Crohn's disease and cystic fibrosis

Autoimmunity in people with cystic fibrosis

Cystic fibrosis (CF) clinicians may see patients who have difficult-to-manage symptoms that do not have a clear CF-related etiology, such as unusual gastrointestinal (GI) complaints, vasculitis, or arthritis. Alterations in immunity, inflammation and intraluminal dysbiosis create a milieu that may lead to autoimmunity, and the CF transmembrane regulator protein may have a direct role as well. While autoantibodies and other autoimmune markers may develop, these may or may not lead to organ involvement, therefore they are helpful but not sufficient to establish an autoimmune diagnosis. Autoimmune involvement of the GI tract is the best-established association. Next steps to understand autoimmunity in CF should include a more in-depth assessment of the community perspective on its impact. In addition, bringing together specialists in various fields including, but not limited to, pulmonology, gastroenterology, immunology, and rheumatology, would lead to cross-dissemination and help define the path forward in basic science and clinical practice.

Epithelial TNF controls cell differentiation and CFTR activity to maintain intestinal mucin homeostasis

The gastrointestinal tract relies on the production, maturation, and transit of mucin to protect against pathogens and to lubricate the epithelial lining. Although the molecular and cellular mechanisms that regulate mucin production and movement are beginning to be understood, the upstream epithelial signals that contribute to mucin regulation remain unclear. Here, we report that the inflammatory cytokine tumor necrosis factor (TNF), generated by the epithelium, contributes to mucin homeostasis by regulating both cell differentiation and cystic fibrosis transmembrane conductance regulator (CFTR) activity. We used genetic mouse models and noninflamed samples from patients with inflammatory bowel disease (IBD) undergoing anti-TNF therapy to assess the effect of in vivo perturbation of TNF. We found that inhibition of epithelial TNF promotes the differentiation of secretory progenitor cells into mucus-producing goblet cells. Furthermore, TNF treatment and CFTR inhibition in intestinal organoids demonstrated that TNF promotes ion transport and luminal flow via CFTR. The absence of TNF led to slower gut transit times, which we propose results from increased mucus accumulation coupled with decreased luminal fluid pumping. These findings point to a TNF/CFTR signaling axis in the adult intestine and identify epithelial cell-derived TNF as an upstream regulator of mucin homeostasis.

Cftr deletion in mouse epithelial and immune cells differentially influence the intestinal microbiota

Cystic fibrosis (CF) is a life-threatening genetic disorder, caused by mutations in the CF transmembrane-conductance regulator gene (cftr) that encodes CFTR, a cAMP-activated chloride and bicarbonate channel. Clinically, CF lung disease dominates the adult patient population. However, its gastrointestinal illness claims the early morbidity and mortality, manifesting as intestinal dysbiosis, inflammation and obstruction. As CF is widely accepted as a disease of epithelial dysfunction, it is unknown whether CFTR loss-of-function in immune cells contributes to these clinical outcomes. Using cftr genetic knockout and bone marrow transplantation mouse models, we performed 16S rRNA gene sequencing of the intestinal microbes. Here we show that cftr deletion in both epithelial and immune cells collectively influence the intestinal microbiota. However, the immune defect is a major factor determining the dysbiosis in the small intestine, while the epithelial defect largely influences that in the large intestine. This finding revises the current concept by suggesting that CF epithelial defect and immune defect play differential roles in CF intestinal disease.

Epidemiology of Eosinophilic Esophagitis in Patients with Cystic Fibrosis: A Population-Based 5-Year Study

PURPOSE

The prevalence of eosinophilic esophagitis (EoE) has been on the rise since it was first described in the 1990s. Several diseases and exogenous factors have been associated with EoE. Our aim was to investigate the epidemiology of EoE in cystic fibrosis (CF) patients.

METHODS

We identified individuals with CF from September 2014 to September 2019 within a database (IBM Explorys Solutions, Inc.). The prevalence of EoE in patients with CF was compared to the general population.

RESULTS

The database included 36,111,860 patients during the 5-year study period: 12,950 with CF (0.036%) and 28,090 with EoE (0.078%). EoE prevalence was higher in CF patients than the general population (46 in 10,000 vs. 7.8 in 10,000, p<0.001). Patients with CF and EoE were more likely to be male (50% vs. 33.5%, p<0.008), children (33.3% vs. 16.5%, p<0.001), and non-Hispanic (100% vs. 88.7%, p<0.001) than CF patients without EoE. CF with EoE patients were more likely to be children than EoE only (33.3% vs. 10.5%, p<0.001). Allergic conditions were generally more prevalent in CF with EoE than CF only (83.3% vs. 68.3%, p=0.01) and EoE only (83.3% vs. 69.3%, p=0.014).

CONCLUSION

EoE is nearly 6-times more prevalent in CF patients. Those patients had higher incidence of other atopic conditions. EoE must be considered in the differential diagnosis of patients with CF presenting with dysphagia, refractory gastroesophageal reflux, vomiting, and other esophagus-related symptoms.

