Search

We undertook a meta-analysis of six Crohn's disease genome-wide association studies (GWAS) comprising 6,333 affected individuals (cases) and 15,056 controls and followed up the top association signals in 15,694 cases, 14,026 controls and 414 parent-offspring trios. We identified 30 new susceptibility loci meeting genome-wide significance (P < 5 × 10⁻⁸). A series of in silico analyses highlighted particular genes within these loci and, together with manual curation, implicated functionally interesting candidate genes including SMAD3, ERAP2, IL10, IL2RA, TYK2, FUT2, DNMT3A, DENND1B, BACH2 and TAGAP. Combined with previously confirmed loci, these results identify 71 distinct loci with genome-wide significant evidence for association with Crohn's disease.

The gut-associated lymphoid tissue (GALT) consists of isolated or aggregated lymphoid follicles forming Peyer's patches (PPs). By their ability to transport luminal antigens and bacteria, PPs can be considered as the immune sensors of the intestine. PPs functions like induction of immune tolerance or defense against pathogens result from the complex interplay between immune cells located in the lymphoid follicles and the follicle-associated epithelium. This crosstalk seems to be regulated by pathogen recognition receptors, especially Nod2. Although TLR exerts a limited role in PP homeotasis, Nod2 regulates the number, size, and T-cell composition of PPs, in response to the gut flora. In turn, CD4(+) T-cells present in the PP are able to modulate the paracellular and transcellular permeabilities. Two human disorders, Crohn's disease and graft-versus-host disease are thought to be driven by an abnormal response toward the commensal flora. They have been associated with NOD2 mutations and PP dysfunction.

Background: Rodents are recognized as hosts for at least 60 zoonotic diseases and may represent a serious threat for human health. In the context of global environmental changes and increasing mobility of humans and animals, contacts between pathogens and potential animal hosts and vectors are modified, amplifying the risk of disease emergence. An accurate identification of each rodent at a specific level is needed in order to understand their implications in the transmission of diseases. Among the Muridae, the Rattini tribe encompasses 167 species inhabiting South East Asia, a hotspot of both biodiversity and emerging and re-emerging diseases. The region faces growing economical development that affects habitats, biodiversity and health. Rat species have been demonstrated as significant hosts of pathogens but are still difficult to recognize at a specific level using morphological criteria. DNA-barcoding methods appear as accurate tools for rat species identification but their use is hampered by the need of reliable identification of reference specimens. In this study, we explore and highlight the limits of the current taxonomy of the Rattini tribe., Results: We used the DNA sequence information itself as the primary information source to establish group membership and estimate putative species boundaries. We sequenced two mitochondrial and one nuclear genes from 122 rat samples to perform phylogenetic reconstructions. The method of Pons and colleagues (2006) that determines, with no prior expectations, the locations of ancestral nodes defining putative species was then applied to our dataset. To give an appropriate name to each cluster recognized as a putative species, we reviewed information from the literature and obtained sequences from a museum holotype specimen following the ancient DNA criteria., Conclusions: Using a recently developed methodology, this study succeeds in refining the taxonomy of one of the most difficult groups of mammals. Most of the species expected within the area were retrieved but new putative species limits were also indicated, in particular within Berylmys and Rattus genera, where future taxonomic studies should be directed. Our study lays the foundations to better investigate rodent-born diseases in South East Asia and illustrates the relevance of evolutionary studies for health and medical sciences.

Background: Total esophagogastric dissociation (TED) was first described in 1997 by Bianchi as a new surgical procedure to treat severe gastroesophageal reflux disease (GERD) in children with neurological impairment. Recently, TED has been proposed in other conditions, such as esophageal atresia, esotracheal cleft, or caustic esophageal lesions. Although the long-term results in terms of GERD control have been previously reported, those regarding the nutritional and metabolic status have never been documented., Patients and Methods: All patients without neurological impairment with TED between 1999 and 2004 at Robert Debre Hospital and Jeanne de Flandre Hospital, France, were prospectively investigated, paying particular attention to their metabolic and nutritional status (blood concentration of iron and vitamins A, D, E, and B12; lipid malabsorption; and hyperglycemia test) and growth., Results: Seventeen children underwent TED. Six received primary procedures, whereas 11 were operated on because of severe respiratory diseases or failure to thrive. The mean follow-up was 6 years (range 3-8 years). Two children died (12%). Seven children were weaned from enteral nutrition support, but 5 of them had failure to thrive, steatorrhea, and/or malabsorption of vitamin B12 and/or fat-soluble vitamins. Eight patients had dumping syndrome, which was symptomatic in 6 cases., Conclusions: TED is an effective procedure for treatment of GERD. However, nutritional and metabolic complications including dumping syndrome and chronic digestive malabsorption are frequent after TED, especially after enteral nutrition weaning. A long-term follow-up of these patients is thus necessary and prolonged enteral nutrition support is recommended.

Aim: The treatment of achalasia consists of reducing distal esophageal obstruction by either Heller myotomy surgery or endoscopic pneumatic dilatation. The aim of the present study was to evaluate the short- and middle-term results of these procedures in children., Methodology: For technical reasons, children under six years old (n=8) were treated by surgery only, whereas patients over six years old (n=14) were treated by either Heller myotomy or pneumatic dilatation., Results: Of the children aged under six years, 75% were symptom-free at six months and 83% at 24 months of follow-up. Of the patients aged over six years, complete remission was achieved by Heller myotomy in 44.5% vs. 55.5% by pneumatic dilatation after six months, and in 40% vs. 65%, respectively, after 24 months. Both pneumatic dilatation and Heller myotomy showed significant rates of failure., Conclusion: These results suggest that pneumatic dilatation may be considered a primary treatment in children over six years old. Also, where necessary, Heller myotomy and pneumatic dilatation may be used as complementary treatments.

This work reports for the first time the presence of two Pneumocystis species in wild Rattus norvegicus specimens from Thailand. Pneumocystis DNA was detected in 57.7% (15/26) wild rats without apparent association with typical pneumocystosis. Pneumocystis carinii was found alone in five rats (19.2%), Pneumocystis wakefieldiae was detected alone in six rats (23.1%), and two rats were infected by both species (7.7%). In addition, a new P. wakefieldiae variant sequence has been identified in three wild R. norvegicus specimens caught in the same geographical area. The high frequency of Pneumocystis in wild rats documented in this study and the apparent scarcity of severe pneumocystosis were consistent with an efficient circulation of rat Pneumocystis species in ecosystems.

