Serological aspects of coeliac disease.

We have evaluated the sensitivity and specificity of serum anti-gliadin, anti-reticulin and anti-endomysium antibody determinations for the diagnosis of coeliac disease. Serum samples from 54 children and 9 adults with untreated coeliac disease were analysed for anti-gliadin antibodies and compared to the results obtained for 111 non coeliac controls (72 children, 39 adults) and 221 healthy blood donors. This yields sensitivities of 87% and 86% for IgA and IgG antibodies. Specificities were respectively of 95.5% and 91%. Anti-reticulin and anti-endomysium IgA were analysed in a more limited number of sera. Specificity of both tests was of 100% for the IgA class of antibody. However sensitivity was only of 64% for anti-reticulin IgA but was of 100% for anti-endomysium IgA. These results indicate that combination of anti-gliadin antibodies (IgA and IgG), anti-reticulin and anti-endomysium IgA may be recommended as screening tests to better select patients suspected of coeliac disease for jejunal biopsy.     

Dietary Intake,Smoking, and Transient Anti-Gliadin Antibodies

Background: The detection of IgA anti-gliadin antibodies in adults can either be helpful in the diagnosis of coeliac disease, be persistent in subjects with normal jejunal mucosa, or occur transiently. We decided to investigate the effects of smoking, alcohol consumption, and dietary intake on the development of IgA anti-gliadin antibodies. Methods: Serum samples from subjects enrolled from a large Northern Ireland population sample (MONICA survey) were screened for IgA anti-endomysium and IgA anti-gliadin antibodies. All subjects with positive antibodies were invited for clinical assessment 3-4 years after the initial screening sample. During this follow-up a repeat serum sample was obtained and a jejunal biopsy performed. At enrolment in the MONICA survey, lifestyle information including smoking, alcohol consumption, and dietary intake was obtained. Results: At follow-up 13 subjects had persistent positive serology and villous atrophy, and 9 had persistent positive serology but normal jejunal histology; in 29 the serology had returned to normal, and the jejunal histology was normal There was no difference in smoking, alcohol consumption, or dietary intake between subjects with and without coeliac disease. Subjects with transient serology findings ate significantly more soda bread than the other groups (at the time of initial screening). Analysis of gliadin content of soda bread and plain white bread showed a significantly higher amount of gliadin present in soda bread. Conclusions: Subjects with transient IgA anti-gliadin antibodies eat significantly more soda bread. The gliadin content of Irish soda bread contained a greater amount of gliadin than white bread. Eating breads with high available gliadin content may cause the appearance of anti-gliadin antibody.     

Significance of IGA antigliadin antibodies during primary glomerulonephritis with mesangial IGA deposits

The association of IgA anti-gliadin antibodies and IgA glomerulonephritis (IgA GN) was first reported in 1987 (Am J Nephrol, 1987, 7, 178-183) and has since been confirmed by other groups. We have developed a second generation ELISA (alkaline phosphatase, biotin-avidin) and used it to test 45 adult IgA GN, 34 idiopathic membranous nephropathy (MN), 31 idiopathic nephrotic syndrome (INS), and 11 idiopathic membranoproliferative glomerulonephritis (MPG) patients. IgA anti-gliadin antibodies were found in 24 IgA GN (53%), 1 MN (3%), 1 INS (3%), and 1 MGP (9%) patients. The presence of these antibodies in a patient with proteinuria strongly suggests IgA GN, with a sensitivity of 53%, a specificity of 96%, a positive predictive value of 88% and a negative predictive value of 77%. The presence of IgA anti-gliadin antibodies in IgA GN did not necessarily indicate coeliac disease because: a) neither IgG nor IgA anti-reticulin nor IgA anti-endomysium antibodies were found; b) intestinal absorption tests (folates, EDTA) were normal; c) biopsies of the small intestine were normal; and d) a gluten-free diet did not alter the evolution of the disease. Immunochemical analysis (footprinting after separation of the gliadins by rocket electrophoresis) showed the variability of the fractions recognized by the IgA antibodies from patients and controls, in addition to the absence of a typical profile. Gliadin does not have a lectin effect, since mannan and mannose did not inhibit the ELISA. Immunofluorescent labeling of human kidney with purified rabbit IgG anti-gliadin antibodies did not reveal a common epitope shared by gliadin and renal structures.(ABSTRACT TRUNCATED AT 250 WORDS)     

