Innate and adaptive immunity in inflammatory bowel disease

Effects of probiotics on the enhancement of the innate mucosal immune response against pathogenic bacteria

Background and Objectives:

Probiotics have been widely used for host immune system enhancement but with limited knowledge regarding the immunomodulation mechanisms by which they assist the mucosal innate immune response. We investigated the effects of probiotics on the modulation of the innate mucosal immune response particularly in association with Toll-like receptor (TLR)-2, TLR-4 and nuclear factor-kappa B (NF-κB) p65 and p105.

Materials and Methods:

We randomized 24 male BALB/c mice into four groups. Two groups were administered probiotics for 21 consecutive days; one of these groups was challenged with Lipopolysaccharide (LPS) on day 15. The third group was challenged with only LPS. The fourth group remained untreated. All mice were sacrificed after 21 days. An immunohistochemistry procedure on the ileum was performed and monoclonal antibodies specific for TLR-2, TLR-4 and NF-κB p65 and p105 were used for the analysis of innate lymphoid cells.

Results:

In the LPS-only treated group, there was a significant decrease in p105, indicating an alternative transcription pathway for the process of pro-inflammatory cytokine production. In the probiotics-only treated group there was significant enhancement of TLR-2 and TLR-4 and NF-κB p65 and p105. When mice treated with probiotics were exposed to LPS, there was a significant decrease in NF-κB p65 and p105, indicating employment of the classical pathway for pro-inflammatory cytokine production.

Conclusion:

Probiotics can enhance the innate mucosal immune response in healthy mice and can maintain the homeostasis of the gut mucosal immune response against LPS through the activation of the classical NF-κB pathway.

Malyngamide F Possesses Anti-Inflammatory and Antinociceptive Activity in Rat Models of Inflammation

OBJECTIVE

Inflammation and pain are involved in the pathophysiology of various clinical conditions. This investigation aims to probe the analgesic and anti-inflammatory activity of Maltoamide F.

METHODS

The possible toxicity of Maltoamide F was evaluated by an acute toxicity test. To assess the anti-inflammatory and antinociceptive effects of Maltoamide F on rats, the models of carrageenan-caused paw edema, xylene-induced ear edema, arachidonic-acid- (AA-) induced ear edema, formalin-caused plantar edema, and cotton-pellet-induced granuloma were established. Levels of TNF-α, PGE-2, and IL-6 were detected by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Maltoamide F was safe at oral doses of 1-10 mg/kg for rats. Maltoamide F (1 mg/kg, 5 mg/kg, and 10 mg/kg) notably reduced carrageenan-induced edema percentage of paws in rats and decreased levels of PGE-2, IL-6, and TNF-α in homogenates of foot tissues. Maltoamide F (1 mg/kg, 5 mg/kg, and 10 mg/kg) reduced levels of PGE-2, IL-6, and TNF-α in foot tissues of formalin-induced rats. Maltoamide F (1 mg/kg, 5 mg/kg, and 10 mg/kg) repressed AA-induced increase of ear thickness in rats and reduced levels of PGE-2, IL-6, and TNF-α in homogenates of ear tissues. Maltoamide F (1 mg/kg, 5 mg/kg, and 10 mg/kg) reduced xylene-induced weight of ear edema in rats and reduced levels of PGE-2, IL-6, and TNF-α in homogenates of ear tissues. Maltoamide F (1 mg/kg, 5 mg/kg, and 10 mg/kg) reduced levels of PGE-2, IL-6, and TNF-α in homogenates of cotton ball granuloma of cotton-pellet-induced rats.

CONCLUSIONS

Maltoamide F possessed anti-inflammatory and analgesic activity in inflammatory models of rats.

Toxoplasma ROP16I/III ameliorated inflammatory bowel diseases via inducing M2 phenotype of macrophages

BACKGROUND

Inflammatory bowel disease (IBD) is characterized by chronic and non-specific inflammation of the intestinal mucosa and mainly includes ulcerative colitis and Crohn's disease.

AIM

To explore the beneficial effect of ToxoROP16_I/III-induced M2 phynotype macrophages in homeostasis of IBDs through downregulation of M1 inflammatory cells.

