Increased pulmonary and intestinal permeability in Crohn's disease

Unraveling the gut-Lung axis: Exploring complex mechanisms in disease interplay

The link between gut and lung starts as early as during organogenesis. Even though they are anatomically distinct, essential bidirectional crosstalk via complex mechanisms supports GLA. Emerging studies have demonstrated the association of gut and lung diseases via multifaceted mechanisms. Advancements in omics and metagenomics technologies revealed a potential link between gut and lung microbiota, adding further complexity to GLA. Despite substantial studies on GLA in various disease models, mechanisms beyond microbial dysbiosis regulating the interplay between gut and lung tissues during disease conditions are not thoroughly reviewed. This review outlines disease specific GLA mechanisms, emphasizing research gaps with a focus on gut-to-lung direction based on current GLA literature. Moreover, the review discusses potential gut microbiota and their products like metabolites, immune modulators, and non-bacterial contributions as a basis for developing treatment strategies for lung diseases. Advanced experimental methods, modern diagnostic tools, and technological advancements are also highlighted as crucial areas for improvement in developing novel therapeutic approaches for GLA-related diseases. In conclusion, this review underscores the importance of exploring additional mechanisms within the GLA to gain a deeper understanding that could aid in preventing and treating a wide spectrum of lung diseases.

The interplay between the microbiota, diet and T regulatory cells in the preservation of the gut barrier in inflammatory bowel disease

Inflammatory bowel disease (IBD) is becoming more common in the Western world due to changes in diet-related microbial dysbiosis, genetics and lifestyle. Incidences of gut permeability can predate IBD and continued gut barrier disruptions increase the exposure of bacterial antigens to the immune system thereby perpetuating chronic inflammation. Currently, most of the approved IBD therapies target individual pro-inflammatory cytokines and pathways. However, they fail in approximately 50% of patients due to their inability to overcome the redundant pro inflammatory immune responses. There is increasing interest in the therapeutic potential of T regulatory cells (Tregs) in inflammatory conditions due to their widespread capability to dampen inflammation, promote tolerance of intestinal bacteria, facilitate healing of the mucosal barrier and ability to be engineered for more targeted therapy. Intestinal Treg populations are inherently shaped by dietary molecules and gut microbiota-derived metabolites. Thus, understanding how these molecules influence Treg-mediated preservation of the intestinal barrier will provide insights into immune tolerance-mediated mucosal homeostasis. This review comprehensively explores the interplay between diet, gut microbiota, and immune system in influencing the intestinal barrier function to attenuate the progression of colitis.

Unravelling the gut-lung axis: insights into microbiome interactions and Traditional Indian Medicine's perspective on optimal health

The microbiome of the human gut is a complex assemblage of microorganisms that are in a symbiotic relationship with one another and profoundly influence every aspect of human health. According to converging evidence, the human gut is a nodal point for the physiological performance matrixes of the vital organs on several axes (i.e. gut-brain, gut-lung, etc). As a result of COVID-19, the importance of gut-lung dysbiosis (balance or imbalance) has been realised. In view of this, it is of utmost importance to develop a comprehensive understanding of the microbiome, as well as its dysbiosis. In this review, we provide an overview of the gut-lung axial microbiome and its importance in maintaining optimal health. Human populations have successfully adapted to geophysical conditions through traditional dietary practices from around the world. In this context, a section has been devoted to the traditional Indian system of medicine and its theories and practices regarding the maintenance of optimally customized gut health.

Idiopathic pulmonary fibrosis and intestinal disorders: An observational study

BACKGROUND AND AIM

Idiopathic pulmonary fibrosis (IPF) is a chronic respiratory disease characterized by a progressive decline in lung function and a specific histopathologic pattern defined as usual interstitial pneumonia. Early diagnosis and new therapeutic protocols have contributed to a reduction in disease progression. Thus, some patients may develop extrapulmonary diseases including malignancies and chronic pathologies. The aim of this study was to investigate the frequency of intestinal disorders such as polyps, colorectal carcinoma (CRC), and chronic inflammatory bowel disease (IBD) in patients with IPF.

METHODS

From the database of 189 patients with IPF (148 males, 78.3 %; 41 females, 21.7 %) residing in the district of Modena, we identified 44 patients (36 males, 81.8 %; 8 females, 18.2 %) with a histologically confirmed intestinal disease.

RESULTS

Intestinal polyps were detected in 41 cases (93.2 %), of which 4 were associated with CRC and 1 with IBD; 1 patient had only CRC (2.3 %), and 2 patients had only IBD (4.5 %). Both males and females developed bowel disease, but males seemed to have a higher number of polyps and high-grade adenomas with a predisposition to malignant transformation.

CONCLUSIONS

As patients with IPF may present with intestinal diseases that can evolve into malignancies in some cases, they should undergo appropriate follow-up and targeted colorectal screening. Thus, colorectal pathologies should not take a back seat. These preliminary results encourage further research to select suitable patients for specific diagnostic and therapeutic procedures in order to prolong survival and improve the quality of life.