High rate of positive anti-tissue transglutaminase antibodies in chronic liver disease. Role of liver decompensation and of the antigen source

BACKGROUND: Since the recognition of tissue transglutaminase (tTG) as the target antigen of anti-endomysium antibodies, several ELISA assays using either guinea pig or human recombinant tTG have been developed. The aim of the study was to compare the behaviour of anti-tTG and anti-endomysium antibodies assays in coeliacs and in patients with chronic liver disease. METHODS: 34 patients (24 women, 34.9 +/- 12.5 years) with coeliac disease and 41 with chronic liver disease (14 women, 57 +/- 11.2 years), including 19 cirrhotics, were evaluated for anti-endomysium antibodies by indirect immunofluorescence and for anti-tTG IgA antibodies by ELISA, using guinea pig liver or human recombinant transglutaminase. RESULTS: The prevalences of anti-tTG and anti-endomysium antibodies were 100% in patients with coeliac disease at diagnosis, 75% and 64.3% in patients on a gluten-free diet. All liver disease patients were negative for anti-endomysium antibodies, while 11 (26.8%) were positive for anti-tTG. All these patients had liver cirrhosis and represented 57.9% of all cirrhotics. The presence of anti-tTG was associated with higher Child-Pugh scores. The use of human transglutaminase determined a reduction in the rate of positive results; however, the rate of positive anti-tTG was still 17.1% in all liver disease patients and 31.6% in cirrhotics. CONCLUSIONS: Our data confirm that anti-tTG have a similar sensitivity compared with anti-endomysium antibodies assay in coeliacs. However, a high prevalence of positive anti-tTG results is observed in cirrhotic patients, even when human recombinant tTG is used. The high prevalence of positive results among cirrhotic patients is associated with more advanced liver disease.     

Dissociation between systemic and mucosal humoral immune responses in coeliac disease

We examined humoral immunity in coeliac disease as expressed in serum (systemic immunity), and in saliva, jejunal aspirate, and whole gut lavage fluid (mucosal immunity). The aims were to define features of the secretory immune response (IgA and IgM concentrations and antibody values to gliadin and other food proteins measured by enzyme linked immunosorbent assay (ELISA)) in active disease and remission, and to establish whether secretions obtained by relatively non-invasive techniques (saliva and gut lavage fluid) can be used for indirect measurements of events in the jejunum. Serum, saliva, and jejunal aspirate from 26 adults with untreated coeliac disease, 22 treated patients, and 28 immunologically normal control subjects were studied, together with intestinal secretions obtained by gut lavage from 15 untreated and 19 treated patients with coeliac disease and 25 control subjects. Jejunal aspirate IgA and IgM and gut lavage fluid IgM concentrations were significantly raised in patients with untreated coeliac disease; the lavage fluid IgM concentration remained higher in patients with treated coeliac disease than in controls. Serum and salivary immunoglobulin concentrations were similar in the three groups. Patients with untreated coeliac disease had higher values of antibodies to gliadin compared with treated patients and control subjects in all body fluids tested; these were predominantly of IgA and IgG classes in serum, and of IgA and IgM classes in jejunal aspirate and gut lavage fluid. Values of salivary IgA antibodies to gliadin were significantly higher in untreated coeliacs, though antibody values were generally low, with a large overlap between coeliac disease patients and control subjects. In treated patients, with proved histological recovery on gluten free diet, serum IgA antigliadin antibody values fell to control values, though serum IgG antigliadin antibody values remained moderately raised. In contrast, there was persistence of secretory antigliadin antibodies in treated patients (particularly IgM antibody) in both jejunal aspirate and gut lavage fluid. Antibody responses to betalactoglobulin and ovalbumin were similar to those for gliadin, including persistence of high intestinal antibody values in patients with treated coeliac disease. There was a positive correlation between antibody values in jejunal aspirate and gut lavage fluid, but not between saliva and jejunal aspirate; thus salivary antibodies do not reflect intestinal humoral immunity.     

