Interleukin-10 polymorphisms in Spanish type 1 diabetes patients

The MHC accounts for half of the genetic susceptibility to type 1 diabetes (T1D). Evidence suggests that an imbalance in Th1/Th2 responses may play a key role in the development of autoimmune diabetes. Since interleukin-10 (IL-10) modulates immune and inflammatory responses and has been implicated in many autoimmune diseases, it seemed interesting to examine whether IL-10 polymorphisms participate in diabetes predisposition. In fact, this is the first association study investigating the role of the IL- 10 polymorphisms in susceptibility to T1D in a Caucasian population. Three promoter polymorphisms (-1082G/A, -819C/T, -592C/A) and two CA-repeat microsatellites (IL-10R and IL-10G at -4 and -1.1 kb) were tested in a case-control study with 294 T1D patients and 574 healthy controls. Our results prove a minor role of IL-10 in the autoimmune diabetes risk, although we found the same association trend with IL-10G(*)12 allele as was previously observed for multiple sclerosis and rheumatoid arthritis.     

Interleukin-4 and Interleukin-10 Gene Polymorphisms in Patients with Inflammatory Bowel Disease

Background: Changes in cytokine expression have been frequently found in patients with inflammatory bowel disease (IBD). Cytokine values outside the normal range may be somewhat related to common polymorphisms within cytokine genes.

Objective: The present study was designed to investigate the possible association between polymorphisms within Interleukin IL-4 and IL-10 genes and susceptibility to and clinical features of IBD.

Methods: The study population was composed of 140 healthy controls and 75 patients with IBD (40 patients with Crohn’s disease (CD) and 35 patients with ulcerative colitis (UC)). Genotyping was performed using polymerase chain reaction with sequence-specific primers.

Results: Higher frequencies for the C allele of IL-4–590 polymorphism (P < 0.0001; odds ratio [OR], 5.68; 95% confidence interval [95% CI], 3.28–9.83) and for the T allele of IL-4–1098 polymorphism (P = 0.016; OR, 1.83; 95% CI, 1.11–3.02) were observed in the whole group of IBD patients. The IL-4–590 C allele was also significantly overrepresented when IBD patients were subdivided into CD and UC (P < 0.0001; OR, 5.2–6.28). While the IL-4–1098 T allele was present at higher frequencies in patients with UC (P = 0.05; OR, 1.95), but not in CD (P = 0.09). Multiple pairwise comparisons indicated that genotypes of all polymorphisms investigated within IL-4 gene are correlated with IBD, CD, and UC. Haplotype analysis showed that the IL-4–1098/-590 TC haplotype might predispose individuals to IBD, CD, and UC whereas the IL-4–1098/-590 TT and GC haplotypes have a protective effect. On the contrary, neither allele nor genotype frequencies of IL-10 polymorphisms (IL-10–1082 A > G, IL-10–592 A > C, and IL-10–819 T > C) were associated with IBD, CD, or UC.

Conclusions: The present study suggests that IL-4 polymorphisms might play a role in susceptibility to IBD and its major subtypes in the Iranian population.     

Autoantibody Frequency in Celiac Disease

AIM:

In our study, we investigated the levels of glutamic acid decarboxylase antibody (anti-GAD), islet cell antibody (ICA), thyroperoxidase antibody (anti-TPO), thyroglobulin antibody (anti-TG), antinuclear antibodies (FANA), antibodies to double-stranded DNA (anti-ds DNA), antibody to Sjögren syndrome A antigen (anti-SSA), antibody to Sjögren syndrome B antigen (anti-SSB), Smith antibody (anti-Sm), smooth muscle antibodies (ASMA), and antimitochondrial antibody liver-kidney microsome (AMA-LKM) in patients with celiac disease as compared to healthy controls and autoimmune hypothyroid patients.