Pathophysiological Concepts and Management of Pulmonary Manifestation of Pediatric Inflammatory Bowel Disease

Pulmonary manifestation (PM) of inflammatory bowel disease (IBD) in children is a rare condition. The exact pathogenesis is still unclear, but several explanatory concepts were postulated and several case reports in children were published. We performed a systematic Medline search between April 1976 and April 2022. Different pathophysiological concepts were identified, including the shared embryological origin, "miss-homing" of intestinal based neutrophils and T lymphocytes, inflammatory triggering via certain molecules (tripeptide proline-glycine-proline, interleukin 25), genetic factors and alterations in the microbiome. Most pediatric IBD patients with PM are asymptomatic, but can show alterations in pulmonary function tests and breathing tests. In children, the pulmonary parenchyma is more affected than the airways, leading histologically mainly to organizing pneumonia. Medication-associated lung injury has to be considered in pulmonary symptomatic pediatric IBD patients treated with certain agents (i.e., mesalamine, sulfasalazine or infliximab). Furthermore, the risk of pulmonary embolism is generally increased in pediatric IBD patients. The initial treatment of PM is based on corticosteroids, either inhaled for the larger airways or systemic for smaller airways and parenchymal disease. In summary, this review article summarizes the current knowledge about PM in pediatric IBD patients, focusing on pathophysiological and clinical aspects.

Simultaneous determination of lactulose, sucrose, sucralose, and mannitol using high-performance liquid chromatography-refractive index to estimate intestinal permeability in patients with active ulcerative colitis

OBJECTIVES

The intestinal permeability (IP) of sugars and their derivatives has been widely used to assess mucosal damage in gastrointestinal diseases. Ulcerative colitis (UC) is a recurring and relapsing disease that causes inflammation of the gut. IP of sugars can be evaluated and correlated with the flare of UC.

MATERIALS AND METHODS

A prospective study was conducted on 91 patients with active UC at the tertiary care center in North India. Mayo grading system assessed disease activity, and IP was assessed by measuring sucrose, lactulose, mannitol, and sucralose in urine samples from UC patients. A high-performance liquid chromatography (HPLC) method to detect all of these sugars simultaneously using a refractive index detector was developed and further validated in patients with UC.

RESULTS

The analytical recovery rate of the tested sugars ranged from 95% to 146% in the urine matrix. The limit of detection and limit of quantification were 78.838 mg/L and 262.79 mg/L for sucrose, 84.994 mg/L and 283.31 mg/L for lactulose, 74.789 mg/L and 249.30 mg/L for mannitol, and 50.908 mg/L and 169.69 mg/L for sucralose.

CONCLUSION

The standardized HPLC method is sensitive and suitable for the simultaneous detection and determination of different sugar moieties in the urine sample. Patients with UC can be evaluated indirectly for the flare by estimating the recovery rate of sugars through gut permeability. The procedure is noninvasive and thus improves the quality of life of chronically ill patients.

The Association of Medications and Vaccination with Risk of Pneumonia in Inflammatory Bowel Disease

BACKGROUND

Patients with inflammatory bowel disease (IBD) are at increased risk for pneumonia, and corticosteroids are reported to amplify this risk. Less is known about the impact of corticosteroid-sparing IBD therapies on pneumonia risk or the efficacy of pneumococcal vaccination in reducing all-cause pneumonia in real-world IBD cohorts.

METHODS

We performed a population-based study using an established Veterans Health Administration cohort of 29,957 IBD patients. We identified all patients who developed bacterial pneumonia. Cox survival analysis was used to determine the association of corticosteroids at study entry and as a time-varying covariate, corticosteroid-sparing agents (immunomodulators and antitumor necrosis-alpha [TNF] inhibitors), and pneumococcal vaccination with the development of all-cause pneumonia.

RESULTS

Patients with IBD who received corticosteroids had a greater risk of pneumonia when controlling for age, gender, and comorbidities (hazard ratio [HR] 2.21; 95% confidence interval [CI], 1.90-2.57 for prior use; HR = 3.42; 95% CI, 2.92-4.01 for use during follow-up). Anti-TNF inhibitors (HR 1.52; 95% CI, 1.02-2.26), but not immunomodulators (HR 0.91; 95% CI, 0.77-1.07), were associated with a small increase in pneumonia. A history of pneumonia was strongly associated with subsequent pneumonia (HR = 4.41; 95% CI, 3.70-5.27). Less than 15% of patients were vaccinated against pneumococcus, and this was not associated with a reduced risk of pneumonia (HR = 1.02; 95% CI, 0.80-1.30) in this cohort.

CONCLUSION

In a large US cohort, corticosteroids were confirmed to increase pneumonia risk. Tumor necrosis-alpha inhibitors were associated with a smaller increase in the risk of pneumonia. Surprisingly, pneumococcal vaccination did not reduce all-cause pneumonia in this population, though few patients were vaccinated.