Neutrophil dysfunction in the pathogenesis of cystic fibrosis

Polymorphonuclear neutrophils (PMNs) figure prominently in host defense against infection and in noninfectious inflammation. Mobilized early in an inflammatory response, PMNs mediate immediate cellular defense against microbes and orchestrate events that culminate in cessation of inflammation and restoration of homeostasis. Failure to terminate the inflammatory response and its causes can fuel exuberant inflammation characteristic of many human diseases, including cystic fibrosis (CF), an autosomal recessive genetic disease caused by mutations in the CF transmembrane conductance regulator. CF affects multiple end organs, with persistent bacterial infection and chronic neutrophilic inflammation in airways predominating the clinical picture. To match the diverse microbial challenges that they may encounter, PMNs possess a variety of antimicrobial systems to slow or kill invading microorganisms confined in their phagosomes. Prominent among PMN defense systems is their ability to generate hypochlorous acid, a potent microbicide, by reacting oxidants generated by the NADPH oxidase with myeloperoxidase (MPO) released from azurophilic granules in the presence of chloride (Cl-). Products of the MPO-H2O2-Cl system oxidize susceptible biomolecules and support robust antimicrobial action against many, but not all, potential human pathogens. Underscoring that the MPO-H2O2-Cl system is integral to optimal host defense and proper regulation of inflammation, individuals with defects in any component of this system, as seen in chronic granulomatous disease or MPO deficiency, incur increased rates or severity of infection and signs of dysregulated inflammatory responses. We focus attention in this review on the molecular basis for and the clinical consequences of defects in the MPO-H2O2-Cl system because of the compromised Cl transport seen in CF. We will discuss first how the MPO-H2O2-Cl system in healthy PMNs participates in host defense and resolution of inflammation and then review how a defective MPO-H2O2-Cl system contributes to the increased susceptibility to infection and dysregulated inflammation associated with the clinical manifestations of CF.

Digestive outcomes in Cystic fibrosis

Cystic fibrosis (CF) is the most frequent life-limiting autosomal recessive disease in Caucasians, affecting the respiratory tract, but also the pancreas, gut, and hepatobiliary tract. CF is caused by variants in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene. Prognosis of CF has markedly improved over the last 20 years because of the management in CF centers and recent introduction of CFTR modulators, aimed at correcting the defective CFTR protein. There are nowadays more CF adults than children, with a predicted median survival age of around 50 years in high-income countries. Around 85% of CF patients have pancreatic insufficiency present at birth. Gastroesophageal reflux disease (GERD) is more frequent in CF patients, but its role on decline in lung health is controversial. Distal small bowel obstruction syndrome (DIOS) caused by meconium-like stool plugs occurs at any age after the neonatal period, affecting up to 15-20% of CF patients. Because of increased life expectancy, most CF patients are expected to live to their fifties or beyond, when cancer is more frequent. In addition, CF is associated with a higher risk for GI malignancy as compared with the general population. Colorectal cancer represents the most significant risk, and colonoscopy-based screening is recommended from 40 years of age onwards. Other digestive outcomes in CF reviewed in this paper include meconium ileus, Clostridium difficile infection, intussusception, acute appendicitis, small intestinal bacterial overgrowth, appendiceal mucocele and rectal prolapse. Every CF Center should comprise a gastroenterologist with expertise in the care of CF patients.

De Novo Inflammatory Bowel Disease Rarely Occurs During Posttransplant Immunosuppression

OBJECTIVES

De novo chronic idiopathic inflammatory bowel disease (CIIBD) is reported to occur at higher rates in posttransplant patients than that of the general population. The previous reports, however, included patients with primary sclerosing cholangitis (PSC), a known association with CIIBD. Hence, we investigated how often posttransplant de novo CIIBD occurs in the absence of PSC.

METHODS

We identified 185 posttransplant adults without a history of PSC or CIIBD, who had undergone colonoscopy between July 2013 and June 2020. Biopsies were reviewed and clinical data were gathered.

RESULTS

CIIBD-like colitis accounted for 1.1% (2/185) of our cohort. The 2 affected patients were already taking multiple immunosuppressive therapies. They were initially placed on standard CIIBD maintenance therapy, but then required escalation therapy. One patient had persistent active colitis despite escalation therapy, while the other subsequently had resolution of symptoms and developed quiescent disease.

CONCLUSIONS

The incidence of CIIBD-like colitis in our study population was lower than what has been previously described. Both patients had a poor response to standard CIIBD therapy, raising the question whether their diagnosis is truly de novo CIIBD or another immunologic process.

The Gut-Lung Axis in Cystic Fibrosis

Cystic fibrosis (CF) is a heritable, multiorgan disease that impacts all tissues that normally express cystic fibrosis transmembrane conductance regulator (CFTR) protein. While the importance of the airway microbiota has long been recognized, the intestinal microbiota has only recently been recognized as an important player in both intestinal and lung health outcomes for persons with CF (pwCF). Here, we summarize current literature related to the gut-lung axis in CF, with a particular focus on three key ideas: (i) mechanisms through which microbes influence the gut-lung axis, (ii) drivers of microbiota alterations, and (iii) the potential for intestinal microbiota remediation.

Approach to chronic abdominal pain in Cystic Fibrosis

Abdominal pain in individuals with CF is challenging for the patient as well as the physician, as the differential diagnosis can be complex. Most gastrointestinal manifestations of CF present with regional abdominal pain. Pain localization, which requires knowledge of gut development and innervation, is crucial to understanding the pathophysiology of abdominal pain in CF. The location of the pain, together with the clinical presentation, shapes the differential diagnosis and thus guides the evaluation and management.

