IgA- and IgG-class antihuman umbilical cord antibody tests in adult coeliac disease

Indirect Markers of Intestinal Damage in IgA Nephropathy

INTRODUCTION

Presence of subclinical intestinal inflammation has repeatedly been shown in IgA nephropathy (IgAN) and the degree of histological inflammation has correlated with abnormal urinary findings. There is lack of noninvasive biomarkers evaluating the presence of subclinical intestinal damage in IgAN. We conducted this study hypothesizing that selected biomarkers regarded as indirect markers of intestinal damage could be elevated in IgAN.

METHODS

Eighty-five primary IgAN patients (median age 55 years, 54% men) participated in this single-center study in Tampere, Finland. None had end-stage kidney disease or previously diagnosed enteropathies. Celiac disease was excluded with serum transglutaminase 2 antibody (TG2Ab) and endomysial antibody tests and inflammatory bowel disease with fecal calprotectin. Intestinal damage was evaluated from sera with analyses of intestinal fatty-acid binding protein (I-FABP), soluble cluster of differentiation molecule 14 (sCD14), and lipopolysaccharide binding protein. Fourteen people suffering from dyspepsia and 15 healthy people served as controls.

RESULTS

I-FABP levels among IgAN patients were higher than in the healthy controls (median 830 pg/mL vs. 289 pg/mL, p < 0.001). Also, sCD14 was increased in IgAN patients compared to dyspepsia controls. Although TG2Ab levels were within the normal range among IgAN patients, they were higher than in the healthy controls (median 1.3 U/mL vs. 0.6 U/mL, p < 0.001).

CONCLUSIONS

Elevated serum levels of I-FABP were present in primary IgAN patients without known enteropathies. Serum I-FABP may indicate the presence of subclinical intestinal damage. These findings encourage further investigation into the role of the intestine in the pathophysiology of IgAN.

Prevalence of vomiting and nausea and associated factors after chronic and acute gluten exposure in celiac disease

BACKGROUND

Vomiting and nausea seem to be relatively specific symptoms related to gluten ingestion in treated celiac disease. However, the overall prevalence and associated factors of these symptoms after chronic gluten exposure at celiac disease diagnosis and acute re-exposure during gluten challenge remain obscure.

METHODS

Medical data on 815 adult celiac disease patients were collected at diagnosis from the medical records and through supplementary interviews. An additional 74 patients underwent a three-day (10 g/day) gluten challenge (wheat, barley, rye or a combination of the three grains) while in remission. Prevalence of vomiting/nausea and associated factors were evaluated in both cohorts. A literature review was conducted to summarize earlier studies.

RESULTS

Twenty-eight (3%) patients presented with vomiting at diagnosis. They were less often screen-detected and suffered from extra-intestinal symptoms, and had more often abdominal pain (71% vs. 49%, p = 0.021), diarrhea (61% vs. 40%, p = 0.031), weight loss (36% vs. 17%, p = 0.019) and childhood symptoms (61% vs. 33%, p = 0.002) than those without vomiting (n = 787). The groups were comparable in other clinical-demographic data and in genetic, serological, and histological findings. Short-term gluten challenge provoked vomiting/nausea in 14/74 (19%) patients. They consumed gluten-free oats less often than those without these symptoms (64% vs. 92%, p = 0.017), whereas the groups did not differ in clinical-demographic features at diagnosis, presence of comorbidities, duration of gluten-free diet, or in other symptoms or grain used ingested during the challenge. According to the literature, prevalence of vomiting/nausea at celiac disease diagnosis has varied 3-46% and during gluten challenge 13-61%.

CONCLUSIONS

In chronic gluten exposure at celiac disease diagnosis, vomiting was associated with other gastrointestinal symptoms and onset of symptoms already in childhood, whereas regular consumption of oats may increase the tolerance against vomiting/nausea after acute re-exposure in treated celiac disease.

Influence of HLA-DQ2.5 Dose on Clinical Picture of Unrelated Celiac Disease Patients

The clinical phenotype of celiac disease varies considerably among patients and the dosage of HLA-DQ2.5 alleles has been suggested to be a contributing factor. We investigated whether HLA-DQ2.5 allele dosage is associated with distinct clinical parameters at the time of diagnosis and with patients’ response to a gluten-free diet. The final cohort included 605 carefully phenotyped non-related Finnish celiac disease patients grouped as having 0, 1 or 2 copies of HLA-DQ2.5. Clinical data at the time of diagnosis and during gluten-free diet were collected systematically from medical records and supplementary interviews. An increasing HLA-DQ2.5 dose effect was detected for celiac disease antibody positivity at diagnosis (p = 0.021) and for the presence of any first-degree relatives with celiac disease (p = 0.011 and p = 0.031, respectively). Instead, DQ2.5-negative patients were suffering most often from classical symptoms at diagnosis (p = 0.007 between HLA groups). In addition, during follow-up they were most often symptomatic despite a gluten-free diet (p = 0.002 between groups). Our results thus suggest that increasing HLA-DQ2.5 dose only has a minor effect on the clinical picture of celiac disease. However, HLA-DQ2.5-negative patients should not be overlooked in clinical practice and particular attention should be paid to this patient group during gluten-free diet.

Clinical characteristics and long-term health in celiac disease patients diagnosed in early childhood: Large cohort study

BACKGROUND

Early detection of celiac disease could theoretically prevent most of the disease-associated complications, but long-term effects of this approach are unclear.

AIMS

To investigate features at diagnosis and adulthood health in celiac disease patients diagnosed in early childhood in 1965-2014.

METHODS

Medical data on 978 pediatric patients were collected and study questionnaires sent to 559 adult patients who were diagnosed in childhood. Results were compared between patients diagnosed in early (≤3.0 years) and later (3.1-17.9 years) childhood.

RESULTS

Early diagnosed patients (n=131) had more often total villous atrophy (37% vs 25%, p=0.001), gastrointestinal presentation (61% vs 47%, p<0.001), growth disturbances (70% vs 32%, p=0.001) and severe symptoms (30% vs 9%, p<0.001) and were less often screen-detected (10% vs 27%, p<0.001) at diagnosis than those diagnosed later (n=847). Among 239 adult responders, early diagnosed patients (n=36) had fewer comorbidities (33% vs 53%, p=0.034) but considered their health less often good/excellent (69% vs 84%, p=0.029). The groups were comparable in current age, dietary adherence, symptoms and health-related quality of life.

CONCLUSION

Despite more severe initial presentation, the long-term health in early diagnosed patients was mostly comparable or even better to those diagnosed later in childhood. Poorer self-perceived health suggests a need for support during the transition to adulthood care.

Intestinal TG3- and TG2-Specific Plasma Cell Responses in Dermatitis Herpetiformis Patients Undergoing a Gluten Challenge

Dermatitis herpetiformis (DH), a cutaneous manifestation of coeliac disease, is characterized by transglutaminase (TG) 3-targeted dermal immunoglobulin A (IgA) deposits. The treatment for DH is the same as for coeliac disease, namely a life-long gluten-free diet. DH patients typically have gluten-dependent circulating autoantibodies targeting TG3 and TG2, and plasma cells secreting such autoantibodies have been detected in the small intestinal mucosa. This study investigates the gluten-responsiveness of intestinal TG3 and TG2 antibody-secreting plasma cells in 16 treated DH patients undergoing a gluten challenge. The frequency of both plasma cell populations increased significantly during the challenge, and their frequency correlated with the corresponding serum autoantibody levels at post-challenge. TG3-specific plasma cells were absent in all 18 untreated coeliac disease patients and seven non-coeliac control subjects on gluten-containing diets. These findings indicate that, in DH, both intestinal TG3- and TG2-antibody secreting plasma cells are gluten-dependent, and that TG3-antibody secreting plasma cells are DH-specific.