Effects of Anti-Cytokine Antibodies on Gut Barrier Function

Anti-cytokine antibodies are used in treating chronic inflammatory diseases and autoimmune diseases such as inflammatory bowel disease and rheumatic diseases. Patients with these diseases often have a compromised gut barrier function, suggesting that anti-cytokine antibodies may contribute to the re-establishment of gut barrier integrity, in addition to their immunomodulatory effects. This paper reviews the effects of anti-cytokine antibodies on gut barrier function and their mechanisms.

The Pathogenesis of Extraintestinal Manifestations: Implications for IBD Research, Diagnosis, and Therapy

This article reports on the sixth scientific workshop of the European Crohn's and Colitis Organisation [ECCO] on the pathogenesis of extraintestinal manifestations [EIMs] in inflammatory bowel disease [IBD]. This paper has been drafted by 15 ECCO members and 6 external experts [in rheumatology, dermatology, ophthalmology, and immunology] from 10 European countries and the USA. Within the workshop, contributors formed subgroups to address specific areas. Following a comprehensive literature search, the supporting text was finalized under the leadership of the heads of the working groups before being integrated by the group consensus leaders.

The Interplay between Defensins and Microbiota in Crohn's Disease

Crohn's disease (CD) is a chronic inflammation of the intestinal mucosa, characterized by periods of acute recurrence and remission. Depending on the specific region affected, CD is classified as ileal CD or colonic CD. It is largely accepted that the intestinal microbiota is involved in the onset of the pathology. Indeed, a reduced immune tolerance to components of the intestinal commensal microbiota and inflammation of the intestinal barrier typifies patients with CD. Several studies have shown defective expression of intestinal antimicrobial peptides (AMPs) in patients with CD compared to controls, particularly defensins. A reduction in α-defensins is observed in ileal CD, while β-defensins are increased in colonic CD. In addition to an immunological basis, the disease is frequently associated with genetic alterations including mutations of NOD2 gene. Several therapeutic strategies to circumvent the dysfunction observed in CD are currently under investigation. These include the use of delivery systems to administer endogenous AMPs and the engineering of peptidomimetics that could ameliorate the severity of CD. In this review, the role defensins play in CD and the strategies aimed at overcoming bacterial resistance will be discussed.

Intestinal permeability in children with recurrent respiratory and gastrointestinal symptoms

AIM

Increased intestinal permeability has been reported in asthmatic subjects as well as in patients with gastrointestinal disease, thus suggesting the involvement of all the mucosal immune system. We aimed to assess intestinal permeability according to recurrent respiratory and gastrointestinal symptoms in children with asthma and children with functional gastrointestinal disorders (FGIDs).

METHODS

In 108 outpatients aged 3-14 years (45 asthmatic, 63 with FGIDs), we measured the urinary lactulose/mannitol (L/M) ratio, performed allergy skin prick tests and administered questionnaires for recurrent respiratory and gastrointestinal symptoms starting from at least 2 months which persisted over the previous 4 weeks. L/M ratios were compared with previously reported normal values yielded by our chromatographic method (liquid chromatography-mass spectrometry).

RESULTS

High L/M ratios (>0.030) were less frequent in asthmatic children than in children with FGIDs (9/45: 20% vs. 41/63: 65%, P < 0.001). High L/M ratios were associated with gastrointestinal symptoms in 8/9 asthmatic (P < 0.05) and 39/41 subjects with FGIDs (P < 0.005). L/M ratios were not associated with respiratory symptoms or atopy. In a regression model, a high L/M was predicted by low height, absence of asthma and presence of gastrointestinal symptoms (r = 0.72, P < 0.001).

CONCLUSIONS

Increased intestinal permeability is associated with recurrent gastrointestinal symptoms rather than with recurrent respiratory symptoms in both asthmatic children and those with FGIDs. Our findings do not support the hypothesis of mucosal intestinal damage following an inflammatory stimulus in the respiratory mucosa.

Food antigen-induced immune responses in Crohn's disease patients and experimental colitis mice

BACKGROUND

In Crohn's disease (CD), the involvement of food antigens in immune responses remains unclear. The objective of this study was to detect immune responses against food antigens in CD patients and examine the mechanism in a mouse model of colitis.

METHODS

We enrolled 98 CD patients, 50 ulcerative colitis patients, and 52 healthy controls (HCs) to compare the levels of serum immunoglobulin (Ig)Gs against 88 foods. The presence of serum IgGs against foods was also examined in interleukin (IL)-10 knockout (KO) mice in which CD4(+) T cell activation by antigenic food protein was assessed. Mice transferred with IL-10 KO cells received diets with or without food antigens, and the development of colitis was evaluated.

RESULTS

The prevalence of IgGs against various foods, especially vegetables, grains, and nuts, was significantly higher in CD patients than in HCs. Similarly, the prevalence of IgGs against food proteins was higher in IL-10 KO mice than in BALB/c mice. Beta-conglycinin, identified as an antigenic food proteins in IL-10 KO mice, induced CD4(+) T cell production of interferon-γ and IL-17 through dendritic cell antigen presentation. Elimination of the food antigens ameliorated the development of colitis in mice without altering the composition of their intestinal microbiota.