Practical approach to the gastrointestinal manifestations of cystic fibrosis

Cystic fibrosis (CF) is the most common, life-shortening, genetic illness affecting children in Australia and New Zealand. The genetic abnormality results in abnormal anion transport across the apical membrane of epithelial cells in a number of organs, including the lungs, gastrointestinal tract, liver and genito-urinary tract. Thus, CF is a multi-system disorder that requires a multi-disciplinary approach. Respiratory disease is the predominant cause of both morbidity and mortality in patients with CF. However, there are significant and clinically relevant gastrointestinal, liver, pancreatic and nutritional manifestations that must be detected and managed in a timely and structured manner. The aim of this review is to provide evidence-based information and clinical algorithms to guide the nutritional and gastrointestinal management of patients with CF.

Gastrointestinal, Pancreatic, and Hepatobiliary Manifestations of Cystic Fibrosis

Pulmonary disease is the primary cause of morbidity and mortality in people with cystic fibrosis (CF), but significant involvement within gastrointestinal, pancreatic, and hepatobiliary systems occurs as well. As in the airways, defects in CFTR alter epithelial surface fluid, mucus viscosity, and pH, increasing risk of stasis through the various hollow epithelial-lined structures of the gastrointestinal tract. This exerts secondary influences that are responsible for most gastrointestinal, pancreatic, and hepatobiliary manifestations of CF. Understanding these gastrointestinal morbidities of CF is essential in understanding and treating CF as a multisystem disease process and improving overall patient care.

Beyond pancreatic insufficiency and liver disease in cystic fibrosis

Cystic fibrosis is a life shortening hereditary disease, primarily leading to progressive pulmonary infection and exocrine pancreatic dysfunction. Several gastrointestinal complications other than malabsorption can arise during the disease course and with the progressively increasing life span of patients with CF; new and more rare complications are being recognized. We review the literature on gastrointestinal manifestations in CF, excluding the liver and pancreas.

CONCLUSION

We describe the clinical presentation and treatment of more common conditions like gastroesophageal reflux, small intestinal bacterial overgrowth, intussusception, meconium ileus, distal intestinal obstruction syndrome, and constipation, and we also discuss what is known on celiac disease, appendicitis, fibrosing colonopathy, inflammation and inflammatory bowel disease and gastrointestinal cancer.

WHAT IS KNOWN

• Gastrointestinal complications arise early in the course of the disease and have a severe impact on the quality of life of the patients. What is New: • This review is a concise summary of the current literature on gastrointestinal complications of cystic fibrosis. • We focused on clinical presentation and diagnostic investigations and provide a comprehensive resume of the current treatment options.

Cystic fibrosis from the gastroenterologist's perspective

Cystic fibrosis is a life-limiting, recessive disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Increased survival outcomes and the multisystem nature of the disease, including the involvement of hepatobiliary and gastrointestinal tracts, now require the need for more extensive knowledge and expertise in cystic fibrosis among gastroenterologists. Manifestations are either a direct consequence of the primary defect in cystic fibrosis or a secondary complication of the disease or therapy. Adult patients with cystic fibrosis also have an increased risk of malignancy in the gastrointestinal and pancreatico-biliary tracts compared with the general population. Novel treatments that target the basic defects in the CFTR protein have emerged, but to date not much is known about their effects on the gastrointestinal and hepatobiliary systems. The introduction of such therapies has provided new opportunities for the application of intestinal endpoints in clinical trials and the understanding of underlying disease mechanisms that affect the gut in cystic fibrosis.

CFTR Knockdown induces proinflammatory changes in intestinal epithelial cells

Background

Hyperinflammation is a hallmark feature of cystic fibrosis (CF) airways. However, inflammation has also been documented systemically and, more recently, in extrapulmonary CF-affected tissues such as the pancreas and intestine. The pathogenesis of CF-related inflammation and more specifically the role of the cystic fibrosis transmembrane conductance regulator (CFTR) in that respect are not entirely understood. We have tested the hypothesis that genetic depletion of CFTR will affect the inflammatory status of human intestinal epithelial cell lines.

Methods

CFTR expression was genetically depleted from Caco-2/15 and HT-29 cells using short hairpin RNA interference (shRNAi). Inflammatory conditions were induced by the addition of human recombinant tumor necrosis factor (TNF) or Interleukin-1β (IL-1β) for various periods of time. Gene expression, mRNA stability and secreted levels of interleukin (IL)-6, −8 and 10 were assessed. Analysis of pro- and anti-inflammatory signaling pathways including mitogen-activated protein kinases (p38, ERK 1/2 and JNK), nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor alpha (IκBα), and nuclear factor-kappa B (NF-κB) was also performed. Eosinophils were counted in the jejunal mucosa of Cftr−/− and Cftr+/+ mice.

Results

CFTR gene and protein knockdown caused a significant increase in basal secretion of IL-8 as well as in IL-1β-induced secretion of IL-6 and −8. Release of the anti-inflammatory cytokine, IL-10, remained unaffected by CFTR depletion. The enhanced secretion of IL-8 stems in part from increased IL8 mRNA levels and greater activation of ERK1/2 MAPK, IκBα and NF-κB in the CFTR knockdown cells. By contrast, phosphorylation levels of p38 and JNK MAPK did not differ between control and knockdown cells. We also found a higher number of infiltrating eosinophils in the jejunal mucosa of Cftr −/− females, but not males, compared to Cftr +/+ mice, thus providing in vivo support to our in vitro findings.