MATERIALS AND METHODS:

A total of 31 patients with celiac disease, 34 patients with autoimmune hypothyroidism and 29 healthy subjects were included in this study. Anti-SSA, anti-SSB, anti-Sm, anti-ds DNA, anti-GAD, anti-TPO and anti-TG were studied by Enzyme-Linked Immunosorbent Assay (ELISA), and AMA-LKM, ASMA, ANA and ICA were studied by immunofluorescence. Clinical data and the results of free thyroxine-thyroid stimulating hormone (FT4-TSH) were collected from the patients’ files by retrospective analysis. SPSS ver 13.0 was used for data analysis, and the χ² method was used for comparisons within groups.

RESULTS:

The frequency of anti-SSA, anti-SSB, anti-GAD, anti-Sm, anti-ds DNA, AMA-LKM, ASMA, ANA and ICA were not significantly different between the groups. Levels of anti-TPO and anti-TG antibodies were found to be significantly higher (<0.001) in autoimmune hypothyroid patients when compared with other groups.

CONCLUSION:

In previous studies, an increased frequency of autoimmune diseases of other systems has been reported in patients with celiac disease. We found that the frequency of autoimmune antibodies specific for other autoimmune diseases was not higher in celiac disease.     

Ancestral haplotypes: conserved population MHC haplotypes

We describe here a number of Caucasoid MHC haplotypes that extend from HLA-B to DR and that have been conserved en bloc. These haplotypes and recombinants between any two of them account for 73% of unselected haplotypes in our Caucasoid population. The existence of ancestral haplotypes implies conservation of large chromosomal segments. Irrespective of the mechanisms involved in preservation of ancestral haplotypes, it is clear that these haplotypes carry several MHC genes, other than HLA, which may be relevant to antigen presentation, autoimmune responses, and transplantation rejection. In light of the existence of ancestral haplotypes, it is critical to evaluate MHC associations with disease and transplantation outcome in terms of associations with ancestral haplotypes rather than individual alleles.     

Frequency in Spanish population of familial complement factor 2 type I deficits and associated HLA haplotypes

We present two familial cases of complement factor 2 (C2) type I deficiency. Probands had experienced severe pyogenic bacteria infections in childhood and had undetectable levels of C2 and very low level of CH50. Both children were homozygous for the deletion of 28 bp in exon 6 of the C2 gene. Human leukocyte antigen (HLA) typing in family 1 had the commonly reported associations, but family 2 demonstrated a new association of the mutated C2 gene to HLA-A*3101, -Cw*0602, -B*1801, and -DRB1*0901. In addition, for the first time, the frequency of the 28-bp deletion of C2 and its HLA haplotypic associations have been analyzed in a sample of the Spanish population containing 790 haplotypes and 105 phenotypes. Cw*0602 is frequently found in Spanish haplotypes linked to the C2 mutated gene instead of the commonly reported -Cw*1203. The presence of heterozygous or homozygous individuals for the C2 deletion with low levels of IgD in both families supports the existence of a putative dominant susceptibility gene for IgD deficiency in haplotype HLA-B18, -S042, and -DR2. The frequency of the C2 28-bp deletion in heterozygosis is 1.4% (gene frequency 0.007) in Spanish healthy controls, similar to that reported in other white populations.     

Interleukin-10 polymorphisms in Spanish IgA deficiency patients: a case-control and family study

Background  

IgA deficiency (IgAD) is the most common primary immunodeficiency in Caucasians. Genetic and environmental factors are suspected to be involved in the development of the disease. Interleukin-10 (IL-10) is a cytokine with stimulatory activity on immunoglobulin production and it may be an important regulator in IgAD pathogenesis. The IL-10 gene contains several single nucleotide polymorphisms (SNPs) and two polymorphic microsatellites located in the 5'-flanking region. Our aim was to ascertain if any of these polymorphic markers are associated or linked to IgAD in Spanish patients.     