CONCLUSIONS

In CD colitis mice, intestinal inflammation via CD4(+) T cell hyperactivation was induced by food antigens associated with high serum IgG levels and was ameliorated by the elimination of food antigens. This disrupted immunological tolerance to food antigen, which might act as an exacerbating factor, remains to be elucidated in CD patients.

Patterns of airway involvement in inflammatory bowel diseases

Extraintestinal manifestations occur commonly in inflammatory bowel diseases (IBD). Pulmonary manifestations (PM) of IBD may be divided in airway disorders, interstitial lung disorders, serositis, pulmonary vasculitis, necrobiotic nodules, drug-induced lung disease, thromboembolic lung disease and enteropulmonary fistulas. Pulmonary involvement may often be asymptomatic and detected solely on the basis of abnormal screening tests. The common embryonic origin of the intestine and the lungs from the primitive foregut, the co-existence of mucosa associated lymphoid tissue in both organs, autoimmunity, smoking and bacterial translocation from the colon to the lungs may all be involved in the pathogenesis of PM in IBD. PM are mainly detected by pulmonary function tests and high-resolution computed tomography. This review will focus on the involvement of the airways in the context of IBD, especially stenoses of the large airways, tracheobronchitis, bronchiectasis, bronchitis, mucoid impaction, bronchial granulomas, bronchiolitis, bronchiolitis obliterans syndrome and the co-existence of IBD with asthma, chronic obstructive pulmonary disease, sarcoidosis and a1-antitrypsin deficiency.

Infectious etiopathogenesis of Crohn’s disease

Important advances during the last decade have been made in understanding the complex etiopathogenesis of Crohn’s disease (CD). While many gaps in our knowledge still exist, it has been suggested that the etiology of CD is multifactorial including genetic, environmental and infectious factors. The most widely accepted theory states that CD is caused by an aggressive immune response to infectious agents in genetically predisposed individuals. The rise of genome-wide association studies allowed the identification of loci and genetic variants in several components of host innate and adaptive immune responses to microorganisms in the gut, highlighting an implication of intestinal microbiota in CD etiology. Moreover, numerous independent studies reported a dysbiosis, i.e., a modification of intestinal microbiota composition, with an imbalance between the abundance of beneficial and harmful bacteria. Although microorganisms including viruses, yeasts, fungi and bacteria have been postulated as potential CD pathogens, based on epidemiological, clinicopathological, genetic and experimental evidence, their precise role in this disease is not clearly defined. This review summarizes the current knowledge of the infectious agents associated with an increased risk of developing CD. Therapeutic approaches to modulate the intestinal dysbiosis and to target the putative CD-associated pathogens, as well as their potential mechanisms of action are also discussed.

Abnormal intestinal permeability in Crohn's disease pathogenesis

Increased small intestinal permeability is a longstanding observation in both Crohn's disease patients and in their healthy, asymptomatic first-degree relatives. However, the significance of this compromised gut barrier function and its place in the pathogenesis of the disease remains poorly understood. The association between abnormal small intestinal permeability and a specific mutation in the NOD2 gene, which functions to modulate both innate and adaptive immune responses to intestinal bacteria, suggests a common, genetically determined pathway by which an abnormal gut barrier could result in chronic intestinal inflammation. Furthermore, rodent colitis models show that gut barrier defects precede the development of inflammatory changes. However, it remains possible that abnormal permeability is simply a consequence of mucosal inflammation. Further insight into whether abnormal barrier function is the cause or consequence of chronic intestinal inflammation will be crucial to understanding the role of intestinal permeability in the pathogenesis of Crohn's disease.

Differences in gut microbial metabolism are responsible for reduced hippurate synthesis in Crohn's disease

Background

Certain urinary metabolites are the product of gut microbial or mammalian metabolism; others, such as hippurate, are mammalian-microbial 'co-metabolites'. It has previously been observed that Crohn's disease (CD) patients excrete significantly less hippurate than controls. There are two stages in the biosynthesis of this metabolite: 1) gut microbial metabolism of dietary aromatic compounds to benzoate, and 2) subsequent hepatorenal conjugation of benzoate with glycine, forming hippurate. Differences in such urinary co-metabolites may therefore reflect systemic consequences of altered gut microbial metabolism, though altered host metabolic pathways may also be involved.

Methods

It was hypothesised that reduced hippurate excretion in CD patients was due to alterations in the gut microbiota, and not differences in dietary benzoate, nor defective host enzymatic conjugation of benzoate. 5 mg/kg sodium benzoate were administered orally to 16 CD patients and 16 healthy controls on a low-benzoate diet. Baseline and peak urinary hippurate excretion were measured.

Results

Baseline hippurate levels were significantly lower in the CD patients (p = 0.0009). After benzoate ingestion, peak urinary levels of hippurate did not differ significantly between the cohorts. Consequently the relative increase in excretion was significantly greater in CD (p = 0.0007).

