Outi Koskinen

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.

Validation of Morphometric Analyses of Small-Intestinal Biopsy Readouts in Celiac Disease

Background Assessment of the gluten-induced small-intestinal mucosal injury remains the cornerstone of celiac disease diagnosis. Usually the injury is evaluated using grouped classifications (e.g. Marsh groups), but this is often too imprecise and ignores minor but significant changes in the mucosa. Consequently, there is a need for validated continuous variables in everyday practice and in academic and pharmacological research. Methods We studied the performance of our standard operating procedure (SOP) on 93 selected biopsy specimens from adult celiac disease patients and non-celiac disease controls. The specimens, which comprised different grades of gluten-induced mucosal injury, were evaluated by morphometric measurements. Specimens with tangential cutting resulting from poorly oriented biopsies were included. Two accredited evaluators performed the measurements in blinded fashion. The intraobserver and interobserver variations for villus height and crypt depth ratio (VH:CrD) and densities of intraepithelial lymphocytes (IELs) were analyzed by the Bland-Altman method and intraclass correlation. Results Unevaluable biopsies according to our SOP were correctly identified. The intraobserver analysis of VH:CrD showed a mean difference of 0.087 with limits of agreement from −0.398 to 0.224; the standard deviation (SD) was 0.159. The mean difference in interobserver analysis was 0.070, limits of agreement −0.516 to 0.375, and SD 0.227. The intraclass correlation coefficient in intraobserver variation was 0.983 and that in interobserver variation 0.978. CD3+ IEL density countings in the paraffin-embedded and frozen biopsies showed SDs of 17.1% and 16.5%; the intraclass correlation coefficients were 0.961 and 0.956, respectively. Conclusions Using our SOP, quantitative, reliable and reproducible morphometric results can be obtained on duodenal biopsy specimens with different grades of gluten-induced injury. Clinically significant changes were defined according to the error margins (2SD) of the analyses in VH:CrD as 0.4 and in CD3+-stained IELs as 30%.

Usefulness of small-bowel mucosal transglutaminase-2 specific autoantibody deposits in the diagnosis and follow-up of celiac disease.

Background Diagnosis of celiac disease may be problematic in that small-bowel villous atrophy sometimes occurs in conjunction with other enteropathies, develops gradually and may be patchy. Furthermore, as the often compromised quality of biopsy specimens renders diagnosis difficult, new diagnostic tools are warranted. Goals As the celiac disease-specific autoantibodies are found deposited at their production site, in the small-bowel mucosa, they may be useful in diagnostics, especially in problematic cases. We therefore systematically assessed the occurrence of celiac-specific autoantibody deposits in a large cohort of celiac patients, and established how IgA deposits decline after initiation of a gluten-free diet. Methods Transglutaminase-2 specific mucosal IgA autoantibody deposits were determined from small-bowel mucosal biopsies in 261 untreated, 71 short-term (1 y), and 105 long-term (2 to 41 y) treated celiac disease patients and in 78 nonceliac controls. The presence of the deposits was compared with celiac serology, mucosal villous morphology and density of intraepithelial lymphocytes. Results All untreated celiac disease patients had mucosal autoantibody deposits and their intensity was moderate or strong in 90% of cases. In contrast, 18% of the controls had weak depositions. During a gluten-free diet the intensity of the deposits diminished, but was still faintly positive in 56% of long-term treated celiac patients. The efficiency of the test in determining mucosal autoantibody deposits was superior to serology and inflammatory markers. Conclusions Mucosal transglutaminase-2 specific autoantibody deposits proved to be accurate gluten-dependent markers of celiac disease and would thus be of value in the diagnostics and dietary monitoring of this disorder.

Oats do not induce systemic or mucosal autoantibody response in children with coeliac disease.

