Exploring childhood immunization among undocumented migrants in Sweden - following qualitative study and the World Health Organizations Guide to Tailoring Immunization Programmes (TIP).

OBJECTIVES: National vaccination coverage in Sweden is high. Recurrent outbreaks of measles and rubella however highlight some immunity gaps in the population. Current knowledge about immunization status of undocumented migrant children is scant. The World Health Organization/Europe has developed the Guide to Tailoring Immunization Programmes (TIP) to assist countries in diagnosing barriers and motivators to vaccination in communities with low vaccination coverage. Based on the TIP guide, the objective of this study was to explore determinants to vaccination among undocumented immigrants, using qualitative approach. STUDY DESIGN: The study consisted of three steps: (i) an initial workshop for problem statement; (ii) qualitative research for increased understanding of the vaccination practices of children in the undocumented community; and (iii) a second workshop to incorporate the qualitative interview findings together with data from key stakeholders into a conceptual framework. METHODS: This was a qualitative study featuring interviews of seven undocumented parents recruited at non-governmental clinics, three nurses at Child Health Centers, and information from key stakeholders retrieved at workshops as part of the TIP process. RESULTS: The content analysis revealed two main themes: parental fear of being questioned and parental acceptance of child immunization. Undocumented parents had a positive view and attitude toward childhood immunization but expressed strong fear of being asked for identification papers at healthcare facilities. Owing to lack of knowledge on entitlements of the undocumented among health personnel, parents were incorrectly rejected when seeking care for their children. Frequent mobility among undocumented may limit access to complete the immunization schedule. Undocumented parents mistrust healthcare providers and avoid health facilities, further delaying childrens' access to health care, including immunization services. CONCLUSIONS: The findings of this study confirm the complexity of barriers that undocumented parents face regarding childhood immunization. The TIP guide offers a valuable process for a deeper understanding of the determinants of immunization challenges among undocumented migrants.

Opportunistic virus DNA levels after pediatric stem cell transplantation: serostatus matching, anti-thymocyte globulin, and total body irradiation are additive risk factors.

Viral opportunistic infections remain a threat to survival after stem cell transplantation (SCT). We retrospectively investigated infections caused by cytomegalovirus (CMV), Epstein-Barr virus (EBV), human herpesvirus type 6 (HHV6), or adenovirus (AdV) during the first 6-12 months after pediatric SCT. Serum samples from 47 consecutive patients were analyzed by quantitative real-time polymerase chain reaction assay. DNAemia at any time point occurred for CMV in 47%, for EBV in 45%, for HHV6 in 28%, and for AdV in 28%. Three patients (6.3%) died of CMV-, EBV-, or AdV-related complications 4, 9, and 24 weeks after SCT, respectively, representing 21% of total mortality. These 3 cases were clearly distinguishable by DNAemia increasing to high levels. Serum positivity for CMV immunoglobulin G in either recipient or donor at the time of SCT, total body irradiation, and anti-thymocyte globulin conditioning were independent risk factors for high CMV or EBV DNA levels. We conclude that DNAemia levels help to distinguish significant viral infections, and that surveillance and prophylactic measures should be focused on patients with risk factors in whom viral complications rapidly can become fatal.

Four novel coeliac disease regions replicated in an association study of a Swedish-Norwegian family cohort.

