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.     

Anti-Saccharomyces cerevisiae antibodies in coeliac disease

OBJECTIVE: To evaluate, retrospectively, the frequency of anti-Saccharomyces cerevisiae antibodies (ASCA) in patients with coeliac disease. MATERIAL AND METHODS: ASCA, IgG and IgA were determined by ELISA in sera of 238 coeliac patients. The patients were divided into three groups: group I - 125 untreated patients; group II - 42 patients under a strict gluten-free diet (GFD); and group III - 71 patients who did not comply with a GFD. Sera of 80 healthy blood donors served as controls. RESULTS: The frequency of ASCA (IgG or IgA) was significantly higher in untreated coeliac patients than in the control group (27.2% versus 3.7%, p=10(-5)). In 238 coeliac patients, the frequency of ASCA was significantly higher in adults than in children (35.4% versus 21.1%, p=0.01). In group III, the frequency of ASCA was significantly higher in adults than in children (60% versus 26.1%, p=0.004). In 238 coeliac patients, ASCA IgG were significantly more frequent than ASCA IgA in both children (19% versus 6.3%, p=0.001) and adults (33.3% versus 12.5%, p=5.10(-4)). In children, ASCA IgG were negative in group II and positive in 20% of group I (p=0.01). In adults, the frequency of ASCA IgG was also significantly lower in group II than in group I (9.5% versus 34%, p=0.03). CONCLUSIONS: A high frequency of ASCA has been found in coeliac patients. The frequency of ASCA was not statistically different between patients with successful adherence to GFD and healthy controls.     

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.     

Correlation between diagnosis and results of serologic tests for antiglobulin antibodies

A study of 1,320 serum samples for rheumatoid factors and serum agglutinators revealed poor correlation between test results for rheumatoid factors and the presence of rheumatoid arthritis in hospitalized patients with a variety of different diseases. Although the correlation between test results for serum agglutinators and the presence of suppurative infection was good in hospitalized patients, correlation was very poor in less sick ambulatory patients.These studies reveal that correlation of serologic test results with specific disease states may be profoundly altered by severe systemic disease of diverse etiology.     

Intestinal permeability and screening tests for coeliac disease.

In disease states of the small intestine--for example, gluten-sensitive enteropathy--there is an increased permeability to large molecules. This increased permeability extends to polar molecules of intermediate size such as disaccharides, whereas small polar molecules are malabsorbed. A recently-developed oral test, based on the simultaneous administration of two test substances, cellobiose (a disaccharide) and mannitol (a small polar molecule) has been used to investigate permeability in a variety of gastrointestinal diseases, the result of the test being expressed as the ratio (cellobiose/mannitol) of the five hour urinary recoveries of the two probe molecules. Results for patients with pancreatic insufficiency, intestinal bacterial overgrowth, primary hypolactasia, ileocolic or colonic Crohn's disease, and ulcerative colitis were comparable with those in normal controls, whereas in 23 out of 24 untreated coeliacs, and five out of eight patients with Crohn's disease involving the more proximal small bowel, the cellobiose/mannitol ratio was clearly abnormal. A study of its application as a screening procedure for coeliac disease showed that the test was both sensitive and accurate, with fewer false-positive and false-negative results than other recognised screening tests--namely, the xylose test, reticulin antibodies, and blood folate estimations.     

A comparison of antibodies to tissue transglutaminase with conventional serological tests in the diagnosis of coeliac disease

BACKGROUND: Tissue transglutaminase is now recognized as the autoantigen for antiendomysial antibodies. Antibodies to tissue transglutaminase have been proposed as a valuable test for coeliac disease. OBJECTIVE: To determine the value of antibodies to tissue transglutaminase in the diagnosis of coeliac disease in our outpatient population. METHODS: Patients who underwent serological tests for coeliac disease during the first 18 months of the tissue transglutaminase antibody assay were retrospectively identified from the regional serology laboratory database. Patients' symptoms were noted, along with serological results and duodenal histology in those patients who underwent duodenal biopsy.RESULTS In total, 586 patients were identified as having been serologically tested for coeliac disease, of whom 92 patients (33 men; mean age 51.7 years) had been followed up with duodenal biopsies. Of these 92 patients, 29 (31%; 14 men; mean age 52.5 years) had histological features of coeliac disease. The 63 patients with normal histology (19 men; mean age 51.8 years) acted as controls. Weight loss was more frequent in coeliac disease patients compared to controls (7 vs 5; P = 0.04) whereas the frequency of anaemia (P = 0.85) and diarrhoea (P = 0.74) did not differ significantly between the two groups. The sensitivity and specificity of tissue transglutaminase antibodies (86%; 84%) were compared to those for antiendomysial antibodies (90%; 98%) and antigliadin antibodies (76%; 79%). CONCLUSIONS: The diagnostic value of tissue transglutaminase antibodies was intermediate between that of antiendomysial antibodies and antigliadin antibodies. However, duodenal biopsy remains the gold standard diagnostic test for coeliac disease.     