Objective: The SAPHO syndrome (synovitis, acne, pustulosis, hyperostosis, and osteitis) is a rare disorder that mainly affects bone and skin. Chronic multifocal osteitis is the main diagnostic feature. Genetic studies of HLA genes have shown no role for these class II antigens, whereas studies of 2 mouse models (cmo and Lupo) point to a role of the PSTPIP2 gene. We analyzed the PSTPIP2 gene in patients with SAPHO syndrome., Methods: In a cohort of 38 patients with SAPHO we analyzed PSTPIP2 and 2 other candidate genes, NOD2/CARD15 (Crohn's disease occurs in about 10% of SAPHO patients), and LPIN2 (clinical similarities of SAPHO with Majeed syndrome)., Results: Rare variants of the 3 genes observed in patients with SAPHO were not specific or were not found more frequently compared to controls, suggesting no major pathogenetic role of these genes in the SAPHO syndrome., Conclusion: We found no association between PSTPIP2, NOD2, and LPIN2 variants and the SAPHO syndrome.

Nucleotide oligomerisation domain 2 (NOD2) mutations are associated with susceptibility to Crohn's disease and graft-versus-host disease, two human disorders related with dysfunctions of Peyer's patches (PPs). In Nod2(-/-) mice transcellular permeability and bacterial translocation are increased in PPs. In this study, we show that both anti-CD4(+) and anti-interferon gamma (anti-IFNgamma) monoclonal antibodies abrogate this phenotype and reduce the expression of tumour necrosis factor (TNF) receptor 2 and the long isoform of myosin light chain kinase, thus demonstrating that immune T cells influence the epithelial functions. In turn, intraperitoneal injection of ML-7 (a myosin light chain kinase inhibitor) normalises the values of CD4(+) T cells, IFNgamma and TNFalpha. This reciprocal cross-talk is under the control of the gut microflora as shown by the normalisation of all parameters after antibiotic treatment. Toll-like receptor 2 (TLR2) and TLR4 expression were increased in Nod2(-/-) mice under basal conditions and TLR2 and TLR4 agonists induced an increased transcellular permeability in Nod2(+/+) mice. Muramyldipeptide (a Nod2 agonist) or ML-7 was able to reverse this phenomenon. It thus appears that Nod2 modulates the cross-talk between CD4(+) T cells and the epithelium recovering PP and that it downregulates the pro-inflammatory effect driven by the ileal microflora, likely by inhibiting the TLR pathways.

The inflammatory bowel diseases (IBD) Crohn's disease and ulcerative colitis are common causes of morbidity in children and young adults in the western world. Here we report the results of a genome-wide association study in early-onset IBD involving 3,426 affected individuals and 11,963 genetically matched controls recruited through international collaborations in Europe and North America, thereby extending the results from a previous study of 1,011 individuals with early-onset IBD. We have identified five new regions associated with early-onset IBD susceptibility, including 16p11 near the cytokine gene IL27 (rs8049439, P = 2.41 x 10(-9)), 22q12 (rs2412973, P = 1.55 x 10(-9)), 10q22 (rs1250550, P = 5.63 x 10(-9)), 2q37 (rs4676410, P = 3.64 x 10(-8)) and 19q13.11 (rs10500264, P = 4.26 x 10(-10)). Our scan also detected associations at 23 of 32 loci previously implicated in adult-onset Crohn's disease and at 8 of 17 loci implicated in adult-onset ulcerative colitis, highlighting the close pathogenetic relationship between early- and adult-onset IBD.

Staphylococcus aureus is a major cause of community-acquired and nosocomial infections including the life-threatening conditions endocarditis, necrotizing pneumonia, necrotizing fasciitis, and septicemia. Toll-like receptor (TLR)-2, a membrane-bound microbial sensor, detects staphylococcal components, but macrophages lacking TLR2 or both TLR2 and TLR4 remain S. aureus responsive, suggesting that an alternative microbial recognition receptor might be involved. The cytoplasmic sensor nucleotide-binding oligomerization domain containing (NOD) 2/caspase recruitment domain (CARD) 15 detects muramyl dipeptide from bacterial peptidoglycans and mediates cytokine responses to S. aureus in vitro, but the physiological significance of these observations is not well defined. Here we show that NOD2-deficient mice exhibit a delayed but ultimately exacerbated ulcerative response and impaired bacterial clearance after s.c. infection with S. aureus. NOD2-dependent recognition of S. aureus and muramyl dipeptide is facilitated by alpha-toxin (alpha-hemolysin), a pore-forming toxin and virulence factor of the pathogen. The action of NOD2 is dependent on IL-1beta-amplified production of IL-6, which promotes rapid bacterial killing by neutrophils. These results significantly broaden the physiological importance of NOD2 in innate immunity from the recognition of bacteria that primarily enter the cytoplasm to the detection of bacteria that typically reside extracellularly and demonstrate that this microbial sensor contributes to the discrimination between commensal bacteria and bacterial pathogens that elaborate pore-forming toxins.

The genetic component of Inflammatory Bowel Diseases is among the best known for complex genetic disorders. If the functional candidate gene approach was rarely fruitful in the past, genome-wide scans allowed finding several susceptibility genes for Crohn disease including NOD2, IL23R, ATG16L1, IRGM, TNFSF15, a region close to PTGER4, PTPN2, PTPN22, NKX2-3 and many others. Only one gene, ECM1, has been reported for ulcerative colitis alone. We now need to further explore these new genes before to understand their biological role. However they clearly demonstrate the importance of innate immunity and autophagy for Crohn's disease and of the TH-17 differentiation for ulcerative colitis, Crohn's disease and other inflammatory disorders., (Copyright 2009 Elsevier Masson SAS. All rights reserved.)

The acute phase of Crohn's disease (CD) is characterized by a large afflux of polymorphonuclear leukocytes (PMNL) into the mucosa and by the release of TNF-alpha. Conversion of inactive TNF-alpha into an active form requires the cleavage of a transmembrane TNF-alpha precursor by the TNF-alpha-converting enzyme (ADAM17), a protease mainly regulated by the tissue inhibitor of metalloproteinase 3 (TIMP3). The aim of the present study was to investigate in an in vitro model of PMNL transepithelial migration and in the intestinal mucosa of patients with CD the expression and regulation of ADAM17 and TIMP3 in intestinal epithelial cells (IEC). ADAM17 and TIMP3 expression was analyzed by Western blotting, RT-PCR, confocal microscopy, and immunohistochemistry by using the T84 model and digestive biopsies. ADAM17 expression in IEC was increased at a posttranscriptional level during the early phase (from 2 to 4 h) of PMNL transepithelial migration whereas TIMP3 was only increased 24 h later. TNF-alpha induced an early upregulation of ADAM17 in T84 cells, whereas PMNL adhesion, H(2)O(2), or epithelial tight junction opening alone did not affect the amount of ADAM17. Immunohistochemistry of intestinal biopsies revealed that strong expression of ADAM17 was associated with a high activity of CD. In contrast, TIMP3 was very poorly expressed in these biopsies. ADAM17 and TIMP3 profiling did not correlated with the NOD2/CARD15 status. The ADAM17 activity was higher both in the early phase of PMNL transepithelial migration and in active CD. These results showed early posttranscriptional upregulation of ADAM17 in IEC linked to PMNL transepithelial migration and a high activity of CD.