Recent genome-wide association studies have identified 1q31 (RGS1), 2q11-12 (IL18RAP), 3p21 (CCR1/CCR3/CCR2), 3q25-26 (IL12A/SCHIP1), 3q28 (LPP), 4q27 (IL2/IL21), 6q25 (TAGAP) and 12q24 (SH2B3) as susceptibility regions for coeliac disease (CD). We have earlier replicated association with the IL2/IL21 region. This study aimed at replicating the remaining regions in a family cohort using the transmission disequilibrium test, which is not prone to population stratification as a source of false-positive results. Nine single nucleotide polymorphisms (SNPs) within these regions were genotyped in 325 Swedish-Norwegian CD families. We found significant associations with the same alleles in the regions 1q31 (rs2816316; P(nc)=0.0060), 3p21 (rs6441961; P(nc)=0.0006), 3q25-26 (rs17810564; P(nc)=0.0316 and rs9811792; P(nc)=0.0434) and 3q28 (rs1464510; P(nc)=0.0037). Borderline, but non-significant, associations were found for rs917997 (IL18RAP), whereas no evidence for association could be obtained for rs13015714 (IL18RAP) or rs1738074 (TAGAP). The lack of replication of the latter SNPs could be because of limited power. rs3184504 (SH2B3) was not analysed because of assay failure. The most significantly associated region, 3p21 (CCR1/CCR3/CCR2), was further analysed by typing of 30 SNPs, with the aim of identifying the causal variant responsible for the initial association. Several SNPs showed association with CD, but none displayed associations stronger than rs6441961, nor did any of them add to the effect initially marked by rs6441961 in a conditional analysis. However, differential effects of rs6441961(*)C carrying haplotypes were indicated, and we thus cannot exclude the possibility that our inability to obtain evidence for multiple independent effects in the CCR1/CCR3/CCR2 gene region was related to a power issue.

Association study of IL2/IL21 and FcgRIIa: significant association with the IL2/IL21 region in Scandinavian coeliac disease families.

The first genome-wide association study performed in a UK coeliac disease (CD) case-control cohort revealed association with a linkage disequilibrium block containing the KIAA1109/Tenr/IL2/IL21 genes. Also recently, an association with a non-synonymous polymorphism in FcgammaRIIa (CD32a) was reported in CD with an unusually strong P-value. We aimed to replicate the reported associations with the single nucleotide polymorphisms rs13119723 A>G and rs6822844 G>T in the KIAA1109/Tenr/IL2/IL21 region and rs1801274 G>A in the FcgammaRIIa gene in a family sample consisting of 325 Swedish/Norwegian families using the robust transmission disequilibrium test. The family sample used in this study included 100 families with two or more children affected by CD and 225 families with one affected child. We could confirm significant association between the polymorphisms rs13119723 A>G and rs6822844 G>T located in the KIAA1109/Tenr/IL2/IL21 region and CD (P-value 0.001 and 0.002, respectively). However, we found no association with the FcgammaRIIa rs1801274 G>A polymorphism (P-value=0.3). In conclusion, our results support the KIAA1109/Tenr/IL2/IL21 region as a true CD susceptibility region.

Fine mapping study in Scandinavian families suggests association between coeliac disease and haplotypes in chromosome region 5q32.

The previous genome-wide scan in Scandinavian families supported earlier evidence for linkage of a region on chromosome 5 (5q31-33) to coeliac disease. This study deals with further genetic mapping of an 18 cM region, spanning from marker GAh18A (131.87 Mb) to D5S640 (149.96 Mb). Linkage and association analyses were performed in a two-step approach. First, seven microsatellites were added. Strong evidence for linkage was obtained with a Zlr score of 3.96, P(nc) = 4 x 10(-5) at marker D5S436. The strongest association was with a haplotype consisting of the markers D5S2033 and D5S2490 (P(nc) < 0.001). In the second step, we added 17 microsatellites and 69 single nucleotide polymorphisms (SNPs) to the analysis. These markers were located close to or within candidate genes across the region of approximately 7 Mb beneath the linkage peak marked by D5S2017 and D5S812. A substantial increase of the linkage signal with a maximum Zlr score of 4.6 at marker rs1972644 (P(nc) = 2 x 10(-6)) was obtained and several SNPs showed association. Seven SNPs that individually showed the strongest association were genotyped in a second independent family sample set (225 trios). In the trio family sample as well as in the multiplex family sample, the strongest association was found with SNPs within the region flanked by the associated microsatellites D5S2033 and D5S2490 at 5q32.

Characterization of the humoral immune response in two paediatric patients transplanted with split livers from ABO-incompatible living-related donors: appearance of cytomegalovirus-induced ABO antibodies.