Small-intestinal TG2-specific plasma cells at different stages of coeliac disease

Background

In coeliac disease, ingestion of gluten induces the production of transglutaminase 2 (TG2)-targeted autoantibodies by TG2-specific plasma cells present at high frequency in the small intestinal mucosa in untreated disease. During treatment with a gluten-free diet (GFD), the number of these cells decreases considerably. It has not been previously investigated whether the cells are also present prior to development of villous atrophy, or in non-responsive patients and those with dietary lapses. We aimed to define the frequency of small bowel mucosal TG2-specific plasma cells in coeliac disease patients with varying disease activity, and to investigate whether the frequency correlates with serum and small intestinal TG2-targeting antibodies as well as mucosal morphology and the number of intraepithelial lymphocytes.

Results

Mucosal TG2-specific plasma cells were found in 79% of patients prior to development of mucosal damage, in all patients with villous atrophy, and in 63% of the patients after 1 year on GFD. In these disease stages, TG2-specific plasma cells accounted for median of 2.3, 4.3, and 0.7% of all mucosal plasma cells, respectively. After long-term treatment, the cells were present in 20% of the patients in clinical remission (median 0%) and in 60% of the patients with poor dietary adherence (median 5.8%). In patients with non-responsive coeliac disease despite strict GFD, the cells were found in only one (9%) subject; the cells accounted for 2.4% of all plasma cells. A positive correlation between the percentage of TG2-specific plasma cells and serum TG2 antibody levels (r_S = 0.69, P < 0.001) and the intensity of mucosal TG2-targeting IgA deposits (r_S = 0.43, P < 0.001) was observed.

Conclusions

Our results show that TG2-specific plasma cells are already detectable prior to villous atrophy, and that generally their frequency increases during overt disease. By contrast, on GFD, the percentage of these cells decreases. Overall, the presence of TG2-specific plasma cells in the small bowel mucosa mirrors the presence of gluten in the diet, but the frequency is not always parallel to the level of serum or intestinal TG2 antibodies. These findings increase the knowledge about the development of the TG2 plasma cell responses especially in the early phases of coeliac disease.

Electronic supplementary material

The online version of this article (10.1186/s12865-018-0275-7) contains supplementary material, which is available to authorized users.

Review article: coeliac disease in later life must not be missed

BACKGROUND

The presenting symptoms of coeliac disease are often subtle and the diagnosis is frequently delayed or overlooked. Therefore, especially elderly patients may be denied the benefits conferred by gluten free diet which can be dramatically life-changing.

AIM

To review the occurrence, clinical features, diagnosis and management in coeliac patients detected later in life.

METHODS

To review manuscripts concerned with coeliac disease in the elderly and to derive subgroups of elderly people from publications on the disorder.

RESULTS

Approximately a quarter of all diagnoses are now made at the age of 60 years or more and a fifth at 65 years or over. About 4% are diagnosed at 80 years or above. Around 60% remain undetected, since their symptoms are often subtle: tiredness, indigestion, reduced appetite. Good compliance with gluten free diet, resolution of symptoms and improvement in laboratory indices can be achieved in over 90% of patients.

CONCLUSIONS

Coeliac disease not uncommonly presents for the first time in older patients and is an important diagnosis to make.

Dermatitis herpetiformis: a cutaneous manifestation of coeliac disease

Dermatitis herpetiformis (DH) is an itchy blistering skin disease with predilection sites on elbows, knees, and buttocks. Diagnosis is confirmed by showing granular immunoglobulin A deposits in perilesional skin. DH is one manifestation of coeliac disease; the skin symptoms heal with gluten free diet (GFD) and relapse on gluten challenge. Of the first-degree relatives, 5% may be affected by either condition. Tissue transglutaminase (TG2) is the autoantigen in coeliac disease and epidermal transglutaminase (TG3) in DH. Both diseases conditions exhibit TG2-specific autoantibodies in serum and small bowel mucosa; patients with DH have IgA-TG3 in the skin. There are some divergencies between these two phenotypes. One-fourth of DH patients do not have small bowel mucosal villous atrophy, but virtually all have coeliac-type inflammatory changes. The skin symptoms respond slowly to GFD. The incidence of coeliac disease is increasing, whereas the opposite is true for DH. A female predominance is evident in coeliac disease, while DH may be more common in males. Coeliac disease carries the risk of small intestinal T-cell lymphoma; in DH B-cell lymphomas at any site may prevail. Adult coeliac disease carries a slightly increased elevated mortality risk, whereas in DH, the relative mortality rate is significantly decreased. Key messages Dermatitis herpetiformis is a cutaneous manifestation of coeliac disease; both conditions are genetically determined and gluten-dependent. Gastrointestinal symptoms and the degree of villous atrophy are less obvious in dermatitis herpetiformis than in coeliac disease. Both show tissue transglutaminase (TG2) specific autoantibodies in serum and small bowel mucosa. In addition, TG3-targeted IgA antibodies are found in the skin of DH patients Both conditions carry an increased elevated risk of lymphoma, in coeliac disease small intestinal T-cell lymphoma, in dermatitis herpetiformis mainly B-cell lymphoma at various sites. Coeliac disease is currently eight times more common that DH; the incidence of DH is decreasing in contrast to that of coeliac disease, where it is increasing.

Gastrointestinal Symptoms in Celiac Disease Patients on a Long-Term Gluten-Free Diet

Experience suggests that many celiac patients suffer from persistent symptoms despite a long-term gluten-free diet (GFD). We investigated the prevalence and severity of these symptoms in patients with variable duration of GFD. Altogether, 856 patients were classified into untreated (n = 128), short-term GFD (1–2 years, n = 93) and long-term GFD (≥3 years, n = 635) groups. Analyses were made of clinical and histological data and dietary adherence. Symptoms were evaluated by the validated GSRS questionnaire. One-hundred-sixty healthy subjects comprised the control group. Further, the severity of symptoms was compared with that in peptic ulcer, reflux disease, inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS). Altogether, 93% of the short-term and 94% of the long-term treated patients had a strict GFD and recovered mucosa. Untreated patients had more diarrhea, indigestion and abdominal pain than those on GFD and controls. There were no differences in symptoms between the short- and long-term GFD groups, but both yielded poorer GSRS total score than controls (p = 0.03 and p = 0.05, respectively). Furthermore, patients treated 1–2 years had more diarrhea (p = 0.03) and those treated >10 years more reflux (p = 0.04) than controls. Long-term treated celiac patients showed relatively mild symptoms compared with other gastrointestinal diseases. Based on our results, good response to GFD sustained in long-term follow-up, but not all patients reach the level of healthy individuals.

Altered duodenal microbiota composition in celiac disease patients suffering from persistent symptoms on a long-term gluten-free diet

OBJECTIVES

A significant fraction of celiac disease patients suffer from persistent symptoms despite a long-term gluten-free diet (GFD) and normalized small bowel mucosa. The commonly suggested reasons, such as inadvertent gluten-intake or presence of other gastrointestinal disease, do not explain the symptoms in all these patients. Recently, alterations in intestinal microbiota have been associated with autoimmune disorders, including celiac disease. This led us to test a hypothesis that abnormal intestinal microbiota may be associated with persisting gastrointestinal symptoms in treated celiac disease patients.