Context: Early prophylactic thyroidectomy in patients with multiple endocrine neoplasia (MEN) type 2 offers the best chance for a normal life expectancy., Objective: To analyze the results of thyroidectomy performed during the first year of life in six patients with MEN 2A (codon 634) or MEN 2B (codon 918) syndrome., Design and Setting: A university hospital-based prospective study from 2001 to 2008., Subjects and Methods: Six family members affected either by MEN 2A (n=3) or MEN 2B (n=3) syndrome were identified through neonatal genetic screening., Results: Total thyroidectomy was performed at a median age of 0.8 year in the six patients, with central lymph node dissection in five. Bilateral millimetric medullary thyroid carcinoma (MTC) was found in all patients, with a unilateral lymph node micrometastasis in two of the three MEN 2B patients. Before thyroidectomy, MEN 2B patients had much higher basal serum calcitonin levels than those with MEN 2A and controls. After thyroidectomy, with a median follow-up of 3.3 years, the six patients had no evidence of persistent MTC., Conclusion: Bilateral millimetric MTC may be present during the first year of life in these patients, with lymph node metastases also occurring in MEN 2B patients. These results support a total thyroidectomy at the age of about one year in MEN 2A (codon 634) children with an abnormal serum calcitonin level, and a total thyroidectomy with central neck dissection within the first weeks of life in MEN 2B patients.

Duodenal duplication is a rare congenital disorder of the gastrointestinal tract. The presentation is highly variable. We report a case of duodenal duplication presenting with hemorrhagic ascites in a 3-month-old girl. The diagnosis of duodenal duplication can be made preoperatively by resonance magnetic imaging. Surgical resection of the duplication was performed. Microscopic examination of the specimen confirmed the duodenal duplication. To our knowledge, this is the 1st reported case of hemorrhagic ascites caused by duodenal duplication and demonstrated by resonance magnetic imaging.

Objectives: Inflammatory bowel disease (IBD), e.g., Crohn's disease (CD) and ulcerative colitis (UC), is a complex genetic disorder. Tumor necrosis factor (ligand) superfamily, member 15 (TNFSF15) has been previously identified as a susceptibility gene for CD in Japanese and UK cohorts. This replication study was designed in order to confirm and further validate the role of TNFSF15 in IBD., Methods: A total of 666 IBD families (corresponding to 2,982 relatives) with European ancestry were genotyped for the rs6478108 and rs7869487 polymorphisms, which define the main TNFSF15 haplotypes previously associated with CD. An association between the main haplotypes and CD, UC and IBD was tested using the Genehunter TDT and Unphased statistics. Caspase recruitment domain 15 (CARD15)/TNFSF15 interaction and genotype/phenotype correlations were also studied., Results: The previously reported "high-risk" haplotype (A) was associated with IBD (P=0.001) (OR=1.25 (1.05-1.50)) and CD (P=0.02) (OR=1.31 (1.03-1.67)) whereas the "protective" (B) haplotype was significantly less transmitted to IBD and CD patients. No interaction between CARD15 and TNFSF15 was detected. We also failed to define a clinical subgroup of CD patients specifically associated with TNFSF15 haplotype A., Conclusions: This study confirms that TNFSF15 or a closely linked gene is involved in the genetic predisposition to CD.

Background: Environmental risk factors playing a causative role in Crohn's Disease (CD) remain largely unknown. Recently, it has been suggested that refrigerated food could be involved in disease development. We thus conducted a pilot case control study to explore the association of CD with the exposure to domestic refrigeration in childhood., Methodology/principal Findings: Using a standard questionnaire we interviewed 199 CD cases and 207 age-matched patients with irritable bowel syndrome (IBS) as controls. Cases and controls were followed by the same gastroenterologists of tertiary referral clinics in Tehran, Iran. The questionnaire focused on the date of the first acquisition of home refrigerator and freezer. Data were analysed by a multivariate logistic model. The current age was in average 34 years in CD cases and the percentage of females in the case and control groups were respectively 48.3% and 63.7%. Patients were exposed earlier than controls to the refrigerator (X2 = 9.9, df = 3, P = 0.04) and refrigerator exposure at birth was found to be a risk factor for CD (OR = 2.08 (95% CI: 1.01-4.29), P = 0.05). Comparable results were obtained looking for the exposure to freezer at home. Finally, among the other recorded items reflecting the hygiene and comfort at home, we also found personal television, car and washing machine associated with CD., Conclusion: This study supports the opinion that CD is associated with exposure to domestic refrigeration, among other household factors, during childhood.

Unlabelled: Intestinal transplantation (IT) is the newest and most difficult of organ transplantations. The first ever (1987) and the longest surviving (1989) IT were performed in our institution. However, IT still has to demonstrate its benefit to children on long-term parenteral nutrition (PN). We tried to clarify this aspect by looking back at our 13 years' experience., Patients: From 1994 to December 2007, 74 IT were performed in 69 children, 39 with an isolated small bowel (IT), 35 combined with a liver transplant (LITx). The indications were: short bowel syndrome (n = 25), congenital mucosal diseases (n = 22), and motility disorders (n = 22). Median age at transplantation was 5 years (1 - 17 years). Follow-up was 1 to 12 years (median 5 years)., Results: Thirty-one children have a functioning graft (42 %), 15/39 IT, 16/35 LITx. They are at home without PN, with a good quality of life. One child is PN-dependent 1.5 years post IT. Post IT, 16 children were detransplanted: 12 early on (1 for mechanical complications, 11 because of resistant rejection; 3 less than 3 years, one 9 years post SBT (chronic rejection). In 2 noncompliant teenagers, PN was reintroduced (one was detransplanted later on). Several years post LITx, 2 children underwent bowel detransplantation due to an acute viral infection complicated with rejection. Twenty-two children died (32 %, 8 IT, 14 LITx), 18 early on from infectious or surgical complications, 4 more than 1 year post IT, 3 after retransplantation (1 in another unit). Bad prognostic factors are multiple previous surgeries, an older age (> 7 y), and chronic intestinal pseudo-obstruction., Discussion: Complications post IT are frequent and life-threatening, especially early on: rejection (IT), infections (LITx). Later on, the rate of complications decreases but remains significant, especially in noncompliant patients. However we describe here a 13-year learning curve; the recent results are encouraging with regard to control of rejection and viral infections., Conclusion: Intestinal transplantation is indicated only in selected patients in whom long-term PN cannot be performed safely any more. In every child with intestinal insufficiency, the therapeutic strategy must be discussed early on in order to perform IT at the right time under optimal conditions. IT should evolve from being a "rescue" procedure to becoming a true therapeutic option.