Two blood group O paediatric patients, 12 and 6 months old, were transplanted with liver segments from their blood group A2Le (a(-)b+) Se and blood group A1Le (a(-)b+) Se fathers, respectively. Recipient anti-A antibody titres were reduced prior to transplantation by blood exchange. Both patients had rejection episodes in the post-transplant period that were reversed by anti-rejection therapy. No anti-A antibody titre rise occurred concomitant with these rejections. Postoperatively both patients had cytomegalovirus (CMV) infections, and simultaneous with these infections, a strong increase in anti-A antibody titres was seen, but no rejection occurred. The anti-A antibody titre increase seemed to be specific for A antigens, because the anti-B and anti-alphaGal (anti-pig) antibody titres did not show any changes. CMV infection is a serious cause of morbidity and mortality in immunosuppressed patients, and the virus can influence glycosylation of infected cells. Whether this can explain the importance of the infection in relation to the increase in titre remains to be elucidated.

Genetic analysis of the CD28/CTLA4/ICOS (CELIAC3) region in coeliac disease.

In order to extend our previous findings of genetic linkage to the CD28/CTLA4/ICOS region on chromosome 2q33 (CELIAC3) in coeliac disease (CD), we have investigated 22 genetic markers in 325 Norwegian/Swedish multiplex and simplex CD families. We found both linkage and association with several markers, primarily in the multiplex material. We observed strong linkage disequilibrium (LD) between SNPs (Single Nucleotide Polymorphisms) within an LD block delimited by MH30 and D2S72. A haplotype of this region marked by the alleles -1147*T: + 49*A:CT60*G:CT61*A was significantly associated with CD, suggesting that one or more polymorphisms of this haplotype, possibly -1147*T, are involved in CD susceptibility. The CT60 SNP, a polymorphism found to be most strongly associated with some other immune-mediated diseases, was not associated with CD, as this SNP was part of both associated and non-associated haplotypes. Moreover, our results suggest that CELIAC3 harbours several independent loci contributing to CD susceptibility.

HLA-DQ relative risks for coeliac disease in European populations: a study of the European Genetics Cluster on Coeliac Disease.

Coeliac disease is an enteropathy due to an intolerance to gluten. The association between HLA-DQ genes and CD is well established. The majority of patients carry the HLA-DQ heterodimer encoded by DQA1*05/DQB1*02, either in cis or in trans. The remaining patients carry either part of the DQ heterodimer or DQA1*03-DQB1*0302. The aim of the study was to estimate the risks associated with different DQ genotypes in European populations. HLA information was available for 470 trio families from four countries: France (117), Italy (128), and Norway and Sweden (225). Five DQA1-DQB1 haplotypes were considered and control haplotype frequencies were estimated from the set of parental haplotypes not transmitted to the affected child. The possible genotypes were grouped into five genotype groups, based on the hierarchy of risk reported in the literature. A north-south gradient in the genotype group frequencies is observed in probands: homogeneity is strongly rejected between all country pairs. For each country, the relative risks associated with each genotype group were computed taking into account the control haplotype frequencies. Homogeneity of relative risks between countries was tested pairwise by maximum likelihood ratio statistics. The hypothesis of homogeneity of relative risks is rejected (P is approximately 10(-6)) for all country pairs. In conclusion, the gradient in the genotype group frequencies in probands is not only due to differences in haplotype frequencies but also due to differences in genotype relative risks in the studied populations; the relative risks associated with each DQ genotype group are different between northern and southern European countries; neither are they ordered in the same way.

Oats to children with newly diagnosed coeliac disease: a randomised double blind study.