Conclusion

Collectively, these data underscore the role played by CFTR in regulating the intestinal inflammatory responses. Such findings lend support to the theory that CFTR exerts functions that may go beyond its role as a chloride channel whereby its disruption may prevent cells to optimally respond to exogenous or endogenous challenges. These observations are of particular interest to CF patients who were found to display alterations in their intestinal microbiota, thus predisposing them to pathogens that may elicit exaggerated inflammatory responses.

Electronic supplementary material

The online version of this article (doi:10.1186/s12950-015-0107-y) contains supplementary material, which is available to authorized users.

Inflammation in cystic fibrosis lung disease: Pathogenesis and therapy

Lung disease is the major cause of morbidity and mortality in patients with cystic fibrosis (CF). Although CF lung disease is primarily an infectious disorder, the associated inflammation is both intense and ineffective at clearing pathogens. Persistent high-intensity inflammation leads to permanent structural damage of the CF airways and impaired lung function that eventually results in respiratory failure and death. Several defective inflammatory responses have been linked to cystic fibrosis transmembrane conductance regulator (CFTR) deficiency including innate and acquired immunity dysregulation, cell membrane lipid abnormalities, various transcription factor signaling defects, as well as altered kinase and toll-like receptor responses. The inflammation of the CF lung is dominated by neutrophils that release oxidants and proteases, particularly elastase. Neutrophil elastase in the CF airway secretions precedes the appearance of bronchiectasis, and correlates with lung function deterioration and respiratory exacerbations. Anti-inflammatory therapies are therefore of particular interest for CF lung disease but must be carefully studied to avoid suppressing critical elements of the inflammatory response and thus worsening infection. This review examines the role of inflammation in the pathogenesis of CF lung disease, summarizes the results of past clinical trials and explores promising new anti-inflammatory options.

Cystic fibrosis related liver disease--another black box in hepatology

Due to improved medical care, life expectancy in patients with cystic fibrosis (CF) has veritably improved over the last decades. Importantly, cystic fibrosis related liver disease (CFLD) has become one of the leading causes of morbidity and mortality in CF patients. However, CFLD might be largely underdiagnosed and diagnostic criteria need to be refined. The underlying pathomechanisms are largely unknown, and treatment strategies with proven efficacy are lacking. This review focuses on current invasive and non-invasive diagnostic standards, the current knowledge on the pathophysiology of CFLD, treatment strategies, and possible future developments.

The clinical significance of the gut microbiota in cystic fibrosis and the potential for dietary therapies

Cystic fibrosis (CF) is characterised by many comorbidities related to aberrant mucosa and chronic inflammation in the respiratory and digestive systems. The intestinal mucosa serves as the primary interface between the gut microbiota and endocrine, neural and immune systems. There is emerging evidence that aberrant intestinal mucosa in CF may associate with an altered gut microbiota. Compared to healthy subjects, the overall bacterial abundance and species richness seems to be reduced in CF, accompanied by a trend in suppression of Firmicutes and Bacteroidetes spp. and an augmentation of potentially pathogenic species. There is also some concordance of gut and respiratory microbiotas in CF infants over time. The clinical significance of these observations awaits investigation. The gut microbiota have some potential in CF management by affecting inflammatory and immune responses, and influencing aberrant mucosa. As an important modifiable factor, diet therapies such as probiotics and prebiotics have shown initial promise in improving CF related conditions associated with chronic inflammation. More studies are needed to confirm this, as well as the efficacy of other dietary strategies such as modulating dietary fat and indigestible carbohydrate. Similarly, dietary modification of gut microbiota to optimise nutritional status in CF may be feasible, although more CF-specific studies are warranted.

The role of endoscopy and biopsy in the management of severe gastrointestinal disease in cystic fibrosis patients

There is increasing evidence to suggest the presence of chronic inflammation in the gastrointestinal (GI) tract of cystic fibrosis (CF) patients. Some CF patients continue to have very severe gastrointestinal symptoms despite conventional CF treatment. In our center, these patients are managed in a CF gastroenterology clinic, jointly with a pediatric gastroenterologist. A number have required GI endoscopy and biopsy. The aim of our study was to characterize these patients and determine whether endoscopy and biopsy changed their management. We reviewed all the patients seen in the CF gastroenterology clinic from 2004 to 2009, who had GI endoscopies performed. The GI symptoms these patients were experiencing included abdominal pain, nausea and vomiting, rectal bleeding, failure to thrive, loose stools, and constipation. Twelve patients had GI endoscopies with mucosal biopsies performed. The median [interquartile range (IQR)] age at referral to the CF gastroenterology clinic was 4 years [0.9-8]. Their body mass index (BMI) was 15.2 [13.7-15.5]. Twenty-five percent were homozygous delta F508. Two patients had previously had meconium ileus as neonates requiring surgical intervention. One other patient had needed abdominal surgery for intussusception. Ninty-two percent were pancreatic insufficient, 25% were chronically infected with Pseudomonas aeruginosa and 17% were on regularly 3 monthly intravenous antibiotics. Of the 10 patients who were able to perform spirometry, FEV1 was 101% [67-125] predicted. Nine of the 12 patients had evidence of mucosal inflammation in their biopsies, including duodenitis with eosinophilic infiltrate, chronic non-specific inactive gastritis, enteropathy with partial villous atrophy, and non-specific colitis. Immunosuppressive and anti-inflammatory therapies were commenced in these nine patients, including prednisolone, azathioprine, methotrexate, ketotifen, mesalazine, and sulfasalazine as well as the use of parenteral nutrition and elemental feeds. All the patients clinically responded to therapy. Five of the patients commenced on anti-inflammatory therapy had repeat biopsies 1-5 years following commencement of treatment and all showed histological improvement of the mucosal inflammation. GI endoscopy with mucosal biopsy has a significant role to play in the management of CF children with severe GI disease. In our study, it influenced the management in the majority of patients with severe GI symptoms. Furthermore, if GI mucosal inflammation is identified on biopsy, management with immunomodulatory agents may be clinically beneficial.