Conclusions

Lower urinary hippurate levels in CD are not due to differences in dietary benzoate. A defect in the enzymatic conjugation of benzoate in CD has been excluded, strongly implicating altered gut microbial metabolism as the cause of decreased hippurate levels in CD.

Pleuropericarditis in a patient with inflammatory bowel disease: a case presentation and review of the literature

Inflammatory bowel disease (IBD) can affect the lung parenchyma and airways. Rarely it involves the pleural space and pericardium, causing inflammatory exudative pleural and/or pericardial effusions. In this report, we describe a 76-year-old patient with recurrent sterile exudative pleuropericarditis that gradually responded to treatment with steroids, and we review the relevant literature. Thoracic serositis in patients with IBD can cause pleuritis, pericarditis, pleuropericarditis, or myopericarditis. This is a relatively rare presentation of the uncommon and probably underreported and underrecognized pulmonary extraintestinal manifestations of IBD. Pleuropericardial inflammatory disease and effusion can be directly related to IBD, its complications, associated infections, or the medications used to treat it. Serositis directly related to IBD is a diagnosis of exclusion. It is important to evaluate the pleural effusion and rule out other etiologies before making this diagnosis. Pleural or pericardial biopsies are rarely necessary, and probably show nonspecific acute and chronic inflammatory changes. Although the specific pathophysiology of pleuropericardial disease in patients with IBD remains unclear, the response to systemic steroids is usually adequate.

Respiratory involvement in inflammatory bowel diseases

Inflammatory bowel diseases (IBD) include ulcerative colitis (UC) and Crohn's disease (CD) and are due to a dysregulation of the antimicrobial defense normally provided by the intestinal mucosa. This inflammatory process may extend outside the bowel to many organs and also to the respiratory tract. The respiratory involvement in IBD may be completely asymptomatic and detected only at lung function assessment, or it may present as bronchial disease or lung parenchymal alterations. Corticosteroids, both systemic and aerosolized, are the mainstay of the therapeutical approach, while antibiotics must be also administered in the case of infectious and suppurative processes, whose sequels sometimes require surgical intervention. The relatively high incidence of bronchopulmonary complications in IBD suggests the need for a careful investigation of these patients in order to detect a possible respiratory involvement, even when they are asymptomatic.

Pulmonary involvement and allergic disorders in inflammatory bowel disease

Inflammatory bowel disease (IBD) has been associated with either clinical or subclinical airway and parenchymal lung involvement and interstitial lung complications. Several studies have reported that atopy has a high prevalence in IBD patients. Overlapping allergic disorders seem to be present in both the respiratory and gastrointestinal systems. The purpose of this review is to update clinicians on recent available literature and to discuss the need for a highly suspicious approach by clinicians.

The interaction of gut microbes with host ABC transporters

ATP binding cassette (ABC) transporters are increasingly recognized for their ability to modulate the absorption, distribution, metabolism, secretion and toxicity of xenobiotics. In addition to their essential function in drug resistance, there is also emerging evidence documenting the important role ABC transporters play in tissue defense. In this respect, the gastrointestinal tract represents a critical vanguard of defense against oral exposure of drugs while at the same time functions as a physical barrier between the lumenal contents (including bacteria) and the intestinal epithelium. Given emerging evidence suggesting that multidrug resistance protein (MDR) plays an important role in host-bacterial interactions in the gastrointestinal tract, this review will discuss the interplay between MDR of the intestinal epithelial cell barrier and gut microbes in health and disease. In particular, we will explore host-microbe interactions involving three apically restricted ABC transporters of the intestinal epithelium; P-glycoprotein (P-gp), multidrug resistance-associated protein 2 (MRP2) and cystic fibrosis transmembrane regulator (CFTR).

Genome-wide association analysis in sarcoidosis and Crohn's disease unravels a common susceptibility locus on 10p12.2

BACKGROUND & AIMS

Crohn's disease (CD) and sarcoidosis (SA) are chronic inflammatory barrier diseases that share several clinical and immunological features, including the occurrence of granulomas.

METHODS

A 100k genome-wide association study with 83,360 single-nucleotide polymorphisms (SNPs) was performed on 382 CD patients, 398 SA patients, and 394 control individuals. The 24 SNPs that were most strongly associated in the combined CD/SA phenotype were selected for verification in an independent sample of 1,317 patients (660 CD and 657 SA) and 1,091 controls.

RESULTS

The most significant association (Bonferroni corrected P = .036) was obtained at SNP rs1398024 on chromosome 10p12.2, with an odds ratio (OR) for both diseases of 0.81 (95% confidence interval [CI], 0.69-0.96) for carriership of the rarer allele A. The P value in the overall combined sample was 4.24 x 10(-6). During further follow-up, a moderate association (OR, 0.83; 95% CI, 0.72-0.96; P = .015) was observed between rs1398024 and ulcerative colitis (1,080 patients vs 1,091 controls), the second main subphenotype of inflammatory bowel disease in addition to CD. Extensive fine mapping of the 10p12.2 locus points to yet unidentified variants in the C10ORF67 gene region as the most likely underlying risk factors.