METHODS

Duodenal microbiota was analyzed in 18 GFD-treated patients suffering from persistent symptoms and 18 treated patients without symptoms by 16S rRNA gene pyrosequencing. The celiac disease patients had been following a strict GFD for several years and had restored small bowel mucosa and negative celiac autoantibodies. Their symptoms on GFD were assessed with Gastrointestinal Symptom Rating Scale.

RESULTS

The results of several clustering methods showed that the treated celiac disease patients with persistent symptoms were colonized by different duodenal microbiota in comparison with patients without symptoms. The treated patients with persistent symptoms had a higher relative abundance of Proteobacteria (P=0.04) and a lower abundance of Bacteroidetes (P=0.01) and Firmicutes (P=0.05). Moreover, their microbial richness was reduced. The results indicated intestinal dysbiosis in patients with persistent symptoms even while adhering to a strict GFD.

CONCLUSIONS

Our findings indicate that dysbiosis of microbiota is associated with persistent gastrointestinal symptoms in treated celiac disease patients and open new possibilities to treat this subgroup of patients.

Early microbial markers of celiac disease

BACKGROUND AND GOALS

Seroreactivity against the Saccharomyces cerevisiae (ASCA), Pseudomonas fluorescens-associated sequence (I2), and Bacteroides caccae TonB-linked outer membrane protein (OmpW) has been detected in celiac disease patients with small-bowel mucosal atrophy. Levels of these antibodies decrease during a gluten-free diet, but their functions and time of appearance in celiac disease are not known. We aimed to search for evidence of possible microbial targets of the immune responses in the early-stage celiac disease patients who showed normal small-bowel mucosal architecture at the time of the first investigations, but later on a gluten-containing diet developed mucosal atrophy.

MATERIALS AND METHODS

Forty-four cases with proven early-stage celiac disease and normal mucosal morphology were enrolled. Patients' sera were tested for celiac disease antibodies against tissue transglutaminase (tTG-ab), endomysium, and for microbial antibodies against I2, OmpW, and ASCA IgG and IgA isotypes in both at the time of diagnosis and while on a gluten-free diet.

RESULTS

Thirty-four (77%) of 44 patients with early-stage celiac disease had elevated serum antibodies to one or more of the antibodies ASCA, I2, and OmpW. Furthermore, 5 of 6 cases negative for both tTG-ab and endomysium showed positivity for the microbial markers. Seroreactivity to ASCA IgA, ASCA IgG, and OmpW decreased significantly during gluten-free diet.

CONCLUSIONS

Seroreactivity to different microbial antigens is evident already in patients with early-stage celiac disease. ASCA antibodies seem to be gluten-dependent. The results indicate that the microbial targets might have a role in the early development of celiac disease.

Predictors of persistent symptoms and reduced quality of life in treated coeliac disease patients: a large cross-sectional study

BACKGROUND

Evidence suggests that many coeliac disease patients suffer from persistent clinical symptoms and reduced health-related quality of life despite a strict gluten-free diet. We aimed to find predictors for these continuous health concerns in long-term treated adult coeliac patients.

METHODS

In a nationwide study, 596 patients filled validated Gastrointestinal Symptom Rating Scale and Psychological General Well-Being questionnaires and were interviewed regarding demographic data, clinical presentation and treatment of coeliac disease, time and place of diagnosis and presence of coeliac disease-associated or other co-morbidities. Dietary adherence was assessed by a combination of self-reported adherence and serological tests. Odds ratios and 95% confidence intervals were calculated by binary logistic regression.

RESULTS

Diagnosis at working age, long duration and severity of symptoms before diagnosis and presence of thyroidal disease, non-coeliac food intolerance or gastrointestinal co-morbidity increased the risk of persistent symptoms. Patients with extraintestinal presentation at diagnosis had fewer current symptoms than subjects with gastrointestinal manifestations. Impaired quality of life was seen in patients with long duration of symptoms before diagnosis and in those with psychiatric, neurologic or gastrointestinal co-morbidities. Patients with persistent symptoms were more likely to have reduced quality of life.

CONCLUSIONS

There were a variety of factors predisposing to increased symptoms and impaired quality of life in coeliac disease. Based on our results, early diagnosis of the condition and consideration of co-morbidities may help in resolving long-lasting health problems in coeliac disease.

Clinical benefit of gluten-free diet in screen-detected older celiac disease patients

BACKGROUND

The utility of serologic screening for celiac disease is still debatable. Evidence suggests that the disorder remains undetected even in the older population. It remains obscure whether screening makes good or harm in subjects with long-standing gluten ingestion. We evaluated whether older subjects benefit from active detection and subsequent gluten free dietary treatment of celiac disease.

METHODS

Thirty-five biopsy-proven patients aged over 50 years had been detected by serologic mass screening. We examined the disease history, dietary compliance, symptoms, quality of life and bone mineral density at baseline and 1-2 years after the commencement of a gluten-free diet. Symptoms were evaluated by gastrointestinal symptom rating scale and quality of life by psychological general well-being questionnaires. Small bowel biopsy, serology, laboratory parameters assessing malabsorption, and bone mineral density were investigated.

RESULTS

Dietary compliance was good. The patients had initially low mean serum ferritin values indicating subclinical iron deficiency, which was restored by a gluten-free diet. Vitamin B12, vitamin D and erythrocyte folic acid levels increased significantly on diet. Celiac patients had a history of low-energy fractures more often than the background population, and the diet had a beneficial effect on bone mineral density. Alleviation in gastrointestinal symptoms was observed, even though the patients reported no or only subtle symptoms at diagnosis. Quality of life remained unchanged. Of all the cases, two thirds would have been diagnosed even without screening if the family history, fractures or concomitant autoimmune diseases had been taken carefully into account.

CONCLUSIONS

Screen-detected patients benefited from a gluten-free diet. We encourage a high index of suspicion and active case-finding in celiac disease as an alternative to mass screening in older patients.

Celiac disease without villous atrophy in children: a prospective study

OBJECTIVE

To establish whether children who are endomysial antibody (EmA) positive and have normal small-bowel mucosal villous morphology are truly gluten-sensitive and may benefit from early treatment with a gluten-free diet.

STUDY DESIGN

Children who were EmA positive with normal small-bowel mucosal villi were compared with children who were seropositive with villous atrophy by using several markers of untreated celiac disease. Thereafter, children with normal villous structure either continued on a normal diet or were placed on a gluten-free diet and re-investigated after 1 year. Seventeen children who were seronegative served as control subjects for baseline investigations.

RESULTS

Normal villous morphology was noted in 17 children who were EmA positive, and villous atrophy was noted in 42 children who were EmA positive. These children were comparable in all measured variables regardless of the degree of enteropathy, but differed significantly from the seronegative control subjects. During the dietary intervention, in children who were EmA positive with normal villi, the disease was exacerbated in children who continued gluten consumption, whereas in all children who started the gluten-free diet, both the gastrointestinal symptoms and abnormal antibodies disappeared.

CONCLUSIONS

The study provided evidence that children who are EmA positive have a celiac-type disorder and benefit from early treatment despite normal mucosal structure, indicating that the diagnostic criteria for celiac disease should be re-evaluated.

Antibodies against deamidated gliadin peptides identify adult coeliac disease patients negative for antibodies against endomysium and tissue transglutaminase

BACKGROUND

This study was done to evaluate the diagnostic utility of antibodies against deamidated gliadin peptides compared to traditional markers for coeliac disease.

