The diagnosis and classification of undifferentiated connective tissue diseases

The term undifferentiated connective tissue disease (UCTD) refers to unclassifiable systemic autoimmune diseases which share clinical and serological manifestations with definite connective tissue diseases (CTDs) but not fulfilling any of the existing classification criteria. In this review we will go through the more recent evidence on UCTD and we will discuss in what extent the availability of new criteria for the CTDs could interfere with the “UCTD concept”. The development of criteria able to identify early phases of defined CTD, may help in the differentiation of stable UCTD form their early stages and may offer a valuable guide to the treating physician to set up appropriate follow up schedules as well as therapeutic protocols. This simplified subset of CTD could offer a model to study clinic pathological correlations as well as the role of possible environmental factors in the development of autoimmunity.     

Low frequency of cytomegalovirus infection during exacerbations of inflammatory bowel diseases

Although numerous reports have described inflammatory bowel diseases (IBDs) complicated with cytomegalovirus (CMV) infection, the virus participation as an exacerbating factor remains unclear. The aim of this study was thus to clarify the clinical significance of CMV infection complicating exacerbation and to correlate CMV detection with various characteristics in IBD patients. Sixty‐seven colonic biopsies obtained from 53 patients admitted for IBD exacerbation were retrospectively analyzed by real‐time PCR assay. The CMV genome was detected in seven (10.4%) colonic biopsies related to seven patients (three ulcerative colitis and four Crohn's diseases). Among the patients with IBD studied, patients with evidence of CMV infection were older (P = &!thinsp;0.047), were more likely male gender (relative risk [RR] 4.48; 95% confidence interval [CI] 0.94–21.36), received corticosteroids (RR 3.2; CI 0.79–13.02) or azathioprine (RR 3.17; CI 0.80–12.57) treatments, presented more extended lesions (RR for rectum‐sigmoid‐left colon 3.75 (0.0–69.37) and for pancolitis 2.45 (0.36–16.23)), and had a more severe disease (RR 3.3; CI 0.87–12.48) than those without CMV infection. Viral loads measured in the colonic mucosa of infected patient ranged from 5 to 236961 genome copies by microgram of total extracted DNA. No relationship was observed between the severity of the disease and the viral load level. Furthermore, CMV disappeared in five infected IBD patients in remission without antiviral agents. In conclusion, these results showed infrequent CMV detection in colonic biopsies of IBD patients during exacerbation leaving open the question of the relationship between CMV reactivation and the onset or the severity of IBD exacerbation. J. Med. Virol. 82:1694–1700, 2010. © 2010 Wiley‐Liss, Inc.     

Nutrigenetics,nutrigenomics and inflammatory bowel diseases

Inflammatory bowel disease includes ulcerative colitis and Crohn’s disease, which are both inflammatory disorders of the gastrointestinal tract. Both types of inflammatory bowel disease have a complex etiology, resulting from a genetically determined susceptibility interacting with environmental factors, including the diet and gut microbiota. Genome Wide Association Studies have implicated more than 160 single-nucleotide polymorphisms in disease susceptibility. Consideration of the different pathways suggested to be involved implies that specific dietary interventions are likely to be appropriate, dependent upon the nature of the genes involved. Epigenetics and the gut microbiota are also responsive to dietary interventions. Nutrigenetics may lead to personalized nutrition for disease prevention and treatment, while nutrigenomics may help to understand the nature of the disease and individual response to nutrients.     

Endothelial cell autoantibodies are a marker of disease susceptibility in inflammatory bowel disease but apparently not linked to persistent measles virus infection

Intestinal vasculitis caused by persistent measles virus infection of intestinal endothelial cells was described in Crohn's disease. Furthermore, endothelial cell autoantibodies have been demonstrated in inflammatory bowel disease (IBD). Autoantibodies against intestinal endothelial cells were visualized by indirect immunofluorescence in patients with IBD, in their healthy first-degree relatives, in patients with infectious enterocolitis, and in healthy, unrelated controls. In intestinal tissue specimens of 22 antibody-positive IBD patients a search for the measles virus genome was performed. Endothelial cell autoantibodies were significantly more frequent in patients with IBD, in both groups of first-degree relatives, and in patients with infectious enterocolitis than in the healthy controls (P = 0.0002 or less). The measles virus genome was found in none of the intestinal biopsies. Endothelial cell autoantibodies are not a genetic but rather an epigenetic (infectious) marker of disease susceptibility. The expression of these autoantibodies is unlikely to be triggered by a persistent measles virus infection.     

