and pathologic evaluation was done according to modified Marsh classification.

RESULT

The mean age of the patients was 18.7 years (range: 2-55 years). Total serum immunoglobulin A was in the normal range for all patients. Immunoglobulin A endomysial antibody was positive in six (2.4%) patients (all of them were females; P = 0.04). Duodenal biopsy samples revealed grade I in two patients, grade II in three patients and grade IIIb in one patient (modified Marsh classification). Patients with coeliac disease and diabetes mellitus were older than patients with diabetes mellitus alone (mean age: 29.5 years versus 18.4 years; P < 0.001). There was a trend for longer duration of diabetes mellitus in coeliac patients than in patients without it (mean age: 17.3 years versus 12.5 years; P = 0.16).

CONCLUSION

The prevalence of coeliac disease in Iranian patients with type I diabetes mellitus is relatively high (2.4%). Since almost half of the patients with coeliac disease are asymptomatic, all patients with type I diabetes mellitus should be screened for coeliac disease regardless of the presence of symptoms, at diagnosis of diabetes mellitus and with regular intervals in the follow up.

HLA-DRB1 andMICAin Autoimmunity

Autoimmune disorders such as type 1 diabetes (T1DM), celiac disease (CD), and Addison's disease (ADD) develop in individuals with genetic susceptibility that are exposed to environmental triggering factors not completely defined. Patients with an autoimmune disease (and their relatives) are at increased risk of developing another disorder, and this might be caused by a common genetic origin of autoimmunity; for example, HLA class II region in 6p21 shows a very strong association with most diseases. The aim of this study was to determine whether shared susceptibility markers extend from the central (DRB1) through the telomeric (MICA) HLA region. We analyzed three independent sets of families with one autoimmune disease, T1DM, CD, or ADD, and genotyped them for HLA-DRB1 and for the exon 5 GCT polymorphism of MICA. For HLA-DRB1, allele DRB1*0301 was the only one associated with risk for all three diseases; in the case of MICA, allele A9 was found to be the common protective allele. Haplotype analysis shows that haplotype A5.1-DRB1*0301 confers risk to autoimmunity. Our results show that there are common risk and protection alleles in both loci, suggesting a core of genetic association with autoimmunity (HLA-DRB1*0301 risk; A9 protection) that could be modulated by other alleles/loci or environmental factors toward one or another disease. Some alleles are part of conserved haplotypes (A5.1-DR3, A5.1-DR2), whereas others seem to have independent effect (A9) and support the idea of two independent loci in this region.

Extrapancreatic autoimmune manifestations in type 1 diabetes patients and their first-degree relatives: a multicenter study

OBJECTIVE

To investigate the prevalence of autoimmune diseases in young patients (probands) with type 1 diabetes and their first-degree relatives, and to determine the spectrum of extrapancreatic manifestations in these subjects.

RESEARCH DESIGN AND METHODS

The study population included 109 probands age 13 +/- 4.9 years and 412 first-degree relatives age 28.7 +/- 16.2 years. The prevalence rates of autoimmune thyroiditis and celiac disease were determined in all probands and in 100 of the 412 first-degree relatives. Control groups included 78 subjects age 14.9 +/- 10.4 years for the prevalence of autoimmune thyroiditis and 120,000 youth ages 16-17 years for the prevalence of celiac disease. Thyroiditis and celiac disease were diagnosed by abnormally high thyroid peroxidase (TPO), thyroglobulin (TG), antigliadin, and antiendomysial antibody titers. Celiac was confirmed by biopsy. A questionnaire was used to interview probands and relatives to determine the spectrum of autoimmune manifestations.

RESULTS

The prevalence of autoimmune thyroiditis determined by high TPO and/or TG titers was 27 and 25% for probands and relatives, respectively. These rates were higher than those for control subjects (P < 000.1). The prevalence of celiac disease among probands and screened relatives was 8.3 and 6%, respectively. These rates were higher than those for control subjects and the 312 family members interviewed only (0.1 and 0.3%, respectively; P < 0.0001). Interviews of participants revealed a wide range of associated autoimmune diseases. The risk of developing an autoimmune disease was higher (P < 0.001) in families with a proband who had an additional autoimmune manifestation.

CONCLUSIONS

Screening for autoimmune thyroiditis and celiac disease should be performed in patients with type 1 diabetes and their first-degree relatives, especially when the probands have an additional autoimmune manifestation.

Transition of care between paediatric and adult gastroenterology. Assessment of growth and nutrition

Growth is a dynamic process that is characterized by physiological changes in an individual from infancy into adulthood. Growth should be monitored sequentially and is an important tool in the early detection of chronic disease in children. Growth occurs in three phases: infancy, childhood and puberty (adolescence). The adequacy of nutritional status can be assessed by anthropometric measurements that include height, weight and body composition as well as laboratory evaluations. Individual patients can then be compared to normative or expected values. Impaired growth and nutritional status can be seen in a variety of gastrointestinal disorders and are described in this chapter.