High Rate of Positive Anti-Tissue Transglutaminase Antibodies in Chronic Liver Disease

Background: Since the recognition of tissue transglutaminase (tTG) as the target antigen of anti-endomysium antibodies, several ELISA assays using either guinea pig or human recombinant tTG have been developed. The aim of the study was to compare the behaviour of anti-tTG and anti-endomysium antibodies assays in coeliacs and in patients with chronic liver disease. Methods: 34 patients (24 women, 34.9 ± 12.5 years) with coeliac disease and 41 with chronic liver disease (14 women, 57 ± 11.2 years), including 19 cirrhotics, were evaluated for anti-endomysium antibodies by indirect immunofluorescence and for anti-tTG IgA antibodies by ELISA, using guinea pig liver or human recombinant transglutaminase. Results: The prevalences of anti-tTG and anti-endomysium antibodies were 100% in patients with coeliac disease at diagnosis, 75% and 64.3% in patients on a gluten-free diet. All liver disease patients were negative for anti-endomysium antibodies, while 11 (26.8%) were positive for anti-tTG. All these patients had liver cirrhosis and represented 57.9% of all cirrhotics. The presence of anti-tTG was associated with higher Child-Pugh scores. The use of human transglutaminase determined a reduction in the rate of positive results; however, the rate of positive anti-tTG was still 17.1% in all liver disease patients and 31.6% in cirrhotics. Conclusions: Our data confirm that anti-tTG have a similar sensitivity compared with anti-endomysium antibodies assay in coeliacs. However, a high prevalence of positive anti-tTG results is observed in cirrhotic patients, even when human recombinant tTG is used. The high prevalence of positive results among cirrhotic patients is associated with more advanced liver disease.     

Antibodies to recombinant human tissue-transglutaminase in coeliac disease: Diagnostic effectiveness and decline pattern after gluten-free diet

BACKGROUND/AIMS: To assess the sensitivity and specificity of IgA and IgG tissue-transglutaminase antibodies assay, the pattern of antibody decline after gluten withdrawal and their modifications with reference to dietary compliance. SUBJECTS: We studied sera from 143 untreated coeliac children and adolescents (8.8+/-6.1 years), 212 sera from 97 of those patients after gluten withdrawal, and 64 control subjects with non-coeliac intestinal disorders (6.8+/-4.8 years). METHODS: Samples were tested for IgA and IgG class tissue-transglutaminase antibodies by radiobinding assay, using human-derived tissue-transglutaminase, and for IgA anti-endomysium antibodies by indirect immunofluorescence on monkey oesophagus. RESULTS: Untreated coeliac patients had significantly higher titres of IgA and IgG tissue-transglutaminase antibodies than controls (p<0.00001); the diagnostic sensitivity was 95.8% and 99.3%, respectively, and the specificity was 95.3%. Three patients with selective IgA deficiency were positive for IgG tissue-transglutaminase antibodies. The concordance rate between IgA tissue-transglutaminase antibodies and anti-endomysium antibodies was 98.1%. Patients on gluten-free diet showed a significant decrease in IgA and IgG tissue-transglutaminase antibodies with respect to untreated patients (p<0.0001). Tissue-transglutaminase was more sensible than anti-endomysium antibodies to detect small amounts of gluten intake when the compliance was poor. CONCLUSIONS: The recombinant human tissue-transglutaminase antibodies assay is a highly sensitive and specific test for diagnosis of coeliac disease, and it is useful in monitoring the compliance to gluten-free diet.     

Serum IgG subclass antibodies to a variety of food antigens in patients with coeliac disease.