Objectives: A gluten-free diet omitting wheat, rye, and barley is the only effective treatment for coeliac disease. The necessity of excluding oats from the diet has remained controversial. We studied the toxicity of oats in children with coeliac disease during a 2-year follow-up by investigating jejunal transglutaminase 2 (TG2)-targeted IgA-class autoantibody deposits, a potentially more sensitive disease marker than serum antibodies or conventional histology. Patients and Methods: Twenty-three coeliac children in remission were randomized to undergo oat or gluten challenge with wheat, rye, barley, and oats. When jejunal histological relapse was evident after gluten challenge, patients excluded wheat, rye, and barley but continued with oats. Mucosal morphology and TG2-targeted autoantibody deposits were studied in jejunal biopsies taken at baseline and after 6 and 24 months. Furthermore, serum IgA-class TG2 antibodies were measured. Results: At baseline, serum TG2 antibodies were negative in all 23 patients, but 7 of them had minor mucosal deposits. In the oats group, there was no significant change in the intensity of the deposits within 2 years. In contrast, during the gluten challenge, the intensity of the deposits clearly increased and decreased again when wheat, rye, and barley were excluded but consumption of oats was continued; this was in line with serum autoantibodies. The intensity of the mucosal deposits correlated well with both villous morphology and serum autoantibody levels. Conclusions: Consumption of oats does not induce TG2 autoantibody production at mucosal level in children with coeliac disease. Measurement of small-intestinal mucosal autoantibody deposits is suitable for monitoring treatment in coeliac patients.

Gluten-dependent Small Bowel Mucosal Transglutaminase 2–specific IgA Deposits in Overt and Mild Enteropathy Coeliac Disease

Objectives: In coeliac disease, immunoglobulin (Ig)A–class autoantibodies against transglutaminase-2 are produced in the small intestinal mucosa, where they are deposited extracellularly. It remains unclear whether positive intestinal transglutaminase-2-targeted IgA deposits in subjects having normal small bowel mucosal morphology are signs of early-stage coeliac disease. We evaluated the gluten dependency of these deposits in overt and mild enteropathy coeliac disease. Patients and Methods: All together 48 subjects suspected of coeliac disease but having normal small bowel mucosal villi were enrolled; 28 of them had latent coeliac disease. The remaining 20 having positive intestinal IgA deposits adopted a gluten-free diet before villous atrophy had developed. For comparison, 13 patients with overt coeliac disease and 42 noncoeliac controls were studied. Small bowel mucosal transglutaminase-2–specific autoantibodies were compared with villous morphology, intraepithelial lymphocyte densities, and serum coeliac autoantibodies. Results: Intestinal IgA deposits were seen in all but 1 of the patients with latent coeliac disease, when the morphology was still intact; the intensity of these deposits increased as villous atrophy developed and decreased again on a gluten-free diet. In 20 patients with intestinal IgA deposits in normal villi, the intensity of the deposits decreased with the diet similarly to that seen in patients with overt coeliac disease. Mucosal IgA deposits were seen initially only in 5% of noncoeliac controls and in 8% after extended gluten consumption. Conclusions: The response of small bowel mucosal transglutaminase-2–specific IgA deposits for dietary intervention was similar in overt and mild enteropathy coeliac disease. Detection of such IgA deposits thus offers a good diagnostic tool to uncover early-stage coeliac disease.

Coeliac disease: a diagnostic and therapeutic challenge

Abstract During the past 20 years the diagnosis of coeliac disease has improved significantly. However, at the same time the true prevalence of the condition has doubled, involving more than 2% of the population in some countries. Due to mild or atypical symptoms, the diagnosis remains a challenge for the health care system. Highly sensitive and specific serum endomysial and transglutaminase-2 antibody tests are helpful in identifying patients for diagnostic endoscopy and small-bowel biopsy. The diagnosis of the disease is still based on the demonstration of gluten-induced small-bowel mucosal villous atrophy with crypt hyperplasia. However, coeliac disease may manifest itself before the development of the overt small-intestinal lesion. Positive endomysial and transglutaminase antibodies in patients with normal small-bowel mucosal villous architecture may indicate early stage coeliac disease. Currently, the only effective treatment for the condition is a life-long strict gluten-free diet. Long-term regular follow-up of patients is recommended in order to maintain good adherence to the diet. Clin Chem Lab Med 2010;48:1205–16.