Hantaviruses belong to the Bunyaviridae family. While usually hosted by wild mammals, they are potentially pathogenic for humans, and several serologically distinct groups associated with different syndromes have been identified. Yet, investigations have mostly been conducted where human infections by hantaviruses constitute a real and well-identified public health problem, i.e., the holarctic and neotropical areas. Some hantaviruses have also been described from a Suncus murinus in India and a Bandicota indica in Thailand. In addition, recent investigations in Cambodia revealed new Hantavirus types. More recently, two new Hantavirus species were described: Sangassou from a Hylomyscus simus, and Tanganya from a Crocidura theresae, both from Africa (Guinea), thus strongly questioning the current views about geographic range, evolution, and epidemiology of hantaviruses. In such a framework, we have conducted a survey of Hantavirus diversity in Southeast Asia which allows us to isolate the Thailand virus and address questions about the taxonomy of their rodent hosts. Here we present a molecular analysis of representatives of all currently known Hantavirus species, thus allowing the comparison between the newly described ones with a large range sample of rodent hantaviruses. Our results clearly point to the presence of a particular lineage of hantaviruses in Southeast Asia. It also strongly suggests that new viruses, additional mammalian hosts and different related syndromes in humans are likely to be discovered in the near future, particularly in Southeast Asia and in Africa, where Muridae rodents are highly diversified. Furthermore, additional work is also urgently needed to investigate the hantaviruses associated with Crociduridae and Soricidae.

Several risk factors for Crohn's disease have been identified in recent genome-wide association studies. To advance gene discovery further, we combined data from three studies on Crohn's disease (a total of 3,230 cases and 4,829 controls) and carried out replication in 3,664 independent cases with a mixture of population-based and family-based controls. The results strongly confirm 11 previously reported loci and provide genome-wide significant evidence for 21 additional loci, including the regions containing STAT3, JAK2, ICOSLG, CDKAL1 and ITLN1. The expanded molecular understanding of the basis of this disease offers promise for informed therapeutic development.

Nucleotide oligomerisation domain 2 (NOD2) is a component of the innate immunity known to be involved in the homeostasis of Peyer patches (PPs) in mice. However, little is known about its role during gut infection in vivo. Yersinia pseudotuberculosis is an enteropathogen causing gastroenteritis, adenolymphitis and septicaemia which is able to invade its host through PPs. We investigated the role of Nod2 during Y. pseudotuberculosis infection. Death was delayed in Nod2 deleted and Crohn's disease associated Nod2 mutated mice orogastrically inoculated with Y. pseudotuberculosis. In PPs, the local immune response was characterized by a higher KC level and a more intense infiltration by neutrophils and macrophages. The apoptotic and bacterial cell counts were decreased. Finally, Nod2 deleted mice had a lower systemic bacterial dissemination and less damage of the haematopoeitic organs. This resistance phenotype was lost in case of intraperitoneal infection. We concluded that Nod2 contributes to the susceptibility to Y. pseudotuberculosis in mice.

Herpetosoma is a homogenous subgenus of several dozen named species that are often described as morphologically indistinguishable T. lewisi-like parasites. These trypanosomes normally infect rodents and utilize fleas as vectors. Although this trypanosome subgenus is considered non-pathogenic to normal hosts, some of them are on rare occasion reported in association with human disease. Recently, a T. lewisi-like infection was detected in a sick Thai infant, thus the objective of this study was to investigate the prevalence of T. lewisi infections among different rodents indigenous to Thailand in order to identify possible sources of human cases. Blood was collected from a total of 276 rodents trapped from urban and rural areas of three Thai provinces between 2006 and 2007. These samples were processed for DNA isolation and tested with a PCR assay universal for the genus Trypanosoma, followed by internal transcribed spacer 1 (ITS-1) sequence analysis to identify infections in positive samples. Herpetosoma known as T. lewisi-like trypanosomes were present among Rattus (14.3%) and Bandicota (18.0%) rodent species and salivarian trypanosomes closely related to T. evansi were detected in Leopoldamys (20%) and Rattus (2.0%) species. Herpetosoma were prevalent among rodents associated with both human and sylvatic habitats, while three of the four salivaria-positive rodents were from a forest biotope. A Herpetosoma ITS-1 sequence amplified from one of these samples was 97.9% identical to that reported for T. lewisi in an experimentally infected rat and 96.4% identical to the sequence amplified from blood from a Thai infant. Habitats where rodents were collected significantly affect rodent infection, at least for T. lewisi, suggesting that the degree of anthropization may influence the transmission of Trypanosoma spp. These results suggest that multiple Herpetosoma species or strains are enzootic to Thailand, and that Rattus and Bandicota species are possible sources of human exposure to these parasites.

Background & Aims: Celiac disease may be associated with autoimmune diseases. The aims of the present study were to determine in celiac patients which factors modulate the risk of autoimmune disease and to evaluate the effect of the gluten-free diet., Methods: The occurrence of autoimmune disease and compliance to gluten-free diet were specified retrospectively in 924 celiac patients recruited from 27 French pediatric and adult gastroenterology centers., Results: One or several autoimmune diseases had developed in 178 patients. The cumulative risk of autoimmune disease was 8.1% +/- 1% at age 15, and 15.7% +/- 1.5% at age 30. Factors associated with an increased risk were family history of autoimmunity (hazard ratio, 2.36; 95% confidence interval, 1.71-3.31) and diagnosis of celiac disease before 36 years of age (hazard ratio, 2.65; 95% confidence interval, 1.79-3.85). After diagnosis of celiac disease, 55 of 788 patients developed an autoimmune disease. The cumulative risk of subsequent autoimmune disease was lower in patients compliant to a gluten-free diet versus noncompliant patients (at 10 years, 6% +/- 2% vs 15.6% +/- 5.9%, respectively; P = .02). The incidence of autoimmune diseases was 5.4 per 1000 patient-years during adherence to a gluten-free diet versus 11.3 per 1000 patient-years during nonadherence to the diet (P = .002). Results were similar in both the pediatric and the adult populations., Conclusions: Celiac patients most at risk for autoimmune disease are those diagnosed early in life and having a family history of autoimmunity. The gluten-free diet has a protective effect.

Objective: Small bowel (SB) transplantation (Tx), long considered a rescue therapy for patients with intestinal failure, is now a well recognised alternative treatment strategy to parental nutrition (PN). In this retrospective study, we analysed graft functions in 31 children after SBTx with a follow-up of 2-18 years (median 7 years)., Patients: Twelve children had isolated SBTx, 19 had combined liver-SBTx and 17 received an additional colon graft. Growth, nutritional markers, stool balance studies, endoscopy and graft histology were recorded every 2-3 years post-Tx., Results: All children were weaned from PN after Tx and 26 children remained PN-free. Enteral nutrition was required for 14/31 (45%) patients at 2 years post-Tx. All children had high dietary energy intakes. The degree of steatorrhoea was fairly constant, with fat and energy absorption rates of 84-89%. Growth parameters revealed at transplantation a mean height Z-score of -1.17. After Tx, two-thirds of children had normal growth, whereas in one-third, Z-scores remained lower than -2, concomitant to a delayed puberty. Adult height was normal in 5/6. Endoscopy and histology analyses were normal in asymptomatic patients. Chronic rejection occurred only in non-compliant patients. Five intestinal grafts were removed 2.5-8 years post-Tx for acute or chronic rejection., Conclusions: This series indicates that long-term intestinal autonomy for up to 18 years is possible in the majority of patients after SBTx. Subnormal energy absorption and moderate steatorrhoea were often compensated for by hyperphagia, allowing normal growth and attainment of adult height. Long-term compliance is an important pre-requisite for long-term graft function.