BACKGROUND: Treatment of coeliac disease (CD) requires lifelong adherence to a strict gluten free diet (GFD) which hitherto has consisted of a diet free of wheat, rye, barley, and oats. Recent studies, mainly in adults, have shown that oats are non-toxic to CD patients. In children, only open studies comprising a small number of patients have been performed. AIM: To determine if children with CD tolerate oats in their GFD. PATIENTS AND METHODS: In this double blind multicentre study involving eight paediatric clinics, 116 children with newly diagnosed CD were randomised to one of two groups: one group was given a standard GFD (GFD-std) and one group was given a GFD with additional wheat free oat products (GFD-oats). The study period was one year. Small bowel biopsy was performed at the beginning and end of the study. Serum IgA antigliadin, antiendomysium, and antitissue transglutaminase antibodies were monitored at 0, 3, 6, and 12 months. RESULTS: Ninety three patients completed the study. Median (range) daily oat intake in the GFD-oats group (n = 42) was 15 (5-40) g at the six month control and 15 (0-43) g at the end of the study. All patients were in clinical remission after the study period. The GFD-oats and GFD-std groups did not differ significantly at the end of the study regarding coeliac serology markers or small bowel mucosal architecture, including numbers of intraepithelial lymphocytes. Significantly more children in the youngest age group withdrew. CONCLUSIONS: This is the first randomised double blind study showing that the addition of moderate amounts of oats to a GFD does not prevent clinical or small bowel mucosal healing, or humoral immunological downregulation in coeliac children. This is in accordance with the findings of studies in adult coeliacs and indicates that oats, added to the otherwise GFD, can be accepted and tolerated by the majority of children with CD.

Candidate gene region 2q33 in European families with coeliac disease.

Chromosome region 2q33 harbours a cluster of genes, CTLA-4, CD28, ICOS and closely located PD-1, all related to immune activation and considered as promising candidate genes for susceptibility to coeliac disease (CD). We present here the results of a genetic linkage and association analysis of nine markers located in this gene region in a large combined European material of 796 families with CD from Finland, Sweden, Norway, UK, France and Italy. The joint analysis supports earlier findings that this susceptibility locus, assigned as CELIAC3, merits further studies. Nominally significant linkage to CD was found in 314 families including affected sib pairs. Each of the five populations showed weak associations to several marker alleles, but the analysis revealed, however, no conclusive evidence for a primary functional gene or gene variant present in the total set of families. The results suggest that the CD risk due to 2q33 gene region is complex and may involve more than one susceptibility allele, which possibly differ from other autoimmune diseases.

Intestinal tissue transglutaminase in coeliac disease of children and adults: ultrastructural localization and variation in expression.

BACKGROUND: Tissue transglutaminase is the main antigen for the anti-endomysial antibodies used for diagnosis of coeliac disease and can with some specificity in vitro deamidate gliadins generating potent epitopes. The intestinal levels and the ultrastructural localization of tissue transglutaminase in normal and affected persons were investigated to provide further information on its role in this disease. Intestinal biopsies were taken from normal and coeliac children and adults. METHODS: The level of transglutaminase was analysed by means of a quantitative enzymatic assay and its ultrastructural localization by immunogold electronmicroscopy using a monoclonal antibody against tissue transglutaminase. RESULTS: In relation to normal individuals, the enzymatic activity of tissue transglutaminase in adult coeliac patients was increased. The enzyme was found in the enterocytes and in increased amount just beneath the enterocytes, where cytosolic and nuclear labelling of distinct elongated cells was seen in addition to extracellular labelling close to collagen fibrils. In children, the enzymatic activity and the immunogold labelling could not be shown to be related to disease. In all cases the enzyme activity was EDTA-sensitive. CONCLUSIONS: The increased amount of tissue transglutaminase activity in coeliac adults was shown to be due to the appearance of the enzyme in enterocytes and increased expression in the lamina propria. No evidence was found to support the idea of a changed localization or changed amounts as primary elements in coeliac disease pathogenesis, nor for the involvement of non-calcium dependent microbial transglutaminases.

Small bowel biopsy in Swedish paediatric clinics.