An Update on the Diagnostics of Celiac Disease

In celiac disease, highly sensitive and specific serum endomysial and transglutaminase 2 antibody tests are widely used in identifying patients for diagnostic endoscopy and small-bowel biopsy. In addition, the recently developed deamidated gliadin peptide antibody tests show promise in celiac disease diagnostics. In view of these apparent problems attending the diagnostic gold standard, gluten-induced small-bowel mucosal villous atrophy with crypt hyperplasia, other diagnostic approaches beyond conventional histology have been introduced. Furthermore, the diagnostic criteria for celiac disease are currently under revision with an eye also to noninvasive diagnostic strategies.

IgA-class autoantibodies against neuronal transglutaminase, TG6 in celiac disease: No evidence for gluten dependency

BACKGROUND It has been suggested that antibodies against transglutaminase (TG) 6 could serve as a biomarker to identify a subgroup of gluten-sensitive patients who may be at risk of developing neurological disease. We here investigated whether TG6-targeted autoantibodies are a characteristic feature of celiac patients, especially those with neurological symptoms, and further, whether such antibodies are gluten-dependent. METHODS Serum IgA-class TG6 autoantibodies were measured in untreated and treated celiac patients with and without neurological manifestions and in non-celiac controls. The results were compared to TG2 autoantibody levels. RESULTS During a gluten-containing diet the number of TG6 autoantibody-positive celiac patients with neurological problems (25%) did not significantly differ from that of TG6-seropositive patients without neurological impairment (16%) or from non-celiac controls (15%). This was in contrast to our finding in TG2 autoantibody-positive individuals, whose numbers differed significantly between all three study groups. On a gluten-free diet the levels of TG6 autoantibodies remained unchanged. CONCLUSIONS We conclude that the serum IgA-class TG6 autoantibody assay is not able to distinguish gluten-sensitive patients with neurological manifestations from celiac patients without neurological problems or from control subjects, and further, that TG6 autoantibodies are not gluten-dependent.

Changing phenotype of celiac disease after long-term gluten exposure.

Celiac disease is an autoimmune disorder wherein the ingestion of gluten causes villous atrophy of the small intestinal mucosa with crypt hyperplasia in genetically susceptible individuals. The classic symptoms are malabsorption, steatorrhea, weight loss, growth retardation, and failure to thrive (1,2). Dermatitis herpetiformis is a well-known extraintestinal manifestation of celiac disease, characterized by granular immunoglobulin A (IgA) deposits in uninvolved skin (3). Approximately 17% of celiac patients have dermatitis herpetiformis (4). Celiac disease can appear at any age after gluten has been introduced into the diet, whereas dermatitis herpetiformis usually manifests in adulthood, the median age of diagnosis being about 40 years (4). It remains obscure why some patients experience celiac disease, overt enteropathy, and no skin involvement, whereas some experience dermatitis herpetiformis with often only mild enteropathy. The following 3 case reports indicate that periods of gluten intake and gluten withdrawal may have an impact on disease expression, and the phenotype may vary in the same person over time.

Serodiagnostic Assays for Celiac Disease Based on the Open or Closed Conformation of the Autoantigen, Transglutaminase 2

The autoantigen of celiac disease, transglutaminase 2 (TG2), adopts an open conformation during enzymatic activation. We studied diagnostic accuracy of serodiagnostic assays using TG2 in its open and closed conformation as antigens in patients with diagnostic difficulties. The open TG2 antibody (TG2ab) test identified 93% of untreated celiac patients in contrast to 44%, 27%, and 68% detected by closed and conventional TG2ab and endomysial antibody (EmA) tests, respectively. The assay was able to detect 60% of non-responding celiac patients seronegative for conventional TG2ab and EmA. The titers of the openTG2abs were higher than those of the closed TG2abs. The serological test utilizing TG2 in an open conformation was more accurate than the other assays in finding active celiac disease even in patients having negative or borderline conventional celiac autoantibodies and in revealing poor dietary response non-invasively. It thus offers a promising tool in the diagnostics and follow-up of celiac disease.