The recent discovery of bacterial receptors such as NOD2 that contribute to crosstalk between innate and adaptive immune systems in the digestive tract constitutes an important challenge in our understanding of liver injury mechanisms. The present study focuses on NOD2 functions during liver injury. NOD2, TNF-alpha and IFN-gamma mRNA were quantified using real-time PCR in liver samples from patients and mice with liver injury. We evaluated the susceptibility of concanavalin A (ConA) challenge in NOD2-deficient mice (Nod2-/-) compared to wild-type littermates. We tested the effect of muramyl dipeptide (MDP), the specific activator of NOD2, on ConA-induced liver injury in C57BL/6 mice. We studied the cellular distribution and the role of NOD2 in immune cells and hepatocytes. We demonstrated that NOD2, TNF-alpha and IFN-gamma were upregulated during liver injury in mice and humans. Nod2-/- mice were resistant to ConA-induced hepatitis compared to their wild-type littermates, through reduced IFN-gamma production by immune cells. Conversely, administration of MDP exacerbated ConA-induced liver injury. MDP was a strong inducer of IFN-gamma in freshly isolated human PBMC, splenocytes and hepatocytes. Our study supports the hypothesis that NOD2 contributes to liver injury via a regulatory mechanism affecting immune cells infiltrating the liver and hepatocytes. Taken together, our results indicate that NOD2 may represent a new therapeutic target in liver diseases.

Inflammatory bowel diseases (IBDs), including Crohn disease (CD) and ulcerative colitis (UC), often affect children and adolescents. Their diagnosis is based on the integration of clinical, biological, endoscopic, histological and radiological data. The paediatric radiologist may help the clinician in many ways. In children presenting with symptoms compatible with IBD, gut exploration by US may identify those who will benefit from more invasive explorations including endoscopy. During the process of diagnosis, small bowel exploration has a crucial role in differentiating CD from UC and in classifying the disease into subphenotypes. Finally, new imaging methods are useful during patient follow-up for assessing disease activity and for the diagnosis of complications.

Acute infectious diarrhea in children remain still a frequent cause of morbidity. 50 % of them are due to rotavirus. Oral rehydration therapy and early realimentation have drastically reduced their mortality and morbidity. Beside oral or eventually IV rehydration therapy no medication has proven its efficacy based on the main HMO criteria (reduction of over 30 % of the stool output) except racecadotril and loperamide which is contre-indicated for the last one in children less than 2 years old. Other medications such as silicates or some probiotics have shown efficacy on diarrhea duration or stool consistency but not on stool output. They have so no formal indication in infectious diarrhea and should be considered as "comfort" treatment. Antibiotics, beside their indication in shigella, cholera and amibiasis could be used in invasive diarrhea in some debilating conditions or infants less than 3 months.

Molecular phylogenetic analyses of 113 taxa representing Ascaridida, Rhigonematida, Spirurida and Oxyurida were used to infer a more comprehensive phylogenetic hypothesis for representatives of 'clade III'. The posterior probability of multiple alignment sites was used to exclude or weight characters, yielding datasets that were analysed using maximum parsimony, likelihood, and Bayesian inference methods. Phylogenetic results were robust to differences among inference methods for most high-level taxonomic groups, but some clades were sensitive to treatments of characters reflecting differences in alignment ambiguity. Taxa representing Camallanoidea, Oxyurida, Physalopteroidea, Raphidascarididae, and Skrjabillanidae were monophyletic in all 9 analyses whereas Ascaridida, Ascarididae, Anisakidae, Cosmocercoidea, Habronematoidea, Heterocheilidae, Philometridae, Rhigonematida and Thelazioidea were never monophyletic. Some clades recovered in all trees such as Dracunculoidea and Spirurina included the vast majority of their sampled species, but were non-monophyletic due to the consistent behaviour of one or few 'rogue' taxa. Similarly, 102 of 103 clade III taxa were strongly supported as monophyletic, yet clade III was paraphyletic due to the grouping of Truttaedacnitis truttae with the outgroups. Mapping of host 'habitat' revealed that tissue-dwelling localization of nematode adults has evolved independently at least 3 times, and relationships among Spirurina and Camallanina often reflected tissue predilection rather than taxonomy.

Estimation of genotype-specific risks at a disease susceptibility locus is an important question that is best carried out in a prospective study. Nevertheless it is usually desirable to make use of data from the families that have already been collected to identify the susceptibility locus. Assuming that the families have been collected without regard to genotype at the locus in question, most of the information can be extracted by writing the likelihood in terms of the risk for a genotype relative to the standard genotype and conditional on the parental mating type. Parameters may then be estimated by explicit solution of likelihood equations. This method permits estimation of risks for heterozygotes and homozygotes for different alleles, testing of different modes of inheritance and heterogeneity of risk between alleles. It is applicable to risk alleles for any disease locus or incompletely penetrant phenotype. We have used the method to estimate risks of Crohn disease for different CARD/NOD2 15 mutations, using the families originally collected to identify this susceptibility locus. The odds ratio of Crohn disease were, respectively, 1.97+/-0.85, 3.05+/-* and 4.55+/-1.34 for the R702W, G9068R and 1007fs heterozygotes and 3.29+/-0.64, 12.13+/-* and 34.66+/-12.87 for the corresponding homozygotes. (* Signifies insufficient data to estimate these values.) These results confirm the dosage effect for CARD15/NOD2 mutations and demonstrate that the disease risks are very different in homozygotes. This last observation illustrates the power of this approach, especially for alleles with low or moderate frequency in the general population.

Background: CARD15/NOD2 mutations are associated with susceptibility to Crohn's Disease (CD) and Graft Versus Host Disease (GVHD). CD and GVHD are suspected to be related with the dysfunction of Peyer's patches (PP) and isolated lymphoid follicles (LFs). Using a new mouse model invalidated for Card15/Nod2 (KO), we thus analysed the impact of the gene in these lymphoid formations together with the development of experimental colitis., Methodology/principal Findings: At weeks 4, 12 and 52, the numbers of PPs and LFs were higher in KO mice while no difference was observed at birth. At weeks 4 and 12, the size and cellular composition of PPs were analysed by flow cytometry and immunohistochemistry. PPs of KO mice were larger with an increased proportion of M cells and CD4(+) T-cells. KO mice were also characterised by higher concentrations of TNFalpha, IFNgamma, IL12 and IL4 measured by ELISA. In contrast, little differences were found in the PP-free ileum and the spleen of KO mice. By using chamber experiments, we found that this PP phenotype is associated with an increased of both paracellular permeability and yeast/bacterial translocation. Finally, KO mice were more susceptible to the colitis induced by TNBS., Conclusions: Card15/Nod2 deficiency induces an abnormal development and function of the PPs characterised by an exaggerated immune response and an increased permeability. These observations provide a comprehensive link between the molecular defect and the Human CARD15/NOD2 associated disorders: CD and GVHD.