AIM

To evaluate diagnostic utility of antibodies against deamidated gliadin peptide (DGP).

METHODS

Sera from 176 adults, referred for endoscopy without previous analysis of antibodies against tissue transglutaminase (tTG) or endomysium (EmA), were retrospectively analysed by ELISAs detecting IgA/IgG antibodies against DGP or a mixture of DGP and tTG, and compared with IgA-tTG and EmA. Seventy-nine individuals were diagnosed with coeliac disease.

RESULTS

Receiver operating characteristic analyses verified the manufacturers' cut-off limits except for IgA/IgG-DGP/tTG. In sera without IgA deficiency, the sensitivity was higher for IgA/IgG-DGP (0.85-0.87) compared with IgA-tTg (0.76) and EmA (0.61). All tests showed high specificity (0.95-1.00). Eighteen coeliac disease-sera were negative regarding IgA-tTG, nine of which were positive for IgA/IgG-DGP. Sera from coeliac disease-patients >70 years were more often negative for IgA-tTG (50%) and IgA/IgG-DGP (36%) than younger patients (15% and 8% respectively) (P < 0.01). Three of the four IgA-deficient patients were positive in the IgA/IgG-DGP assay.

CONCLUSIONS

In this study of patients unselected regarding IgA-tTg/EmA, thus unbiased in this respect, IgA/IgG-DGP identified adult coeliac disease patients negative for antibodies against endomysium and tissue transglutaminase. Serology is often negative in elderly patients with coeliac disease; a small bowel biopsy should therefore be performed generously before coeliac disease is excluded.

Comparison of a novel whole blood transglutaminase-based ELISA with a whole blood rapid antibody test and established conventional serological celiac disease assays

OBJECTIVES

Serum immunoglobulin A-class tissue transglutaminase (tTG-ab) and endomysial antibody (EMA) tests play a key role in the diagnostic evaluation of celiac disease. Recently, a novel whole blood rapid test based on self-tissue transglutaminase (tTG) was developed for celiac disease case finding. Based on the same principle, a whole blood self-tTG enzyme-linked immunosorbent assay (ELISA), especially applicable to large-scale screening of celiac disease, has been produced. We assessed the value of this new test in celiac disease antibody detection.

PATIENTS AND METHODS

The new test uses endogenous tTG found in red blood cells of whole blood in IgA-class tTG-ab measurement by detecting tTG-tTG-ab complexes formed after hemolysis of the whole blood sample. Stored whole blood samples from 150 untreated celiac disease patients and 107 control individuals without celiac disease were evaluated, and the test results were compared with those of the whole blood rapid test, 2 conventional serum-based tTG-ab ELISA tests, and 2 EMA tests.

RESULTS

A total of 15 whole blood samples were found to be clotted or dried after storage and were excluded from further evaluation. The whole blood ELISA test had a specificity (98%) comparable to that of the conventional serological tests, the sensitivity (91%) being slightly lower. The test was concordant with the whole blood rapid test in 92% of cases, with 2 serological ELISA tests in 91% and 94% of cases and with EMA tests in 94% and 93% of cases.

CONCLUSIONS

Whole blood self-tTG-based testing is accurate in celiac antibody detection, also when an ELISA method is applied. The testing requires no serum separation or external tTG.

Elevated serum anti-Saccharomyces cerevisiae, anti-I2 and anti-OmpW antibody levels in patients with suspicion of celiac disease

OBJECTIVES

Expression of anti-Saccharomyces cerevisiae antibodies (ASCA) identifies patients and individuals at risk for Crohn's disease and has also been reported in 40-60% of celiac disease (CD) cases, suggesting a role of host response to enteric microbiota in the development of inflammatory lesions. In this prospective study in patients with suspicion of CD, we evaluate the frequency and association of ASCA to serological responses for other host microbial targets formally associated with Crohn's disease, including the Pseudomonas fluorescens associated sequence I2 and a Bacteroides caccae TonB-linked outer membrane protein, OmpW.

METHODS

Small bowel mucosal biopsies were taken from 242 patients with suspicion of CD, their sera were tested for antibodies to tissue transglutaminase (tTG), ASCA, I2, and OmpW. Eighty adult healthy blood donors were used as controls.

RESULTS

The diagnosis of CD was confirmed on biopsy in 134 cases. The occurrence of ASCA and I2 positivity was significantly higher in adult CD patients than in patients with non-CD disease. Anti-I2 levels in the sera were significantly higher in adult CD patients than in non-CD disease or the controls and anti-OmpW levels in CD and non-CD patients when compared to controls. Positive seroreactivity to OmpW seemed to increase with age. Of the CD patients, 90% were seropositive for at least one microbial antigen tested.

CONCLUSIONS

This study demonstrates a mosaic of disease-related serological responses to microbial antigens in patients with CD. Immune responses to commensal enteric bacteria may play a role in the small intestine mucosal damage in CD.

Performance of a new rapid whole blood coeliac test in adult patients with low prevalence of endomysial antibodies

BACKGROUND

In coeliac disease endomysial and transglutaminase autoantibodies are directed against the human autoantigen, transglutaminase. The conventional coeliac antibody tests are performed from serum samples in centralized laboratories.

AIMS

To evaluate a rapid and easy immunoglobulin A-class whole blood point-of-care test and its commercial application, the Biocard test, in coeliac autoantibody detection.

METHODS

In the whole blood point-of-care test transglutaminase is liberated from the red blood cells by haemolysis. Transglutaminase antibodies, if present, complex with the liberated antigen, and are visualized. Altogether 51 biopsy-proven untreated coeliac adult patients, 48 of the same patients after treatment, and 36 controls were tested. The point-of-care test results were compared with serum endomysial and transglutaminase antibody and Biocard test results and histology.

RESULTS

The whole blood point-of-care test was as sensitive (82%) as the serum endomysium test (80%) in detecting untreated coeliac disease while the serum transglutaminase antibody test was superior (88%). The tests had 100% specificity. A positive point-of-care test result seroconverted or the test reaction weakened in 90% of the treated coeliac patients. Biocard test-positive were 22 of the 24 tested untreated coeliac patients. Biocard test-negative were 15 of 19 controls.

CONCLUSIONS

The whole blood rapid tests are as reliable as the conventional serological tests in detecting untreated coeliac disease and in coeliac disease diet monitoring.

Testing for IgG class antibodies in celiac disease patients with selective IgA deficiency. A comparison of the diagnostic accuracy of 9 IgG anti-tissue transglutaminase, 1 IgG anti-gliadin and 1 IgG anti-deaminated gliadin peptide antibody assays

BACKGROUND

To evaluate the diagnostic characteristics of commercially available IgG anti-tTG assays in selective IgA deficiency (SIgAD), we tested different IgG anti-tTG methods and compared the results with those obtained from two other tests: one for IgG anti-gliadin (AGA) and one for IgG to deaminated gliadin peptides (DGP).

METHODS

20 CD patients with SIgAD and 113 controls (9 patients with SIgAD without CD; 54 patients with chronic liver disease; 50 healthy subjects) were tested with 9 IgG anti-tTG assays (2 of which are enriched with gliadin peptides), one IgG AGA assay and one IgG anti-DGP assay.

RESULTS

Using optimal cutoffs as determined by ROC curves, the sensitivity of IgG anti-tTG methods ranged from 75% (1 kit) to 95% (7 kits) and the specificity from 94% (1 kit) to 100% (5 kits). Sensitivity and specificity were 40% and 87% for IgG AGA, and 80% and 98% for IgG anti-DGP, respectively.