Interleukin-10 in the brain

Interleukin (IL)-10 is synthesized in the central nervous system (CNS) and acts to limit clinical symptoms of stroke, multiple sclerosis, Alzheimer's disease, meningitis, and the behavioral changes that occur during bacterial infections. Expression of IL-10 is elevated during the course of most major diseases in the CNS and promotes survival of neurons and all glial cells in the brain by blocking the effects of proapoptotic cytokines and by promoting expression of cell survival signals. Stimulation of IL-10 receptors regulates numerous life- or death-signaling pathways--including Jak1/Stat3, PI 3-kinase, MAPK, SOCS, and NF-kappaB--ultimately promoting cell survival by inhibiting both ligand- and mitochondrial-induced apoptotic pathways. IL-10 also limits inflammation in the brain; it does so by three major pathways: (1) reducing synthesis of proinflammatory cytokines, (2) suppressing cytokine receptor expression, and (3) inhibiting receptor activation. Finally, IL-10 induces anergy in brain-infiltrating T cells by inhibiting cell signaling through the costimulatory CD28-CD80/86 pathway. The multiple functions of IL-10 in the brain will create new and intriguing vistas that will promote a better understanding of neurodegenerative diseases. These discoveries could lead to development of innovative approaches for the use of antiinflammatory cytokines in major debilitating diseases of the CNS.     

Interleukin-10

Interleukin-10 (IL-10) is a potent anti-inflammatory and immunosuppressive cytokine secreted by several cell types. Most anti-inflammatory effects of IL-10 are caused by its ability to deactivate macrophages and monocytes, whereas its immunosuppressive properties are due to functional inhibition of both antigen-presenting cells and T cells. On the other hand, IL-10 also exerts immunostimulatory effects, especially on B cells, CD8+ cytotoxic T cells and natural killer cells. In vivo administration of recombinant IL-10 (rIL-10) efficiently prevents experimental septic shock induced by endotoxin, staphylococcal superantigen or cecal ligation and puncture, as well as experimental autoimmune diseases mediated by T helper type 1 (T(H)1) cells and other inflammatory disorders. rIL-10 exerts paradoxical effects in cancer models, where it promotes tumour rejection, probably due to its stimulatory properties on cytotoxic cells. On the other hand, rIL-10 increases the severity of experimental infections caused by fungi or bacteria, and enhances systemic autoimmune features in mice with spontaneous lupus syndrome. Although the therapeutic potential of rIL-10 in human diseases seems promising, the multiple facets of rIL-10 in experimental immunopathology indicate that the success of clinical trials with rIL-10 will depend both on the appropriate selection of the patient populations to be treated and on the early detection of possible adverse effects.     

Immunomodulatory Strategies for Celiac Disease

Celiac disease (CD) is the most common food-sensitive enteropathy in humans and is caused by the lack of immune tolerance (oral tolerance) to gluten. The identification of gluten-specific T cells in the lamina propria of celiacs and the strong association with HLA-DQ2 and -DQ8 genes support a central role of CD4⁺ T cells in CD pathogenesis. Studies focused on the modulation of autoimmunity in different experimental models highlighted possible immune therapeutic protocols useful also for the management of CD. On the basis of these observations, a series of strategies have been designed: some of them are based on the identification of immunogenic epitopes and their suppression via enzymatic treatment or by using peptide analogues; others rely on the delivery of unmodified antigen through the nasal route or coadministered with downregulatory cytokines. studies are generally early stage but encouraging in paving a way for an alternative treatment for celiac disease.     

A Novel Algorithm for the Diagnosis of Celiac Disease and a Comprehensive Review of Celiac Disease Diagnostics

There is an urgent clinical need for a better laboratory celiac disease diagnosis with both less false positive results and minimal underdetection. The aim of the present study was to evaluate the performance and diagnostic accuracy of different assays in an outpatient population setting for the diagnosis for celiac disease (CD) in order to design an optimal algorithm. We used 15 different ELISA assays to assess 47 blood samples of newly diagnosed children (positive biopsy results) and 52 samples from age- and sex-matched children with negative biopsy results for CD. Scoring criteria were established for grading the assays performance and characteristics. The combined gliadin and tTG assays exhibited the best sensitivity (100%). The addition of other assays to the CeliCheck neo-epitopes assay improved specificity so that the final algorithm had 100% sensitivity, 96.2% specificity, and 98.1% accuracy. The clinical demand for both maximal sensitivity and maximal specificity cannot be achieved with a single test. Using a combination of a sensitive assay together with specific assays improved celiac disease detection rates, with an acceptable number of false positive results. This model, however, needs to be confirmed prospectively in both children and adults.     