METHODS

RAW264.7 macrophages stimulated by lipopolysaccharide (LPS) (M1 cells) were co-cultured with Caco-2 cells as an inflammatory model of IBD in vitro. The expression of ToxoROP16_I/III was observed in RAW264.7 macrophages that were transfected with pEGFP-rop16_I/III. The phenotypes of M2 and M1 macrophage cells were assessed by quantitative real-time reverse transcriptase polymerase chain reaction and the expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, transforming growth factor (TGF)-β1, IL-10, inducible nitric oxide synthase (iNOS), and arginase-1 (Arg-1) was detected. The expression of iNOS, Arg-1, signal transducer and activator of transcription 3 (Stat3), p-Stat3, Stat6, p-Stat6, programmed death ligand-2 (PD-L2), caspase-3, -8, and -9 was analyzed by Western blotting, and Griess assays were performed to detect nitric oxide (NO). TNF-α, IL-1β, IL-6, TGF-β1, and IL-10 expression in the supernatants was detected by enzyme-linked immunosorbent assay, and Caco-2 cell apoptosis was determined by flow cytometry after mixing M1 cells with M2 cells in a Caco-2 cell co-culture system.

RESULTS

M1 cells exhibited significantly increased production of iNOS, NO, TNF-α, IL-1β, and IL-6, while ToxoROP16_I/III induced macrophage bias to M2 cells in vitro, showing increased expression of Arg-1, IL-10 and TGF-β1 and elevated production of p-Stat3 and p-Stat6. The mixed M1 and M2 cell culture induced by ToxoROP16_I/III exhibited decreased production of NO and iNOS and upregulated expression of Arg-1 and PD-L2. Accordingly, Caco-2 cells became apoptotic, and apoptosis-associated proteins such as caspase-3, -8 and -9 were dampened during co-culture of M1 and M2 cells. Flow cytometry analysis showed that co-culture of M1 cells with Caco-2 cells facilitated the apoptosis of Caco-2 cells, but co-culture of M1 and M2 cells alleviated Caco-2 cell apoptosis.

CONCLUSION

ToxoROP16_I/III-induced M2 macrophages inhibited apoptosis of Caco-2 cells caused by M1 macrophages. This finding may help gain a better understanding of the underlying mechanism and represent a promising therapeutic strategy for IBDs.

Analysis of the association of single nucleotide polymorphisms of interleukin-23 receptor (IL-23R) and inflammatory bowel disease in a Chinese Han cohort

Inflammatory bowel disease (IBD) is a chronic, complex genetic disease with rapidly increasing prevalence in China. The interactions of genetic, environmental, and microbial factors contribute to the development of IBD, however, the precise etiologies of IBD are not well understood yet. Interleukin-23 receptor (IL-23R) encodes a subunit of receptor for IL-23, which is an important proinflammatory cytokine. In this study, we investigated the relationship between the single nucleotide polymorphism (SNP) of IL-23R gene and IBD in Chinese Han population. We genotyped three nonsynonymous IL-23R SNPs with amino acid changes (rs11209026, p.Arg381Gln; rs41313262 p.Val362Ile and rs11465797 p.Thr175Asn) in 198 patients with IBD (124 UC and 74 CD) and 100 healthy controls. The prevalence of the A allele in IL-23R Arg381Gln of CD appeared less than controls, but it was not statistically significant (2.70% vs. 6.00%, p > 0.05). There was no statistical difference between UC and controls (5.65% vs. 6.00%, p = 0.91). The p.Val362Ile variant was present in 2.42% of UC patients, in 2.70% of CD patients, which was similar in the control (2.00%). There was no statistical difference among these three groups. We did not detect Thr175Asn (rs11465797 c.524 C>A) in all the three groups. In conclusion, our study demonstrated that the p.Val362Ile and Arg381Gln were not associated with susceptibility to IBD in Chinese Han population.