Levels of serum IgA, IgG, and IgG subclass antibodies to a variety of dietary antigens were determined by enzyme linked immunosorbent assays in 14 adults with untreated coeliac disease and in 10 disease controls selected because of raised total IgG activities. The untreated coeliacs showed somewhat higher total IgG activity (p approximately 0.05) and significantly raised IgA and IgG1 + IgG3 activities to gliadin but reduced IgG4 activity (p less than 0.02) compared with the controls. High IgA and IgG1 + IgG3 activities were positively correlated (r = 0.67, p less than 0.01), and so were IgG and IgG4 activities (r = 0.64, p less than 0.02). Conversely, a high IgG2 response to gliadin appeared related to a low IgA response (r = 0.55, p less than 0.05). The IgG2 response was most prominent to oat flour antigens, followed by IgG1; and the main response to soy antigens resided in IgG1, followed by IgG2 in both disease groups. There was no difference in antibody activities to oat and soy between the two groups, and raised activity to bovine serum albumin was seldom encountered. The IgA activity to alpha-lactalbumin and ovalbumin tended to be increased in the coeliacs compared with the controls. The IgG4 subclass dominated the IgG response to beta-lactoglobulin and ovalbumin and was often raised to alpha-lactalbumin, especially in the disease controls. The IgG subclass pattern to casein parallelled that to gliadin with dominance of the IgG1- and IgG3-subclass activities, especially in the coeliacs. The phlogistic potential of a response in these two subclasses might be relevant to the pathogenesis of coeliac disease and could contribute to a raised IgA gliadin response by increasing mucosal permeability. IgA activity seemed to be highest against antigens usually involved in IgE mediated food allergy.     

Determination of anti-omega-gliadin antibodies in serologic tests for coeliac disease

BACKGROUND: Serologic detection of coeliac disease in the general population or in subjects belonging to risk groups implies the use of a test with high efficiency, large-scale use, and low cost. The enzyme-linked immunosorbent assay (ELISA) technique is the most appropriate assay for performing this kind of studies. Even though anti-gliadin determination has been the test most frequently used as the first step in screening procedures, many false-positive results produced a low-specificity test. In a previous work a selective recognition of omega-gliadins, mainly by IgA antibodies, was observed. Results also indicated that omega-gliadins can be useful as antigens in serologic detection of coeliac disease. We therefore wanted to analyse the anti-gliadin antibody reactivity by using purified gliadins and to evaluate the actual performance of the anti-omega-gliadin antibody test. METHODS: A population consisting of 105 coeliac patients, 81 healthy controls, and 73 subjects in a disease control group was analysed. Anti-endomysium (EMA), both IgG and IgA anti-omega-gliadins, and anti-tissue transglutaminase (tTG) antibodies were determined. RESULTS: Concordant results, positive and negative, in the EMA and IgG and IgA anti-gliadin determinations were observed in 220 of 259 samples from the total population analysed. The three assays showed high efficiency, being 96.9%, 90.7%, and 91.1% for EMA and anti-omega-gliadins IgG and IgA, respectively. Anti-tTG determination was performed on 103 samples (69 controls and 34 coeliac patients), finding 4 false results (2 false positive and 2 false negative), whereas anti-omega-gliadins showed 10 false results (5 false negative and 5 false positive), 3 of which were coincident with anti-tTG determination. To compare the reactivity of anti-gliadin antibodies, alpha-, beta-, gamma- and omega-gliadins were isolated under non-denaturing conditions by acid preparative electrophoresis and cation-exchange fast protein liquid chromatography (FPLC) and used in an indirect ELISA test. The composition of these fractions was analysed by means of capillary electrophoresis, showing no cross-contamination among them. CONCLUSIONS: The comparison of results using purified gliadins shows that omega-gliadins present a differential reactivity that has not previously been documented. Results using omega-gliadins isolated by either preparative electrophoresis or FPLC were similar. Tests using the purified omega-gliadin fraction present the best performance when anti-gliadin antibodies are evaluated.     