The cystic fibrosis intestine

The clinical manifestations of cystic fibrosis (CF) result from dysfunction of the cystic fibrosis transmembrane regulator protein (CFTR). The majority of people with CF have a limited life span as a consequence of CFTR dysfunction in the respiratory tract. However, CFTR dysfunction in the gastrointestinal (GI) tract occurs earlier in ontogeny and is present in all patients, regardless of genotype. The same pathophysiologic triad of obstruction, infection, and inflammation that causes disease in the airways also causes disease in the intestines. This article describes the effects of CFTR dysfunction on the intestinal tissues and the intraluminal environment. Mouse models of CF have greatly advanced our understanding of the GI manifestations of CF, which can be directly applied to understanding CF disease in humans.

Gastrointestinal complications of cystic fibrosis

The cystic fibrosis transmembrane regulator protein (CFTR) is an ion channel in the apical surface of epithelial membranes that regulates other ion channels. Dysfunction of CFTR leads to the clinical entity of CF when mutations in CFTR are inherited in an autosomal recessive fashion. Although airway obstruction, inflammation, and infection are usually the most serious consequences of CFTR dysfunction because they lead to respiratory failure, CFTR dysfunction affects the intestinal tract and the pancreatic and hepatobiliary ducts in a similar fashion, leading to significant morbidity. This review outlines pathophysiology and common gastrointestinal ailments in the CF population along with current medical and surgical management.

Gastrointestinal surgery in adult patients with cystic fibrosis

OBJECTIVE

Gastrointestinal conditions requiring surgical intervention are becoming increasingly frequent in adults with cystic fibrosis (CF) as life expectancy increases. In addition, patients with CF are at risk of specific gastrointestinal complications associated with their disease. This includes distal intestinal obstruction syndrome (DIOS), which may affect up to 15% of patients, and can present diagnostic and therapeutic challenges. The aim of this study was to determine the nature and frequency of general surgical procedures undertaken in a large cohort of adult CF patients so as to guide future care.

DESIGN

The medical records of all surviving adult CF patients followed at a large tertiary referral centre in the UK were scrutinised and details retrieved on those who had undergone abdominal surgery after the age of 16 years.

RESULTS

A total of 377 patients with CF were identified from the prospectively held database. Thirty-three patients had undergone 43 abdominal operations. The median age at surgery was 22.7 years (range 16-58 years). The three most commonly performed operations were: surgery for DIOS (n=9); cholecystectomy (n=8) and fundoplication (n=6). A past history of surgically treated meconium ileus at birth was a significant risk factor for requiring surgery for DIOS as an adult.

CONCLUSIONS

The treatment of DIOS-related complications is one of the main reasons for abdominal surgery in the adult CF population. The general surgical community needs to be increasingly aware of the existence of disease-related gastrointestinal conditions in adult CF patients so that treatment can be optimised.

Increased levels of anti-glycan antibodies in patients with cystic fibrosis

Background

The prevalence of Crohn's disease (CD) is increased in patients with cystic fibrosis (CF). Anti-Saccharomyces cerevisiae antibodies (ASCA) have been suggested as a screening tool to detect CD in CF. Recently, several new anti-glycan antibodies have been reported in CD.

Materials and methods

The sera of 119 CF patients of various age groups were prospectively screened for ASCA type IgG (gASCA), anti-laminaribioside carbohydrate IgG antibodies (ALCA), anti-chitobioside carbohydrate IgA antibodies (ACCA), and anti-mannobioside carbohydrate IgG antibodies (AMCA). The frequency of these anti-glycan antibodies was then compared in patients with CD, ulcerative colitis, rheumatoid arthritis and healthy volunteers.

Results

A significant number of CF patients were positive for gASCA (51.3% [41.6-60.6]) and up to three other anti-glycan antibodies concurrently. Serum levels of anti-glycan antibodies in CF and CD were not related to parameters of inflammation. Despite the well-documented difference in clinical course between male and female CF patients no gender difference of anti-glycan antibodies was found. In contrast, there was a significant positive correlation between anti-glycan markers and age in CF patients.