Refractory iron deficiency anemia as the primary clinical manifestation of celiac disease

In the absence of dietary insufficiency, iron deficiency is usually caused by chronic blood loss or intestinal malabsorption. Celiac disease is one of the most common causes of intestinal malabsorption during childhood, and its association with insulin-dependent diabetes mellitus has been previously reported. Here the authors describe an otherwise asymptomatic diabetic adolescent boy with iron deficiency anemia that was not responsive to oral iron therapy. A diagnosis of celiac disease was made based on both anti-endomysial antibody titers and small intestinal biopsy. Institution of a gluten-free diet resulted in correction of the anemia. These observations emphasize the importance of considering a diagnosis of celiac disease in patients with nonresponsive iron deficiency anemia, particularly in the setting of insulin-dependent diabetes mellitus.

Screening for coeliac disease in type 1 diabetes

The average prevalence of coeliac disease among children with diabetes mellitus in 26 reports was 4.5% (0.97-16.4%). Malabsorption, unstable diabetes, and growth failure, indicate that coeliac disease may be present. Even those who are apparently asymptomatic may have subtle complaints indicative of coeliac disease if a careful history is taken. Ill health may only be recognised in retrospect following the benefits conferred by a gluten free diet. For these reasons it is recommended that a screening programme should be instituted to detect coeliac disease in these children. Parents and where possible children themselves, should be fully involved at all stages of the screening, diagnostic, and treatment process.

Endocrinological disorders and celiac disease

Celiac disease is a permanent intolerance to dietary gluten. Its well known features are abdominal symptoms, malabsorption of nutrients, and small-bowel mucosal inflammation with villous atrophy, which recover on a gluten-free diet. Diagnosis is challenging in that patients often suffer from subtle, if any, symptoms. The risk of clinically silent celiac disease is increased in various autoimmune conditions. The endocrinologist, especially, should maintain high suspicion and alertness to celiac disease, which is to be found in 2-5% of patients with insulin-dependent diabetes mellitus or autoimmune thyroid disease. Patients with multiple endocrine disorders, Addison's disease, alopecia, or hypophysitis may also have concomitant celiac disease. Similar heredity and proneness to autoimmune conditions are considered to be explanations for these associations. A gluten-free diet is essential to prevent celiac complications such as anemia, osteoporosis, and infertility. The diet may also be beneficial in the treatment of the underlying endocrinological disease; prolonged gluten exposure may even contribute to the development of autoimmune diseases. The diagnosis of celiac disease requires endoscopic biopsy, but serological screening with antiendomysial and antitissue transglutaminase antibody assays is an easy method for preliminary case finding. Celiac disease will be increasingly detected provided the close association with autoimmune endocrinological diseases is recognized.

HLA-DRB1 and MHC class 1 chain-related A haplotypes in Basque families with celiac disease

The contribution of HLA genes to the genetic risk for celiac disease (CD) has been known for a long time. Recent publications have pointed to the possibility that a second, independent susceptibility locus could be located in the same genomic region, and a triplet repeat polymorphism in exon 5 of the gene MHC class I chain-related protein A (MICA; located between TNFA and HLA-B) has been associated with several autoimmune disorders, including type 1 diabetes mellitus (DM1) and Addison's disease. On the other hand, a single amino acid change in exon 3 of MICA (M129V) has been shown to strongly reduce MICA binding to NKG2D, an activating natural killer receptor expressed also on T cells, and this could have significant effects on autoimmune reactions. In this study, we have analyzed the contribution of these polymorphisms to CD in 37 Basque families, and have constructed MICA-HLA-DRB1 haplotypes to determine whether MICA has an effect independent from the HLA class II conferred risk. In our population, HLA-DRB1*0301 was associated with an increased risk for CD, while HLA-DRB1*1501 conferred protection from the disease (OR: 7.38 and 0.06, respectively). On the other hand, MICA allele A4 was positively associated with the disease (OR: 4.69) whereas allele A9 showed a trend towards protection (OR: 0.18), although significance did not hold after correction. No association of the exon 3 biallelic polymorphism was observed. A positive allelic association was found for haplotypes A5.1-DRB1*0301 (associated with risk for disease), A4-DRB1*0301 and A6-DRB1*07. In view of our results, both HLA-DRB1 and MICA are associated with CD, but stratification analysis did not show any independent contribution of the MICA polymorphisms analyzed to CD risk. Besides, MICA allele A4 (also A5.1 was associated with risk for CD and other diseases) is in strong linkage disequilibrium with HLA-DRB1*0301. Finally, the major histocompatibility complex region's conferred susceptibility to CD, at least in Basque, is very similar to that observed for DM1, with shared risk and protective haplotypes.