Interleukin-10 Directly Inhibits the Interleukin-6 Production in T-Cells

IL-6 is a potent regulator of T-cell activation, proliferation and differentiation. Since IL-10 inhibits cytokine production by T cells, the effect of IL-10 on IL-6 production by T cells was investigated. IL-6 production by purified monocytes or T cells was detected from cell-free culture supernatants by ELISA after stimulation of the cells with LPS or an anti-CD3 monoclonal antibody for 3 days. Although the main source of IL-6 are LPS activated monocytes (29.6 × lOng/ml), T cells secreted sufficiently high levels of IL-6 (790 × 200pg/ml) to stimulate the high affinity IL-6 receptor. IL-10 decreased anti-CD3 induced IL-6 mRNA expression by up to 80%. In addition, IL-10 significantly inhibited IL-6 release from T-cells. Highly purified, anti-CD3 activated T-cells secreted 600 × 150pg/ml IL-6 compared to 21 × 2pg/ml IL-6 following addition of IL-10 (10ng/ml; P <0.001). FACS analysis revealed a monocyte contamination of the T-cell preparations of less than 0.5%. In addition, no IL-1 production was detectable. Thus, in our experiments the effect of TL-10 on IL-6 production was independent of the presence of monocytes. Finally, inhibition of IL-6 production was not reversed by IL-2 (100U/ml). In conclusion, IL-10 suppressed the synthesis of IL-6 by T-cells via a monocyte-and IL-2-independeni mechanism. These results may help to understand the complex regulation of T-cell mediated cytokine production by IL-10.     

Intestinal Microbiota and Probiotics in Celiac Disease

SUMMARY

Celiac disease (CD) is a common chronic autoimmune enteropathy caused by gluten intake. To date, the only therapy for CD is the complete exclusion of dietary sources of grains and any food containing gluten. It has been hypothesized that the intestinal microbiota is somehow involved in CD. For this reason, probiotics are appearing as an interesting adjuvant in the dietetic management of CD. This review aims to discuss the characteristics of the microbiota in CD subjects and the use of probiotics as a novel therapy for CD. Comparisons between children with CD and controls show that their microbiota profiles differ; the former have fewer lactobacilli and bifidobacteria. Specific probiotics have been found to digest or alter gluten polypeptides. It has also been demonstrated that some bacterial species belonging to the genera Lactobacillus and Bifidobacterium exert protective properties on epithelial cells from damage caused by gliadin.     

An Update on the Diagnostics of Celiac Disease

In celiac disease, highly sensitive and specific serum endomysial and transglutaminase 2 antibody tests are widely used in identifying patients for diagnostic endoscopy and small-bowel biopsy. In addition, the recently developed deamidated gliadin peptide antibody tests show promise in celiac disease diagnostics. In view of these apparent problems attending the diagnostic gold standard, gluten-induced small-bowel mucosal villous atrophy with crypt hyperplasia, other diagnostic approaches beyond conventional histology have been introduced. Furthermore, the diagnostic criteria for celiac disease are currently under revision with an eye also to noninvasive diagnostic strategies.     

Interleukin-10.

Despite the short history of interleukin-10, accumulated evidence indicates that this interleukin plays a major role in suppressing immune and inflammatory responses. Yet interleukin-10 also maintains cell viability and acts as a cofactor to promote the growth of lymphoid and myeloid cells in vitro. Here we review the present knowledge on the structure and function of interleukin-10.     

