Anti-food and anti-microbial IgG subclass antibodies in inflammatory bowel disease

Adverse Food Reactions in Inflammatory Bowel Disease: State of the Art and Future Perspectives

Limited knowledge is available about the relationship between food allergies or intolerances and inflammatory bowel disease (IBD). Clinicians frequently encounter patients who report food allergies or intolerances, and gastroenterologists struggle distinguishing between patients with organic disorders and those with functional disorders, which the patients themselves may associate with specific dietary components. This task becomes even more arduous when managing patients with significant underlying organic conditions, like IBD. The aim of this review is to summarize and emphasize any actual associations between food allergies and intolerances and inflammatory diseases, such as ulcerative colitis and Crohn's disease. Through a narrative disceptation of the current literature, we highlight the increased prevalence of various food intolerances, including lactose, fructose, histamine, nickel, and non-celiac gluten sensitivity, in individuals with IBD. Additionally, we explore the association between increased epithelial barrier permeability in IBD and the development of food sensitization. By doing so, we aim to enhance clinicians' awareness of the nutritional management of patients with IBD when facing complaints or evidence of food allergies or intolerances.

Associations between food-specific IgG and health outcomes in an asymptomatic physical examination cohort

Background

Although the association of food-specific IgG with the development and progression of specific diseases was shown by many studies, it is also present in the population without clinical symptoms. However, the association between food-specific IgG and physical examination outcomes in healthy people has not been studied yet.

Methods

An asymptomatic physical examination cohort (APEC) was selected according to the inclusion and exclusion criteria, the physical examination data were compared between IgG positive and IgG negative groups, and their odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using multivariable logistic regression.

Results

The data of 28,292 subjects were included in the analysis. The overall IgG positive rate was up to 52.30%, mostly with mild to moderate IgG positivity. The multivariable Logistic regression showed the prevalence of hypertriglyceridemia, abnormal fasting blood glucose and overweight was lower in the IgG (+) positive group (OR 0.87, 95% CI 0.83–0.92; OR 0.93, 95% CI 0.87–0.99; OR 0.92, 95% CI 0.87–0.96) but there was a higher prevalence of thyroid disease (OR 1.09, 95% CI 1.04–1.15).

Conclusion

Food-specific IgG positivity was widespread in the APEC and was associated with lower prevalence of hypertriglyceridemia, abnormal fasting blood glucose and overweight. The underlying physiological mechanism merits further study.

Predisposition of hypersensitivity in patients with exfoliative cheilitis

Background/purpose

Exfoliative cheilitis (EC) is a chronic and reversible inflammatory disease of the lips without definite etiology. Clinically, different types of allergens can be found in exfoliative cheilitis patients, however, few studies have focused on the relationship between exfoliative cheilitis and hypersensitivity. This research aimed to investigate the prevalence of hypersensitivity in EC patients.

Materials and methods

A prospective study was conducted in 30 patients with exfoliative cheilitis and 30 healthy controls, matched in age and sex. Laboratory tests included serum total IgE, allergen-specific IgE, and food-specific IgG.

Results

Increased serum total IgE level, positive food-specific IgG were seen more frequently in exfoliative cheilitis patients than in healthy control (P < 0.05). Special IgE level to FX5 and the degree of food-specific IgG to wheat were seen higher in exfoliative cheilitis patients than in healthy control (P < 0.05).

Conclusion

This study suggests that patients with exfoliative cheilitis may have predisposition of hypersensitivity. The detection of allergens should be strengthened in the future clinical work.

Allergic manifestations in autoimmune gastrointestinal disorders

Allergic disorders target a young population, are increasing in both incidence and prevalence and are associated with significant disease burden. They result from the complex interplay between (epi)genetic and environmental factors, resulting in a Th2 inflammatory process targeting the epithelium of the respiratory tract (allergic rhinitis and asthma), skin (atopic dermatitis), and gastrointestinal tract (food allergy). Although the exact pathogenic mechanisms remain elusive, an altered immune system response in the gut is increasingly recognized as a relevant step. Allergic and gastrointestinal autoimmune disorders share several epidemiological, pathogenic and risk factors and several treatment modalities. Here we revise the current literature and show that allergic disorders are highly prevalent in gastrointestinal autoimmune diseases, including celiac disease, inflammatory bowel disease, autoimmune pancreatitis, and autoimmune cholangiopathies. No data are available for some autoimmune diseases, such as autoimmune gastritis and autoimmune enteropathy. To ensure the comprehensive care of patients with autoimmune gastrointestinal disorders, along with disease-specific factors, the presence of allergic disorders should be evaluated and treated when present, possibly targeting shared molecular pathways. Future studies are needed to define the exact pathogenic mechanisms underpinning the association between allergic and autoimmune diseases of the gastrointestinal tract.

