Päivi Saavalainen

Diagnosing Mild Enteropathy Celiac Disease: A Randomized, Controlled Clinical Study

BACKGROUND & AIMS The diagnostic criteria for celiac disease require small-bowel mucosal villous atrophy with crypt hyperplasia (Marsh III). However, mucosal damage develops gradually and patients may evince clinical symptoms before histologic changes appear. Endomysial antibodies are specific in predicting forthcoming villous atrophy. We hypothesized that patients with mild enteropathy but positive endomysial antibodies benefit from a gluten-free diet (GFD) similarly to patients with more severe enteropathy. METHODS Small-bowel endoscopy together with clinical evaluations was performed in all together 70 consecutive adults with positive endomysial antibodies. Of these, 23 had only mild enteropathy (Marsh I-II) and they were randomized either to continue on a gluten-containing diet or start a GFD. After 1 year, clinical, serologic, and histologic evaluations were repeated. A total of 47 participants had small-bowel mucosal lesions compatible with celiac disease (Marsh III), and these served as disease controls. RESULTS In the gluten-containing diet group (Marsh I-II) the small-bowel mucosal villous architecture deteriorated in all participants, and the symptoms and abnormal antibody titers persisted. In contrast, in the GFD group (Marsh I-II) the symptoms were alleviated, antibody titers decreased, and mucosal inflammation diminished equally to celiac controls (Marsh III). When the trial was completed, all participants chose to continue on a life-long GFD. CONCLUSIONS Patients with endomysial antibodies benefit from a GFD regardless of the degree of enteropathy. The diagnostic criteria for celiac disease need re-evaluation: endomysial antibody positivity without atrophy belongs to the spectrum of genetic gluten intolerance, and warrants dietary treatment.

Celiac disease without villous atrophy in children: a prospective study.

OBJECTIVE To establish whether children who are endomysial antibody (EmA) positive and have normal small-bowel mucosal villous morphology are truly gluten-sensitive and may benefit from early treatment with a gluten-free diet. STUDY DESIGN Children who were EmA positive with normal small-bowel mucosal villi were compared with children who were seropositive with villous atrophy by using several markers of untreated celiac disease. Thereafter, children with normal villous structure either continued on a normal diet or were placed on a gluten-free diet and re-investigated after 1 year. Seventeen children who were seronegative served as control subjects for baseline investigations. RESULTS Normal villous morphology was noted in 17 children who were EmA positive, and villous atrophy was noted in 42 children who were EmA positive. These children were comparable in all measured variables regardless of the degree of enteropathy, but differed significantly from the seronegative control subjects. During the dietary intervention, in children who were EmA positive with normal villi, the disease was exacerbated in children who continued gluten consumption, whereas in all children who started the gluten-free diet, both the gastrointestinal symptoms and abnormal antibodies disappeared. CONCLUSIONS The study provided evidence that children who are EmA positive have a celiac-type disorder and benefit from early treatment despite normal mucosal structure, indicating that the diagnostic criteria for celiac disease should be re-evaluated.

Evolutionary and Functional Analysis of Celiac Risk Loci Reveals SH2B3 as a Protective Factor against Bacterial Infection

Celiac disease (CD) is an intolerance to dietary proteins of wheat, barley, and rye. CD may have substantial morbidity, yet it is quite common with a prevalence of 1%-2% in Western populations. It is not clear why the CD phenotype is so prevalent despite its negative effects on human health, especially because appropriate treatment in the form of a gluten-free diet has only been available since the 1950s, when dietary gluten was discovered to be the triggering factor. The high prevalence of CD might suggest that genes underlying this disease may have been favored by the process of natural selection. We assessed signatures of selection for ten confirmed CD-associated loci in several genome-wide data sets, comprising 8154 controls from four European populations and 195 individuals from a North African population, by studying haplotype lengths via the integrated haplotype score (iHS) method. Consistent signs of positive selection for CD-associated derived alleles were observed in three loci: IL12A, IL18RAP, and SH2B3. For the SH2B3 risk allele, we also show a difference in allele frequency distribution (Fst) between HapMap phase II populations. Functional investigation of the effect of the SH2B3 genotype in response to lipopolysaccharide and muramyl dipeptide revealed that carriers of the SH2B3 rs3184504*A risk allele showed stronger activation of the NOD2 recognition pathway. This suggests that SH2B3 plays a role in protection against bacteria infection, and it provides a possible explanation for the selective sweep on SH2B3, which occurred sometime between 1200 and 1700 years ago.