CONCLUSION

Our study demonstrates that the combined analysis of different, albeit clinically related, phenotypes can lead to the identification of common susceptibility loci.

Concept of Crohn's disease being conditioned by four main components, and irritable bowel syndrome being an incomplete Crohn's disease

Several mechanisms have been proposed for the development of Crohn's disease. Evidence in favour of a unifying 4-component concept to explain the development of Crohn's disease is presented. The four components are a genetic predisposition to an increased intestinal permeability, the key and initial triggering factor being an oral-pharyngeal bacterium that increases the mucosal permeability of the small intestine with only a minimal inflammatory reaction, an adherent-invasive strain of Escherichia coli that penetrates the mucosa and causes an acute inflammatory reaction in the intestinal wall, and finally a secondary invasion of bacteria causing the chronic inflammatory characteristics. Irritable bowel syndrome (IBS) is a functional bowel disorder with intermittent symptoms of varying intensity. Clinically, there is evidence to suggest a link between IBS patients with diarrhoea and patients with Crohn's disease. The common denominator and initial trigger for IBS with diarrhoea and Crohn's disease seems to be an increased small intestinal permeability, probably caused by an oral-pharyngeal bacterial strain. The important missing factor in IBS patients seems to be the adherent-invasive strain of E. coli in the proximal colon, causing the acute inflammatory process in patients with Crohn's disease. IBS with diarrhoea can then be looked upon as an incomplete Crohn's disease.

Intestinal permeability and its association with the patient and disease characteristics in Crohn’s disease

AIM: To assess the intestinal permeability (IP) in patients with Crohn’s disease (CD) and study the association of IP with the patient and disease characteristics.

METHODS: One hundred and twenty five consecutive patients of CD (Males: 66) were diagnosed on the basis of a combination of standard clinical, endoscopic, imaging and histological features. CD activity index (CDAI) was used to calculate the activity of the disease while the behavior of the disease was assessed by the modified Montreal classification. IP was measured by the ratio of the percentage excretion of ingested doses of lactulose and mannitol in urine (LMR). The upper limit of normality of LMR (0.037) was derived from 22 healthy controls.

RESULTS: Thirty six percent of patients with CD had increased IP. There was no significant difference in mannitol excretion (patients vs controls = 12.5% vs 14.2%, P = 0.4652), but lactulose excretion was significantly higher in patients compared to healthy controls (patients vs controls = 0.326% vs 0.293%, P = 0.0391). The mean LMR was also significantly higher in the patients as compared to healthy controls [0.027 (0.0029-0.278) vs 0.0164 (0.0018-0.0548), P = 0.0044]. Male patients had a higher LMR compared to females [0.036 (95% CI 0.029, 0.046) vs 0.022 (95% CI 0.0178, 0.028) (P = 0.0024), though there was no difference in the number of patients with abnormal IP in both the sexes. Patients with an ileo-colonic disease had a higher LMR than those with only colonic disease [0.045 (95% CI 0.033, 0.06) vs 0.021 (95% CI 0.017, 0.025) (P < 0.001)]. Of patients with ileo-colonic disease, 57.8% had an abnormal IP, compared to 26.7% with colonic and 15.6% with small intestinal disease. Patients with a stricturing disease had significantly higher LMR compared to non-fistulising non-stricturing disease [0.043 (95% CI 0.032, 0.058) vs 0.024 (95% CI 0.019, 0.029) (P = 0.0062)]. There was no correlation of IP with age, disease activity, duration of illness, D-xylose absorption, upper GI involvement, perianal disease, and extra-intestinal manifestations. On multiple regression analysis, male gender and ileo-colonic disease were independent factors associated with increased IP. Gender, location, behavior of the disease and upper GI involvement could explain up to 23% of variability in IP (R² = 0.23).

CONCLUSION: IP was increased in 36% of patients with CD. Male gender and an ileo-colonic disease were the independent factors associated with increased IP.

A case-control study of bronchial asthma associated with ulcerative colitis: role of airway microvascular permeability

BACKGROUND

Recent attention has been devoted to the respiratory manifestations that may be associated with diseases of distant organs. The most prevalent and distinctive pattern of respiratory involvement in ulcerative colitis (UC) is airway inflammation.

OBJECTIVE

This study was designed to examine the contribution of airway microvascular permeability to the pathophysiological association of asthma with UC.

METHODS

Sputum induction and methacholine provocation test were performed in 27 asthmatic patients (15 without UC and 12 with UC), nine patients with UC and 15 normal controls. Inflammatory indexes, vascular endothelial growth factor (VEGF) levels in induced sputum, airway vascular permeability index and exhaled nitric oxide (NO) levels were examined in all subjects.