Searching for coeliac disease in patients with non-alcoholic fatty liver disease

BACKGROUND: A non-negligible percentage of patients with non-alcoholic fatty liver disease, a leading cause of hepatic progressive disorder related to insulin resistance, have no metabolic risk factors, and abnormal intestinal permeability has been suggested to be involved in the pathogenesis of the liver damage. Coeliac disease, a curable disorder characterised by inflammatory mucosal damage, may show hepatic histological features similar to steatohepatitis. Conflicting data have been reported on the prevalence of coeliac disease in non-alcoholic steatohepatitis. AIM: To search for coeliac disease in a series of patients with non-alcoholic fatty liver disease by screening with anti-tissue transglutaminase and anti-endomysium antibodies. PATIENTS AND METHODS: Fifty-nine consecutive patients with hypertransaminasemia and non-alcoholic fatty liver disease, 38 (64%) with steatohepatitis. Anti-endomysium antibodies were assayed by indirect immunofluorescence, IgA anti-tissue transglutaminase by ELISA. Patients who tested positive underwent HLA DQ typing and endoscopy. RESULTS: Tissue transglutaminase antibodies were positive in six (10%) patients and anti-endomysium in two (3.4%); only two (3.4%), positive for both anti-endomysium positive and anti-transglutaminase, resulted to have coeliac disease based on histological findings. After 6 months of gluten-free diet, liver enzymes normalised. CONCLUSIONS: The prevalence of silent coeliac disease is 3.4% in patients with non-alcoholic fatty liver. The inclusion of anti-endomysium antibodies test in studying patients with non-alcoholic fatty liver and persistent biochemical abnormalities has to be taken into account, since positivity for tissue transglutaminase antibodies, in the absence of confirmatory anti-endomysium antibodies, is not sufficient to perform diagnostic endoscopy.     

Coeliac Disease: Frequent Occurrence After Clinical Onset of Insulin-dependent Diabetes Mellitus

Coeliac disease was searched for in a series of 776 children with newly diagnosed IDDM. During the follow-up of 2 to 3 years from diagnosis, reticulin and gliadin antibodies were measured, and a jejunal biopsy was performed in those cases with high levels of antibodies; 19 children were identified with coeliac disease, giving the prevalence of 2.4 %. In only one case had coeliac disease been diagnosed before IDDM. Nine patients with proven coeliac disease were negative for antibodies when IDDM was diagnosed, but became positive within 24 months. All patients found to have coeliac disease were positive for IgA reticulin antibodies, but only 12 of 18 (67 %) showed a high level of IgA gliadin antibodies. Of the 18 patients genotyped for HLA DR locus, 14 (78 %) were positive for DR3 and 10 (56 %) were positive for DR4. DQB1*0201 allele was present in 17 of 18 patients (94 %). Coeliac disease in children with IDDM tends to develop soon after diabetes is diagnosed. Routine screening for coeliac disease is recommended repeatedly during the first years after the diagnosis of IDDM.     

Is small bowel biopsy necessary in adults with suspected celiac disease and IgA anti-endomysium antibodies?

The comparative diagnostic value of IgA anti-endomysium and IgA antigliadin antibodies in adults with histologically confirmed celiac disease is reported. Sera from 144 adult patients (without concurrent dermatitis herpetiformis or IgA deficiency) who underwent small bowel biopsy were analyzed for both IgA anti-endomysium and IgA anti-gliadin antibodies. Nineteen patients (13%) had celiac disease. The presence of IgA antiendomysium antibodies had a sensitivity of 74% and a specificity of 100%. The positive and negative predictive values were 100% and 96%, respectively, and the diagnostic accuracy was 97%. In contrast, IgA anti-gliadin antibodies had positive and negative predictive values of 28% and 96%, respectively, with a diagnostic accuracy of 71%. Based on these data, we suggest that small bowel biopsy is not necessary to diagnose celiac disease in symptomatic adults with IgA antiendomysium antibodies. Due to a negative predictive value of 96%, some symptomatic adults lacking anti-endomysium antibodies will not be correctly diagnosed without small bowel biopsy.     