Anti-ganglioside antibodies in coeliac disease with neurological disorders

BACKGROUND: Anti-ganglioside antibodies have been described in sera of coeliac patients with peripheral neuropathy and cerebellar ataxia. AIMS: To investigate the correlation between anti-ganglioside antibodies and neurological involvement in coeliac disease before and after gluten-free diet. PATIENTS AND METHODS: Twenty-two untreated coeliac patients with neurological dysfunction and 30 untreated coeliacs without neurological dysfunction, 20 patients with neurological disorders, 50 autoimmune disease and 20 blood donors were tested for anti-GM1, anti-GD1b and anti-GQ1b IgG and IgM antibodies by enzyme-linked immunosorbent assay. RESULTS: IgG antibodies to at least one of the three antigens tested were positive in 64% of coeliac patients with neurological symptoms compared to 30% of coeliacs without neurological dysfunction (P=0.02), 50% of patients with neurological disorders (P=ns), 20% with autoimmune diseases (P=0.003) and none of blood donors (P=0.0001). A strict gluten-free diet determined anti-ganglioside antibody disappearance in about half of coeliacs. CONCLUSIONS: A significant correlation between anti-ganglioside antibodies and neurological disorders in patients with an underlying coeliac disease has been found. Anti-ganglioside antibodies may represent a new immunological marker to identify neurological impairment in patients with coeliac disease.     

Immunoglobulins and dietary protein antibodies in childhood coeliac disease

Twenty-four children with coeliac disease were compared with a control group, comprising 17 children with a variety of gastroenterological disorders, with respect to serum immunoglobulins and dietary protein antibodies. Elevated levels of IgA and abnormally low levels of IgM were demonstrated in one third of the coeliac patients. Antibodies to at least one of eight dietary proteins were found in 50% of coeliac children. Three children with raised levels of serum IgA and two with deficient IgM were re-examined after varying periods on a gluten-free diet. Antibodies to dietary proteins had waned and immunoglobulin levels returned to normal in all cases. The raised IgA was considered to have resulted from an extensive immunological response to antigens of dietary origin which had entered through the abnormal gut mucosa. It is suggested that IgM deficiency was due to specific inhibition of IgM synthesis by dietary components which had also entered through the mucosa.     

Problems in the use of serologic tests for the diagnosis of Lyme disease

Lyme disease can be reliably diagnosed in the presence of erythema migrans. When erythema migrans is absent, serologic tests are often used to confirm the diagnosis. To choose a test for our Lyme disease diagnostic center, serum samples were obtained from 34 patients and tested for antibodies to Borrelia burgdorferi. We evaluated five enzyme-linked immunosorbent assays from Stony Brook (NY) University Hospital, Cambridge Bioscience (Worcester, Mass), Hillcrest Biologicals (Cypress, Calif), Sigma Diagnostics (St Louis, Mo), and Zeus-Wampole Scientific Inc (Raritan, NJ) and two fluorescent antibody tests (3M [Diagnostic Systems Inc, Santa Clara, Calif] and FIAX [Whittaker M.A. Bioproducts Inc, Walkersville, Md]). A positive sample by any test was further analyzed by Western blot. Using the Centers for Disease Control (Atlanta, Ga) epidemiologic case definitions, patients were classified into those with clinical Lyme disease, patients not meeting the Centers for Disease Control definitions, and asymptomatic patients. Sensitivities of Lyme serologies varied from 13% to 73%, with Hillcrest showing the highest value and Sigma the lowest value. False-positive test results were found in 0% to 27% of patients. Western blot analysis was positive in six of 15 patients with clinical Lyme disease. These results emphasize the need for better serologic testing for Lyme disease and underline their usefulness only as adjuncts in the clinical diagnosis of Lyme disease.     

Prevalence of coeliac disease in primary biliary cirrhosis and of antimitochondrial antibodies in adult coeliac disease patients in Italy