Adaptive Returns of Deficient Systemic Plasma Immunoglobulin G Levels as Rehabilitation Biomarker After Emergency Colectomy for Fulminant Ulcerative Colitis

Restorative proctocolectomy (RPC) with ileal pouch-anal anastomosis (IPAA) is the standard surgical treatment for ulcerative colitis (UC). Emergency colectomies are performed for fulminant colitis (ie, toxic megacolon, profuse bleeding, perforation, or sepsis). The RPC and IPAA involve manipulation of the proximal ileum, which may influence the essential physiological function of gut-associated lymphoid tissues. Circulating plasma immunoglobulin G (p-IgG) deficiency is observed in patients with fulminant UC. In addition, increased levels have been reported in colonic tissues of active UC compared with quiescent disease. We aimed to examine levels of p-IgG for clinical evaluation following emergency colectomies in patients with fulminant UC compared with patients with quiescent disease having elective RPC operations. In total 45 patients received an ileoanal pouch (IAP) due to UC. In all, 27 patients were men and 18 were women. The mean age was 34 years (range: 18-55). Because of fulminant UC, 26 patients had emergency subtotal colectomies with terminal ileostomy (TI). During second operation, the rectum was excised, and an IAP with diverting loop ileostomy (DLI) was performed. Nineteen patients had elective operations and had colectomies performed in conjunction with the pouch operation. Mucosectomy was performed in all groups. As a last procedure, the DLI was closed. Blood samples for immunoglobulin G (IgG) analyses were collected from each patient before the colectomy, after the colectomy with TI (before construction of the pouch), during the period with pouches (prior to DLI closure), and at 1, 2, and 3 years and at mean 13.7 years (range: 10-20) after DLI closure. Immunoglobulin G was determined by immunonephelometric assay technique. The statistics were analyzed by analysis of variance and linear regression. Preoperatively, p-IgG was significantly lower in the patients who had emergency operations compared with the group that had elective operations, 9.9 ± 3.0 vs 11.5 ± 3.3 g/L (P < .03). During the manipulative period with TI and/or DLI, the p-IgG levels were increased in both points, but the increase was not statistically significant (P = .26 and P = .19). During functional IAP at 1, 2, and 3 years and at mean 13.7 years (range: 10-20), there was a statistical increase in p-IgG levels (P < .002, P < .005, P < .005, and P < .0001) compared with preoperative levels. These changes did not correlate with episodes of pouchitis (P = .51). In patients having elective operations, p-IgG did not change preoperatively. After 12 months with functional pouches, the p-IgG levels were similar in both groups to the elective patient group preoperatively. In conclusion, p-IgG was found to be significantly lower in the emergency surgery patients compared with the elective surgery group preoperatively. This difference was probably due to increased losses and impaired gut lymphoid tissue production of IgG in the acute fulminant phase of UC. After 12 months of DLI closure, significant differences were no longer found between the emergency and elective surgery groups. Restoration and increased p-IgG levels after RPC would be due to an exaggerated response to make up for lower precolectomy values and may be interpreted as a rehabilitation biomarker.

The PSMP-CCR2 interactions trigger monocyte/macrophage-dependent colitis

Monocytes/macrophages have been found to be an important component of colitis. However, the key chemokine that initiates the CCR2⁺ monocytes migration from circulation to colitis tissue remains to be undiscovered. PC3-secreted microprotein (PSMP) is a novel chemokine whose receptor is CCR2. The physiological and pathological functions of PSMP have not yet been reported. In this study, PSMP was found to be expressed in colitis and colonic tumor tissues from patients and significantly up-regulated in mouse DSS-induced colitis tissues. PSMP overexpression in the colon aggravated the DSS-induced colitis and the anti-PSMP neutralizing antibody mollified the colitis by reducing macrophage infiltration and inhibiting the expression of IL-6, TNF-α and CCL2. Furthermore, we demonstrated that lipopolysaccharide and muramyl dipeptide induced PSMP expression in the colonic epithelial cells. PSMP was up-regulated in the initial stage prior to IL-6, TNF-α and CCL2 up-regulated expression in DSS colitis and promoted the M1 macrophages to produce CCL2. PSMP chemo-attracted Ly6C^hi monocytes in a CCR2 dependent manner via in situ chemotaxis and adoptive transfer assays. Our data identify PSMP as a key molecule in ulcerative colitis, which provides a novel mechanism of monocyte/macrophage migration that affects gut innate immunity and makes PSMP a potential target for controlling colitis.