RESULTS

The percentage of eosinophils and concentration of eosinophil cationic protein in induced sputum were similar in all four groups. Though exhaled NO levels were significantly higher in asthmatics with or without UC than in normal controls or UC patients, these levels were comparable in asthmatics with and without UC. VEGF levels in induced sputum and airway vascular permeability index were significantly higher in asthmatics without UC (VEGF: 1920 (990) pg/mL; airway vascular permeability index: 0.018 (0.008)) and asthmatics with UC (6570 (1000) pg/mL; 0.040 (0.006)) than in normal controls (950 (700) pg/mL; 0.009 (0.003)), whose levels were comparable to those of UC patients (900 (600) pg/mL; 0.011 (0.003)). In particular, these parameters were markedly increased in asthmatics with UC than in asthmatics without UC. VEGF level was significantly correlated with airway vascular permeability index in asthmatics with UC. Moreover, VEGF level and airway vascular permeability index was inversely correlated with degree of airway obstruction and airway hyper-reactivity to methacholine in these asthmatics.

CONCLUSION

Airway microvascular hyper-permeability induced by VEGF may have a profound effect on airway function and can explain the heightened airway hyper-responsiveness characteristic of asthma associated with UC.

Subclinical alveolar involvement in ulcerative colitis

BACKGROUND

Although pulmonary dysfunction has been described in patients with ulcerative colitis (UC), the pathogenesis remains unclear. Our aim was to study alveolar epithelial damage using technetium-99m diethylene triamine penta acetic acid (Tc-99m DTPA) aerosol scintigraphy in patients with UC but without respiratory symptoms.

METHODS

We enrolled 32 patients (18 women and 14 men; mean age, 36.4 +/- 11.6 yr) with active UC, 10 patients with inactive UC (6 women and 4 men; mean age, 43.4 +/- 11.8 yr), and 31 healthy controls (24 women and 7 men; mean age, 40 +/- 10 yr). Tc-99m DTPA aerosol scintigraphy was performed on all patients and controls. The relationship between alveolar epithelial permeability and the activity, localization, and duration of the disease was studied.

RESULTS

There was a significant difference between alveolar epithelial permeability results in patients with active UC and those of the controls (P < 0.001). The same correlation was also found between the patients with inactive UC and the control group (P < 0.001). There was no correlation between Tc-99m DTPA alveolar scintigraphic test results and the stage of activity, localization, and duration of the disease.

CONCLUSIONS

A latent pulmonary involvement may exist in patients with active and inactive UC. The alveolar involvement may be the earliest pulmonary damage, and a DTPA clearance test may show the early changes in pulmonary epithelial permeability that precedes clinical symptoms. Increased alveolar epithelial permeability is an extraintestinal manifestation in patients with UC and is not related to the activity of the colitis.

Bronchial hyperresponsiveness and analysis of induced sputum cells in Crohn's disease

With the aim of investigating the presence of latent inflammatory process in the lungs of patients with Crohn's disease, 15 patients with Crohn's disease were evaluated by spirometry, the methacholine challenge test, induced sputum, and skin tests for inhaled antigens. Serum IgE, erythrocyte sedimentation rate and hematocrit were also determined. The patients were compared with 20 healthy controls by the Mann-Whitney and Fisher exact tests. Their respiratory physical examination was normal. None had a personal or family history of clinical atopy. None had a previous history of pulmonary disease, smoking or toxic bronchopulmonary exposure. None had sinusitis, migraine, diabetes mellitus, or cardiac failure. Four (26.6%) of the patients with Crohn's disease had a positive methacholine challenge test whereas none of the 20 controls had a positive methacholine test (P = 0.026, Fisher exact test). Patients with Crohn's disease had a higher level of lymphocytes in induced sputum than controls (mean 14.59%, range 3.2-50 vs 5.46%, 0-26.92%, respectively; P = 0.011, Mann-Whitney test). Patients with Crohn's disease and a positive methacholine challenge test had an even higher percentage of lymphocytes in induced sputum compared with patients with Crohn's disease and a negative methacholine test (mean 24.88%, range 12.87-50 vs 10.48%, 3.2-21.69%; P = 0.047, Mann-Whitney test). The simultaneous findings of bronchopulmonary lymphocytosis and bronchial hyperresponsiveness in patients with Crohn's disease were not reported up to now. These results suggest that patients with Crohn's disease present a subclinical inflammatory process despite the absence of pulmonary symptoms.

Bronchial Hyperresponsiveness in Patients with Inflammatory Bowel Disease

Pulmonary complications have been described in patients with inflammatory bowel disease. The aim of this study was to evaluate bronchial hyppersponsiveness (BHR) in patients with Crohn's disease (CD) and ulcerative colitis (UC). Fifteen patients (8 men, 7 women, mean age: 42.20 ± 12.20 years) participated in the study. None of the patients had a prior history of respiratory disease or suffered from other systematic disease. Skin prick tests for common allergens (such as pollens, mites, foods and moulds) were administered to all patients of the study. The control group included 15 healthy volunteers (10 men, 5 women, mean age: 40.33 ± 5.06 years). The skin tests showed that 3 of 15 patients with inflammatory bowel disease were sensitive to common allergens (two patients to mix grasses and one to D. Pteronysinnus). In the control group, one subject was sensitive to D. Pteronysinnus. BHR was estimated after methacholine challenge. The frequency of BHR among the patients with inflammatory bowel disease was 7 of 15 (46.60%), compared with only one in the control group who was positive at the maximum dosage of methacholine (16 mg/dl). Our results indicate that there is an increased frequency of BHR in patients with inflammatory bowel disease.

