Update on the evaluation and diagnosis of celiac disease

Prevalence and clinical features of celiac disease in patients with autoimmune thyroiditis: cross-sectional study

CONTEXT AND OBJECTIVE

Celiac disease is an autoimmune disorder with an average prevalence of 1% in Europe and the United States. Because of strong European ancestry in southern Brazil, this study aimed to evaluate the seroprevalence of celiac disease among autoimmune thyroiditis patients.

DESIGN AND SETTING

Cross-sectional study in a public university hospital.

METHODS

This cross-sectional prevalence study included autoimmune thyroiditis patients who were tested for anti-endomysial and anti-transglutaminase antibodies between August 2010 and July 2011.

RESULTS

Fifty-three patients with autoimmune thyroiditis were included; 92.5% were women, with mean age of 49.0 ± 13.5 years. Five patients (9.3%) were serologically positive for celiac disease: three of them (5.6%) were reactive for anti-endomysial antibodies and two (3.7%) for anti-transglutaminase. None of them exhibited anemia and one presented diarrhea. Endoscopy was performed on two patients: one with normal histology and the other with lymphocytic infiltrate and villous atrophy.

CONCLUSION

The prevalence of celiac disease among patients with autoimmune thyroid disease was 9.3%; one patient complained of diarrhea and none presented anemia. Among at-risk populations, like autoimmune thyroiditis patients, the presence of diarrhea or anemia should not be used as a criterion for indicating celiac disease investigation. This must be done for all autoimmune thyroiditis patients because of its high prevalence.

Impact of coexistent celiac disease on phenotype and natural history of inflammatory bowel diseases

OBJECTIVES

Inflammatory bowel disease (IBD) and celiac disease are the two most common immune-mediated gastrointestinal diseases. There is limited knowledge regarding the course of IBD in those with coexisting celiac disease. We conducted this study to determine whether patients with coexisting celiac disease present a unique phenotype of IBD and to examine the frequency of co-occurrence of celiac disease and IBD in comparison with other autoimmune disorders.

METHODS

This was a case-control study performed at two tertiary referral centers. Cases comprised of patients with known diagnoses of celiac disease and IBD. Two random IBD controls without celiac disease were selected for each case after matching for IBD type. Disease phenotype and natural history for both Crohn's disease (CD) and ulcerative colitis (UC) were noted from medical record review, and were compared between IBD patients with and without celiac disease.

RESULTS

We identified a total of 51 patients with IBD (22 UC, 1 indeterminate colitis, 28 CD) and celiac disease. There was no significant difference in the age, gender, or ethnicity between celiac-IBD and controls. Pancolitis was more common in celiac-UC patients as compared with controls (odds ratio (OR) 3.30, 95% confidence interval (CI) 1.05-21.50). There was also a trend toward increased use of immunomodulators (IMMs) among celiac-UC patients than in non-celiac UC controls (OR 2.83, 95% CI 0.95-8.48). No phenotypic differences were found in celiac-CD patients. There were no significant differences in IBD-related medication usage, hospitalizations, or surgeries.

CONCLUSIONS

Patients with UC and celiac disease were more likely to have pancolitis and had a trend toward greater use of IMMs. Coexisting celiac disease did not influence natural history of CD.

[Seroprevalence of celiac disease at a general pediatric outpatient clinic]

BACKGROUND

Celiac disease is a common problem affecting children and adults, for which early diagnosis and treatment prevent complications and deaths. Seroprevalence studies in our environment are still scarce.

AIMS

To determine the seroprevalence of celiac disease by using human tissue antiendomysial and anti-transglutaminase antibodies, among children and adolescents who were attended at a general pediatric outpatient clinic.

METHODS

This was a seroprevalence study of descriptive cross-sectional design. First, assays for guinea pig tissue anti-transglutaminase antibodies were performed. Subsequently, in the positive cases, assays for human tissue antiendomysial and anti-transglutaminase antibodies were performed.

RESULTS

The seroprevalence of celiac disease by means of anti-guinea pig tissue anti-transglutaminase antibodies was 5% (42/831; 95% CI: 3.76%-6.90%). Considering three positive tests, the seroprevalence was 1.9% (16/831; 95% CI: 1.83%-1.97%). The concordance of human anti-transglutaminase with antiendomysial was 71%.

CONCLUSIONS

The seroprevalence of celiac disease was high. Serological screening for celiac disease among children and adolescents who present signs and/or symptoms compatible with celiac disease should be performed routinely, as well as in groups already known to be at risk, given the high seroprevalence of celiac disease observed in our environment.