A reliable screening test for coeliac disease: enzyme-linked immunosorbent assay to detect anti-gliadin antibodies in serum

Abstract A simple, rapid, highly reproducible enzyme-linked immunosorbent assay detecting anti-gliadin antibodies in serum to screen for coeliac disease (CD) is described. By combining the results of anti-gliadin IgA and IgG determinations the overall sensitivity of the assay was found to be 100% and the specificity 96% for children and 99% for adults. Significantly elevated anti-gliadin IgA and IgG antibodies were detected in all 20 children and all 25 adults with untreated CD. False positive results were found in 1/79 histologically normal control and 5/86 disease control children, while for adults false positive rates were 0/74 and 1/34 for the healthy and disease control groups, respectively. Anti-gliadin IgA and IgG was measured in serum samples from 52 coeliac patients (11 children and 41 adults) treated with a gluten-free diet (GFD). Each of the children and 28 of the adults who followed a strict GFD had significantly lower IgA and IgG levels than untreated CD patients. The serum anti-gliadin IgA and IgG levels of the 13 adults not complying with a GFD were similar to those found for untreated CD patients. This assay is recommended as a screening test for CD as well as a tool for follow-up of treated patients.     

Do IgA antigliadin and IgA antiendomysium antibodies show there is latent coeliac disease in primary IgA nephropathy?

The finding in primary IgA nephropathy of increased levels of IgA to food antigens and particularly to gliadin prompted the hypothesis that a subgroup of these patients may have latent coeliac disease. The observation that gliadin may experimentally induce IgA mesangial deposits supported this hypothesis. We evaluated specific immunological markers of coeliac disease (antiendomysium antibodies) which parallel histological changes of gluten sensitive enteropathy, and an IgA immunofluorescent test for antigliadin antibodies in 18 patients with IgA nephropathy, in 56 untreated coeliac disease patients, in 254 controls (58 healthy and 196 disease controls). Antiendomysium antibodies were positive in 89.28% of coeliac patients, but negative in all IgA nephropathies and controls. IgA immunofluorescent test for antigliadin antibodies, negative in all IgA nephropathy patients, was positive in 76.78% of coeliac patients and in 4.91% of controls. ELISA IgA antigliadin antibodies were negative in controls, but positive in 22.22% of IgA nephropathy patients and in 60.71% of coeliac patients. Our data would suggest that in most patients with IgA nephropathy there is no evidence of latent coeliac disease.     

A primary care cross-sectional study of undiagnosed adult coeliac disease

OBJECTIVES: To establish the prevalence of coeliac disease in the general population and in specific conditions, such as irritable bowel syndrome, iron deficiency anaemia, fatigue and other coeliac-related conditions. METHODS: Primary-care-based cross-sectional study using immunoglobulins, IgA/IgG antigliadin antibodies and endomysial antibodies to initially recognize coeliac disease. A total of 1200 volunteers were recruited from January 1999 to June 2001 from five general practices in South Yorkshire, UK. Any participant with a positive IgA antigliadin antibody, positive endomysial antibody, or only IgG antigliadin antibody in the presence of IgA deficiency was offered a small-bowel biopsy to confirm the diagnosis of coeliac disease. RESULTS: Twelve new cases of coeliac disease were diagnosed from 1200 samples. The prevalence of coeliac disease in this primary care population sample is 1% (95% CI 0.4-1.3%). The prevalence of coeliac disease was 3.3% (4/123) in participants with irritable bowel syndrome, 4.7% (3/64) in participants with iron deficiency anaemia, and 3.3% (3/92) in participants with fatigue. CONCLUSIONS: This study describes the prevalence of undiagnosed adult coeliac disease in primary care patients with irritable bowel syndrome, iron deficiency anaemia and fatigue. Underdiagnosis of coeliac disease is common in primary care. A case-finding approach would avoid delays in diagnosis and the associated morbidity or potential complications of coeliac disease. A low threshold for serological screening of patients with coeliac-associated symptoms or conditions would be an optimal strategy.     

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.     

Atypical coeliac disease found with serologic screening

Eighteen patients with coeliac disease were found by screening for reticulin antibodies of unselected sera at the time when determination of various tissue antibodies was requested. Joint disease, allergic and pulmonary disorders, and diabetes were particularly observed. IgA class reticulin antibody, in particular, proved to be specific for coeliac disease. Most patients with coeliac disease also had positive serum gliadin antibodies. Abdominal symptoms and signs of malabsorption were slight and infrequent. In most patients a gluten-free diet resulted in the improvement of jejunal mucosal histology, and serum reticulum and gliadin antibody titres decreased simultaneously, reflecting the appropriateness of the diet. Coeliac disease often has mild and atypical symptoms, and, particularly in certain disease groups, screening with reticulin antibody test seems to be appropriate.     