Altered Duodenal Microbiota Composition in Celiac Disease Patients Suffering From Persistent Symptoms on a Long-Term Gluten-Free Diet

Objectives:A significant fraction of celiac disease patients suffer from persistent symptoms despite a long-term gluten-free diet (GFD) and normalized small bowel mucosa. The commonly suggested reasons, such as inadvertent gluten-intake or presence of other gastrointestinal disease, do not explain the symptoms in all these patients. Recently, alterations in intestinal microbiota have been associated with autoimmune disorders, including celiac disease. This led us to test a hypothesis that abnormal intestinal microbiota may be associated with persisting gastrointestinal symptoms in treated celiac disease patients.Methods:Duodenal microbiota was analyzed in 18 GFD-treated patients suffering from persistent symptoms and 18 treated patients without symptoms by 16S rRNA gene pyrosequencing. The celiac disease patients had been following a strict GFD for several years and had restored small bowel mucosa and negative celiac autoantibodies. Their symptoms on GFD were assessed with Gastrointestinal Symptom Rating Scale.Results:The results of several clustering methods showed that the treated celiac disease patients with persistent symptoms were colonized by different duodenal microbiota in comparison with patients without symptoms. The treated patients with persistent symptoms had a higher relative abundance of Proteobacteria (P=0.04) and a lower abundance of Bacteroidetes (P=0.01) and Firmicutes (P=0.05). Moreover, their microbial richness was reduced. The results indicated intestinal dysbiosis in patients with persistent symptoms even while adhering to a strict GFD.Conclusions:Our findings indicate that dysbiosis of microbiota is associated with persistent gastrointestinal symptoms in treated celiac disease patients and open new possibilities to treat this subgroup of patients.

IL23R in the Swedish, Finnish, Hungarian and Italian populations: association with IBD and psoriasis, and linkage to celiac disease

BackgroundAssociation of the interleukin-23 receptor (IL23R) with inflammatory bowel disease (IBD) has been confirmed in several populations. IL23R also associates with psoriasis, suggesting that the gene may be an important candidate for many chronic inflammatory diseases.MethodsWe studied association of single-nucleotide variants in IL23R with IBD in Swedish patients, in both Crohns disease (CD) and ulcerative colitis (UC) subsets. The same genetic variants were also studied in Finnish patients with psoriasis or celiac disease, and in Hungarian and Italian patients with celiac disease.ResultsAssociation of IL23R with IBD was replicated in our Swedish patients, and linkage and association of the IL23R region with psoriasis was found in the Finnish population. The IL23R region was also linked to celiac disease in Finnish families, but no association of IL23R variants with celiac disease was found in the Finnish, Hungarian or Italian samples.ConclusionOur study is the first to demonstrate association of IL23R with CD and UC in Swedish patients with IBD. It is also the first study to report linkage and association of the IL23R region with psoriasis in the Finnish population. Importantly, this is the first report of linkage of the IL23R region to celiac disease, a chronic inflammatory condition in which IL23R has not been previously implicated.

Association of IL23R, TNFRSF1A, and HLA-DRB1*0103 allele variants with inflammatory bowel disease phenotypes in the Finnish population

