Efficacy Study of Anti-Endomysium Antibodies for Celiac Disease Diagnosis: A Retrospective Study in a Spanish Pediatric Population

The aim of this study was to assess the efficacy of anti-endomysium antibodies (EMA) as a serological marker for celiac disease (CD) diagnosis in a pediatric population. A retrospective study of pediatric patients who underwent a CD serological markers study: EMA and anti-tissue transglutaminase antibodies (anti-TG2). Clinical symptomatology, degree of histological lesion, human leukocyte antigen (HLA) haplotype compatible with CD (HLA DQ2 and/or DQ8), and final diagnosis were taken into account. We included 445 patients who were classified in two groups according to the final diagnosis. Group 1: 232 children with CD, 91.4% of whom exhibited small intestinal villous atrophy, 228 being EMA-positive and four EMA-negative. Group 2: 213 children with a non-CD diagnosis, 212 EMA negative and one EMA positive. Both antibodies, EMA and anti-TG2, reached similar sensitivities, 98% and 99% respectively, while EMA had a higher specificity (99%) than anti-TG2 (93%). By using both markers combined, compared to using anti-TG2 alone, 5.7% of patients are better diagnosed. However, when we compare the efficacy of EMA and anti-TG2 in asymptomatic and symptomatic patients, the sensitivity of EMA is 98% irrespective of symptoms, thus higher than for anti-TG2 ≥10 × upper limit of normal (ULN) (respectively 77% and 84%). Our results support the use of EMA to increase CD diagnostic accuracy in a non-biopsy approach, especially in asymptomatic children.

Quality of Life in Patients with Gluten Neuropathy; Case-Controlled Study

Background: Gluten neuropathy (GN) is defined as an otherwise idiopathic peripheral neuropathy in the presence of serological evidence of gluten sensitivity (positive antigliadin and/or transglutaminase or endomysium antibodies). We aimed to compare the quality of life (QoL) of GN patients with control subjects and to investigate the effect of a gluten free diet (GFD) on the QoL. Methods: All consecutive patients with GN attending a specialist neuropathy clinic were invited to participate. Overall Neuropathy Limitations Scale (ONLS) was used to assess the severity of neuropathy. The SF-36 questionnaire was used to measure participants’ QoL. A strict GFD was defined as effectively been able to eliminate all circulating gluten sensitivity-related antibodies whilst on the diet. Results: Fifty-three patients with GN and 53 age and gender matched controls were recruited. Compared to controls, GN showed significantly worse scores in physical functioning, role limitations due to physical health, energy/fatigue and general health subdomains of SF-36. After having adjusted for age, gender and disease severity, being on a strict GFD correlated with better SF-36 scores on the pain domain of the SF-36 (beta 0.317, p=0.019) and the overall health change domain of the SF-36 (beta 0.306, p=0.017). Conclusion: In GN physical dysfunctioning is the major determinant of poor QoL compared to controls. Routine checking for elimination of gluten sensitivity-related antibodies that results from a strict GFD should be encouraged as such elimination ameliorates the overall pain and health scores, indicating better QoL.

PREVALENCE OF CELIAC DISEASE IN CHILDREN WITH EPILEPSY

ContextNeurological symptoms have been well-documented in patients with celiac disease, nevertheless, the presumption of a greater prevalence of epilepsy in celiac patients remains controversial.ObjectivesTo determine the frequency of celiac disease in children and adolescents with idiopathic or cryptogenic epilepsy.MethodsA cross-sectional study. One hundred pediatric patients with non-symptomatic epilepsy were followed-up at two public pediatric neurology clinics in Salvador, Bahia, Brazil. Screening for celiac disease was performed by serial measurements of IgA anti-transglutaminase and IgA anti-endomysium antibodies, followed by bowel biopsy in positive cases. HLA DQ02 and DQ08 were investigated in seropositive individuals, assessing the type of seizures, the number of antiepileptic drugs used and the presence gastrointestinal symptoms.ResultsThree (3.0%) patients tested anti-tTG-positive, two with normal duodenal mucosa (Marsh 0) and one with intraepithelial infiltrate (Marsh I). No villous atrophy of the duodenal mucosa (Marsh III) celiac disease was found. Two patients tested positive for HLA DQ02; none were DQ08 positive.ConclusionThe present study failed to prove the association between celiac disease and epilepsy.