Conclusions

Our findings demonstrate for the first time the increased frequency of a panel of anti-glycan antibodies in CF and provide a link between the presence of these serological biomarkers and patient's age. Anti-glycan antibody profiling may therefore become a valuable tool in the care of patients with CF.

Guidelines for the diagnosis and management of distal intestinal obstruction syndrome in cystic fibrosis patients

Complete or incomplete intestinal obstruction by viscid faecal material in the terminal ileum and proximal colon - distal intestinal obstruction syndrome (DIOS) - is a common complication in cystic fibrosis. Estimates of prevalence range from 5 to 12 episodes per 1000 patients per year in children, with higher rates reported in adults. DIOS is mainly seen in patients with pancreatic insufficiency, positive history of meconium ileus and previous episodes of DIOS. DIOS is being described with increasing frequency following organ transplantation. Diagnosis is based on suggestive symptoms with a right lower quadrant mass confirmed on X-ray. The main differential is chronic constipation. Treatment consists of rehydration combined with stool softening laxatives or gut lavage with balanced electrolyte solutions. Rapid fluid shifts have been described following osmotic agents. Avoiding dehydration and optimizing pancreatic enzyme dosage may reduce the chance of further episodes. Prophylactic laxative therapy is widely used, but is not evidence-based.

Enhanced Ca2+ entry due to Orai1 plasma membrane insertion increases IL-8 secretion by cystic fibrosis airways

Cystic fibrosis (CF) is caused by mutations in the gene encoding the CF transmembrane conductance regulator (CFTR). The most common mutation, ΔF508, causes retention of CFTR in the endoplasmic reticulum (ER). Some CF abnormalities can be explained by altered Ca(2+) homeostasis, although it remains unknown how CFTR influences calcium signaling. This study examined the novel hypothesis that store-operated calcium entry (SOCE) through Orai1 is abnormal in CF. The significance of Orai1-mediated SOCE for increased interleukin-8 (IL-8) expression in CF was also investigated. CF and non-CF human airway epithelial cell line and primary cells (obtained at lung transplantation) were used in Ca(2+) imaging, electrophysiology, and fluorescence imaging experiments to explore differences in Orai1 function in CF vs. non-CF cells. Protein expression and localization was assessed by Western blots, cell surface biotinylation, ELISA, and image correlation spectroscopy (ICS). We show here that store-operated Ca(2+) entry (SOCE) is elevated in CF human airway epithelial cells (hAECs; ≈ 1.8- and ≈ 2.5-fold for total Ca(2+)(i) increase and Ca(2+) influx rate, respectively, and ≈ 2-fold increase in the I(CRAC) current) and is caused by increased exocytotic insertion (≈ 2-fold) of Orai1 channels into the plasma membrane, which is normalized by rescue of ΔF508-CFTR trafficking to the cell surface. Augmented SOCE in CF cells is a major factor leading to increased IL-8 secretion (≈ 2-fold). CFTR normally down-regulates the Orai1/stromal interaction molecule 1 (STIM1) complex, and loss of this inhibition due to the absence of CFTR at the plasma membrane helps to explain the potentiated inflammatory response in CF cells.

Cystic fibrosis and Crohn’s disease: Successful treatment and long term remission with infliximab

The association of cystic fibrosis and Crohn’s disease (CD) is well known, but to date, there are very few cases in the literature of patients suffering from mucoviscidosis who have required treatment with infliximab. We report the case of a 23-year-old patient suffering from cystic fibrosis and severe CD treated successfully with infliximab without any infective complications or worsening of the pulmonary disease and with a long term (2 years) complete remission.

[Inflammatory bowel disease: genetic or environmental diseases?]

Pathophysiology of inflammatory bowel diseases depends on the interaction between genetic susceptibility and environmental factors leading to a deregulated immune intestinal response resulting in bowel lesions. Epidemiologic variations of inflammatory bowel diseases with time (incidence, prevalence) and space suggest a role for risk environmental factors, but so far only smoking habits and appendectomy have been identified as influencing the risk of occurrence and the course of the diseases. Studies of monozygotic and dizygotic twins and the existence of familial aggregation are strong evidence for an important, but not exclusive, role for genetic susceptibility. Since the discovery of NOD2/CARD15 mutations, numerous genes have been associated with inflammatory bowel diseases, some of them involved in the regulation of innate immunity and cellular clearance of infectious agents (autophagy). Thus, new hypothesis include a key role of mucosal human microbiota which could be partly influenced by environmental factors generated by modern life. The improvement of life hygiene, the change of food composition and habits, the industrial pollution in developed countries, may influence, directly or by the way of modifying intestinal human microbiota, inflammatory bowel diseases risk occurrence.

Lymphocytic leiomyositis and myenteric ganglionitis are intrinsic features of cystic fibrosis: studies in distal intestinal obstruction syndrome and meconium ileus

BACKGROUND

Cystic fibrosis (CF) is a multisystem disorder intrinsically associated with inflammation of mucosal surfaces. Because inflammation can result in enteric neuromuscular dysfunction we hypothesized that terminal ileitis in patients with CF may predispose to distal ileal obstruction syndrome (DIOS).

METHODS AND PATIENTS

Full-thickness terminal ileal tissues from 6 children with CF and severe DIOS, 6 infants with complicated meconium ileus (MI), and 6 children with non-CF intestinal atresia were studied.