CONCLUSIONS

All IgG anti-tTG methods evaluated are reliable serologic assays for the diagnosis of CD in patients with SIgAD and perform better than the gliadin-based assays used in this study. The tests containing both tTG and gliadinic peptides are burdened by a lower specificity than the anti-tTG assays.

HLA genotyping is useful in the evaluation of the risk for coeliac disease in the 1st-degree relatives of patients with coeliac disease

OBJECTIVE

Coeliac disease (CD) is a common disease with a strong heredity. About 10-20% of 1st-degree relatives of probands develop CD. Relatives should be screened for CD, because if not treated, CD exposes patients to numerous complications. The heterogeneity of symptoms and the lifetime-spanning risk of CD render the timing of CD antibody and/or gastroscopy screenings difficult. As CD susceptibility has been shown to be strongly associated with the HLA alleles DQA1*0501 and DQB1*0201 (together encoding the DQ2 heterodimer) and DRB1*04 (associated with the DQ8 heterodimer), our aim was to investigate whether HLA genotyping might be useful in the identification of 1st-degree relatives of CD patients who do not need further screening for CD.

MATERIAL AND METHODS

The study comprised 54 Finnish CD families including 54 CD probands and 382 living 1st-degree relatives. All subjects who were willing to participate were screened for CD (duodenal and skin biopsies; endomysial, reticulin and gliadin antibodies). The DQA1*0501, DQB1*0201 and DRB1*04 allele frequencies of CD patients and the 1st-degree relatives were determined.

RESULTS

Altogether 17.6% (5.9% of the parents, 15.7% of the siblings, 25.8% of the offspring) of the investigated 1st-degree relatives (n = 245) did not carry any of the alleles studied. All of the CD patients (n = 136) with the exception of one (0.7%) carried at least one of the alleles investigated.

CONCLUSIONS

By using the HLA genotyping a considerable proportion of 1st-degree relatives of CD probands could be excluded from further screening for CD.

Development of an immunocapture method for measuring IgA antibodies to tissue transglutaminase in the sera of patients with coeliac disease

One of the most reliable sero-diagnostic tests for coeliac disease (CD) is the measurement, by ELISA, of serum IgA antibodies to tissue transglutaminase (tTG) adsorbed to the wells of microtitre plates. In spite of its reliability, however, some discrepancies exist with the results obtained by the antiendomysium histological assay (EMA) and by biopsy the accepted gold standard. Among the reasons for these differences in titres between the ELISA and the last 2 mentioned assays are the conformational changes that proteins undergo on adsorption and the importance of conformational epitopes on tTG for diagnosing CD. To address this problem, a novel procedure was developed using guinea-pig tTG (gptTG) free in solution to interact with IgA antibodies in the sera of CD patients. Any immune complexes so formed are then captured by anti-tTG antibodies preadsorbed to the wells of microtitre plates. This immunocapture method was optimized for the amount of soluble gptTG needed to interact with all the IgA's anti-tTG present in fixed dilutions of serum samples, the amount of rabbit IgG anti-gptTG used to coat the wells of microtitre plates and the order of addition of the reaction components. Comparison of the IgA titres obtained by immunocapture with those by EMA and ELISA (adsorbed tTG) on 9 highly positive and 6 weakly positive sera from clinically characterized CD patients and 5 negative sera from non-CD control subjects revealed that the IgA titres by the immunocapture procedure were well correlated with those obtained by EMA, whereas the titres on ELISA showed discrepancies with both immunocapture and EMA.

Celiac disease in Tunisia: serological screening in healthy blood donors

BACKGROUND

Recent epidemiological studies in Europe and in USA using antigliadin antibodies and antiendomysium antibodies for initial screening have shown that the overall prevalence of celiac disease (CD) is about 1:200 (0.5%).

AIM

To screen for CD in healthy blood donors in Tunisia.

PATIENTS AND METHODS

Sera from 2500 healthy blood donors (median age: 21 years, 70% men and 30% women) were screened for IgG-antigliadin antibodies and IgA-antigliadin antibodies with an enzyme-linked immunosorbent assay. All sera with positive antigliadin antibodies were tested for antiendomysium antibodies using human umbilical cord cryosections as substrate.

RESULTS

Seven healthy blood donors (median age: 21 years; four men, three women) have antiendomysium antibodies. The prevalence of antiendomysium antibodies in healthy blood donors in Tunisia is 1:355 (0.28%).

CONCLUSIONS

On the basis of a high specificity of the antiendomysium antibodies, it is likely that the seven blood donors identified in this study have CD. These data suggest that CD is frequent in Tunisia.

Gene dose effect of the DQB1*0201 allele contributes to severity of coeliac disease

OBJECTIVE

Coeliac disease (CD) susceptibility has been shown to be associated with the HLA alleles DQA1*0501 and DQB1*0201. This HLA-associated risk has been estimated to account for 29-40% of the genetic component of CD. Conflicting data have been published on the gene dose effect of these HLA alleles on the risk and severity of CD. In this study the aim was to investigate the association between the number of HLA risk alleles and the severity of CD.

MATERIAL AND METHODS

Fifty-four Finnish CD families, including 144 CD patients mainly diagnosed in adulthood (94.4%), were enrolled in the study. The association between the number of DQA1*0501 and DQB1*0201 alleles and villous atrophy, symptoms and laboratory parameters at the time of diagnosis, and the association with villous atrophy after one year of treatment on a gluten-free diet were studied.

RESULTS

The homozygosity for the DQB1*0201 allele was associated with a more severe form of CD assessed by more severe villous atrophy (p=0.011), younger age (p=0.036), more severe diarrhoea (p=0.048) and a lower level of blood haemoglobin at the time of diagnosis (p=0.010). Furthermore, the homozygosity for the DQB1*0201 allele was associated with a slower recovery of villous atrophy after a gluten-free diet (p=0.041). In contrast, the DQA1*0501 allele did not have a significant association with the severity of CD.

CONCLUSIONS

Our results demonstrate a gene dose effect of the DQB1*0201 allele on the clinical heterogeneity of CD and on the rate of recovery from villous atrophy in patients on a gluten-free diet.

Is coeliac disease screening in risk groups justified? A fourteen-year follow-up with special focus on compliance and quality of life

BACKGROUND

The benefits of serologic screening for coeliac disease in asymptomatic individuals are debatable.

AIM

To investigate dietary compliance, quality of life and bone mineral density after long-term treatment in coeliac disease patients found by screening in risk groups.

METHODS

The study comprised 53 consecutive screen-detected coeliac patients diagnosed 14 years (median) ago. Dietary compliance was assessed by interview, 4-day food record and serology. Quality of life was evaluated by the Psychological General Well-Being and SF-36 questionnaires, gastrointestinal symptoms by the Gastrointestinal Symptom Rating Scale and bone mineral density by dual-energy x-ray absorptiometry. Comparisons were made to 44 symptom-detected-treated coeliac patients, 110 non-coeliac subjects and the general population.

RESULTS

A total of 96% of screen-detected and 93% of symptom-detected coeliac patients adhered to a strict or fairly strict gluten-free diet. In screen-detected patients, quality of life and gastrointestinal symptoms were similar to those in symptom-detected patients or non-coeliac controls and bone mineral density was similar to that in the general population.