AIM: A correct diagnosis of coeliac disease, one of the most common chronic diseases in Swedish children, demands small bowel biopsy, which can be performed endoscopically or by means of a peroral capsule. Recently there was a debate among Swedish paediatric gastroenterologists, with some advocating the cessation of capsule biopsy in favour of endoscopic biopsies. To gain information on which to base a recommendation for which technique to use, the Swedish Working Group for Childhood Coeliac Disease was commissioned to carry out a national questionnaire study on current small bowel biopsy routines in Swedish paediatric clinics. METHODS: A questionnaire concerning biopsy routines in the year 2000 was sent to all paediatric clinics performing biopsies. A reply was obtained from 39 of 40 clinics, covering 98% of the Swedish population. RESULTS: Some 1400 biopsies were performed, 64% of which were capsule biopsies and 36% endoscopic. Three clinics performed all biopsies endoscopically and 11 clinics all via a capsule. At endoscopy all children were under deep sedation or full anaesthesia, while most children undergoing capsule biopsy were under light or deep sedation. The oxygen saturation was monitored during endoscopy but less often or never during routine capsule biopsy. The presence of the parents during biopsy varied according to the degree of sedation: at 97% of the clinics performing capsule biopsy on children under light sedation, the parents were present during the whole procedure, whereas no parents were present at clinics where the biopsy was performed endoscopically under anaesthesia. CONCLUSION: Compared with the results of a similar questionnaire concerning biopsy routines performed in the early 1990s, children are now more effectively sedated. Furthermore, there is an obvious trend from capsule towards endoscopic biopsy. Both the endoscopic and the capsule biopsy techniques are useful and satisfactory for obtaining small bowel mucosal samples providing that the children are effectively sedated. For practical and economic reasons the capsule biopsy technique will probably continue to be used, although to a lesser extent than today.

HLA in coeliac disease families: a novel test of risk modification by the 'other' haplotype when at least one DQA1*05-DQB1*02 haplotype is carried.

Predisposition to coeliac disease (CD) involves HLA genes. We investigated whether any haplotypes modify risk when carried trans to a known high-risk haplotype, DQA1*05-DQB1*02. Earlier attempts to rank levels of risk contributed by the 'other' haplotype were burdened by use of case-control populations; haplotype frequencies were estimated and homozygosity was only presumed. In contrast, exact haplotypes can be determined and allele transmission can be traced in families. A similar study in narcolepsy reported strata of different degrees of predisposition, attributable to the 'other' haplotype. A gene dosage effect similar to that described for DQB1*02 in CD, has also been reported in narcolepsy. We genotyped 439 simplex/multiplex trios for DQA1 and DQB1. We designed a new statistic to test risk modulation by the trans haplotype, even if the affected offspring was homozygous. We tested for significant deviation in transmission of the 'other' haplotype, i.e., modification of DQA1*05-DQB1*02 risk. We also addressed the proposed difference in risk, between DQA1*05-DQB1*02 homozygotes and DQA1*05-DQB1*02/DQA1*0201-DQB1*02 heterozygotes, reported in Southern Europe. We confirmed a DQB1*02 gene dosage effect. However, no haplotypes were found to modify risk when carried trans to DQA1*05-DQB1*02, except DQA1*05-DQB1*02 and DQA1*0201-DQB1*02 which were already known. We did not find credible evidence for a difference in risk conferred by DQA1*05-DQB1*02 and DQA1*0201-DQB1*02, when carried with DQA1*05-DQB1*02. The new test, which directly inspects haplotype transmissions rather than estimated haplotype frequencies, was used to demonstrate that the 'other' haplotype (except DQA1*05-DQB1*02 and DQA1*0201-DQB1*02) does not modify risk conferred by DQA1*05-DQB1*02. The test is applicable to other diseases.

Coeliac disease candidate genes: no association with functional polymorphisms in matrix metalloproteinase 1 and 3 gene promoters.