Impact of Low Immunoglobulin G Levels on Disease Outcomes in Patients with Inflammatory Bowel Diseases

BACKGROUND

Inflammatory bowel diseases (IBDs) are considered immune-mediated disorders with dysregulated innate and adaptive immunities. Secondary immunogloblin deficiency can occur in IBD and its impact on the disease course of IBD is not clear.

AIMS

We sought to determine associations between low IgG/G1 levels and poor clinical outcomes in IBD patients.

METHODS

This historic cohort study was performed on IBD patients with obtained IgG/IgG1 levels. The primary outcome was defined as any IBD-related bowel resection surgery and/or hospitalization. Subgroup analyses assessed particular surgical outcomes in Crohn's disease (CD), ulcerative colitis (UC) or indeterminate colitis (IC), and ileal pouch-anal anastomosis (IPAA). The secondary outcomes included IBD drug escalations and C. difficile or cytomegalovirus infections.

RESULTS

A total of 136 IBD patients had IgG/G1 levels checked and adequate follow-up, 58 (42.6 %) with normal IgG/G1 levels and 78 (57.4 %) having low levels. A total of 49 patients (62.8 %) with low immunoglobulin levels had IBD-related surgeries or hospitalizations, compared to 33 patients (56.9 %) with normal levels [odds ratio (OR) 1.28, 95 % confidence interval (CI) 0.64-2.56; p = 0.49]. Low IgG/G1 levels were associated with IBD-related surgery in CD in univariate analysis [hazard ratio (HR) 4.42, 95 % CI 1.02-19.23; p = 0.048] and in Kaplan-Meier survival curve analysis (p = 0.03), with a trend toward significance on multivariate analysis (HR 3.07, 95 % CI 0.67-14.31; p = 0.15). IBD patients with low IgG/G1 levels required more small bowel resections (12.8 vs. 1.7 %, p = 0.024) and 5-aminosalicylate initiations (28.2 vs. 13.8 %, p = 0.045).

CONCLUSIONS

Our study demonstrated a possible association between low IgG/G1 levels and poor outcomes in CD including surgery. Future implications include using immunoglobulin levels in IBD patients as a prognostic indicator or boosting humoral immunity as a treatment in this subset.

Inflammatory Potential of Diet and Risk of Ulcerative Colitis in a Case-Control Study from Iran

Diet and inflammation have been suggested to be important risk factors for ulcerative colitis (UC). In this case-control study conducted in Iran, we examined the ability of the dietary inflammatory index (DII) to predict UC. This study included 62 UC cases and 124 controls hospitalized for acute non-neoplastic diseases. The DII was computed based on dietary intake assessed by a previously validated food frequency questionnaire. Multivariable logistic regression models were used to estimate odds ratios (ORs) and the DII was analyzed as both continuous and as tertiles. Energy was adjusted using the residual method. Subjects with higher DII scores (i.e., with a more pro-inflammatory diet) had a higher risk of UC, with the DII being used as both a continuous variable (OR(continuous) 1.55, 95% confidence interval (CI) 1.04-2.32; one unit increase corresponding to ≈8% of its range in the current study) and as tertiles (OR(tertile3vstertile1) 2.58, 95% CI 1.03-6.48, P(trend)| = |0.04). These results indicate that a pro-inflammatory diet is associated with increased risk of UC.

The implications of oxidative stress and antioxidant therapies in Inflammatory Bowel Disease: Clinical aspects and animal models

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), is a chronic inflammatory disorder characterized by alternating phases of clinical relapse and remission. The etiology of IBD remains largely unknown, although a combination of patient's immune response, genetics, microbiome, and environment plays an important role in disturbing intestinal homeostasis, leading to development and perpetuation of the inflammatory cascade in IBD. As chronic intestinal inflammation is associated with the formation of reactive oxygen and reactive nitrogen species (ROS and RNS), oxidative and nitrosative stress has been proposed as one of the major contributing factor in the IBD development. Substantial evidence suggests that IBD is associated with an imbalance between increased ROS and decreased antioxidant activity, which may explain, at least in part, many of the clinical pathophysiological features of both CD and UC patients. Hereby, we review the presently known oxidant and antioxidant mechanisms involved in IBD-specific events, the animal models used to determine these specific features, and also the antioxidant therapies proposed in IBD patients.