CONCLUSIONS

Long-term dietary compliance in screen-detected patients was good. Quality of life and bone mineral density were comparable with those in non-coeliac subjects and the general population. Active screening in coeliac disease risk groups seems to be reasonable rather than harmful.

Celiac disease-related antibodies in an epilepsy cohort and matched reference population

Celiac disease (CD) is a common immunologically mediated enteropathic condition manifesting in genetically predisposed individuals after exposure to wheat gluten. CD may be associated with a number of neurological disorders, and the prevalence of epilepsy is reported to be increased in patients with CD. We studied the prevalence of CD-associated antibodies in a cohort of 968 patients with epilepsy and in a population-based reference group of 584 subjects. There was no difference in the prevalence of IgA and IgG class antigliadin antibodies (AGAbA and AGAbG, respectively), endomysial antibodies (EMA), and tissue transglutaminase antibodies (tTGAbA) between patients with epilepsy and the control population. This suggests the presence of CD to be the same in patients with epilepsy and the reference population. However, AGAbA was more prevalent in patients with primary generalized epilepsy (19.6%) than in the reference population (10.6%, relative risk 1.8, 95% confidence interval 1.1-3.0, P=0.012).

The diagnostic accuracy of serologic tests for celiac disease: a systematic review

Clinicians are increasingly utilizing noninvasive serologic tests for the diagnosis and screening of celiac disease (CD). The aim of this study was to conduct a systematic review of the diagnostic performance of serologic tests for the diagnosis and screening of 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. A weighted mean of the sensitivity and specificity along with 95% confidence intervals and summary receiver operating characteristic (ROC) curves were calculated. The pooled specificity of endomyseal antibody (EMA)-monkey esophagus (ME) or EMA-human umbilical cord (HU) was close to 100% in adults and children. The pooled specificity of transglutaminase antibody (tTG)-guinea pig (GP) and tTG-human recombinant (HR) were between 95% and 99%. IgA-EMA-ME demonstrated sensitivities of 96% and 97% in children and adults, respectively. EMA-HU demonstrated a similar sensitivity of 97% in children but 90% in adults. The pooled sensitivity of tTG-GP in adults and children was 90% and 93%, respectively. The sensitivity of tTG-HR was 98% and 96%, respectively. The performance of antigliadin antibody was inferior to that of EMA and tTG. EMA and tTG offer high sensitivity and specificity. The sensitivity of these tests appears to be lower than reported when milder histologic grades are used to define CD (below 90%). If true, the nearly perfect negative predictive value of these tests would drop. The positive predictive value of these tests is likely lower than reported when the tests are applied in low-prevalence populations.

Antiendomysial and antihuman recombinant tissue transglutaminase antibodies in the diagnosis of coeliac disease: a biopsy-proven European multicentre study

OBJECTIVE

To investigate the value of serum antitissue transglutaminase IgA antibodies (IgA-TTG) and IgA antiendomysial antibodies (IgA-EMA) in the diagnosis of coeliac disease in cohorts from different geographical areas in Europe. The setting allowed a further comparison between the antibody results and the conventional small-intestinal histology.

METHODS

A total of 144 cases with coeliac disease [median age 19.5 years (range 0.9-81.4)], and 127 disease controls [median age 29.2 years (range 0.5-79.0)], were recruited, on the basis of biopsy, from 13 centres in nine countries. All biopsy specimens were re-evaluated and classified blindly a second time by two investigators. IgA-TTG were determined by ELISA with human recombinant antigen and IgA-EMA by an immunofluorescence test with human umbilical cord as antigen.

RESULTS

The quality of the biopsy specimens was not acceptable in 29 (10.7%) of 271 cases and a reliable judgement could not be made, mainly due to poor orientation of the samples. The primary clinical diagnosis and the second classification of the biopsy specimens were divergent in nine cases, and one patient was initially enrolled in the wrong group. Thus, 126 coeliac patients and 106 controls, verified by biopsy, remained for final analysis. The sensitivity of IgA-TTG was 94% and IgA-EMA 89%, the specificity was 99% and 98%, respectively.

CONCLUSIONS

Serum IgA-TTG measurement is effective and at least as good as IgA-EMA in the identification of coeliac disease. Due to a high percentage of poor histological specimens, the diagnosis of coeliac disease should not depend only on biopsy, but in addition the clinical picture and serology should be considered.

Genomewide search and association studies in a Finnish celiac disease population: Identification of a novel locus and replication of the HLA and CTLA4 loci

It has been reported that celiac disease (CD) is strongly associated with the HLA-DQ2 alleles DQA1*0501 and DQB1*0201. However, this association only accounts for a portion of the genetic component of CD. Several non-HLA loci and candidate genes that potentially contribute to CD susceptibility have been reported, but have not been confirmed. The aim of this study was to identify loci that contribute to disease susceptibility in a CD population from Finland. We performed a genomewide linkage scan and identified two regions of significant linkage to CD (6p and 2q23-32) and one region of suggestive linkage (10p). We also performed targeted typing and analyses that replicated the associations of the HLA and CTLA4 loci.

Villous tip intraepithelial lymphocytes as markers of early-stage coeliac disease

BACKGROUND

An investigation was conducted to determine whether the density of small-intestinal villous tip intraepithelial lymphocytes would be of value in clinical practice in uncovering early-stage coeliac disease.

METHODS

Villous tip, CD3+ and gammadelta+ intraepithelial lymphocytes were counted in patients with definite early-stage coeliac disease without villous atrophy, in classic coeliac disease with manifest mucosal lesion and in non-coeliac controls with normal mucosal structure. Villous tip analysis was made of haematoxylin-eosin specimens and CD3+ and gammadelta+ of immunohistochemical stainings from frozen samples.

RESULTS

The villous tip intraepithelial lymphocyte count was statistically significantly higher in patients with early-stage coeliac disease than in non-coeliac controls. The sensitivity of this method to detect untreated coeliac disease with normal villous architecture was 0.84; the specificity was 0.88. This method proved superior to CD3+ analysis and was at least as good as gammadelta+ analysis in detecting early-stage coeliac disease. In detecting classic coeliac disease, villous tip analysis also reached a higher sensitivity than CD3+ and gammadelta+ cells.

CONCLUSIONS

Villous tip analysis seems to distinguish early coeliac from non-specific changes, thus providing a valuable tool in routine practice, especially when borderline findings are involved. Its value appears to be similar to counting of gammadelta+ cells, which, however, requires frozen biopsy samples.

Prevalence of Celiac disease among children in Finland

BACKGROUND

Wheat, rye, and barley proteins induce celiac disease, an autoimmune type of gastrointestinal disorder, in genetically susceptible persons. Because the disease may be underdiagnosed, we estimated the prevalence of the disease and tested the hypothesis that assays for serum autoantibodies can be used to detect untreated celiac disease and that positive findings correlate with specific HLA haplotypes.

METHODS

Serum samples were collected from 3654 students (age range, 7 to 16 years) in 1994 and screened in 2001 for endomysial and tissue transglutaminase antibodies. HLA typing was also performed on stored blood samples. All antibody-positive subjects were asked to undergo small-bowel biopsy in 2001.

RESULTS

Of the 3654 subjects, 56 (1.5 percent) had positive antibody tests, as determined in 2001. Results of the two antibody tests were highly concordant. As of 1994, none of the subjects had received a clinical diagnosis of celiac disease, but 10 who had positive tests for both antibodies in serum obtained in 1994 received the diagnosis between 1994 and 2001. Of the 36 other subjects with positive antibody assays who agreed to undergo biopsy in 2001, 27 had evidence of celiac disease on biopsy. Thus, the estimated biopsy-proved prevalence was 1 case in 99 children. All but two of the antibody-positive subjects had either the HLA-DQ2 or the HLA-DQ8 haplotype. The prevalence of the combination of antibody positivity and an HLA haplotype associated with celiac disease was 1 in 67.