Type 1 diabetes: new perspectives on disease pathogenesis and treatment

As our knowledge of type 1 (insulin-dependent) diabetes increases, so does our appreciation for the pathogenic complexity of this disease and the challenges associated with its treatment. Many new concepts about the pathogenesis of this disorder have arisen. The role of genetics versus environment in disease formation has been questioned, and the basis on which type 1 diabetes is characterised and diagnosed is the subject of much debate. Additionally, the care and treatment of patients with type 1 diabetes has seen a rapid evolution; with genetically engineered insulins, glucose monitoring devices, and algorithms all contributing to a decrease in disease-related complications. We focus this seminar on these changing views, and offer a new perspective on our understanding of the pathogenesis of type 1 diabetes and on principles for therapeutic management of patients with this disorder.

Celiac disease-associated autoimmune endocrinopathies

Celiac disease (CD) is an autoimmune disorder induced by gluten intake in genetically susceptible individuals. It is characterized by the presence of serum antibodies to endomysium, reticulin, gliadin, and tissue transglutaminase. The incidence of CD in various autoimmune disorders is increased 10- to 30-fold in comparison to the general population, although in many cases CD is clinically asymptomatic or silent. The identification of such cases with CD is important since it may help in the control of type I diabetes or endocrine functions in general, as well as in the prevention of long-term complications of CD, such as lymphoma. It is believed that CD may predispose an individual to other autoimmune disorders such as type I diabetes, autoimmune thyroid, and other endocrine diseases and that gluten may be a possible trigger. The onset of type I diabetes at an early age in patients with CD, compared to non-CD, and the prevention or delay in onset of diabetes by gluten-free diet in genetically predisposed individuals substantiates this antigen trigger hypothesis. Early identification of CD patients in highly susceptible population may result in the treatment of subclinical CD and improved control of associated disorders.

Frequency of celiac disease in individuals with Down syndrome in the United States

Ninety-three individuals with Down syndrome (DS) were screened to investigate the prevalence of celiac disease (CD) in the United States. Five of the 93 individuals were antiendomysial antibody (EMA) positive. Of the 5 who tested positive for EMA, 4 were biopsied, 1 refused biopsy. Three of the 4 individuals biopsied manifested changes of CD on small bowel biopsy. This gives a frequency of 3.2% of confirmed CD in our DS individuals and suggests the need for periodic screening for celiac disease in this population.

Autoantibodies predicting diabetes mellitus type I in celiac disease

Celiac disease (CD) and diabetes mellitus type I (DM-I) are both autoimmune diseases. Abnormal first-phase insulin response (FPIR) is associated with the prediabetic phase. Glutamic acid decarboxylase (GAD) and islet cell antibodies (ICAs) - especially the tyrosine phosphatase-like protein IA-2 antibodies - are considered to be serological markers of DM-I future development. The aim of this study is to investigate the presence of autoantibodies (GAD, IA-2) in individuals with CD, on a gluten-free diet, who have normal intestinal morphology. Thirty patients with CD (4-22, mean 15 years), 30 newly diagnosed diabetic children (2.5-16, mean 10 years) and 30 healthy subjects (7-35, mean 18 years) were investigated. Serum GAD and IA-2 autoantibodies were assessed by a quantitative enzyme-linked immunosorbent assay (ELISA) method in all patients and controls. Seven CD patients (23%), 28 diabetic children (93%) and none in the control group had positive GAD and IA-2 antibodies. The FPIR was normal in CD patients (>/=46 mU/l).

CONCLUSIONS

GAD and IA-2 antibodies are detected in 23% of patients with CD. These patients may be at risk to develop DM-I. Regular follow-up and determination of FPIR for the early diagnosis of the prediabetic phase in patients with CD having circulating autoantibodies is recommended.