Proteomics and chronic inflammatory bowel diseases

Inflammatory bowel diseases (IBD) are relatively frequent in developed countries. Physiopathological events involved in the etiology of IBDs include activation of immune, mesenchymal and epithelial cells. This review gives an overview of the currently applied proteomics technologies. It describes metabolic changes and goes into the approaches using this methodology to understand the molecular mechanisms implicated in the development of the disease.     

Antineutrophil cytoplasmic antibodies, anti-Saccharomyces cerevisiae antibodies, and specific IgE to food allergens in children with inflammatory bowel diseases

Differential diagnosis between ulcerative colitis (UC) and Crohn's disease (CD) is difficult in the initial phases in pediatric patients with inflammatory bowel diseases (IBD). This study was performed to determine the significance of anti-neutrophil cytoplasmic antibodies (ANCA) and anti-Saccharomyces cerevisiae antibodies (ASCA) in IBD. ANCA were specified with regard to their antigenic specifity, significance to the diagnosis, and correlation of titer with the disease activity. The occurrence of food allergy was questioned, too. Serum samples from 44 children with UC (n = 23) or CD (n = 21) and from disease-control children (coeliac disease, n = 21) were analyzed for IgG ANCA, ANCA target antigens, IgA and IgG ASCA, and IgE to food allergens. Results show that ANCA occur more frequently in UC than in CD and disease-control (74, 24, and 10%, respectively). The presence of ANCA does not reflect disease activity. Antigenic specificity does not differ in any group. IgA-ASCA are found more often in patients with CD (76% versus 17% in UC). The testing for both ANCA and ASCA enabled clear-cut differential diagnosis between UC and CD based on the high specificity (ANCA+ ASCA- 92.5% for UC, ANCA- ASCA+ 93.2% for CD). Specific IgE to food allergens were found in 8.7, 14.3, and 23.8% of patients with UC, CD, and coeliac disease, respectively. We conclude that combined testing of ANCA and ASCA represents a valuable tool in the differential diagnosis between UC and CD in pediatric patients, minimizing invasive diagnostic procedures. Monitoring of ANCA, its specificity, and titer determination does not bring more information. Testing for specific IgE to food allergens may be considered in individual patients.     

Innate mucosal‐associated invariant T (MAIT) cells are activated in inflammatory bowel diseases

Inflammatory bowel diseases are characterized by a deregulated immune response targeting the gut bacterial flora. Mucosal‐associated invariant T (MAIT) cells are major histocompatibility complex (MHC) class Ib‐restricted innate‐like lymphocytes with anti‐bacterial functions. They display an effector/memory phenotype and are found in large numbers in the blood, mucosae and liver. They have also been implicated in inflammatory diseases such as multiple sclerosis. Therefore, we aimed to analyse the possible involvement of MAIT cells in Crohn's disease (CD) and ulcerative colitis (UC). To this end, a phenotypical and functional analysis of MAIT cells isolated from the blood of healthy subjects, CD and UC patients was undertaken. MAIT cells were also quantified in ileal biopsies of CD patients. The frequency of blood MAIT cells was specifically reduced in IBD patients compared with healthy donors, whereas it was dramatically greater in the inflamed versus healthy tissue. MAIT cells were activated as they expressed significantly more the Ki67 antigen, and this was accompanied by phenotypical changes such as increased expression of natural killer (NK)G2D and B and T lymphocyte attenuator (BTLA). Finally, in‐vitro‐activated MAIT cells from CD and UC patients secreted significantly more interleukin (IL)‐17, together with a decreased interferon (IFN)‐γ in CD but an increased IL‐22 in UC. These data show that MAIT cells are activated in IBD, which results in an increased recruitment towards the inflamed tissues, an altered phenotype and a switch in the pattern of cytokine secretion. This is the first demonstration that MAIT cells are immune players in IBD, whose precise functions in this context need to be addressed.     