Atypical Coeliac Disease Found with Serologic Screening

Eighteen patients with coeliac disease were found by screening for reticulin antibodies of unselected sera at the time when determination of various tissue antibodies was requested. Joint disease, allergic and pulmonary disorders, and diabetes were particularly observed. IgA class reticulin antibody, in particular, proved to be specific for coeliac disease. Most patients with coeliac disease also had positive serum gliadin antibodies. Abdominal symptoms and signs of malabsorption were slight and infrequent. In most patients a gluten-free diet resulted in the improvement of jenunal mucosal histology, and serum reticulum and gliadin antibody titres decreased simultaneously, reflecting the appropriateness of the diet. Coeliac disease often has mild and atypical symptoms, and, particularly in certain disease groups, screening with reticulin antibody test seems to be appropriate.     

Tissue transglutaminase and endomysial autoantibodies measured in an historical cohort of children and young adults in whom coeliac disease was suspected.

OBJECTIVE : To evaluate whether anti-endomysial and anti-transglutaminase antibodies are relevant important markers of coeliac disease in an historical group of patient sera. DESIGN : Sera from 196 children suspected to suffer from coeliac disease were analysed for these antibodies. METHODS : A total of 233 serum samples were obtained simultaneously with a biopsy. Coeliac disease was confirmed in 37 (19%) patients. Antibodies against guinea pig transglutaminase were determined by enzyme-linked immunosorbent assay (ELISA); endomysial antibodies were determined by immunofluorescence. RESULTS : In 17 samples, immunoglobulin A (IgA) anti-transglutaminase levels were increased; 16 of these came from coeliac patients. High levels correlated with high prediagnostic or challenge-related gluten intake. The additional anti-transglutaminase-positive patient was assumed to suffer from sequelae to gastroenteritis. CONCLUSIONS : Raised IgA anti-transglutaminase levels were correlated with presence of coeliac disease. Negative tests were seen in some coeliac patients when on a gluten-containing diet. The IgA anti-transglutaminase test using guinea pig antigen was less sensitive than anti-endomysial antibodies but rather specific for active coeliac disease. In our study, anti-endomysial antibodies were more specific than anti-transglutaminase antibodies for active coeliac disease.     

Anti-transglutaminase antibodies and coeliac disease

Background: Anti-endomysial antibodies have high specificity for coeliac disease but measurements are limited by the requirement for monkey oesophagus, a substrate that is expensive, and of limited availability and ethical acceptance. Tissue transglutaminase has recently been identified as the endomysial autoantigen in coeliac disease.
Aims: To examine the validity of serum tissue transglutaminase antibody levels in patients with coeliac disease and to assess their sensitivity and specificity against standard serological tests.
Methods: Serum IgA anti-tissue transglutaminase antibody titres (measured by ELISA), IgA anti-gliadin antibody litres (measured by a commercial ELISA) and anti-endomysial antibody titres (measured by indirect immunofluorescence) were determined in 46 untreated and 14 treated patients biopsy-proven coeliac disease and 145 disease and healthy controls.
Results: All patients with untreated coeliac disease were positive for anti-endomysial and anti-tissue transglutaminase antibodies (sensitivity 100%). Seventy-one per cent of treated coeliac patients were anti-tissue transglutaminase antibody negative. Five of 145 disease and healthy controls had low titres of anti-tissue transglutaminase antibody (specificity 97%); no controls were anti-endomysial antibody positive.
Conclusions: Our results demonstrated the sensitivity and specificity of IgA anti-tissue transglutaminase antibodies to correlate highly with anti-endomysial antibodies in the diagnosis of coeliac disease. The ELISA for IgA anti-tissue transglutaminase antibodies is quantitative and easy to perform and is a valid alternative to indirect immunofluorescence for anti-endomysial antibodies in screening for suspected coeliac disease.