CONCLUSIONS

The presence of serum tissue transglutaminase and endomysial autoantibodies is predictive of small-bowel abnormalities indicative of celiac disease. There is a good correlation between autoantibody positivity and specific HLA haplotypes. We estimate that the prevalence of celiac disease among Finnish schoolchildren is at least 1 case in 99 children.

Intraepithelial lymphocytes in celiac disease

OBJECTIVE

The aim of this study was to investigate the value of immunohistochemical characterization of different intraepithelial lymphocytes (IELs) in the diagnostic workup of celiac disease (CD).

METHODS

The study involved 928 consecutive adult patients undergoing endoscopy undertaken on suspicion of CD or to ascertain the dietary compliance; the control group consisted of 59 adults who underwent endoscopy because of indigestion. Small bowel mucosal morphology, CD3+, alphabeta+, and gammadelta+ IELs were determined.

RESULTS

CD was detected in 138 and excluded in 545 adults. CD3+ and gammadelta+ IELs both showed a sensitivity of 93% for CD; specificity was 73% and 88%, respectively. For alphabeta+ cells, the sensitivity was 83% and specificity, 66%. The mucosal morphology recovered on a gluten-free diet and the densities of different IELs, even gammadelta+ cells, decreased. Only the density of gammadelta+ cells remained elevated compared with controls.

CONCLUSIONS

Counting of IELs is recommended in borderline cases where the histology is difficult to interpret. An increase especially in gammadelta+ cells strengthens the probability of CD. However, IELs are not invariably increased in CD.

Recognition and management of the cutaneous manifestations of celiac disease: a guide for dermatologists

In celiac disease, the ingestion of gluten-containing cereals, such as wheat, rye, and barley, results in small-bowel mucosal inflammation and villous atrophy with crypt hyperplasia. The prevalence of the condition may be as high as 1% in the adult population. The disease can also embrace various extraintestinal manifestations, of which dermatitis herpetiformis is the best known. Earlier, dermatitis herpetiformis was considered a skin disease occurring often concomitantly with celiac disease. At present, a body of evidence shows that dermatitis herpetiformis is a cutaneous manifestation of celiac disease, and affects approximately 25% of patients with celiac disease. Both conditions can appear in the same family and are closely linked to HLA class II locus in chromosome 6; 90% of patients have HLA DQ2 and, almost all the remainder, HLA DQ8. All patients with dermatitis herpetiformis have at least some-degree of mucosal inflammation or lesion consistent with celiac disease. The etiology of celiac disease in not fully understood, but tissue transglutaminase seems to be the predominant autoantigen both in the intestine and the skin. Serum antibodies against tissue transglutaminase can be used in the serologic screening and follow-up of dietary compliance of patients with celiac disease. Gluten-free diet is essential in the treatment of both conditions, and oral dapsone is usually needed in newly detected dermatitis herpetiformis in order to alleviate symptoms. Oral mucosal lesions, alopecia areata, and vitiligo probably occur more frequently in patients with dermatitis herpetiformis than in the general population. By contrast, the reported association of celiac disease with psoriasis seems to be coincidental.

Coeliac disease in patients with cerebellar ataxia of unknown origin

BACKGROUND

Neurological symptoms of unknown origin are common in coeliac disease (CD). Evidence suggests that CD may also contribute to the development of idiopathic late-onset ataxia.

AIM

To evaluate the frequency of CD in patients with cerebellar ataxia of unknown origin.

METHODS

The medical files of adult patients with the diagnosis of cerebellar ataxia of unknown origin (n=44) were evaluated. Serum gliadin, endomysial, and serum tissue transglutaminase antibodies were used as screening tests for CD. Subjects with positive results were referred to small-bowel biopsy.

RESULTS

The frequency of CD was as high as 9.1% in all patients. A thorough interview and review of the patient files indicated alcohol abuse as a cause for cerebellar disease in almost half (45.5%) of our patients. When the cases with alcohol abuse were omitted, the calculated frequency of CD was 16.7% in patients with ataxia of unknown origin.

CONCLUSION

CD is a common association with cerebellar disease and the disease should be considered in all patients with ataxia of unknown origin.

Serological markers for coeliac disease: is it time to change?

BACKGROUND

Anti-gliadin and anti-endomysium antibodies are useful markers in the screening and follow-up of coeliac disease. The recent finding that tissue transglutaminase is the main auto-antigen of anti-endomysium has led to the discovery of anti-tissue transglutaminase antibodies.

AIM

To compare, in a prospective study, the diagnostic accuracy of anti-tissue transglutaminase, anti-gliadin and anti-endomysium antibodies in a large series of adult patients.

METHODS

The study involved 80 consecutive subjects undergoing upper gastrointestinal tract endoscopy for suspected coeliac disease (subsequently confirmed in 40 cases), 195 coeliac patients on a gluten-free diet, and 70 patients with different gastrointestinal disor ders and normal duodenal histology. Anti-gliadin, anti-endomysium and anti-tissue transglutaminase antibodies levels were measured using commercial kits.

RESULTS

The diagnostic sensitivity and specificity of anti-gliadin, anti-endomysium and anti-tissue transglutaminase antibodies were, respectively, 95% and 89.1%, 100% and 97.3%, and 100% and 98.2%: the agreement between the markers was substantial or almost perfect. In terms of follow-up, the positivity of the markers varied according to the strict adherence to, and duration of the gluten-free diet; the agreement between antiendomysium and anti-tissue transglutaminase antibodies was almost perfect.

CONCLUSIONS

Anti-endomysium and anti-tissue transglutaminase antibodies are both highly efficient for routine laboratory screening: the choice of one or the other will depend on the available facilities. However, neither can replace intestinal biopsy for general population screening because, in this case, their respective positive predictive values are only 15.7% and 21.8%. During follow-up, anti-gliadin retain their value as an early predictor of gluten ingestion.

Antiendomysium antibodies in Brazilian patients with celiac disease and their first-degree relatives

BACKGROUND

Literature data have shown high specificity of antiendomysial antibodies (EmA IgA) in celiac disease. The scarcity of Brazilian reports concerning this subject motivated the present study.

OBJECTIVES

To determine the sensitivity and specificity of antiendomysial IgA antibodies in Brazilian celiac patients at diagnosis and after treatment, to confirm patient adherence to a gluten-free diet and to screen first-degree relatives.

METHODS

An extensive clinical and serological study was performed by investigating the presence of these antibodies in 392 individuals from Southern Brazil. Indirect immunofluorescence using human umbilical cord as substrate was employed and the total levels of IgA were determined by turbidimetry in all groups. The study was conducted on 57 celiac patients (18 at diagnosis, 24 who adhered to a gluten-free diet and 15 with marked or slight transgression of the diet), 115 relatives of celiac patients (39 families), 94 patients with other gastrointestinal diseases, and 126 healthy individuals from the general population.