SS-B/La antigen purification, and ELISA detection of anti-SS-B/La antibodies in sera from patients with inflammatory connective tissue diseases

SS-B/La antigen was purified by immunoadsorbent columns with immunoglobulin from a patient with primary Sjögren's syndrome. Monitoring of the purification was facilitated by the fused rocket-immunoelectrophoresis technique. Technical ELISA variables for the detection of serum antibodies against the SS-B/La antigen were evaluated, and a recommended procedure is described. Prospective investigation of anti-SS-B/La antibodies in 103 blood donors and 131 patients with chronic inflammatory connective tissue diseases, including 43 patients with primary Sjögren's syndrome was performed. Anti-SS-B/La antibody concentrations were above normal in 65% of the patients with primary Sjögren's syndrome (verified by the strictly objective Copenhagen criteria for keratoconjunctivitis sicca and xerostomia) and 9% of patients with other chronic connective tissue diseases. The predictive value for primary Sjögren's syndrome among patients with increased levels of the anti-SS-B/La antibodies attending a rheumatology clinic was 78%.     

Autoantibodies reactive to PEP08 are clinically related with morbidity and severity of interstitial lung disease in connective tissue diseases

Anti‐Ro52 autoantibodies (Ro52‐autoAbs) appear in the sera of connective tissue disease (CTD) patients with interstitial lung disease (ILD). Studies using patient sera have shown a correlation between the generation of Ro52‐autoAbs and the clinical morbidity and severity of CTD with ILD. In this study, we used a single B‐cell manipulating technology and obtained 12 different monoclonal Ro52‐autoAbs (mRo52‐autoAbs) from the selected four patients suffering from severe ILD with a high titer of Ro52‐autoAbs in their sera. Western blot analysis revealed that 11 of 12 mRo52‐autoAbs bound to the coiled‐coil domain of Ro52. Competitive ELISA demonstrated that mRo52‐autoAbs competed with each other to bind to Ro52. Epitope mapping showed that two of them specifically bound to a peptide (PEP08) in the coiled‐coil domain. We then examined the titer of Ro52‐autoAbs in the sera of 192 CTD patients and assessed the relationship between the serum levels of Ro52‐autoAbs that were reactive to PEP08 peptide and the clinical morbidity and severity of ILD. Statistical analysis revealed that the production of PEP08‐reactive Ro52‐autoAbs correlated with the morbidity and severity of ILD in CTD. Assessment of the production of PEP08‐reactive Ro52‐autoAbs in autoimmune diseases is useful for predicting the clinical morbidity of ILD.     

Potential methods for improving the efficacy of mesenchymal stem cells in the treatment of inflammatory bowel diseases

Inflammatory bowel diseases (IBD) are a group of chronic recurrent gastrointestinal inflammatory diseases, including ulcerative colitis (UC), Crohn's disease (CD) and IBD unclassified. The pathogenesis may be related to the mucosal immune dysfunction in genetically susceptible hosts affected by environmental factors. Current therapeutic agents mainly include aminosalicylates, corticosteroids, immunosuppressive drugs and novel biological agents. The purpose of treatment is to suppress inflammation and prevent irreversible structural damage. However, long-term application of these drugs may lead to multiple adverse effects and is not always effective. Mesenchymal stem cells (MSCs) are multipotent progenitors with low immunogenicity, which can be obtained and expanded easily. They play an important role in regulating immune responses and repairing damaged tissues in vivo. Therefore, MSCs are considered to be a promising option for the treatment of IBD. Nonetheless, there are many factors that can reduce the efficacy of MSCs, such as gradual deterioration of functional stem cells with age, low recruitment and persistence in vivo and different routes of administration. In recent years, researchers have been able to improve the efficacy of MSCs by pretreatment, genetic modification or co-application with other substances, as well as using different tissue-derived cells, administration methods or doses. This article reviews these methods to provide references for more effective application of MSCs in the treatment of IBD in the future.     

Plasma and tissue interleukin-2 receptor levels in inflammatory bowel disease.

Plasma and tissue interleukin-2 receptor (IL-2R) levels were determined in patients with active ulcerative colitis and Crohn's disease. Compared with healthy controls (median 440 U/ml; range 240-900), significantly higher levels of plasma IL-2R were present in patients with active ulcerative colitis (median 1180 U/ml; range 580-7150; P less than 0.002) and Crohn's disease (median 1340 U/ml; range 480-9000; P less than 0.002). Compared with other laboratory parameters, plasma IL-2R levels were related most closely to clinical score of disease activity in Crohn's disease. Plasma IL-2R levels also reflected the clinical course and may provide a more accurate assessment of disease activity in Crohn's disease. In plasma of patients undergoing intestinal resection of active inflammatory bowel disease, raised levels of IL-2R were present in samples from mesenteric vein (draining inflamed intestine) compared with those from peripheral vein. In tissue homogenates of colonic biopsies, significantly higher levels of IL-2R were present in specimens from colons with active ulcerative colitis compared with healthy controls (median 230.2, range 20.7-581.5 versus 77.9, range 34.2-291.3; P less than 0.02).     