Integrated Analysis of Multiple Microarray Studies to Identify Novel Gene Signatures in Ulcerative Colitis

Background: Ulcerative colitis (UC) is a chronic, complicated, inflammatory disease with an increasing incidence and prevalence worldwide. However, the intrinsic molecular mechanisms underlying the pathogenesis of UC have not yet been fully elucidated.

Methods: All UC datasets published in the GEO database were analyzed and summarized. Subsequently, the robust rank aggregation (RRA) method was used to identify differentially expressed genes (DEGs) between UC patients and controls. Gene functional annotation and PPI network analysis were performed to illustrate the potential functions of the DEGs. Some important functional modules from the protein-protein interaction (PPI) network were identified by molecular complex detection (MCODE), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG), and analyses were performed. The results of CytoHubba, a plug for integrated algorithm for biomolecular interaction networks combined with RRA analysis, were used to identify the hub genes. Finally, a mouse model of UC was established by dextran sulfate sodium salt (DSS) solution to verify the expression of hub genes.

Results: A total of 6 datasets met the inclusion criteria (GSE38713, GSE59071, GSE73661, GSE75214, GSE87466, GSE92415). The RRA integrated analysis revealed 208 significant DEGs (132 upregulated genes and 76 downregulated genes). After constructing the PPI network by MCODE plug, modules with the top three scores were listed. The CytoHubba app and RRA identified six hub genes: LCN2, CXCL1, MMP3, IDO1, MMP1, and S100A8. We found through enrichment analysis that these functional modules and hub genes were mainly related to cytokine secretion, immune response, and cancer progression. With the mouse model, we found that the expression of all six hub genes in the UC group was higher than that in the control group (P < 0.05).

Conclusion: The hub genes analyzed by the RRA method are highly reliable. These findings improve the understanding of the molecular mechanisms in UC pathogenesis.

Levels of serum IgG subclasses in patients with liver disease: A retrospective study

Viral and alcoholic liver disease, drug induced liver disease (DILD), primary biliary cirrhosis (PBC) and autoimmune hepatitis (AIH) are among the most common liver diseases observed in clinical practice. These diseases lack unique clinical characteristics at the beginning of pathogenesis, which renders specific diagnosis difficult. Immunoglobulin G (IgG) subclasses are the main isoform of antibodies that can be found in the serum that serve important protective roles in immunity. The present study aimed to investigate the serum IgG subclass distribution in patients with the five common liver diseases aforementioned. The present study retrospectively recorded and analyzed the serum IgG subclass levels of different patients, who were grouped according to their clinical diagnosis. Serum IgG subclass levels were measured using immunonephelometric assays. IgG3 levels were found to be significantly increased whereas IgG4 levels were significantly decreased in patients with PBC. In patients with AIH, IgG1 levels were significantly increased. By contrast, IgG1/IgG level ratios in patients with viral liver disease were significantly increased. No clear pattern in the distribution characteristics of IgG subclasses could be observed in cohorts with alcoholic liver disease and DILD in the present study. Additionally, model for end-stage liver disease scores regarding IgG1 in patients with AIH shared a synergistic relationship. Anti-mitochondrial antibody subtype M2 (AMA-M2) and IgG3 in patients with PBC demonstrated a synergistic relationship. These results suggested that IgG subclasses may be used as biomarkers to further the understanding of liver disease, which could allow for early diagnosis.

Dietary Strategies for Maintenance of Clinical Remission in Inflammatory Bowel Diseases: Are We There Yet?

The etiopathogenesis of Inflammatory bowel disease (IBD) is a result of a complex interaction between host immune response, the gut microbiome and environmental factors, such as diet. Although scientific advances, with the use of biological medications, have revolutionized IBD treatment, the challenge for maintaining clinical remission and delaying clinical relapse is still present. As exclusive enteral nutrition has become a well-established treatment for the induction of remission in pediatric Crohn's disease, the scientific interest regarding diet in IBD is now focused on the development of follow-on dietary strategies, which aim to suppress colonic inflammation and delay a disease flare. The objective of this review is to present an extensive overview of the dietary strategies, which have been used in the literature to maintain clinical remission in both Crohn's disease and Ulcerative colitis, and the evidence surrounding the association of dietary components with clinical relapse. We also aim to provide study-related recommendations to be encompassed in future research studies aiming to investigate the role of diet during remission periods in IBD.