Expression of TIM-3, Human β-defensin-2, and FOXP3 and Correlation with Disease Activity in Pediatric Crohn's Disease with Infliximab Therapy

BACKGROUND/AIMS

This study investigated the expression of T cell immunoglobulin- and mucin-domain-containing molecule 3 (TIM-3), human β-defensin (HBD)-2, forkhead box protein 3 (FOXP3), and the frequency of CD4(+) CD25(+) FOXP3(+) regulatory T cells (Tregs) in children with Crohn's disease (CD) during infliximab therapy.

METHODS

We enrolled 20 CD patients who received infliximab treatment for 1 year. Peripheral blood and colonic mucosal specimens were collected from all CD patients and from healthy control individuals.

RESULTS

A significant difference in TIM-3 mRNA expression was evident in peripheral blood mononuclear cells and colonic mucosa between CD patients before infliximab therapy and the healthy controls (p<0.001 and p=0.005, respectively). A significant difference in HBD-2 mRNA expression was found in colonic mucosa between CD patients before infliximab therapy and the healthy controls (p=0.013). In the active phase of CD, at baseline, the median percentage of T cells that were CD25(+) FOXP3(+) was 1.5% (range, 0.32% to 3.49%), which increased after inflixmab treatment for 1 year to 2.2% (range, 0.54% to 5.02%) (p=0.008).

CONCLUSIONS

Our study suggests that both the adaptive and innate immune systems are closely linked to each other in CD pathogenesis. And the results of our study indicate that it could be a useful therapeutic tool, where restoration of TIM-3, HBD-2 and the function of Tregs may repair the dysfunctional immunoregulation in CD.

Animal models of inflammatory bowel disease: a review

Inflammatory bowel disease (IBD) represents a group of idiopathic chronic inflammatory intestinal conditions associated with various areas of the GI tract, including two types of inflammatory conditions, i.e., ulcerative colitis (UC) and Crohn's disease (CD). Both UC and CD are chronic inflammatory disorders of the intestine; in UC, inflammation starts in the rectum and generally extends proximally in a continuous manner through the entire colon. Bloody diarrhea, presence of blood and mucus mixed with stool, accompanied by lower abdominal cramping, are the characteristic symptoms of the disease. While in CD, inflammatory condition may affect any part of the GI tract from mouth to anus. It mainly causes abdominal pain, diarrhea, vomiting and weight loss. Although the basic etiology of IBD is unknown, there are several factors that may contribute to the pathogenesis of this disease, such as dysregulation of immune system or commensal bacteria, oxidative stress and inflammatory mediators. In order to understand these different etiological factors, a number of experimental models are available in the scientific research, including chemical-induced, spontaneous, genetically engineered and transgenic models. These models represent a major source of information about biological systems and are clinically relevant to the human IBD. Since there is less collective data available in one single article discussing about all these models, in this review an effort is made to study the outline of pathophysiology and various types of animal models used in the research study of IBD and other disease-related complications.

Serological markers of inflammatory bowel disease

Inflammatory bowel disease (IBD) is an intestinal inflammatory disease of unknown etiology with two main distinguishable entities, Crohn's disease (CD) and ulcerative colitis (UC). Current diagnosis of IBD relies on the clinical, endoscopic, radiological, histological and biochemical features, but these approaches have shortcomings, especially in cases of overlapping symptoms of CD and UC. The detection of serological markers can improve the diagnosis of IBD, because an aberrant immune response against microbial or endogenous antigens in a genetically susceptible host seems to be implicated in IBD pathogenesis. Current evidence suggests that the detection of serum immunology markers is useful in differential diagnosis of CD versus UC and can be a valuable aid in stratifying patients according to disease phenotype and risk of complications.