RESULTS

The results demonstrated 100% positivity for the recently diagnosed patients and for those consuming gluten, in contrast to the patients who complied with the diet (0%). In the control group one individual was positive, but refused to undergo a biopsy. In the group of other gastrointestinal diseases, one positive patient presented ulcerative colitis, Down's syndrome and epilepsy, and the intestinal biopsy was diagnostic for celiac disease. These data showed 99.3% specificity for the test. Eighteen relatives were positive for antiendomysial antibodies IgA (15.65%), and comparison with the healthy population revealed a significant difference. An intestinal biopsy was obtained from seven subjects (one with total villous atrophy and six without alterations in the mucosal architecture, but all with a high number of intra-epithelial lymphocytes).

CONCLUSIONS

The method revealed 100% sensitivity and 99.3% specificity. Because it is not an invasive method it can be used for the screening of atypical and latent forms of celiac disease to avoid serial biopsies and to control adherence to a gluten-free diet with implications in the prevention of malignancy in celiac disease.

Reliance on serum endomysial antibody testing underestimates the true prevalence of coeliac disease by one fifth

BACKGROUND

Although IgA endomysial antibody (EmA) is currently the serologic test of choice in selecting suspected coeliac patients for duodenal biopsies, false-negative cases have been reported and may be more common than previous studies suggest. We assessed the sensitivity of EmA for patients with biopsy-confirmed villous atrophy (VA).

METHODS

We studied 89 patients without IgA deficiency for whom biopsy had not been primarily prompted by a positive EmA result. VA was graded as partial, subtotal, or total (PVA, STVA, TVA). Serum EmA was assayed with indirect immunofluorescence.

RESULTS

The sensitivity of EmA for VA was 78% (69 of 89) and was similar for PVA (79%) and ST/TVA (77%). Only 4 of the 20 EmA-negative patients had increased serum IgA-class antigliadin antibody levels as measured with enzyme-linked immunosorbent assay. All seronegative patients who complied with dietary gluten exclusion responded clinically, with histologic improvement after 12 months in 8 (67%) of 12 patients who had follow-up biopsies.

CONCLUSIONS

EmA-negative coeliac disease is common. Reliance on EmA testing to select patients for biopsy will result in significant underdiagnosis.

Salivary antigliadin and antiendomysium antibodies in coeliac disease

The definitive diagnosis of coeliac disease is based on typical changes in the small intestine biopsy specimens. To screen individuals for coeliac disease serum IgA and IgG antigliadin (AGA), IgA antireticulin (ARA) and IgA antiendomysium (EmA) antibodies are used. The aim of this study was to investigate whether these antibodies can also be detected in saliva as diagnostic markers of coeliac disease. The study population comprised 30 patients with coeliac disease treated with a gluten-free diet, 14 patients with untreated coeliac disease and 13 healthy control subjects. Sera and saliva were tested simultaneously for the presence of IgA and IgG AGA and IgA EmA. None of patients studied had a selective IgA deficiency. There was no significant difference in salivary IgA AGA levels between the three groups tested and there was no correlation between the individual serum and salivary values of IgA AGA. Salivary IgG AGA levels were very low or undetectable. Serum IgA AGA showed a low sensitivity (36.4%) to detect an untreated patient with coeliac disease. All salivary samples, regardless of the study group were negative for IgA EmA. Serum IgA EmAs were universally detected in the sera of patients with newly diagnosed coeliac disease and also in the sera of five of 30 patients with treated coeliac disease. No IgA EmA was detected in the sera of controls. None of the patients studied had a selective IgA deficiency either. Serum IgA EmA is the most sensitive, and IgA and IgG AGA are good indicators for coeliac disease, but salivary IgA or IgG AGA and salivary IgA EmA are not helpful for the diagnosis or follow-up of coeliac disease patients.

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.

High prevalence of celiac disease in apparently healthy blood donors suggests a high prevalence of undiagnosed celiac disease in the Dutch population

BACKGROUND

In the last few years the prevalence of celiac disease (CD) seems to have increased. It is clear that subclinical and silent CD exist in a large subgroup of the celiac population.

METHODS

The aim of this study was to evaluate the prevalence of CD in an apparently healthy population. Blood samples were obtained from 1000 apparently healthy blood donors at Arnhem and Nijmegen Blood Donation Centers from January 1997 through April 1998. Sera from 660 blood donors were assayed for total IgA. By means of immunofluorescence, antibodies, including those to endomysium (EMA), were determined. Serum immunoglobulin levels (IgA) were assayed by means of nephelometry. All donors who had positive serology for EMA underwent small-intestinal biopsy.

RESULTS

Of the 1000 healthy blood donors 3 had positive EMA. Small-intestinal biopsy of two of these showed subtotal villous atrophy (Marsh IIIb), and the third had intraepithelial lymphocytosis and crypt hyperplasia (Marsh II). The prevalence of gluten sensitivity was 1 of 330. Low IgA (0.60-0.23 g/l) in our study group was found in 9 of 660 (1%), but no one showed an IgA < or = 0.02 g/l.

CONCLUSION

Our study shows that the prevalence of gluten-sensitivity in apparently healthy blood donors is 3 of 1000, which suggests a high prevalence of CD in the Dutch population, in contrast to the results of the last published Dutch epidemiologic studies. The recorded prevalence will increase further with greater recognition of subclinical and asymptomatic forms detected by screening tests.

Wheat starch-containing gluten-free flour products in the treatment of coeliac disease and dermatitis herpetiformis. A long-term follow-up study

BACKGROUND

We investigated whether wheat starch-based gluten-free products are safe in the treatment of gluten intolerance.

METHODS

The study involved 41 children and adults with coeliac disease and 11 adults with dermatitis herpetiformis adhering to a gluten-free diet for 8 years on average. Thirty-five newly diagnosed coeliac patients at diagnosis and 6 to 24 months after the start of a gluten-free diet and 27 non-coeliac patients with dyspepsia were investigated for comparison. Daily dietary gluten and wheat starch intake were calculated. Small-bowel mucosal villous architecture, CD3+, alphabeta+, and gammadelta+ intraepithelial lymphocytes, mucosal HLA-DR expression, and serum endomysial, reticulin, and gliadin antibodies were investigated.

RESULTS

Forty of 52 long-term-treated patients adhered to a strict wheat starch-based diet and 6 to a strict naturally gluten-free diet; 6 patients had dietary lapses. In the 46 patients on a strict diet the villous architecture, enterocyte height, and density of alphabeta+ intraepithelial lymphocytes were similar to those in non-coeliac subjects and better than in short-term-treated coeliac patients. The density of gammadelta(+)cells was higher, but they seemed to decrease over time with the gluten-free diet. Wheat starch-based gluten-free flour products did not cause aberrant upregulation of mucosal HLA-DR. The mucosal integrity was not dependent on the daily intake of wheat starch in all patients on a strict diet, whereas two of the six patients with dietary lapses had villous atrophy and positive serology.

CONCLUSION

Wheat starch-based gluten-free flour products were not harmful in the treatment of coeliac disease and dermatitis herpetiformis.

Antibodies in relation to gluten intake

Serum reticulin, endomysial and gliadin antibody tests are used in serological screening and case finding of coeliac disease, as well as the novel tissue transglutaminase antibody test. None of these tests are 100% predictive, however. Reticulin/endomysial antibodies predict forthcoming coeliac disease in individuals with normal small-bowel mucosal morphology. The effect of a gluten-free diet can be monitored with serological tests. A positive test result often indicates an inadequate gluten-free diet. However, slight dietary transgressions and minor mucosal damages cannot always be revealed with the serological tests. Therefore, small-bowel mucosal biopsy remains the most sensitive method to monitor the effect of a gluten-free diet.