Dynamic immunoglobulin responses to gut bacteria during inflammatory bowel disease

Aberrant immune responses against gut microbiota are thought to be key drivers of inflammatory bowel disease (IBD) pathogenesis. However, the extent and targets of immunoglobulin (Ig) A versus IgG responses to gut bacteria in IBD and its association with IBD severity is not well understood. Here, we address this by analyzing fecal samples from Crohn's disease (CD), ulcerative colitis (UC), and Non-IBD patients by flow cytometry for the frequency of bacteria that were endogenously bound with IgA and/or IgG. Assessment of IBD patients from two geographically distinct cohorts revealed increased percentages of IgA- and IgG-bound fecal bacteria compared to non-IBD controls. Notably, the two major subsets of IBD showed distinct patterns of Ig-bound bacteria, with CD activity associated with increases in both IgA and IgG-bound bacteria, whereas UC activity correlated only with increases in IgG-bound bacteria. Analysis of the flow sorted Ig-bound bacterial repertoire by 16S rDNA sequencing revealed taxa that were Ig-bound specifically in IBD. Notably, this included bacteria that are also thought to reside in the oral pharynx, including Gemella, Peptostreptococcus, and Streptococcus species. These data show that the pattern of IgA and IgG binding to fecal bacteria is distinct in UC and CD. In addition, the frequency of Ig-bound fecal bacteria may have potential as a non-invasive biomarker for disease activity. Finally, our results support the hypothesis that immune responses to oral pharyngeal bacteria may play an important role in the pathogenesis of IBD.

Serum Biomarkers for Inflammatory Bowel Disease

Background: Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a chronic, inflammatory disorder of the gastrointestinal tract. As the novel therapeutic goal and biologicals are widely recognized, accurate assessment of disease and prediction of therapeutic response have become a crucial challenge in clinical practice. Also, because of the continuously rising incidence, convenient and economical methods of diagnosis and clinical assessment are urgently needed. Recently, serum biomarkers have made a great progress and become a focus in IBD study because they are non-invasive, convenient, and relatively inexpensive than are markers in biopsy tissue, stool, breath, and other body fluids.

Aims: To review the available data on serological biomarkers for IBD.

Methods: We searched PubMed using predefined key words on relevant literatures of serum biomarkers regarding diagnosis, evaluation of therapeutic efficacy, surveillance of disease activity, and assessment of prognosis for IBD.

Results: We reviewed serological biomarkers that are well-established and widely used (e.g., C-reactive protein), newly discovered biomarkers (e.g., cytokines, antibodies, and non-coding RNAs), and also recently advancements in serological biomarkers (e.g., metabolomics and proteomics) that are used in different aspects of IBD management.

Conclusions: With such a wealth of researches, to date, there are still no ideal serum biomarkers for IBD. Serum profiling and non-coding RNAs are just starting to blossom but reveal great promise for future clinical practice. Combining different biomarkers can be valuable in improving performance of disease evaluation.

Fecal Eosinophil Cationic Protein Is a Diagnostic and Predictive Biomarker in Young Adults with Inflammatory Bowel Disease

BACKGROUND AND AIMS

Fecal biomarkers are important non-invasive markers monitoring disease activity in inflammatory bowel disease (IBD). We compared the significance of fecal eosinophil cationic protein (fECP) and fecal calprotectin (fCal).

METHODS

fECP and fCal were measured in patients with Crohn's disease (CD, n = 97), ulcerative colitis (UC, n = 53), Clostridioides difficile infection (CDI, n = 9), primary food allergy (PFA, n = 11), pollen-associated food allergy (n = 25) and non-inflammatory controls (n = 78). Results were correlated with clinical and endoscopic IBD activity scores.

RESULTS

fECP was significantly elevated in CD, UC, CDI and PFA compared to controls. fCal was significantly increased in CD, UC and CDI. fECP had lower diagnostic accuracy than fCal (area under the curve (AUC) = 0.88) in differentiating between endoscopically active and inactive patients with IBD (AUC = 0.77, ROC analysis). In contrast to fCal, fECP correlated negatively with age and levels were also elevated in clinically and endoscopically inactive patients with IBD <45 years (endoscopically inactive IBD vs controls; AUC for fECP = 0.86; AUC for fCal = 0.62). However, in those patients with low inflammatory activity (fCal <250 mg/kg), high fECP indicated the need for treatment modification or surgery (fECP <200 µg/kg = 22%; 200-600 µg/kg = 44%; >600 µg/kg = 82%) at month 48 of follow-up.

CONCLUSIONS

fECP is a diagnostic and prognostic marker in young patients with IBD in remission.

