Hospital screening of coeliac disease in Estonian children by anti-gliadin antibodies of IgA class

Nationwide study of childhood celiac disease incidence over a 35-year period in Estonia

The aims of the study were to analyze the trends and characteristics of the incidence and clinical presentation of childhood celiac disease (CD) from 1976 to 2010 in Estonia. The study included all children up to 19 years of age diagnosed with small bowel biopsy proven CD. During a 35-year period, CD was diagnosed in 152 children in Estonia (68 boys, median age 2.3 years). From 1976 to 1980, the age-standardized incidence rate of CD was 0.10 per 100,000 person-years. After the introduction of gliadin and endomysium antibody screening (in conjunction with activities directed to increase the physicians awareness), the incidence rate increased from 0.48 in 1986-1990 to 1.55 per 100,000 person-years in 1991-1995. After initiating screening with anti-tissue transglutaminase antibodies in 2003 and routine screening for CD among all children with newly diagnosed type 1 diabetes in 2005, the incidence rate increased from 1.59 in 2001-2005 to 3.14 per 100,000 person-years in 2006-2010 (median age 6.8 years). Our nationwide study demonstrates a more than 30-fold increase in the incidence of childhood CD over a 35-year period in Estonia, along with changing patterns in the presentation of pediatric CD. In addition to the impact of use of novel CD screening methods, active search and rising of the awareness among doctors may have strongest effect. Both environmental and social factors could be also involved in the increase in CD incidence.

Helicobacter pylori infection in children in Estonia: decreasing seroprevalence during the 11-year period of profound socioeconomic changes

BACKGROUND

The prevalence of Helicobacter pylori infection is inversely associated with socioeconomic conditions in childhood. In Estonia, a high prevalence of H. pylori infection has been observed among children born in 1987 and earlier. Since 1991, after the dissolution of the USSR, profound social and economic changes have taken place in the country. The aim of the study was to evaluate changes in the seroprevalence of H. pylori infection among children in the period 1991-2002.

MATERIALS AND METHODS

The hospital-based study population consisted of two groups of children enrolled in 1991 (n = 425) and 2002 (n = 296) according to the same inclusion criteria. The immunoglobulin G antibodies to the cell surface proteins of H. pylori were determined by enzyme-linked immunosorbent assay, and the sera with the borderline results were analyzed by immunoblot analysis. Multiple regression analysis was used to determine the associations between H. pylori seropositivity and different variables such as demographic characteristics, diagnoses and year of enrollment.

RESULTS

The only two variables linked independently to H. pylori serostatus were age and year of enrollment: the adjusted odds of being H. pylori seropositive were 1.92 [95% confidence interval (CI) 1.33-2.76] times higher for the children enrolled in 1991 compared with the children enrolled in 2002. The age-standardized seroprevalence rate was 42.2% (95% CI 37.4-47.0%) for the group of 1991 and 28.1% (95% CI 23.1-33.6%) for the group of 2002.

CONCLUSION

The prevalence of H. pylori infection among children has significantly decreased during the 11-year period of profound socioeconomic changes in Estonia.

[Anti-endomysium, anti-reticulin and anti-gliadin antibodies, value in the diagnosis of celiac disease in the child]

Coeliac disease is associated with gluten intolerance in genetically predisposed subjects. Environmental factors, particularly of viral origin, may also play a major role. In this study, the presence of IgA class anti-endomysium antibodies (AEA-IgA), IgA class anti-reticulin antibodies (ARA-IgA) and IgA class anti-gliadin antibodies (AGA-IgA) was investigated in 120 serum samples from 120 children (60 patients with coeliac disease and 60 control subjects). The AEA were detected by indirect immunofluorescence on sections of human umbilical cord. The ARA were also investigated by the same technique in rat kidney, liver and stomach. The AGA were determined by an enzyme-linked immunosorbent assay (ELISA). In the patients with coeliac disease, the sensitivity of AEA and ARA was 86% and 76% respectively. In both cases, the specificity was 100%. In children below two years of age, the sensitivity of AEA and ARA was too low, i.e., 57% and 35% respectively. In children aged between two and 15 years, the sensitivity of AEA and ARA was 95% and 89% respectively. The sensitivity of IgA class AGA was 86%, and their specificity was 83%. In this study population, these results show that IgA class AEA are interesting markers for the diagnosis of coeliac disease in the child, and could be used in screening for coeliac disease in a high-risk population.

Biochemical tests in diseases of the intestinal tract: their contributions to diagnosis, management, and understanding the pathophysiology of specific disease states

Biochemical testing plays a major role in the complete evaluation of patients with suspected or established intestinal disease. We have classified these tests according to the medium in which they are performed: breath tests, including isotopic and nonisotopic tests, fecal tests, urine tests, serum tests, tissue tests, and other tests. The principles of various tests are outlined, and the role of each test in the evaluation of particular gastrointestinal disorders is discussed.

Results of coeliac disease screening in Estonia in 1990-1994

In the period of 1990-94, 2895 individuals (629 children with suspicion of coeliac disease selected throughout Estonia; 700 consecutively hospitalized children; 105 children with atopic dermatitis; 1461 inhabitants of a small Estonian town) were serologically screened for coeliac disease. The enzyme-linked immunosorbent assay was used for antigliadin antibody determinations and R1-type antireticulin antibodies were detected using an indirect immunofluorescence method. Coeliac disease was diagnosed according to recent criteria recommended by the European Society for Paediatric Gastroenterology and Nutrition. Antigliadin antibody testing was positive in 44 (3.1%) of 1434 children studied, and in 33 of whom coeliac disease was confirmed. In all the coeliac patients R1-type antireticulin antibody test was positive. However, 52 (3.5%) of 1461 adults studied who did not have coeliac disease had positive antigliadin antibody test but negative antireticulin antibody test. Thus, in Estonia, the antigliadin antibody test can be used in screening for coeliac disease in children but not in adults.

Coeliac disease: screened by a new strategy

The incidence of coeliac disease is different throughout Europe. The aim of our study was to investigate its true prevalence using antigliadin and endomysial antibodies in 4615 healthy adults within two different population groups in Northern Italy: 140 were positive for antigliadin antibodies (AGA), 111 only for AGA IgG, 17 for AGA IgA and 12 for IgG and IgA. Of those positive for AGA, nine had an abnormal small-intestine mucosa and were positive for endomysium antibodies (EmA) using the umbilical cord test, a novel methodology. The prevalence, 163/100,000 in the Italian group and 216/100,000 in the German group, is much higher than what was assumed. The positive predictive value of the EmA, confirmed by biopsy, is 100%, that of AGA IgG 2%, of AGA IgA 12% and of the combined AGA IgA and IgG 33%. AGA positive but EmA negative patients displayed normal histological features and distributions of alpha/beta and gamma/delta T-cell receptors on intraepithelial lymphocytes. We can therefore conclude that antigliadin antibodies are not an ideal tool for screening purposes; the umbilical cord EmA test is superior owing to its optimal sensitivity, specificity, high positive predictive value and low cost.