Association of Interleukin-10 A-592C Polymorphism in Taiwanese Children with Kawasaki Disease

Elevated serum levels of interleukin-10 (IL-10) have been reported in patients with Kawasaki disease (KD). IL-10 reduces the inflammatory actions of macrophages and T cells and it may play a significant role in the regulation of inflammatory vascular damage associated with systemic vasculitis. The aim of this study was to examine whether -592 IL-10 promoter polymorphism is a susceptibility or severity marker of KD in Chinese patients in Taiwan. The study included 105 KD patients and 100 normal controls. Genotype and allelic frequencies for the IL-10 gene polymorphism in both groups were compared. There were no significant between-group differences in the genotype distribution of IL-10 A-592C gene polymorphism (P=0.08). However, the frequency of the -592*A allele was significantly increased in the patients with KD compared with controls (71.9% vs. 61.0%, P=0.019). The odds ratio for developing KD in individuals with IL-10-592*A allele was 1.64 (95% confidence interval, 1.06-2.52) compared to individuals with the IL-10-592*C allele. No significant difference was observed in the genotype and allelic frequencies for the IL-10 A-592C polymorphism between patients with and without coronary artery lesions. The IL-10-592*A allele may be involved in the development of KD in Taiwanese children.     

In Situ Expression of Interleukin-10 in Noninflamed Human Gut and in Inflammatory Bowel Disease

A dysregulated secretion of contra-inflammatory cytokines such as interleukin-10 (IL-10) could play a role in the pathogenesis of inflammatory bowel disease (IBD). We have investigated the expression of IL-10 in gut tissues from patients with Crohn’s disease (CD), ulcerative colitis (UC) and controls by mRNA in situ hybridization and immunohistochemistry. Intestinal epithelial cells were found to express IL-10 mRNA and IL-10 protein in all of the tissues investigated without any major differences in the expression patterns. However, compared with noninflamed gut, significantly increased numbers of mononuclear cells (MNCs) producing IL-10 were present in inflamed gut, both in CD and UC. This cytokine was expressed most prominently by inflammatory infiltrates enriched in macrophages, although T cells seem to contribute to its production as well. Elevated IL-10 expression in IBD was mainly detected in the submucosa, whereas IL-10 production by lamina propria cells remained comparably low. In contrast, the expression of IL-1β mRNA was preferentially increased in the lamina propria. Our data argue against a general deficiency in IL-10 production in IBD. The results suggest rather that the local production of IL-10 by mucosal MNCs in IBD is insufficient to down-regulate pro-inflammatory cytokines such as IL-1β in the lamina propria compartment.     

Cutting-Edge Issues in Celiac Disease and in Gluten Intolerance

Celiac disease (CD) is a gluten-dependent immune-mediated disease with a prevalence in the general population estimated between 0.3% and 1.2%. Large-scale epidemiological studies have shown that only 10?C20% of cases of CD are identified on the basis of clinical findings and that laboratory tests are crucial to identify subjects with subtle or atypical symptoms. The correct choice and clinical use of these diagnostic tools may enable accurate diagnosis and early recognition of silent CD cases. In this review, we have considered some relevant aspects related to the laboratory diagnosis of CD and, more extensively, of gluten intolerance, such as the best combination of tests for early and accurate diagnosis, the diagnostic role of new tests for detecting antibodies against neoepitopes produced by the transglutaminase?Cgliadin complex, the forms of non-celiac gluten intolerance (gluten sensitivity), and the use and significance of measuring cytokines in CD.     

Unraveling the Ties between Celiac Disease and Intestinal Microbiota

Celiac disease is a multifactorial disorder that involves interactions between genetic and environmental factors. Gluten proteins are responsible for the symptoms of celiac disease, but other environmental factors that influence the intestinal ecosystem, including the milk-feeding type and gastrointestinal infections, may also play a role. Moreover, intestinal dysbiosis, characterized by increased Gram-negative bacteria and reduced bifidobacteria, has been detected in celiac disease patients. This review summarizes current knowledge of the associations between the intestinal microbiota and celiac disease and its possible modes of action in pathogenesis. Deeper understanding of these interactions can help redefine how this disorder is investigated.