BACKGROUND: Coeliac disease is polygenic with a large genetic component. Matrix metalloproteinase-1 (MMP-1) and MMP-3 degrade extracellular matrix; expression levels are increased in the coeliac lesion where tissue damage is observed. Polymorphisms associated with elevated expression (MMP-3 -1171 allele 5A; MMP-1 -1607 2G), at 11q22.2, a region repeatedly showing evidence of linkage in coeliac disease, are associated with other chronic inflammatory disorders which may share a common molecular pathology. We tested for an association between these candidate gene polymorphisms and coeliac disease. METHODS: Two independent collections of 225 and 102 combined (Norwegian and Swedish) simplex families, and 160 independent healthy controls from the Norwegian Bone Marrow Donor Registry were used. Each individual was genotyped by PCR and fragment length analysis on an automated sequencer. The transmission/disequilibrium test was applied. Odds ratios were calculated employing probands or affected sibs where available, as cases versus independent controls. RESULTS: MMP-1 allele 2G did not show evidence of association in any tests undertaken. Neither did we find evidence for association of MMP-3 allele 5A, except among the combined family data: a non-significant tendency toward reduced risk was observed among males carrying MMP-3 allele 5A (40.2% transmission, Pc = 0.2). Further testing to clarify this observation did not reveal a significant association (odds ratio = 0.67 (95% confidence interval: 0.42-1.07), P = 0.08). CONCLUSIONS: We did not find significant evidence to support an association of MMP-3 allele 5A or MMP-1 allele 2G with coeliac disease in Norwegian and Swedish populations.

Paediatric aspects of coeliac disease: old challenges and new ones...

The concept of coeliac disease has expanded from a gastrointestinal disease with malabsorption to a systemic immunological disease with a genetic basis. Epidemiological studies indicate that environmental factors, like the infant feeding pattern, affect the clinical presentation while population-screening studies indicate that the prevalence, at least in Caucasian populations, is similar. Secondary complications, like malignancies, osteopenia - osteoporosis, gynaecological and obstetrical problems and autoimmune diseases, are common. The risk is reduced or prevented by treatment with a gluten-free diet. The basis for such a secondary prevention is: 1. early case-finding by a) knowledge about different presentations of the disease and factors affecting that, b) generous serological testing in patients with vague symptoms, c) screening of risk groups, and, 2. support for children and adolescents with coeliac disease to comply with the gluten-free diet.

The IL12B gene does not confer susceptibility to coeliac disease.

Coeliac disease (CD) is a chronic inflammatory disorder where dietary gluten is not tolerated. In the lesion there are gluten reactive T cells predominantly secreting gamma-interferon. Both HLA and non-HLA genes contribute to CD susceptibility. Interleukin-12 (IL-12) regulates gamma-interferon production. The IL12B gene is located in a region (5q31.1-33.1) where there is evidence for linkage with CD. Allele 1 of an IL12B 3'UTR single-nucleotide polymorphism leads to increased expression of IL-12, and was recently implicated in susceptibility for type 1 diabetes (T1D). We found no evidence for association of allele 1 to CD by the transmission/disequilibrium test or case-control approach. No increased frequency was observed in patients belonging to families where the disease was linked to markers on chromosome 5q. Unlike T1D, allele 1 does not appear to confer susceptibility to CD.

Electrogenic ion transport in duodenal biopsies from children with coeliac disease.

BACKGROUND: The aim of this work was to study whether different degrees of duodenal mucosal damage in coeliac disease (CD) influenced secretory responses to well-known secretagogues. METHODS: Intestinal biopsies from 53 patients in different clinical phases of CD and 34 patients without CD and with normal histology were studied in a modified Ussing chamber. The electrogenic responses-with and without pretreatment with indomethacin-to prostaglandin E2, aminophylline, dibutyryl-cAMP and acetylcholine were followed by continuous measurements of potential difference (Pd). Tissue resistance and epithelial current (Im) were calculated. RESULTS: All secretagogues induced a similar pattern, with a greater increase in Pd and Im in biopsies with villous atrophy compared to controls. The electrophysiological response was correlated to the serum levels of IgA gliadin antibodies. The most prominent electrophysiological increase was found in the biopsies with partial atrophy. Indomethacin had a greater impact on the response to secretagogues in the more severely damaged mucosa. CONCLUSION: The electrogenic secretory response in the proximal small intestine was enhanced and related to serum levels of IgA gliadin antibodies and to the degree of mucosal damage in biopsies from children with active CD compared to controls.