Background: Crohn's disease (CD) has been associated with CARD15/NOD2 mutations in Caucasians. The R702W, G908R, and 1007fs mutations represent 82% of the mutated chromosomes. The relative risk of developing CD in homozygous or compound heterozygous people has been estimated as between 10 and 40 times that of the general population. This high risk may support the opinion that CARD15/NOD2 variants are strong CD risk factors at the individual and population levels., Subjects and Methods: The allele and genotype frequencies were calculated for the R702W, G908R, and 1007fs mutations in 3,575 Caucasian healthy controls recruited by 15 groups distributed on three continents. Geographic homogeneity was tested and the observed proportion of double mutants was compared with the expected value using chi2 tests., Results: The allele frequencies of the R702W, G908R, and 1007fs mutations were 4.3% (3.6-4.9), 1.2% (0.8-1.6), and 2.3% (1.8-2.8), respectively, with large geographic fluctuations of the G908R, 1007fs, and wild-type alleles (P<0.0001). At the population level, no simple relationship was observed between mutation frequencies and the disease incidences in the studied populations. At the individual level, no significant deficit of double-dose mutation carriers among healthy controls was found, providing strong evidence that the penetrances of the most at-risk genotypes are low., Conclusion: Altogether, these data confirm that CARD15/NOD2 acts in interaction with other unknown risk cofactors.

Remote sensing, referring to the remote study of objects, was originally developed for Earth observation, through the use of sensors on board planes or satellites. Improvements in the use and accessibility of multi-temporal satellite-derived environmental data have, for 30 years, contributed to a growing use in epidemiology. Despite the potential of remote-sensed images and processing techniques for a better knowledge of disease dynamics, an exhaustive analysis of the bibliography shows a generalized use of pre-processed spatial data and low-cost images, resulting in a limited adaptability when addressing biological questions.

NOD2 plays an important role in the innate immunity of the intestinal tract. By sensing the muramyl dipeptide (MDP), a bacterial wall component, NOD2 triggers the NF-kappaB signaling pathway and promotes the release of proinflammatory cytokines such as interleukin-8. Mutations in Nod2 (1007FS, R702W, G908R) impinge on NOD2 functions and are associated with the pathogenesis of Crohn disease, a chronic inflammatory bowel disease. Although NOD2 is usually described as a cytosolic receptor for MDP, the protein is also localized at the plasma membrane, and the 1007FS mutation delocalizes NOD2 to the cytoplasm (Barnich, N., Aguirre, J. E., Reinecker, H. C., Xavier, R., and Podolsky, D. K. (2005) J. Cell Biol. 170, 21-26; McDonald, C., Chen, F. F., Ollendorff, V., Ogura, Y., Marchetto, S., Lecine, P., Borg, J. P., and Nunez, G. (2005) J. Biol. Chem. 280, 40301-40309). In this study, we demonstrate that membrane-bound versions of NOD2 and Crohn disease-associated mutants R702W and G908R are capable of responding to MDP and activating the NF-kappaB pathway from this location. In contrast, the 1007FS mutant remains unable to respond to MDP from the plasma membrane. We also show that NOD2 promotes the membrane recruitment of RICK, a serine-threonine kinase involved in NF-kappaB activation downstream of NOD2. Furthermore, the artificial attachment of RICK at the plasma membrane provokes a constitutive and strong activation of the NF-kappaB pathway and secretion of interleukin-8 showing that optimal RICK activity depends upon its subcellular localization. Finally, we show that endogenous RICK localizes at the plasma membrane in the THP1 cell line. Thus, our data suggest that NOD2 is responsible for the membrane recruitment of RICK to induce a regulated NF-kappaB signaling and production of proinflammatory cytokines.

The Enterobiinae includes 47 species of pinworms parasite of primates. A previous cladistic analysis of this subfamily supported its monophyly and its subdivision into three genera. Based on morphological characters, this cladistic analysis excluded characters describing the shape of the genital papillae of male pinworms, because the corresponding patterns could not be described using discrete characters. In this study, the shape of the genital papillae of the males of 35 within the 47 species is analyzed using geometric morphometric approaches. The aims of this study are to investigate: (i) the relationships between the phylogeny and the shape patterns of the caudal bursa, (ii) the shape differences between and within monophyletic groups, and (iii) the functional implications of the shape patterns observed within the subfamily. Results demonstrate that different patterns of evolution of the caudal bursa, each one characterized by a particular spatial distribution of the phasmids and genital papillae may be recognized, which are consistent with the classification of the Enterobiinae into three groups. On the whole, these patterns may be related to particular mating behavior of the pinworms. When incongruence is observed between shape patterns distribution and species distribution into monophyletic groups, they are found to correspond to homoplasic events. This suggests that convergent selective pressures are involved in the evolution of the shape of the genital papillae. This analysis also confirms that morphometric shape patterns cannot be interpreted unequivocally without the support of a pre-existing phylogenetic framework.

Listeria monocytogenes is a human intracellular pathogen that is able to survive in the gastrointestinal environment and replicate in macrophages, thus bypassing the early innate immune defenses. Peptidoglycan (PG) is an essential component of the bacterial cell wall readily exposed to the host and, thus, an important target for the innate immune system. Characterization of the PG from L. monocytogenes demonstrated deacetylation of N-acetylglucosamine residues. We identified a PG N-deacetylase gene, pgdA, in L. monocytogenes genome sequence. Inactivation of pgdA revealed the key role of this PG modification in bacterial virulence because the mutant was extremely sensitive to the bacteriolytic activity of lysozyme, and growth was severely impaired after oral and i.v. inoculations. Within macrophage vacuoles, the mutant was rapidly destroyed and induced a massive IFN-beta response in a TLR2 and Nod1-dependent manner. Together, these results reveal that PG N-deacetylation is a highly efficient mechanism used by Listeria to evade innate host defenses. The presence of deacetylase genes in other pathogenic bacteria indicates that PG N-deacetylation could be a general mechanism used by bacteria to evade the host innate immune system.