Cellular and humoral immunity against cow's milk proteins in type 1 diabetes

Cow's milk beta-casein has been proposed as a candidate trigger of autoimmunity associated with type 1 diabetes. In this study, cellular and humoral immunity against beta-casein was compared to that against other major cow's milk proteins in patients with recent onset type 1 diabetes and control subjects. T cell responses were found against alpha-casein, beta-casein, beta-lactoglobulin and bovine serum albumin in both patients with type 1 diabetes (stimulation index: 0.2-22.8, n=23) and control subjects (stimulation index: 0.1-18.2, n=22), with no significant differences between groups. Twelve (52%) patients and nine (41%) control subjects had stimulation indices >3 to at least one protein, including 9 (39%) patients and 4 (18%) control subjects against beta-casein, all but one of these also having elevated responses to alpha-casein. The highest responses (stimulation index >9) were against alpha- and beta-casein in some patients and control subjects who had the HLA DR3 allele. Antibody levels against alpha-casein, beta-casein and beta-lactoglobulin were low in both patients (n=59) and control subjects (n=52). Nevertheless, significantly higher IgG binding to both alpha-casein in ELISA (P=0.02) and beta-casein using ELISA (P=0.02) and RIA (P=0.04) was observed in patients aged <15 years compared to control subjects of similar age. No relationship was found between cellular and humoral immunity against individual antigens. These data show that immune responses to cow's milk are not limited to patients with diabetes and not solely against beta-casein.

Antibodies to gliadin, endomysium, and tissue transglutaminase for the diagnosis of celiac disease

BACKGROUND

Tissue transglutaminase has recently been identified as the main autoantigen recognized by antiendomysial antibodies in celiac disease. Serum immunoglobulin (Ig)A antibodies to tissue transglutaminase (tTG-ab) determined by an enzyme-linked immunosorbent assay (ELISA) technique have been reported to correlate closely with IgA antiendomysial antibodies (EMA). The purpose of this study was to assess the sensitivity, specificity, and predictive value of tTG-ab measured by a commercially available ELISA technique, compared with those of EMA and IgA antigliadin antibodies (AGA) for the diagnosis of celiac disease.

METHODS

Twenty-seven serum samples were obtained from patients with untreated celiac disease, 37 from patients who had had gluten withdrawn from their diets for varying time spans, and 34 from control subjects without celiac disease. All were younger than 14 years. Presence of tTG-ab and AGA was determined by ELISA and of EMA by indirect immunofluorescence.

RESULTS

Twenty-six of 27 serum samples obtained from patients at the time of diagnosis of celiac disease were AGA positive. All 27 (concordance rate 100%) were positive for EMA and tTG-ab. Of the 34 control subjects, 1 was for AGA and 2 for tTG-ab. All 34 were negative for EMA. Sensitivity, specificity, positive predictive value, and negative predictive value within this group were, for tTG-ab: 100%, 94%, 93%, and 100%, respectively; for EMA: all four indexes were 100%; and for AGA: 96%, 97%, 96%, and 97%, respectively. Of the 37 with treated celiac disease, 2 were AGA positive, 9 were EMA positive, and 6 were tTG-ab positive. The concordance rate between EMA and tTG-ab was 100% in the group with untreated celiac disease, 94% in the control subjects, and 76% in the group with treated celiac disease.

CONCLUSIONS

Immunoglobulin A antibodies to tissue transglutaminase are new, highly sensitive, and specific markers of celiac disease. They can be determined easily by an accurate, comparatively cheap technique and thereby may advantageously replace the EMA marker traditionally used.

One third of HLA DQ2 homozygous patients with type 1 diabetes express celiac disease-associated transglutaminase autoantibodies

Type 1 diabetes and celiac disease are both immunologic disorders where specific HLA alleles are associated with disease risk. We have developed a radioassay for autoantibodies to tissue transglutaminase (tTG) following the report that this enzyme is 'the' endomysial autoantigen (EMA) of celiac disease. The radioassay for transglutaminase autoantibodies is similar to that utilized for detecting anti-islet autoantibodies. The 'cut-off' for the IgA autoantibody assay was established as 3 x 100th percentile of 184 healthy control subjects at an index of 0.05. Ninety-eight of 847 patients with type 1 diabetes (11.6%) had tissue transglutaminase autoantibodies (tTG). All EMA-positive patients were positive (49/49) for transglutaminase autoantibodies, as were 49/540 EMA-negative patients. Twenty transglutaminase-positive patients consented to intestinal biopsy and 15 biopsies were positive for celiac disease. All patients with a transglutaminase level greater than 0.70 (13/13) had a positive biopsy, while none (0/3) with a level <0.3 had a positive biopsy. The prevalence of transglutaminase autoantibodies was higher in diabetic patients with HLA DQ2 or DQ8. One third of DQ2 homozygous patients (22/68) expressed transglutaminase autoantibodies vs. less than 2% of patients lacking DQ2 or DQ8. A simple radioassay for IgA transglutaminase autoantibodies detects all endomysial antibody positive patients and detects transglutaminase autoantibodies in 5% of endomysial autoantibody negative patients. The prevalence of transglutaminase autoantibodies is associated with DQ2 and DQ8 and in particular DQ2 homozygosity. Autoimmunity to transglutaminase is remarkably prevalent amongst patients with type 1 diabetes expressing certain class II HLA alleles.