Endothelial cell-binding activity of anti-U1-ribonucleoprotein antibodies in patients with connective tissue diseases.

In order to elucidate the immunological properties of anti-U1-ribonucleoprotein (RNP) antibody, one of the autoantibodies detected in patients with connective tissue diseases (CTDs), we tested the endothelial cell-binding by anti-U1-RNP antibodies and epitopes on human pulmonary artery endothelial cells (HPAECs) to which the autoantibody bound. IgG fractions positive for anti-U1-RNP from patients with CTDs bound to the HPAECs. Furthermore, intact and F(ab')2 IgG anti-U1-RNP purified by affinity chromatography also bound to endothelial cells. The binding activity of IgG fractions positive for anti-U1-RNP to the endothelial cells could be effectively absorbed by U1-RNP-Sepharose. An immunoblotting assay of purified IgG anti-U1-RNP antibodies showed that these antibodies could bind to various membrane proteins of NP40-treated HPAECs such as 68, 48, 43, 38, 33, 29, 28 and 24 kDa. Some bands, 68, 33, 28 and 24 kDa, seemed to correspond to components of U1-RNP, i.e. 68 kDa, A, B' and C peptides, respectively. We confirmed that the anti-U1-RNP antibody from patients with CTDs can directly recognize a variety of antigens on the endothelial surface of the pulmonary artery, including the components of U1-RNP or other unknown polypeptides. These results suggest that binding to pulmonary artery endothelial cells of this autoantibody may be one of the triggers of endothelial cell inflammation in CTDs.     

Nitric oxide in inflammatory bowel disease: a universal messenger in an unsolved puzzle

In recent years, nitric oxide (NO), a gas previously considered to be a potentially toxic chemical, has been established as a diffusible universal messenger that mediates cell-cell communication throughout the body. Constitutive and inducible NO production regulate numerous essential functions of the gastrointestinal mucosa, such as maintenance of adequate perfusion, regulation of microvascular and epithelial permeability, and regulation of the immune response. Up-regulation of the production of NO via expression of inducible nitric oxide synthase (iNOS) represents part of a prompt intestinal antibacterial response; however, NO has also been associated with the initiation and maintenance of inflammation in human inflammatory bowel disease (IBD). Recent studies on animal models of experimental IBD have shown that constitutive and inducible NO production seems to be beneficial during acute colitis, but sustained up-regulation of NO is detrimental. This fact is also supported by studies on mice genetically deficient in various NOS isoforms. However, the mechanism by which NO proceeds from being an indispensable homeostatic regulator to a harmful destructor remains unknown. Furthermore, extrapolation of data from animal colitis models to human IBD is questionable. The purpose of this review is to update our knowledge about the role of this universal mediator and the enzymes that generate it in the pathogenesis of IBD.     

肠上皮淋巴细胞与炎症性肠病相关性的研究进展

肠上皮淋巴细胞（iIEL）定位于消化道黏膜上皮细胞间,与肠上皮细胞紧密接触并相互作用,介导黏膜局部免疫防御和维持肠黏膜组织稳定性。iIEL通过其细胞毒活性及所分泌的细胞因子调节肠上皮细胞的凋亡及再生,在炎症性肠病的发生及发展中起一定作用。     

NOD1和NOD2与炎性肠病

NOD1和NOD2蛋白是一类新型胞浆内模式识别受体,在宿主固有免疫和自噬过程中起着关键的作用,对维持肠道微生态和黏膜屏障作用至关重要,研究表明NOD1和NOD2基因多态性和表达异常与炎性肠病的发生密切有关.     