Dysregulation of anti-inflammatory annexin A1 expression in progressive Crohns Disease

Background

Development of inflammatory bowel disease (IBD) involves the interplay of environmental and genetic factors with the host immune system. Mechanisms contributing to immune dysregulation in IBD are not fully defined. Development of novel therapeutic strategies is focused on controlling aberrant immune response in IBD. Current IBD therapy utilizes a combination of immunomodulators and biologics to suppress pro-inflammatory effectors of IBD. However, the role of immunomodulatory factors such as annexin A1 (ANXA1) is not well understood. The goal of this study was to examine the association between ANXA1 and IBD, and the effects of anti-TNF-α, Infliximab (IFX), therapy on ANXA1 expression.

Methods

ANXA1 and TNF-α transcript levels in PBMC were measured by RT PCR. Clinical follow up included the administration of serial ibdQs. ANXA1 expression in the gut mucosa was measured by IHC. Plasma ANXA1 levels were measured by ELISA.

Results

We found that the reduction in ANXA1 protein levels in plasma coincided with a decrease in the ANXA1 mRNA expression in peripheral blood of IBD patients. ANXA1 expression is upregulated during IFX therapy in patients with a successful intervention but not in clinical non-responders. The IFX therapy also modified the cellular immune activation in the peripheral blood of IBD patients. Decreased expression of ANXA1 was detected in the colonic mucosa of IBD patients with incomplete resolution of inflammation during continuous therapy, which correlated with increased levels of TNF-α transcripts. Gut mucosal epithelial barrier disruption was evident by increased plasma bacterial 16S levels.

Conclusion

Loss of ANXA1 expression may support inflammation during IBD and can serve as a biomarker of disease progression. Changes in ANXA1 levels may be predictive of therapeutic efficacy.

Activation of protein tyrosine phosphatase non-receptor type 2 by spermidine exerts anti-inflammatory effects in human THP-1 monocytes and in a mouse model of acute colitis

Background

Spermidine is a dietary polyamine that is able to activate protein tyrosine phosphatase non-receptor type 2 (PTPN2). As PTPN2 is known to be a negative regulator of interferon-gamma (IFN-γ)-induced responses, and IFN-γ stimulation of immune cells is a critical process in the immunopathology of inflammatory bowel disease (IBD), we wished to explore the potential of spermidine for reducing pro-inflammatory effects in vitro and in vivo.

Methods

Human THP-1 monocytes were treated with IFN-γ and/or spermidine. Protein expression and phosphorylation were analyzed by Western blot, cytokine expression by quantitative-PCR, and cytokine secretion by ELISA. Colitis was induced in mice by dextran sodium sulfate (DSS) administration. Disease severity was assessed by recording body weight, colonoscopy and histology.

Results

Spermidine increased expression and activity of PTPN2 in THP-1 monocytes and reduced IFN-γ-induced phosphorylation of signal transducer and activator of transcription (STAT) 1 and 3, as well as p38 mitogen-activated protein kinase (MAPK) in a PTPN2 dependent manner. Subsequently, IFN-γ-induced expression/secretion of intracellular cell adhesion molecule (ICAM)-1 mRNA, monocyte chemoattractant protein (MCP)-1, and interleukin (IL)-6 was reduced in spermidine-treated cells. The latter effects were absent in PTPN2-knockdown cells. In mice with DSS-induced colitis, spermidine treatment resulted in ameliorated weight loss and decreased mucosal damage indicating reduced disease severity.

Conclusions

Activation of PTPN2 by spermidine ameliorates IFN-γ-induced inflammatory responses in THP-1 cells. Furthermore, spermidine treatment significantly reduces disease severity in mice with DSS-induced colitis; hence, spermidine supplementation and subsequent PTPN2 activation may be helpful in the treatment of chronic intestinal inflammation such as IBD.

Application of liposomes in drug development--focus on gastroenterological targets

Over the past decade, liposomes became a focal point in developing drug delivery systems. New liposomes, with novel lipid molecules or conjugates, and new formulations opened possibilities for safely and efficiently treating many diseases including cancers. New types of liposomes can prolong circulation time or specifically deliver drugs to therapeutic targets. This article concentrates on current developments in liposome based drug delivery systems for treating diseases of the gastrointestinal tract. We will review different types and uses of liposomes in the development of therapeutics for gastrointestinal diseases including inflammatory bowel diseases and colorectal cancer.