BACKGROUND: Although an association between primary biliary cirrhosis and coeliac disease has recently been reported in Northern Europe, there are still conflicting data concerning this issue. AIM: To evaluate both the prevalence of coeliac disease in a series of primary biliary cirrhosis patients and that of antimitochondrial antibodies in a series of adult biopsy proven coeliac disease patients from Northern Italy. PATIENTS AND METHODS: A total of 87 primary biliary cirrhosis patients (79 female, 8 male) were screened for both IgA-transglutaminase antibodies and antiendomysium antibodies and, in those with either IgA-transglutaminase antibodies or antiendomysium antibodies positivity, upper endoscopy with distal duodenum biopsy was offered. In those who refused upper endoscopy, the intestinal permeability test with lactulose/mannitol excretion was performed. RESULTS: Antiendomysium antibodies positivity was detected in 3 subjects (3.4%), all of whom had serum IgA-transglutaminase antibodies above the normal range, and fulfilled the diagnosis of coeliac disease. Of 21 other patients with serum IgA-transglutaminase antibodies above the normal range, 17 underwent upper endoscopy which revealed normal duodenum architecture. The remaining 4 patients underwent the lactulose/mannitol excretion test which was within the normal range. Sera from 108 adult coeliac disease patients were tested for antimitochondrial antibodies and positivity was found in 4 patients (3.7%): all had normal liver biochemistry tests, whereas 2 of them also presented thyroid disease. Antibodies directed to the 74-kDa polypeptide of antimitochondrial antibodies were found in 3 out of 4 antimitochondrial antibodies+ve patients. CONCLUSIONS: These results suggest an association between primary biliary cirrhosis and coeliac disease similar to that observed in the Northern European series. In conclusion, screening for coeliac disease with antiendomysium antibodies in primary biliary cirrhosis is justified, and screening for antimitochondrial antibodies is advisable in adult coeliac disease patients.     

Antiendomysium versus antigliadin antibodies in screening the general population for coeliac disease

BACKGROUND: It has recently been shown that mass screening for coeliac disease, using either the serum antigliadin (AGA) or antiendomysium antibodies (EMA) as screening test, can detect large numbers of cases that had escaped clinical diagnosis. The influence of the diagnostic algorithm on the results of the coeliac screening has not yet been evaluated. Our aim was to compare the validity of the AGA and the EMA protocols in 2096 students living in northwest Sardinia, who took part in a serologic screening for coeliac disease. METHODS: The sample included 2096 of 2345 eligible students (89%) aged 11-15 years who underwent serum IgG AGA, IgA AGA, and IgA EMA determinations. Total serum IgA level was measured in sera showing isolated IgG AGA positivity. Subjects showing at least one of the following: a) EMA positivity, b) IgA AGA positivity, or c) IgG AGA positivity and IgA deficiency (<5 mg/dl) were asked to submit to a small-intestinal biopsy. RESULTS: The prevalence of coeliac disease was 19 (16 showing typical enteropathy, 1 potential case, and 2 known cases) of 2096 (0.91%; 95% confidence interval = 0.50-1.31). Seventeen small-intestinal biopsy specimens were needed to confirm 16 cases of manifest coeliac disease (positive predictive value (PPV) = 94%) by the EMA protocol, whereas the AGA protocol required 21 biopsy specimens for 12 cases of coeliac disease (PPV = 57%). None of six IgA-deficient, IgG AGA-positive cases detected by the AGA protocol also had coeliac disease. CONCLUSIONS: The EMA protocol is superior to the AGA protocol for mass screening of coeliac disease because of higher sensitivity, decreased need for intestinal biopsy, and possibility to detect potential cases of coeliac disease.     

Serum antibodies to gliadin in coeliac disease after gluten withdrawal

Serum gliadin antibodies of the IgA and IgG classes were determined by the diffusion-in-gel enzyme-linked immunosorbent assay (DIG-ELISA) in 10 adult patients with villous atrophy of the small-intestinal mucosa. After introduction of a gluten-free diet a gradual decrease in serum gliadin antibody levels occurred, reaching statistical significance at 3 months of treatment for the IgA class (p less than 0.01) and at 6 months for the IgG class (p less than 0.05). A decrease of serum gliadin antibody levels after gluten withdrawal was related to an improvement of the intestinal mucosa and should thus be indicative of whether the patient is following the dietary recommendations. However, determination of gliadin antibody levels cannot replace small-intestinal biopsy, as there are a few patients in whom the antibody levels are not related to the morphology of the gut mucosa.     

Endomysium antibodies in coeliac disease: an improved method.

The ultra structural binding sites of endomysium antibodies have been studied on human umbilical cord tissue. The sensitivity and specificity of IgA endomysium antibodies were compared with recently described methods using basement membrane of smooth muscle of monkey oesophagus. Thirty adults affected by coeliac disease (10 in remission) and 75 healthy adult controls with normal intestinal mucosa (35 false antigliadin positive) were investigated. Sensitivity and correlation of endomysium antibodies with total villous atrophy in untreated coeliac disease patients were 100% on the human umbilical cord smooth muscles, and only 90% on the muscular layer of primate oesophagus. Indirect immunofluorescence was superior to peroxidase staining in detecting these IgA antibodies. The easy availability and enhanced testing sensitivity of the umbilical cord is an advance towards a better diagnostic tool for coeliac disease.