Kristian Lynch

Celiac disease is associated with tissue transglutaminase autoantibodies (tTGAb) and the human leukocyte antigen (HLA)-risk alleles DQB1*02 and DQB1*0302. The aim was to estimate the proportion of undiagnosed celiac disease in children with HLA risk at 3 years of age. From a population-based HLA-DQ screening study of newborns born between June 2001 and August 2004 in the southern part of Sweden, 6206 children with HLA-risk alleles were identified and asked to participate at a mean 3.3 +/- 0.4 years of age. As controls, 7654 children with HLA-nonrisk alleles were asked to participate. In all, 1620 (26.1%) children with HLA risk and 1815 (23.7%) controls were screened for tTGAb using radioligand-binding assays. Celiac disease was established by intestinal biopsy in children with a confirmed positive tTGAb test. Twenty-three children reported already having clinically diagnosed celiac disease and did not participate further. In children with HLA-risk genotypes, 73 of 1620 (4.5%, 95% CI 3.5%-5.5%) were tTGAb-positive compared with none of 1815 from the controls (P < 0.0001). Seventy-one children underwent biopsy (1 refused biopsy and 1 biopsy failed), of whom 56 of 1618 (3.5%, 95% CI 2.6%-4.4%) had damaged intestinal mucosa classified as celiac disease. The ratio between clinically and screening detected celiac disease in this study was 1:2.4 (23:56). The proportion of clinically undetected celiac disease may be particularly high among 3-year-old children with HLA-DQB1*02 and DQB1*0302 in Sweden, where these 2 HLA-risk alleles frequently occur.

ABSTRACT The GAD65 epitope immunoglobulin binding pattern in cord blood of children (n=37), who later developed type 1 diabetes at 3.2-14.9 years of age, was analyzed. First, the binding at diagnosis was compared with that in the cord blood serum. The next comparison was between the cord blood serum and the mothers' serum taken at delivery. Basal GAD65 binding levels were determined in Protein A Sepharose-based radiobinding assays with (35)S-labeled human and rat GAD65, rat GAD67 and GAD65/67 fusion proteins representing N-terminal (N), middle (M) and C-terminal (C) epitopes. In the first comparison, 28/37 children had GAD65 binding above 2.44 relative units (RU) (upper three quartiles), representing a marked increase from birth in the binding to human GAD65 (p<0.0001), rat GAD65 (p<0.0001), N- (p=0.04), M- (p<0.0001), C- (p=0.001), and M + C-epitopes (p<0.0001), but not to rat GAD67. At birth, 9/37 had GAD65 binding above 1.56 RU (upper quartile) demonstrating that their binding of human (35)S-GAD65 was higher in cord blood than in the mother (p=0.008). Higher cord blood binding was also observed for the N- (p=0.02) terminal epitope but not for rat GAD65, rat GAD67, and the remaining epitopes. These data suggest that differences in the epitope GAD65 binding between mother and child at birth are limited. In contrast, the epitope pattern at diagnosis differed from that at birth, supporting the view that disease-associated epitopes develop between birth and diagnosis.

Early childhood environmental exposures, possibly infections, may be responsible for triggering islet autoimmunity and progression to type 1 diabetes (T1D). The Environmental Determinants of Diabetes in the Young (TEDDY) follows children with increased HLA-related genetic risk for future T1D. TEDDY asks parents to prospectively record the child's infections using a diary book. The present paper shows how these large amounts of partially structured data were reduced into quantitative data-sets and further categorized into system-specific infectious disease episodes. The numbers and frequencies of acute infections and infectious episodes are shown. Study subjects (n = 3463) included children who had attended study visits every three months from age 3 months to 4 years, without missing two or more consecutive visits during the follow-up. Parents recorded illnesses prospectively in a TEDDY Book at home. The data were entered into the study database during study visits using ICD-10 c...

Social epidemiology investigates both individuals and their collectives. Although the limits that define the individual bodies are very apparent, the collective body's geographical or cultural limits (eg "neighbourhood") are more difficult to discern. Also, epidemiologists normally investigate causation as changes in group means. However, many variables of interest in epidemiology may cause a change in the variance of the distribution of the dependent variable. In spite of that, variance is normally considered a measure of uncertainty or a nuisance rather than a source of substantive information. This reasoning is also true in many multilevel investigations, whereas understanding the distribution of variance across levels should be fundamental. This means-centric reductionism is mostly concerned with risk factors and creates a paradoxical situation, as social medicine is not only interested in increasing the (mean) health of the population, but also in understanding and decreasing inappropriate health and health care inequalities (variance). Critical essay and literature review. The present study promotes (a) the application of measures of variance and clustering to evaluate the boundaries one uses in defining collective levels of analysis (eg neighbourhoods), (b) the combined use of measures of variance and means-centric measures of association, and (c) the investigation of causes of health variation (variance-altering causation). Both measures of variance and means-centric measures of association need to be included when performing contextual analyses. The variance approach, a new aspect of contextual analysis that cannot be interpreted in means-centric terms, allows perspectives to be expanded.

The GAD65 epitope immunoglobulin binding pattern in cord blood of children (n=37), who later developed type 1 diabetes at 3.2-14.9 years of age, was analyzed. First, the binding at diagnosis was compared with that in the cord blood serum. The next comparison was between the cord blood serum and the mothers' serum taken at delivery. Basal GAD65 binding levels were determined in Protein A Sepharose-based radiobinding assays with (35)S-labeled human and rat GAD65, rat GAD67 and GAD65/67 fusion proteins representing N-terminal (N), middle (M) and C-terminal (C) epitopes. In the first comparison, 28/37 children had GAD65 binding above 2.44 relative units (RU) (upper three quartiles), representing a marked increase from birth in the binding to human GAD65 (p<0.0001), rat GAD65 (p<0.0001), N- (p=0.04), M- (p<0.0001), C- (p=0.001), and M + C-epitopes (p<0.0001), but not to rat GAD67. At birth, 9/37 had GAD65 binding above 1.56 RU (upper quartile) demonstrating that their binding of human (35)S-GAD65 was higher in cord blood than in the mother (p=0.008). Higher cord blood binding was also observed for the N- (p=0.02) terminal epitope but not for rat GAD65, rat GAD67, and the remaining epitopes. These data suggest that differences in the epitope GAD65 binding between mother and child at birth are limited. In contrast, the epitope pattern at diagnosis differed from that at birth, supporting the view that disease-associated epitopes develop between birth and diagnosis.