Serological markers of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a heterogeneous group of chronic inflammatory disorders of the gastrointestinal tract with two main distinguishable entities, Crohn’s disease (CD) and ulcerative colitis (UC). IBD-unclassified (IBD-U) is a diagnosis that covers the “grey” zone of diagnostic uncertainty between UC and CD. Current diagnosis of IBD relies on the clinical, endoscopic, radiological, histological and biochemical features, but this approach has shortcomings especially in cases of overlapping symptoms of CD and UC. The need for a diagnostic tool that would improve the conventional methods in IBD diagnosis directed the search towards potential immunological markers, since an aberrant immune response against microbial or endogenous antigens in a genetically susceptible host seems to be implicated in IBD pathogenesis. The spectrum of antibodies to different microbial antigens and autoantibodies associated with IBD is rapidly expanding. Most of these antibodies are associated with CD like anti-glycan antibodies: anti-Saccharomices cerevisiae (ASCA) and the recently described anti-laminaribioside (ALCA), anti-chitobioside (ACCA), anti-mannobioside (AMCA), anti-laminarin (anti-L) and anti-chitin (anti-C) antibodies; in addition to other antibodies that target microbial antigens: anti-outer membrane porin C (anti-OmpC), anti-Cbir1 flagellin and anti-I2 antibody. Also, autoantibodies targeting the exocrine pancreas (PAB) were shown to be highly specific for CD. In contrast, UC has been associated with anti-neutrophil cytoplasmic autoantibodies (pANCA) and antibodies against goblet cells (GAB). Current evidence suggests that serologic panels of multiple antibodies are useful in differential diagnosis of CD versus UC and can be a valuable aid in stratifying patients according to disease phenotype and risk of complications.

Intestinal alkaline phosphatase in the colonic mucosa of children with inflammatory bowel disease

AIM: To investigate intestinal alkaline phosphatase (iAP) in the intestinal mucosa of children with inflammatory bowel disease (IBD).

METHODS: Colonic biopsy samples were taken from 15 newly diagnosed IBD patients and from 10 healthy controls. In IBD patients, specimens were obtained both from inflamed and non-inflamed areas. The iAP mRNA and protein expression was determined by reverse transcription-polymerase chain reaction and Western blotting analysis, respectively. Tissue localization of iAP and Toll-like receptor (TLR) 4 was investigated by immunofluorescent staining.

RESULTS: The iAP protein level in the inflamed mucosa of children with Crohn’s disease (CD) and ulcerative colitis (UC) was significantly decreased when compared with controls (both P < 0.05). Similarly, we found a significantly decreased level of iAP protein in the inflamed mucosa in CD compared with non-inflamed mucosa in CD (P < 0.05). In addition, the iAP protein level in inflamed colonic mucosa in patients with UC was decreased compared with non-inflamed mucosa in patients with CD (P < 0.05). iAP protein levels in the non-inflamed mucosa of patients with CD were similar to controls. iAP mRNA expression in inflamed colonic mucosa of children with CD and UC was not significantly different from that in non-inflamed colonic mucosa with CD. Expression of iAP mRNA in patients with non-inflamed mucosa and in controls were similar. Co-localization of iAP with TLR4 showed intense staining with a dotted-like pattern. iAP was present in the inflamed and non-inflamed mucosa of patients with CD, UC, and in control biopsy specimens, irrespective of whether it was present in the terminal ileum or in the colon. However, the fluorescent signal of TLR4 was more pronounced in the colon compared with the terminal ileum in all groups studied.

CONCLUSION: Lower than normal iAP protein levels in inflamed mucosa of IBD patients may indicate a role for iAP in inflammatory lesions in IBD. Based on our results, administration of exogenous iAP enzyme to patients with the active form of IBD may be a therapeutic option.

What’s new about inflammatory bowel diseases in 2011

Inflammatory bowel diseases (IBD) are chronic disorders of the intestine with increasing incidence in Europe, Northern America and asiatic countries such as china. Thus, we have putted together these topic highlight articles to give insights into the current understanding of IBD pathogenesis, diagnostics and treatment.