IgG Antibodies against Deamidated Gliadin Peptides for Diagnosis of Celiac Disease in Patients with IgA Deficiency

Background: Assays for IgG antibodies against deamidated gliadin (IgG-anti-dGli) are comparable in performance with tests detecting IgA antibodies against tissue transglutaminase (IgA-anti-tTG) in diagnosing celiac disease (CD). IgA-anti-tTG are absent in IgA deficiency, a condition often associated with CD. In IgA deficiency, IgG-anti-tTG, which have a lower overall diagnostic accuracy, are routinely measured. We examined whether IgG-anti-dGli would be useful for diagnosing CD in patients with IgA deficiency.Methods: We studied 34 IgA-deficient CD patients, 185 IgA-competent newly diagnosed children with CD, 316 children without CD, 400 adult blood donors, and 6 control IgA-deficient individuals without CD. Anti-dGli and anti-tTG were measured by ELISA, and endomysium antibodies (EmA) were measured by immunofluorescence on monkey esophagus (IgA as well as IgG class for all antibodies). We calculated diagnostic sensitivity (percentage of patients above cutoff with 95% CIs) according to age-specific cutoffs for 95% diagnostic specificity and according to cutoffs proposed by the manufacturer of the assays.Results: No IgA-deficient CD patients were positive for any IgA-based antibody assay. Diagnostic sensitivity of IgG-anti-tTG was 91.2% (95% CI 76.3%–97.7%) according to age-specific cutoffs and 82.4% (66.1%–92.0%) according to manufacturer cutoffs. The diagnostic sensitivity of IgG-EmA was 75.8% (58.8%–87.4%) and the sensitivity of IgG-anti-dGli was 88.2% (72.8%–95.9%) according to both cutoffs.Conclusions: IgG-anti-dGli and IgG-anti-tTG have comparable diagnostic sensitivities for IgA-deficient celiac patients. IgG-anti-dGli may be useful for diagnosing CD in IgA-deficient patients.

Diagnostic Accuracy of Ten Second-Generation (Human) Tissue Transglutaminase Antibody Assays in Celiac Disease

Background: Anti-tissue transglutaminase (tTG) assays that use human tTG as antigen have recently become available. We evaluated commercially available assays with human tTG antigen to estimate their diagnostic accuracies and to determine whether they agree sufficiently to be used interchangeably. Methods: Ten commercially available second-generation anti-tTG assays were evaluated. The following populations were studied: celiac disease (CD) patients at the time of diagnosis without (n = 70) or with (n = 5) IgA deficiency; diseased controls (n = 70); and CD patients without (n = 28) or with (n = 2) IgA deficiency during follow-up. All individuals included in the study underwent intestinal biopsy. Technical performance (linearity, interference, precision, correlation, and agreement) and diagnostic accuracy (sensitivity and specificity) were compared. Anti-gliadin and anti-endomysium antibodies were also measured. Results: IgA anti-tTG results correlated well overall, but numerical values differed. Diagnostic sensitivity ranged between 91% and 97% and specificity between 96% and 100%. These were higher than the sensitivity and specificity of the IgA endomysium assay and the IgA gliadin assay. Generally, IgG anti-tTG was less sensitive but more specific than IgG anti-gliadin for the diagnosis of CD in the small group of IgA-deficient patients. Conclusions: Overall diagnostic performance of IgA tTG assays is acceptable and comparable among the different assays, but numerical values differ. Standardization is needed.