With the discovery of CARD15 as susceptibility gene for Crohn's disease (CD) a first link to a potential defect in the innate immune system was made. In this work we aimed to analyze enterocyte NOD2/CARD15 expression and regulation in response to bacterial motifs and the consequences of the most common CD-specific CARD15 mutation on antibacterial responses of normal intestinal epithelial cells (IEC). Under normal conditions, IEC lines and ileal enterocytes did not express NOD2/CARD15 mRNA or protein, contrary to IEC derived from inflammatory CD sections. In vitro analyses revealed that the simple contact with non-pathogenic commensal E. Coli K12 was sufficient to induced NOD2/CARD15 mRNA and protein in human IEC (HIEC). We identified bacterial flagellin interacting with TLR5 as major motif in this regulation of NOD2/CARD15. E. Coli mutants not expressing flagellin (DeltaFliC) failed to induce CARD15. Similarly, in HIEC transfected with a plasmid encoding dominant negative TLR5, no CARD15 induction was observed after K12 contact. Isolated TLR2 or TLR4 stimulation had no or only a marginal effect on NOD2/CARD15 expression. NOD2/CARD15 negative HIEC were unresponsive to muramyl dipeptide (MDP), but once NOD2/CARD15 was induced, HIEC and Caco2 cells responded to intra or extracellular MDP presentation with the activation of the NFkB pathway. IEC transfected with the Crohn-specific CARD15 mutant (F3020insC, FS) failed to activate NFkB after MDP-challenge, in contrast to CARD15WT IEC. In response to MDP, IEC induced a massive antibacterial peptide (ABP) response, seen in the apical release of CCL20. This was completely abolished in IEC carrying CARD15FS. These data suggest a critical role of NOD2/CARD15 in the bacterial clearance of the intestinal epithelium while CD-specific mutated NOD2/CARD15 causes an impaired epithelial barrier., (Copyright 2006 Wiley-Liss, Inc.)

Geographic information systems (GIS) and remote sensing have been increasingly used in ecology and epidemiology, providing a spatial approach for animal health issues. Recent development of earth environmental satellites--i.e., their growing number, improving sensor resolutions and capabilities--has offered new opportunities to delineate possible habitats and understand animals and associated parasites in their environment, by identifying the nature and structure of land use, hydrological network, soil hydromorphy, and human settlements. Integrated into GIS, remotely sensed and other geo-referenced data allow both spatial and temporal analyses of animal ecology and health. However, a review of their applications has showed the poor quality of data sources and processing used, revealing limitations between theory and practical implementations. As an example, the assessment of the expected distribution of Bandicoot rats, main agricultural pest and vector of zoonoses in Phrae province (North Thailand), illustrates a rational use of spatial analysis, with the choice of relevant data, scales, and processing. Vegetation indices are computed on a TERRA ASTER image and further classified using elevation data. The biotopes of Bandicota indica and Bandicota savilei are delimited, providing a major source of knowledge for rodent and human health analyses.

Hantaviruses' distribution is reassessed after performing a cladistic analysis on 93 strains isolated from rodents, and one used as outgroup: Thottapalayam isolated from a shrew. While most hantaviruses found in wild animals were collected in northern Asia, Europe, North America, and South America, only Thottapalayam and Thailand were found in South and Southeastern Asia. Thottapalayam is highly divergent from the other known hantaviruses and may represent the emerging tip of a different lineage. Serological surveys carried out to detect evidence of Hantavirus in human populations revealed positive samples not only in West and Central Africa but also in Thailand, with a first case recently confirmed. This suggests that Hantaan-related viruses may infect humans out of their well-documented range. Thus, if rodents are probably the primary reservoir, other mammals may be involved in the cycle of hantaviruses. Additional work is needed out of the traditional areas where hantaviruses have been recorded. New viruses, different hosts, and different human syndromes may be discovered in the future mainly in Southeastern Asia and in Africa where Muridae rodents are present and highly diversified.

Sixty one tissue samples from several rodent species trapped in five provinces of Thailand were examined for the presence of hantaviral markers by enzyme-immunoassay and immunoblotting. Four samples, all from the great bandicoot rat Bandicota indica, were confirmed positive for the hantaviral N-antigen. Two of them were trapped in Nakhon Pathom province, the other two in Nakhon Ratchasima province, approximately 250 km from the other trapping site. When analysed by RT-nested PCR, all four rodents were found positive for the hantaviral S- and M-segment nucleotide sequences. Genetic analysis revealed that the four newly described wild-type strains belong to Thailand hantavirus. On the phylogenetic trees they formed a well-supported cluster within the group of Murinae-associated hantaviruses and shared a recent common ancestor with Seoul virus.

Inflammatory bowel diseases (IBDs) are complex genetic disorders characterized by a complex interplay between genetic and environmental risk factors. At least ten genes or anonymous loci have been proposed to play a role in IBD. Among them, the best studied is CARD15/NOD2, a gene coding for a protein involved in bacterial recognition by cells involved in innate immunity. Despite a large amount of work, a consensus model explaining the effect of Card 15/NoD2 mutations did not emerge, and the disease mechanisms are still subject to debate.

We evaluated 131 patients (6 months-14 years) who experienced 21 deaths before listing, 11 continuing on the waiting list, 38 well on home parenteral nutrition, 6 off parenteral nutrition and 59 transplanted (20 girls) aged 2.5 to 15 years, (18 >7 years). They received cadaveric isolated intestine (ITx, n = 31) or liver-small bowel (LITx, n = 32), including right colon (n = 43; 23 LITx) for short bowel (n = 19), enteropathy (n = 20), Hirschsprung (n = 14), or pseudo-obstruction (n = 6). Treatment included tacrolimus, steroids, azathioprine, or interleukin-2 blockers. After 6 months to 10.5 years, the patient and graft survivals were 75% and 54%. Sixteen patients (10 LITx) died within 3 months from surgery (n = 3), bacterial (n = 5) or fungal (n = 6) sepsis, or posttransplant lymphoproliferative disorder (n = 2). Rejection occurred in 27 patients, including 10 steroid-resistant episodes requiring antilymphoglobulins. The grafts were removed due to uncontrolled rejection in seven ITx recipients. Surgical complications were observed in 38 recipients (25 LSBTx) within 2 months, including bacterial (n = 22) or fungal (n = 11) sepsis, cytomegalovirus disease (n=12), adenovirus (n = 11), or posttransplant lymphoproliferative disorder (n = 12). Forty-two children (19 LSBTx) are alive. Weaning from parenteral nutrition was achieved after 42 days (median). Factors related to death or graft loss were pre-Tx surgery (P < .01), pseudo-obstruction (P < .01), age over 7 years (P < .03), fungal sepsis (P < .03), steroid resistant rejection (P < .05), hospitalized versus home patient (P < .01), and retransplantation (P < .05). Colon transplant did not affect the outcome. Interleukin-2 blockers improved isolated ITx (P < .05). Early referral and close monitoring of intestinal failure and related disorders are mandatory to achieve successful ITx.

Rare cases of dysimmune phenomena after solid organ transplantation were described in the past. In the present series, we describe six children who developed severe dysimmune anemia or thrombocytopenia while treated with tacrolimus after liver or small bowel transplantation. All patients were off steroids or under low doses alternate day steroid medication when dysimmune cytopenia developed. All patients had positive anti-platelets antibodies and/or Coombs' positive anemia. Therapy was successful in all six patients with a rapid response to corticosteroids in three children, and to anti-CD20 monoclonal antibodies (rituximab) in the three others. The pathogenesis of these rare dysimmune/autoimmune disorders might be related to the interference of tacrolimus with T-cell functions and/or the endogenous control mechanisms of T-lymphocyte activation and down-regulation. Although rare, these complications must be known when discussing protocols of immunosuppression.