RESULTS

Lymphocyte-predominant mucosal and transmural ileal inflammation was present in 6 of 6 patients with DIOS. Lymphocytic ganglionitis was present in 4 of 6 although numbers of myenteric neurons were not decreased (5/5). Myocyte proteins were preserved (6/6). Mild submucosal fibrosis was common in DIOS (5/6) and transformation of submucosal fibroblasts to a myofibroblastic phenotype was noted in 4 of 6. Inflammatory changes were distinct from those described in fibrosing colonopathy. Antroduodenal manometry in an individual who had experienced MI/DIOS was consistent with a neuropathic pseudo-obstructive process. Submucosal or transmural lymphocyte predominant inflammation was also present in 6 of 6 infants with complicated MI, which, when coupled with submucosal myofibroblast proliferation (5/6), appeared highly predictive of CF rather than non-CF atresia. Histological findings at birth were similar, although milder, than those seen in DIOS, suggesting that these changes are a primary abnormality in CF.

CONCLUSIONS

Submucosal or transmural inflammation of the ileum is common in newborns with CF and MI and older children with DIOS. Severe recurrent DIOS should be investigated with seromuscular and mucosal biopsy of the ileum to seek a transmural ileitis potentially amenable to anti-inflammatory therapies.

Cystic fibrosis: a review of epidemiology and pathobiology

Improvements in outcomes for patients who have cystic fibrosis (CF) have been striking in the last 30 years. Median survival now approaches the fifth decade of life. Advances in the understanding of the basic defect and the pathobiology of CF have led to new treatments, some of which have undoubtedly contributed to this success. Improved understanding of the basic defect and the acquisition and maintenance of epidemiologic resources for the CF population in the United States have allowed us to determine predictors of survival and identify genetic, environmental, and therapeutic factors that may influence it. This article reviews some of the key epidemiologic and pathobiologic factors discovered thus far.

Soft tissue inflammation: presenting feature of Crohn's disease in a cystic fibrosis adolescent

We report Crohn's disease in an adolescent with cystic fibrosis (CF). The patient suffered from recurrent abdominal symptoms, which were attributed to distal intestinal obstruction syndrome (DIOS) until a soft tissue inflammation at the right lumbar region and iliac crest revealed an enterosubcutaneous fistula. The diagnosis of Crohn's disease was confirmed on the basis of radiological, endoscopic and histological findings.

[Digestive complications in adults with cystic fibrosis]

In France the median life expectancy of patients with cystic fibrosis (CF) is 36 years and one third of patients are adults. Respiratory disorders are the main determinants of survival during adulthood, although gastrointestinal complications can also have a major impact on quality of life and nutritional status. We reviewed gastro-intestinal and pancreatic manifestations of CF in adults. Some complications (diabetes, distal intestinal obstruction syndrome and acute pancreatitis) are more frequent in adulthood than in childhood. Clinical and therapeutic aspects of specific conditions (such as distal intestinal obstruction syndrome) or atypical presentations (including appendicular complications) are presented herein.

Giant inflammatory polyposis coli as a manifestation of Crohn's disease in patients with coexistent cystic fibrosis

Crohn's disease (CD) arising in children with cystic fibrosis (CF) is well recognized. Indeed, reports suggest that CD is significantly more common in patients with CF than in the general population. Giant inflammatory polyposis is a rare manifestation of idiopathic inflammatory bowel disease and may complicate both ulcerative colitis and CD. Giant inflammatory polyposis has not been specifically reported in patients with coexistent CF and CD. Herein, we report the occurrence of giant inflammatory polyposis in 2 boys attending a tertiary care hospital, with an established diagnosis of CF who subsequently developed CD. Both boys required surgical treatment for CD. In addition to classical features of CD, both colonic resection specimens showed giant inflammatory polyposis. The appearances were modified by the presence of a layer of thick mucus. It is suggested that the coexistence of CF in patients with CD may predispose to the development of giant inflammatory polyposis. In addition to contributing to their development, it also appears that there is a propensity for CF to alter the morphological appearance of giant inflammatory polyposis. This may lead to diagnostic confusion when examining endoscopic biopsies.

Diagnosis and treatment of intestinal malabsorption in cystic fibrosis

Intestinal malabsorption is severe and of early onset in virtually all people who have cystic fibrosis. The main cause is deficiency of pancreatic enzymes. Bicarbonate deficiency, abnormal bile salts, mucosal transport problems, motility differences, and anatomical structural changes are other contributory factors. Effective treatment should allow a normal to high-fat diet to be taken, control symptoms, correct malabsorption, and achieve a normal nutritional state and growth. Appropriate pancreatic enzyme replacement therapy will achieve normal or near-normal absorption in most people with cystic fibrosis. Early identification and treatment of intestinal malabsorption is critical to achieving optimal nutritional status. The occurrence of fibrosing colonopathy in a few patients on very high doses of those enzymes which have the copolymer Eudragit L30 D55 in their covering resulted in guidelines in the UK to avoid doses equivalent to more than 10,000 IU lipase per kg per day, and also to avoid preparations containing this copolymer in children and adolescents. For patients not responding to 10,000 IU lipase per kg per day review of adherence to treatment, change of enzyme preparation, variation in time of administration, and reduction in gastric acid may improve absorption. The importance of early investigation to exclude other gastrointestinal disorders as a cause of the patient's symptoms, rather than merely increasing the dose of enzymes, is stressed. With modern pancreatic enzymes in doses up to or only slightly in excess of 10,000 IU lipase per kg per day, adequate control of gastrointestinal symptoms and absorption can be achieved, and a normal nutritional state and growth rate maintained in most people with cystic fibrosis.