Emergent Behavior of IBD-Associated Escherichia coli During Disease

Inflammatory bowel diseases are becoming increasingly common throughout the world, both in developed countries and increasingly in rapidly developing countries. Multiple lines of evidence point to a role for the microbial composition of the gastrointestinal tract in the etiology of IBD, but to date, attempts to define a specific microbial cause for IBD have proved unsuccessful. Microbial 16S rRNA profiling shows that IBD patients have elevated levels of Enterobacteriaceae, in particular Escherichia coli, and reduced levels of Faecalibacterium prausnitzii. The observed E. coli have been assigned to a specific pathovar, adherent-invasive E. coli (AIEC). Adherent-invasive E. coli are a genomically heterogenous group, and whereas many groups have attempted to identify specific genetic markers that differentiate AIEC from non-AIEC strains, very few concrete genetic associations have been uncovered. Here, we highlight the advantages of applying a phenotyping approach to the study of these organisms, rather than solely depending on a sequencing or genomic-based screening strategy because virulence-associated phenotypes exhibit behaviors of emergent systems. In this respect, attempts at genetic reductionism are prone to failure because there are numerous metabolic, regulatory or genetic paths that can underlie these virulence-associated behaviors. Here, we review these IBD-associated phenotypes in E. coli and make recommendations for experimental approaches to advance our understanding of IBD-associated bacteria more generally. With advances in high-throughput screening and nongenetically based metabolomic characterization of IBD-associated bacteria, we anticipate a fuller understanding of how altered microbial communities contribute to the development of IBD.

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.

Gut biofilm forming bacteria in inflammatory bowel disease

Inflammatory bowel disease (IBD) symbolizes a group of intestinal disorders in which prolonged inflammation occur in the digestive tract (esophagus, large intestine, small intestine mouth, stomach). Both genetic and environmental factors (infections, stress, diet) are involved in the development of IBD. As we know that bacteria are found in the intestinal mucosa of human and clinical observations revealed bacterial biofilms associated with patients of IBD. Various factors and microbes are found to play an essential role in biofilm formation and mucosal colonization during IBD. Biofilm formation in the digestive tract is dependent on an extracellular matrix synthesized by the bacteria and it has an adverse effect on the immune response of the host. There is no satisfactory and safe treatment option for IBD. Therefore, the current research aims to disrupt biofilm in IBD and concentrates predominantly on improving the drug. Here, we review the literature on bacterial biofilm and IBD to gather new knowledge on the current understanding of biofilm formation in IBD, host immune deregulation and dysbiosis in IBD, molecular mechanism, bacteria involved in biofilm formation, current and future regimen. It is urgently required to plan new ways to control and eradicate bacteria in biofilms that will open up novel diagnostic and therapeutic avenues for IBD. This article includes the mechanism of signaling molecules with respect to the biofilm-related genes as well as the diagnostic methods and new technologies involved in the treatment of IBD.

Prevalence of IgG-mediated food intolerance among patients with allergic symptoms

BACKGROUND

Food intolerance mediated by food specific IgG antibodies has been implicated in a variety of disorders.

OBJECTIVES

To assess the prevalence of food specific IgG antibodies among patients clinically presenting with allergic symptoms lacking laboratory evidence of allergy.

DESIGN

Descriptive retrospective cross-sectional study.

SETTING

King Khalid University Hospital, Riyadh between 2010-2015.

PATIENTS AND METHODS

Patients were screened for food specific IgG antibodies. All symptomatic patients lacking laboratory evidence of allergy who underwent food specific IgG testing during the study duration were included.

MAIN OUTCOME MEASURE(S)

Levels of IgG antibodies in patients with unidentified allergic symptoms.

RESULTS

We selected 71 patients with allergic symptoms lacking laboratory evidence of allergy. There were 49 female and 22 male patients mean age 38.8 (16.0) years. The majority (85.7%) had urticaria. The most frequently occurring food specific IgG antibodies were against cola nut in 80.3% of patients followed by yeast in 78.9%, wheat in 77.5%, red kidney bean in 71.8%, pea in 63.4%, corn in 62% and egg white in 62% of the patients. Compared with male patients, females harbored significantly higher food specific IgG antibodies for frequently occurring food materials, particularly against wheat (74% vs 25.5%; P < .0001), corn (77.3% vs 22.7%; P < .0001) and cola nut (71.9% vs 28.1%; P < .001). Patients aged less than 40 years had higher levels of food specific IgG against gliadin (P < .003), egg white (P < .03) and barley (P < .05) compared with older patients.

CONCLUSION

The detection of a variety of food specific IgG antibodies among patients with allergic symptoms indicates a possible link to food intolerance allergy. Females are prone to develop food intolerance more than males.

LIMITATIONS

Difficulty of comparison of results with previous studies because of lack of data. Follow-up studies could not be performed to assess the effects of elimination from the diet due to limited time allocated for this study.