Background: Crohns disease (CD) and ulcerative colitis (UC), 2 major forms of inflammatory bowel disease (IBD), are complex disorders with significant genetic predisposition. The first CD‐associated gene, CARD15/NOD2, was recently identified and since then several reports on novel IBD candidate genes have emerged. We investigated disease phenotype association to genetic variations in IL23R, ATG16L1, DLG5, ABCB1/MDR1, TLR4, TNFRSF1A, chromosome 5 risk haplotype including SLC22A4 and SLC22A5, and HLA‐DRB1*0103 allele among Finnish IBD patients. Methods: A total of 699 IBD patients were genotyped for disease‐associated variants by polymerase chain reaction (PCR) and restriction enzyme digestion or Sequenom iPLEX method. Results: Five markers spanning the IL23R gene were associated with CD. The SNP (single nucleotide polymorphism) rs2201841 gave the strongest association (P = 0.002). The rare HLA‐DRB1*0103 allele was found to associate with UC (P = 0.008), and the TNFRSF1A A36G variant was associated with familial UC (P = 0.007). Upon phenotypic analysis we detected association between familial UC and rare TNFRSF1A alleles 36G and IVS6+10G (P = 0.001 and P = 0.042, respectively). In addition, IL23R markers were associated with stricturing CD (P = 0.010–0.017), and ileocolonic CD was more prevalent in the carriers of the same 2 TNFRSF1A variants (P = 0.021 and P = 0.028, respectively). Less significant genotype–phenotype associations were observed for the TLR4 and HLA variants. Conclusions: We were able to replicate the association of the IL23R variants with CD as well as HLA‐DRB1*0103 with UC; confirmation of TNFRSF1A association with UC needs additional studies. Our findings also suggest that polymorphisms at IL23R and TNFRSF1A, and possibly HLA and TLR4, loci may account for phenotypic variation in IBD.

Antigenic Differences between AS03 Adjuvanted Influenza A (H1N1) Pandemic Vaccines: Implications for Pandemrix-Associated Narcolepsy Risk

Background Narcolepsy results from immune-mediated destruction of hypocretin secreting neurons in hypothalamus, however the triggers and disease mechanisms are poorly understood. Vaccine-attributable risk of narcolepsy reported so far with the AS03 adjuvanted H1N1 vaccination Pandemrix has been manifold compared to the AS03 adjuvanted Arepanrix, which contained differently produced H1N1 viral antigen preparation. Hence, antigenic differences and antibody response to these vaccines were investigated. Methods and Findings Increased circulating IgG-antibody levels to Pandemrix H1N1 antigen were found in 47 children with Pandemrix-associated narcolepsy when compared to 57 healthy children vaccinated with Pandemrix. H1N1 antigen of Arepanrix inhibited poorly these antibodies indicating antigenic difference between Arepanrix and Pandemrix. High-resolution gel electrophoresis quantitation and mass spectrometry identification analyses revealed higher amounts of structurally altered viral nucleoprotein (NP) in Pandemrix. Increased antibody levels to hemagglutinin (HA) and NP, particularly to detergent treated NP, was seen in narcolepsy. Higher levels of antibodies to NP were found in children with DQB1*06∶02 risk allele and in DQB1*06∶02 transgenic mice immunized with Pandemrix when compared to controls. Conclusions This work identified 1) higher amounts of structurally altered viral NP in Pandemrix than in Arepanrix, 2) detergent-induced antigenic changes of viral NP, that are recognized by antibodies from children with narcolepsy, and 3) increased antibody response to NP in association of DQB1*06∶02 risk allele of narcolepsy. These findings provide a link between Pandemrix and narcolepsy. Although detailed mechanisms of Pandemrix in narcolepsy remain elusive, our results move the focus from adjuvant(s) onto the H1N1 viral proteins.

Cost-effective HLA typing with tagging SNPs predicts celiac disease risk haplotypes in the Finnish, Hungarian, and Italian populations.

Human leukocyte antigen (HLA) genes, located on chromosome 6p21.3, have a crucial role in susceptibility to various autoimmune and inflammatory diseases, such as celiac disease and type 1 diabetes. Certain HLA heterodimers, namely DQ2 (encoded by the DQA1*05 and DQB1*02 alleles) and DQ8 (DQA1*03 and DQB1*0302), are necessary for the development of celiac disease. Traditional genotyping of HLA genes is laborious, time-consuming, and expensive. A novel HLA-genotyping method, using six HLA-tagging single-nucleotide polymorphisms (SNPs) and suitable for high-throughput approaches, was described recently. Our aim was to validate this method in the Finnish, Hungarian, and Italian populations. The six previously reported HLA-tagging SNPs were genotyped in patients with celiac disease and in healthy individuals from Finland, Hungary, and two distinct regions of Italy. The potential of this method was evaluated in analyzing how well the tag SNP results correlate with the HLA genotypes previously determined using traditional HLA-typing methods. Using the tagging SNP method, it is possible to determine the celiac disease risk haplotypes accurately in Finnish, Hungarian, and Italian populations, with specificity and sensitivity ranging from 95% to 100%. In addition, it predicts homozygosity and heterozygosity for a risk haplotype, allowing studies on genotypic risk effects. The method is transferable between populations and therefore suited for large-scale research studies and screening of celiac disease among high-risk individuals or at the population level.