Soropositividade para doença celíaca em crianças e adolescentes com baixa estatura

OBJETIVO: Avaliar a frequência da positividade do marcador sorológico para doença celíaca em crianças e adolescentes com baixa estatura, utilizando-se o anticorpo anti-transglutaminase humana como teste de triagem. MÉTODOS: Estudo descritivo com amostra obtida por conveniência. Foi realizado no período de abril a setembro de 2004 no Ambulatório Geral de Pediatria do Instituto Materno Infantil Professor Fernando Figueira e no Ambulatório de Crescimento e Desenvolvimento do Hospital das Clínicas. Foram considerados casos as crianças e os adolescentes portadores de baixa estatura, definida como aquela abaixo do percentil 3 para idade e sexo, utilizando como referência o gráfico de altura/idade do National Center for Health Statistics, 2000. Foi pesquisado o anticorpo anti-transglutaminase humana (AATGh), considerado positivo se concentração >20U/mL e, nos positivos, o anticorpo antiendomísio (AAE). RESULTADOS: Foram avaliados 78 pacientes, sendo 41 (53%) do sexo feminino. O AATGh foi positivo em 3/78 (3,8%) dos pacientes. O AAE foi positivo em um paciente, naquele com concentração mais elevada do AATGh. Considerando-se a positividade para os dois testes, a soropositividade foi de 1,3%. CONCLUSÕES: A presença de marcador sorológico para doença celíaca em crianças e adolescentes portadoras de baixa-estatura e pertencentes a famílias de baixa-renda aponta para a necessidade de investigação sistemática da doença celíaca nesses pacientes.

In vivo confocal endomicroscopy in the diagnosis and evaluation of celiac disease

BACKGROUND & AIMS

Accurate histopathology of endoscopic duodenal biopsy specimens is critical in the diagnosis of celiac disease (CD) but sampling error and poor quality specimens may generate a false-negative result. Confocal endomicroscopy (CEM) is a novel technology allowing real-time in vivo microscopy of the mucosa that may diagnose CD and evaluate its severity and response to treatment more accurately than histopathology.

METHODS

Subjects with CD and controls prospectively underwent CEM. Features of villous atrophy and crypt hypertrophy were defined. A CEM score measuring CD severity was devised and validated against the diagnosis of CD and blinded histopathology. Receiver operator characteristics, sensitivity to change after treatment, and reliability of findings were assessed.

RESULTS

From 31 patients (6 untreated CD, 11 treated CD, and 14 controls), 7019 CEM images paired with 326 biopsy specimens were obtained. The accuracy of CEM in diagnosing CD was excellent (receiver operator characteristics area under the curve, 0.946; sensitivity, 94%, specificity, 92%) and correlated well with the Marsh grading (R-squared, 0.756). CEM differentiated CD from controls (P < .0001) and was sensitive to change after treatment with gluten-free diet (1787 optical biopsies; P = .012). The intraclass correlation of reliability was high (0.759-0.916). Of the 17 cases with diagnosed CD, 16 (94%) were diagnosed correctly using CEM but only 13 (76%) had detectable histopathology changes. The procedure was safe and well-tolerated.

CONCLUSIONS

CEM effectively diagnoses and evaluates CD severity in vivo. This promising technique has the potential to improve endoscopy efficiency.

Mucosal tissue transglutaminase expression in celiac disease

Tissue transglutaminase (tTG) plays an important role in celiac disease pathogenesis and antibodies to tTG are a diagnostic marker of gluten-sensitive enteropathy. The aim of this study was to investigate the localization of tTG in the duodenal mucosa in control tissues and in different histological stages of celiac disease by using a commercial and a novel set of anti-tTG monoclonal antibodies, to see whether this assessment can be useful for diagnostic purpose. The distribution of tTG was firstly evaluated in 18 untreated celiac patients by using a commercial monoclonal antibody (CUB7402) against tissue transglutaminase enzyme and directed against the loop-core region of the enzyme. Thereafter, in further 30 untreated celiac patients we employed three newly characterized anti-tTG monoclonal antibodies produced against recombinant human-tTG. The epitopes recognized are located in three distinct domains of the protein corresponding to the core, C1 and C2 protein structure. Eleven age- and sex-matched patients with chronic duodenitis acted as controls. All subjects underwent upper endoscopy to obtain biopsy samples from the duodenum. Overall, we found that (i) tTG is equally expressed in CD at different stages of disease; (ii) tTG is expressed, at similar level, in CD and controls with duodenitis. Assessment of tTG level in biopsy samples by immunohistochemical methods is not useful in the clinical diagnostic work-up of CD.

Nutritional deficiencies in celiac disease

Celiac disease is characterized by small bowel enteropathy, precipitated in genetically susceptible individuals by the ingestion of "gluten," which is a term used to encompass the storage proteins of wheat, rye, and barley. Although the intestine heals with removal of gluten from the diet, the intolerance is permanent and the damage recurs if gluten is reintroduced. This damage causes a wide variety of consequence including maldigestion and malabsorption, resulting in the characteristic, although not universal, features of malnutrition. This article examines recent advances in the understanding of the spectrum of celiac disease, illustrates the impact of celiac disease on nutrition, and describes approaches to the management of the disease.