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- Rosén, Anna, 1975-
(author)
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Mass screening for celiac disease in 12-year-olds : Finding them and then what?
- 2012
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Doctoral thesis (other academic/artistic)abstract
- Background Mass screening for celiac disease (CD) as a public health intervention is controversial. Before implementation, a suitable screening strategy should be outlined, and the acceptability of the screening scrutinized. Also, the benefits of early detection and possible negative consequences should be explored and compared. The overall aim of this thesis was to evaluate different strategies for finding 12-year-olds with undiagnosed CD in the general population, and to explore the experiences of those receiving the diagnosis in a mass screening.Methods A school-based CD screening of 12-year-olds was conducted in five study sites across Sweden. Out of 10041 children who were invited, 7208 had a blood sample analyzed for CD-marker tissue transglutaminase of isotype IgA (tTG-IgA) and 7161 for total serum IgA (s-IgA). If the s-IgA value was low, tTG-IgG was also measured. Additional analysis of endomysial antibodies (EMA) was performed if borderline values of tTG were found. In total, 192 had elevated CD-markers, 184 underwent a small intestinal biopsy and 153 eventually had CD diagnosed. Before receiving knowledge about their CD status, children and their parents filled in questionnaires regarding symptoms and CD-associated conditions. Questionnaires were returned by 7054 children (98%) and 6294 parents (88%). Later, all adolescents who had been diagnosed with CD more than one year ago (n=145), and their parents, were invited to a mixed-method follow-up study in which they shared their experiences in questionnaires, written narratives and focus group discussions. In total, we have information on 117 (81%) of these adolescents, either from the adolescents themselves (n=101) and/or from their parent/s (n=125). Data were analyzed using a combination of descriptive and analytical quantitative and qualitative methodologies.Results We found that information on symptoms and CD-associated conditions were poor predictors for finding undiagnosed CD in the study population. Questionnaire-based case-finding by asking for CD-associated symptoms and conditions would have identified 52 cases (38% of all cases) at a cost of blood-sampling 2282 children (37% of the study population). The tTG-IgA test had an excellent diagnostic accuracy with the area under the receiver operating characteristic curve of 0.988. If using the recommended cut-off for tTG-IgA (>5 U/mL) 151 had fulfilled biopsy criteria and 134 CD cases had been identified. The strategy of lowering the cut-off to tTG-IgA>4 U/mL, and adding the EMA analysis in those with tTG-IgA between 2-4 U/mL, identified another 17 cases (a 12% increase) at the cost of performing 32 additional biopsies. Measuring total s-IgA in 7161 children discovered only two additional cases at the cost of performing 5 additional biopsies. The positive predictive value of our screening strategy was 80%. Results from the follow-up study of the screening-detected CD cases illustrated that 54% reported health improvement after initiated treatment, but also that these health benefits had to be balanced against social sacrifices. We also found that although the screening-detected diagnosis was met with surprise and anxiety, the adolescents and their parents were grateful for being made aware of the diagnosis. A majority of parents (92%) welcomed a future screening, but both adolescents and parents suggested that it should be conducted earlier in life.Conclusion Obtaining information on symptoms and CD-associated conditions was not a useful step in finding undiagnosed CD cases in a general population. The serological marker tTG-IgA, however, had excellent diagnostic accuracy also when lowering the cut-off. The diagnosis had varying impact on adolescents’ quality of life, and their perceived change in health had to be balanced against the social sacrifices resulting from the diagnosis. Overall, CD mass screening seemed acceptable to most of those who were diagnosed and their parents.
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| 2. |
- Olsson, Cecilia, 1963-
(author)
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Celiac disease in Swedish children and adolescents : variations in incidence and essentials of gluten-free eating with a youth perspective
- 2008
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Doctoral thesis (other academic/artistic)abstract
- Background Sweden has experienced a unique epidemic of celiac disease (CD) in children younger than 2 years of age. The epidemic was partly explained by changes over time in infant feeding and indicated a multifactorial aetiology. In CD, a strict lifelong gluten-free diet (GFD) is crucial for health but noncompliance is often reported among adolescents. Knowledge is limited regarding their own perspectives and experiences of managing the disease and adhering to GFD. Objectives To analyse the incidence of CD in epidemic and post epidemic birth cohorts, and explore and understand how adolescents with CD perceive and manage their everyday lives in relation to the GFD. Methods A population-based incidence register of CD in children covering the entire nation from 1998 to 2003, and part of the country back to 1973. ESPGHAN diagnostic criteria for CD and NUTS classification of regions were used. Incidence rates for each year of diagnosis, age group, gender and region, and cumulative incidence by age for each birth cohort were calculated. Ten focus groups were conducted with 47 CD adolescents aged 15-18 years. Transcribed interviews were analysed to illustrate and explain adolescents’ own perspectives concerning life with a GFD, and to search for recurrent stigma-related themes across the groups. Results A considerable gap in the cumulative incidence of CD at comparable ages was demonstrated between birth cohorts of the epidemic and post-epidemic periods. The gap persisted during pre-school years, although it decreased somewhat with age. During the final years of follow-up there was again a gradual increase in incidence rate among children younger than 2 years of age. The childhood populations in ‘West Sweden’ and ‘Småland and the islands’ had a significantly higher incidence rate compared to ‘North Middle Sweden’ and ‘Stockholm’. CD adolescents described an awareness of being different from others produced by meal appearance and the poor availability of gluten-free (GF) food. Eating in public had the effect of making an invisible condition visible and thereby creating a context for felt or enacted stigma. Maintaining invisibility avoided the negative consequences of stigma. The probability of compliance with the GFD was compromised by insufficient knowledge of significant others, problems with the availability and sensory acceptance of GF food, insufficient social support and their perceived dietary deviance. Three different approaches to the GFD emerged: compliers, occasional non-compliers, and non-compliers. Conclusions The difference in CD risk between birth cohorts at comparable ages may suggest an opportunity for primary prevention. Based on post-epidemic incidence trends, the Swedish epidemic might not have been as unique as previously thought, even though its magnitude was striking. The regional variation in CD risk supports multifactorial aetiology. Continued efforts are warranted to define factors besides gluten exposure that modulate CD risk. CD adolescents experience various dilemmas related to the GFD. It can produce stigma experiences in adolescence, and dietary compliance (or lack of) can be understood in terms of dealing with GFD concealment and disclosure. The increase in CD prevalence over time and unmet needs in young celiacs require resources to attain adequate levels of dietetic provision, regulated subsidies for covering additional costs for GF food, evidence-based practice, and increased general CD awareness for optimum clinical outcomes.