Utility of the New Espghan Criteria for the Diagnosis of Celiac Disease in At-risk Groups

Objective: Demonstration of small-bowel mucosal damage has been the basis of celiac disease diagnosis, but the diagnostic approach is undergoing changes. The European Society for Pediatric Gastroenterology, Hepatology, and Nutrition recently stated that in a subgroup of children, high positive transglutaminase 2 antibody (TG2ab) values may be sufficient for the diagnosis. The utility of these new criteria was evaluated by applying the human red blood cell TG2 antibody test (RBC-TG2ab) to a large cohort of children and adults belonging to at-risk groups. Methods: RBC-TG2ab and endomysial antibodies (EmA) were measured in 3031 family members or other relatives of patients with celiac disease. The RBC-TG2ab values were classified as weak (20–29 U), moderate (30–99 U), and strong (≥100 U) positive. Seropositive subjects were further tested by human recombinant TG2ab (Hr-TG2ab) and for the presence of celiac disease–associated human leukocyte antigen-DQ alleles. Gastroscopy was recommended for all with positive RBC-TG2ab, EmA, or Hr-TG2ab, or weak positive RBC-TG2ab and symptoms. Results: Strong positive RBC-TG2ab has good correlation with EmA and Hr-TG2ab and positivity of DQ2/8, and the diagnosis was established in 94% of both children and adults. In contrast, moderately positive (≥30 U) RBC-TG2ab showed poor correlation with the other tests, and celiac disease was diagnosed in 69% of children and 86% of adults. Most participants with weak positive RBC-TG2ab were negative for EmA and Hr-TG2ab. Conclusions: In accordance with the new European Society for Pediatric Gastroenterology, Hepatology, and Nutrition criteria, strong positive RBC-TG2ab showed good accuracy and excellent correlation with the other antibodies and celiac-type human leukocyte antigen. In contrast, low or moderately positive RBC-TG2ab values were of unsatisfactory prognostic value for a subsequent diagnosis.

Degree of Damage to the Small Bowel and Serum Antibody Titers Correlate With Clinical Presentation of Patients With Celiac Disease

BACKGROUND & AIMS In patients with celiac disease, gluten-induced lesions of the small-bowel mucosa develop gradually. However, it is not clear whether clinical presentation correlates with the degree of mucosal damage based on histology analysis. We investigated whether the degree of mucosal damage to the small bowel correlates with clinical presentation and serum markers of celiac disease. METHODS We collected results from serology tests and mucosal biopsy samples from 638 consecutive patients with celiac disease and compared them with reported gastrointestinal symptoms, health-related quality-of-life scores, results from laboratory tests, and bone mineral densities of patients. We assessed mucosal injury based on the ratio of villous height to crypt depth, numbers of intraepithelial CD3(+) cells, and semiquantitative Marsh classification criteria. Correlations were established based on the Pearson or Spearman coefficients. RESULTS The ratio of the villous height to crypt depth correlated with the severity of gastrointestinal symptoms, quality-of-life scores, laboratory test results, numbers of intraepithelial CD3(+) cells, and serum levels of antibodies associated with celiac disease. There was no correlation between the ratio of villous height to crypt depth and bone mineral density. The number of intraepithelial CD3(+) cells was not associated with symptoms, whereas the Marsh classification and serum levels of antibodies associated with celiac disease correlated with gastrointestinal symptoms, laboratory test results, and numbers of intraepithelial CD3(+) cells. CONCLUSIONS The ratio of small-bowel villous height to crypt depth and results from serology tests correlate with reported symptoms and quality of life of patients with celiac disease. Patient-reported outcomes are therefore of value, in addition to histology findings, in assessing patients with celiac disease.