Frequency of ASCA seropositivity in children with cystic fibrosis

OBJECTIVE

To determine the frequency of anti-Saccharomyces cerevisiae antibodies (ASCA) seropositivity in pediatric patients with cystic fibrosis (CF) and correlate ASCA with clinical features.

METHODS

Prospective study of children with CF aged 2 to 21 years enrolled from The Children's Hospital Cystic Fibrosis Center. Exclusion criteria included Crohn disease, immunodeficiency or immunoglobulin A deficiency. The frequency of ASCA (ASCA immunoglobulin A and immunoglobulin G) was measured by an enzyme-linked immunosorbent assay kit provided by Inova, Inc. (San Diego, CA). The CF Foundation database was queried for clinical data on ASCA seropositive patients.

RESULTS

Seventeen (20.7%) of 82 patients were seropositive for ASCA. Of these, eight had immunoglobulin A antibodies, six had immunoglobulin G antibodies and three had both. ASCA seropositivity in CF patients was significantly greater than the general population (20.7% versus 4%, P < 0.0001), using an exact binomial test on a single proportion. The 95% confidence limits around our observed proportion were 12.6% to 31.1%. Of 17 ASCA positive patients, 1 (5.8%) had a history of meconium ileus, 14 (82.4%) had DeltaF508 gene mutation, 9 (52.9%) had positive sputum cultures for fungal organisms, and 17 (100%) had an ideal body weight % >or=85%.

CONCLUSION

Patients with CF have a higher frequency of ASCA seropositivity than the general population. When evaluating CF patients for Crohn disease, ASCA should be used with caution. The reasons for higher ASCA seropositivity in CF patients are unknown, but may include exposure to fungal organisms via intestinal or pulmonary sources.

Prevalence and significance of mutations in the familial Mediterranean fever gene in patients with Crohn's disease

The concurrence of Crohn's disease (CD) and familial Mediterranean fever was repeatedly reported. In this study we determined the distribution and contribution of MEFV gene mutations to CD susceptibility and clinical heterogeneity. An Israeli cohort of 209 CD patients (120 men and 89 women) was investigated for mutations in the MEFV gene. A detailed chart review, interview and physical examination were used to determine sociodemographic and clinical characteristics. MEFV and NOD2/CARD15 genotypes were analyzed in all patients and a genotype-phenotype correlation analysis was undertaken. The results of this study do not implicate MEFV mutations as major modifiers in CD. However, the E148Q MEFV variant was associated with susceptibility to perianal disease. More specifically, 19% (9/47) of CD patients with perianal disease carried the E148Q mutation compared to 6.7% (11/162) of CD patients without perianal involvement (OR 3.26, 95% CI 1.2-8.8, P=0.02). Although, for all mutations taken together, the prevalence of MEFV gene mutations among CD patients and controls was similar, the hypothesis that E148Q mutation modulates the phenotypic expression of CD is corroborated by the results of this study and needs to be further evaluated.

Manifestations digestives au cours de la mucoviscidose

The prognosis of cystic fibrosis (CF) is strongly linked to the pulmonary status, nevertheless digestive disorders should be taken into account in order to prevent malnutrition which may increase pulmonary surinfections and speed up the deterioration of the respiratory function. Digestion, gut motility and absorption are the three major functions of the gastrointestinal tract. Functional disorders may involve the whole gut; in addition to pancreatic insufficiency we describe the failure of chloride secretion with dehydration of bowel content. Insufficient knowledge of the pathophysiology stresses the need for further studies to allow development of more rational and effective therapy.

State of the art: why do the lungs of patients with cystic fibrosis become infected and why can't they clear the infection?

Cystic Fibrosis (CF) lung disease, which is characterized by airway obstruction, chronic bacterial infection, and an excessive inflammatory response, is responsible for most of the morbidity and mortality. Early in life, CF patients become infected with a limited spectrum of bacteria, especially P. aeruginosa. New data now indicate that decreased depth of periciliary fluid and abnormal hydration of mucus, which impede mucociliary clearance, contribute to initial infection. Diminished production of the antibacterial molecule nitric oxide, increased bacterial binding sites (e.g., asialo GM-1) on CF airway epithelial cells, and adaptations made by the bacteria to the airway microenvironment, including the production of virulence factors and the ability to organize into a biofilm, contribute to susceptibility to initial bacterial infection. Once the patient is infected, an overzealous inflammatory response in the CF lung likely contributes to the host's inability to eradicate infection. In response to increased IL-8 and leukotriene B₄ production, neutrophils infiltrate the lung where they release mediators, such as elastase, that further inhibit host defenses, cripple opsonophagocytosis, impair mucociliary clearance, and damage airway wall architecture. The combination of these events favors the persistence of bacteria in the airway. Until a cure is discovered, further investigations into therapies that relieve obstruction, control infection, and attenuate inflammation offer the best hope of limiting damage to host tissues and prolonging survival.