Background: Laparoscopic surgery in patients with Crohn's disease (CD) has been demonstrated to have advantages over a conventional approach in children. The aim of this study was to review the children treated for CD with a laparoscopic approach, to report our indications, the surgical procedure, the complications, and to compare the children with pancolitis or ileocaecal (segmental) Crohn's disease., Patients and Method: We reviewed the files of 11 children treated for CD in a single institution between 1999 and 2004 for a retrospective study of clinical and surgical data. Mann-Whitney U-test was used for statistical analysis of nonparametric data., Results: Eleven children were operated. The average age when initial clinical symptoms became apparent was 12.1 years (range 6.6 - 15), and surgery was performed after an average of 3.4 years of disease (range 1 - 7.6). The surgical indications were stenosis in 6 cases, failure to thrive in 1 case (segmental CD, SCD group) and pancolitis refractory to medical treatment in 4 cases (pancolitis group, PCD group). Mean operative time was 207 minutes (range 140 - 270) for the SCD group and 285 minutes (range 260 - 300) for the PCD group (p < 0.05). Three cases needed a conversion to open surgery (2 in PCD group, one in SCD group), mainly in relation to anastomosis performed with an EEA stapler. The average length of surgical unit stay was 6.5 days (range 4 - 8) for the PCD group and 6.4 days (range 4 - 8) for the SCD group; average follow-up was 16 months (range 3 - 38). Two patients had a relapse of CD (stenosis of the anastomosis in one, skin fistula in the other)., Conclusion: A laparoscopic approach for ileocolic resection in Crohn's disease is a feasible procedure, even in cases of pancolitis. We recommend an extra-corporeal anastomosis because, in relation to the inflammatory bowel, the mechanical anastomosis is not a safe procedure in cases of pancolitis.

Tracheal cytotoxin (TCT) was originally described as the minimal effector that was able to reproduce the cytotoxic response of Bordetella pertussis on ciliated epithelial cells. This molecule triggers pleiotropic effects such as immune stimulation or slow-wave sleep modulation. Further characterization identified TCT as a specific diaminopimelic acid (DAP)-containing muropeptide, GlcNAc-(anhydro)MurNAc-L-Ala-D-Glu-mesoDAP-D-Ala. Here, we show that the biological activity of TCT depends on Nod1, an intracellular sensor of bacterial peptidoglycan. However, Nod1-dependent detection of TCT was found to be host specific, as human Nod1 (hNod1) poorly detected TCT, whereas mouse Nod1 (mNod1) did so efficiently. More generally, hNod1 required a tripeptide (L-Ala-D-Glu-mesoDAP) for efficient sensing of peptidoglycan, whereas mNod1 detected a tetrapeptide structure (L-Ala-D-Glu-mesoDAP-D-Ala). In murine macrophages, TCT stimulated cytokine secretion and NO production through Nod1. Finally, in vivo, injection of the tetrapeptide structure in mice triggered a transient yet strong release of cytokines into the bloodstream and the maturation of macrophages, in a Nod1-dependent manner. This study thereby identifies Nod1 as the long sought after sensor of TCT in mammals.

Multiple factors are incriminated in the etiopathogeny of necrotizing enterocolitis (NEC) in premature infants, including oral feeding, vascular abnormalities, increase in pro-inflammatory cytokines, and inappropriate response of the intestinal barrier to bacterial microflora. CARD15/NOD2 is a gene recently recognized as important in the innate response to gut flora and is involved in Crohn's disease susceptibility. We thus tested its putative role in NEC. Ten children (seven boys and three girls) suffering from NEC who were admitted to Robert Debré hospital between 1999 and 2002 were retrospectively included in the study. Genetic screening of the 11 constant exons and the exon-intron junctions of CARD15/NOD2 by direct sequencing revealed no novel mutations of that gene in NEC patients. Furthermore, the three main mutations of CARD15/NOD2 (R702W, G908R, and 1007fs) associated with susceptibility to Crohn's disease were not found in these patients. Our results suggest that CARD15/NOD2 does not play a major role in genetic susceptibility to NEC.

Background: Lymphoid follicles (LFs) have been suggested to play a role at the early stage of Crohn's disease (CD) lesions. In the small bowel, LFs are grouped, forming Peyer's patches, which develop early in fetal life, grow in size and number until puberty, and undergo involution. In contrast, colonic LFs are isolated and undergo little change during life. As a result, if LFs play a role in the occurrence of CD lesions, the distribution of ileal and colonic lesions is expected to be altered in small children., Methods: Medical records of 2 independent French (n = 136) and Swedish (n = 55) cohorts of consecutive pediatric CD were reviewed. Disease sites and age of onset were recorded, and the age-dependent probability to develop ileal lesions was computed. The CARD15/NOD2 genotype was also analyzed when available (n = 99)., Results: The curves of disease occurrence were significantly different in case of CD with or without ileal lesions (P < 0.0001). At the age of 8 years, the probability (95% confidence interval) of small bowel involvement was 0.19 (0.07-0.39). It increased until 16 years of age to 0.61 (0.54-0.68). It was slightly higher in patients carrying 1 or more CARD15/NOD2 mutations [0.75 (0.55-0.89)] than in wild-type patients [0.46 (0.34-0.58)]. CARD15 mutations also influenced the age of onset of ileal disease (P < 0.02)., Conclusions: In children, ileal CD lesions are delayed compared with colonic lesions. This observation is in agreement with the previously proposed hypothesis of a pathophysiological role of Peyer's patches in ileal CD. The rarity of small bowel lesions should be a warning to be cautious when classifying chronic colitis in small children.

Background: The cladistic approach proposed by Templeton has been presented as promising for the study of the genetic factors involved in common diseases. This approach allows the joint study of multiple markers within a gene by considering haplotypes and grouping them in nested clades. The idea is to search for clades with an excess of cases as compared to the whole sample and to identify the mutations defining these clades as potential candidate disease susceptibility sites. However, the performance of this approach for the study of the genetic factors involved in complex diseases has never been studied., Results: In this paper, we propose a new method to perform such a cladistic analysis and we estimate its power through simulations. We show that under models where the susceptibility to the disease is caused by a single genetic variant, the cladistic test is neither really more powerful to detect an association nor really more efficient to localize the susceptibility site than an individual SNP testing. However, when two interacting sites are responsible for the disease, the cladistic analysis greatly improves the probability to find the two susceptibility sites. The impact of the linkage disequilibrium and of the tree characteristics on the efficiency of the cladistic analysis are also discussed. An application on a real data set concerning the CARD15 gene and Crohn disease shows that the method can successfully identify the three variant sites that are involved in the disease susceptibility., Conclusion: The use of phylogenies to group haplotypes is especially interesting to pinpoint the sites that are likely to be involved in disease susceptibility among the different markers identified within a gene.