High resolution MIC genotyping: design and application to the investigation of inflammatory bowel disease susceptibility

The highly polymorphic nonclassical MHC class I chain-related (MIC) genes MICA and MICB encode stress inducible glycoproteins expressed on a variety of epithelial cells including intestinal cells. Interaction with the receptor NKG2D is likely to provide an important costimulatory signal for activation and proliferation of NK cells, activated macrophages and CD8 alphabeta and gammadelta T cells. Fifty-four MICA and 17 MICB alleles have been described to date. Although the functional significance of this polymorphism is not known, the high degree of nonconservative substitution, concentration to the putative ligand-binding site and recent observation that different MICA alleles bind to NKG2D with varying affinity has generated much interest. The MIC genes are attractive functional and positional candidate genes for inflammatory bowel disease susceptibility as a consequence of their position in the HLA region and expression on the gastrointestinal epithelium. We developed a robust, high-resolution PCR-SSP genotyping method that can be incorporated into the standard 'Phototyping' system and which effectively identifies 46 of 54 MICA alleles, and all 17 MICB alleles. We applied this system in combination with microsatellite genotyping of the exon 5 variable number of tandem repeats (VNTR) to the investigation of genetic susceptibility to the inflammatory bowel diseases, ulcerative colitis and Crohn's disease. We studied 248 patients with Crohn's disease, 329 with ulcerative colitis and 354 ethnically matched controls. Linkage disequilibrium patterns between HLA-B, MICA and MICB are presented. Analysis by individual allele or by multilocus haplotype failed to identify any significant disease associations.     

Pathogenic T cell subsets in allergic and chronic inflammatory bowel disorders

Homeostasis in the gastrointestinal tract relies on a sensitive equilibrium between permissive and protective functions. This is closely reflected in the regulation of the intestinal immune system and especially T cells in the gut. This balance, however, is susceptible to disturbances as demonstrated by pathological conditions like food allergy, celiac disease, or inflammatory bowel disease. In these allergic and chronic inflammatory bowel disorders, luminal antigens get access to the lamina propria where they trigger a dysregulated immune response with crucial involvement of different T cell subsets. We will begin this review with some comprehensive remarks on current concepts on the pathogenesis of these diseases before taking a closer look at the life cycle of intestinal T cells consisting of priming, homing, differentiation and proliferation and apoptosis respectively. Subsequently we will discuss the specific implication of distinct T cell subsets in allergic and chronic inflammatory conditions of the gastrointestinal tract in detail and comment on current and future approaches to targeted therapy in this context.     

Eosinophilia – associated basal plasmacytosis: an early and sensitive histologic feature of inflammatory bowel disease

Basal plasmacytosis is an early‐onset and highly predictive feature of inflammatory bowel disease (IBD), but may have several restrictions in routine histology. Considering evidences about cooperation between eosinophils and plasma cells in IBD pathogenesis, we investigated immunostain of these two cells as a marker of disease. 343 samplings from 83 patients (52 IBD, 31 non‐IBD colitis) were evaluated. The sections were stained with monoclonal antibodies against plasma cells (CD138 and MUM1), and eosinophils (CD193). Eosinophilia‐associated basal plasmacytosis (EBP) was related with the histologic diagnosis of IBD (90.3% IBD and 35.4% non‐IBD colitides, p < 0.005, sensitivity 90.4%). A strong relation was detected between the occurrence of EBP and (i) the achieving of a complete endoscopic mapping; (ii) the presence of other characteristic lesions of IBD in single segmental sampling, although EBP was evident in more than 40% of samples without other IBD‐related lesions. EBP is a sensitive histologic feature of IBD, especially at the first endoscopic sampling, even in the absence of the other characteristic histologic lesions, and may help in formulating a more precise diagnosis in this setting.     

Very early onset inflammatory bowel disease: Investigation of the IL-10 signaling pathway in Iranian children

Background & aimComparing to adult inflammatory bowel disease (IBD), those with early onset manifestations have different features in terms of the underlying molecular pathology, the course of disease and the response to therapy. We investigated the IL-10 signaling pathway previously reported as an important cause of infantile (Very Early Onset) IBD to find any possible variants.MethodWith the next generation sequencing technique we screened IL-10, IL-10RA and IL10RB genes of 15 children affected by very early onset-GI (gastrointestinal) disorders. Additionally, we analyzed them based on Thermo Fisher immune deficiency panel for genes either having a known role in IBD pathogenesis or cause the disorders with overlapping manifestations. We performed multiple functional analyses only for the cases showing variants in IL-10- related genes.ResultIn 3 out of 15 patients we identified variants including a homozygous and heterozygote mutations in IL-10RA and a novel homozygous mutation in IL-12RB1. Our functional studies reveal that in contrast to the IL-10RA heterozygote mutation that does not have deleterious effects, the homozygous mutation abrogates the IL-10 signaling pathway.ConclusionOur study suggests we need to modify the classical diagnostic approach from functional assays followed by candidate- gene or genes sequencing to the firstly parallel genomic screening followed by functional studies.