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| 3. |
- Grodzinsky, Ewa, 1958-
(author)
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Serological markers in subclinical and clinical gluten enteropathy
- 1994
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Doctoral thesis (other academic/artistic)abstract
- An enzyme-linked immunosorbent assay (ELISA) has been developed for the measurement of anti-gliadin antibodies (AGA), thereby providing a practical and cheap assay for use in the diagnosis of coeliac disease (CD). Since gliadin is a common food antigen for most people, a large group of apparently healthy blood donors (n=l866) was analysed, as well as children and adults with symptoms more or less suggesting CD. The effects of various cut-offvalues on the sensitivity, specificity and predictive value (PV) of the test were calculated, both alone and together with anti-endomysium antibodies (EMA). A high prevalence value, of at least 1/256 (7!1866), for gluten enteropathy (GE) was found in the blood donor population. Moreover, a high frequency of CD among fanners with diffuse symptoms, conceivably due to a high exposure to gluten by inhalation, was also observed. It was impossible to combine high sensitivity with high specificity for both IgA- and IgG AGA, and vice versa, in adults. A significant increase in the mean lgA AGA level with age was seen when the blood donors were divided into age groups. A positive PV of 18-25% was found for IgA-AGA, depending on how-the cut-off value was defined. For IgG-AGA the positive PV was 0% (0/35) among asymptomatic subjects. IgA-EMA yielded both high specificity and a high positive PV, but a lower sensitivity than IgA-AGA, especially in children younger than 2 years, with signs of CD. When screening for GE in a population with expected low prevalence, measurement of IgA-AGA is suggested as a primary test because of fairly good sensitivity, technical simplicity, and low cost. Sera found to be positive are then re tested with IgA-EMA, which gives a positive PV close to 100%. For populations with a moderate or high expected prevalence for CD, our results indicate that different tests should be used depending on the age of the population studied. In younger children ( < 2 years old) lgA-AGA yielded a high sensitivity (lOO%) and a high specificity (86%). fu older children (> 2 years old) and adults the use of IgA-EMA seems more suitable, because of the high specificity (99-100%) and positive PV (95-100% ). Since, however, the negative PV was not 100%, a negative test result does not exclude CD.
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| 4. |
- Stenberg, Reidun, 1954-
(author)
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Dietary antibodies and gluten related seromarkers in children and young adults with cerebral palsy
- 2012
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Doctoral thesis (other academic/artistic)abstract
- Background & Aims: Cerebral palsy (CP), the most common physical disorder in children that affect motor function, is associated with a low weight and height. Celiac disease (CD), an autoimmune disorder precipitated by ingestion of gluten, is another common chronic disease in children that has a negative impact on growth. Based on our findings in a small pilot study, antibodies against gluten, dietary antigens and antibodies against transglutaminase 6(TG6) a new possible gluten related neurological marker have been investigated in an extended group of children with CP. The main aim of this thesis was to find out if the children with elevated gluten related antibodies have enteropathy consistent with CD and if they have antibodies to other dietary antigens as well. We further wanted to study if elevated levels of antibodies were associated to their weight, subtypes of CP and also to investigate if there were an association between the brain damage seen in CP and antibodies against TG6.Methods: Ninety nine children with CP and matched (study4) controls (study3) were analysed for antibodies against gluten, TG6, egg white, lacto-globulin, casein and wheat. Small bowel biopsies were analysed in the majority of the children with antibody positivity, both by routine procedures and by extended analyse (study 2).Results: Significantly elevated levels of gluten related seromarkers and antibodies against casein, lacto globulin and egg white were found in the CP-group compared to matched controls. The overall elevated levels of antibodies were more frequent in the tetraplegic (TP) and dyskinetic (DK) CP -subtypes having the most severe neurologic handicap and undernourishment. Routine and extended small bowel biopsies analysis did not indicate an increased prevalence of CD. Elevated antibodies against TG6 were found in the CP-group and significantly in the tetraplegic CP-subgroup.Conclusion: Children with CP do not have increased prevalence of celiac disease but have elevated levels of gluten related seromarkers as well as antibodies against other dietary proteins compared to matched controls. There was a correlation between underweight, CP-subtypes (TP/DK) and occurrence of the tested antibodies suggesting disturbed intestinal permeability related to underweight. Compared to controls TG6 autoantibodies were found in the TP-subtype of CP that could be a result due to the brain damage.
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