Pulmonary involvement in Crohn's disease report of a case and review of the literature

Crohn's disease (CD) is a granulomatous systemic disorder of unknown etiology. Obvious pulmonary involvement is exceptional in patients with CD. We report a case of a 38-year-old man who suffered from CD for more than 14 years and was treated with oral steroids for more than 10 years. Surgical excision of parts of the ileum was performed for life-threatening ileal bleeding caused by CD. After acute tapering of oral steroids, pulmonary symptoms and radiologic abnormalities were noted. Lung biopsy through thoracoscopy was performed and revealed signs of chronic inflammation with multiple subepithelial noncaseating and epithelioid granulomas on pathologic examination. Intravenous steroids were required in the initial management of life-threatening pulmonary dysfunction after diagnostic thoracoscopy and led to marked improvement. Tuberculocidal therapy was performed until all microbiological cultures were negative. Oral steroid dosage had slowly been tapered over 1 month. He was discharged with clinical and radiologic improvements. After 36 months, the patient's condition is stable on continued treatment with prednisolone and mesalazine.

Granulomatous pulmonary disease in a child: an unusual presentation of Crohn's disease

Crohn's disease (CD) is a chronic inflammatory disorder of the bowel which may be associated with an extensive list of extraintestinal manifestations involving almost every organ system. The most common organs involved are the eyes, skin, joints, and liver. Symptomatic bronchopulmonary disorders have been reported only rarely in pediatric CD. We report on an 11-year-old child who had a recurrent cough and increasing dyspnea with exercise for 8 months before developing any gastrointestinal symptoms. He was demonstrated to have granulomatous inflammation of the lung, as well as of the gastrointestinal tract. Similarities between CD and sarcoidosis are discussed.

Pulmonary manifestations of inflammatory bowel disease

Extraintestinal manifestations of both Crohn's disease and ulcerative colitis (UC) have been well described, although pulmonary findings are often overlooked. We summarize the experience of more than 400 cases of pulmonary manifestations of inflammatory bowel disease (IBD). These manifestations will be categorized by disease mechanism into drug-induced disease, anatomic disease, over-lap syndromes, autoimmune disease, physiologic consequences of IBD, pulmonary function test abnormalities, and nonspecific lung disease. We intend to provide the clinician with a practical working update on the spectrum of pulmonary dysfunction associated with IBD.

Anti-tumor necrosis factor treatment restores the gut barrier in Crohn's disease

OBJECTIVES

A primary defect of the tight junctions and, hence, increased intestinal epithelial permeability has been proposed as a basic pathogenic event in Crohn's disease. Challenge of the mucosal immune system by the commensal gut flora would then result in chronic inflammation. Alternatively, increased permeability could be the result of inflammation. Our aim was to study intestinal permeability in refractory Crohn's disease before and after treatment with monoclonal chimeric antibodies directed against tumor necrosis factor (TNF) to investigate whether the abnormal permeability persists after control of inflammation.

METHODS

Twenty-three patients with active Crohn's disease were evaluated before and 4 wk after a single infusion of 5 mg/kg infliximab. Intestinal permeability was studied by measurement of urinary excretion of 51Cr-EDTA after oral intake.

RESULTS

The increased permeation of 51Cr-EDTA through the small intestine (1.63% interquartile range [IQR] 1.06-2.07) and the overall permeation (3.27% IQR 2.40-4.38) before therapy decreased significantly after infliximab infusion to values (1.04% IQR 0.74-1.54 and 2.42% IQR 2.03-2.80, respectively) in the range of those found in normal volunteers (1.12% IQR 0.85-1.58 and 2.28% IQR 1.88-2.86, respectively).

CONCLUSION

Inhibiting the proinflammatory cytokine tumor necrosis factor dramatically reduces gut inflammation and largely restores the gut barrier in Crohn's disease. Our data confirm the central role of TNF in gut barrier modulation in inflammatory conditions in vivo.

Activity related increase of exhaled nitric oxide in Crohn's disease and ulcerative colitis: a manifestation of systemic involvement?

Nitric oxide (NO) is an important mediator of inflammation in several pathological conditions. Patients with lung diseases, like asthma, have higher levels of exhaled NO (eNO) in active disease in comparison with healthy volunteers. Aspirated colonic gas in patients with ulcerative colitis (UC) showed more than 100 times higher levels of NO in comparison with normal subjects. Crohn's disease (CD) and UC are associated with a variety of systemic manifestations, although lung diseases as an extra-intestinal expression of inflammatory bowel disease (IBD) are not well investigated. In some studies, clinical and subclinical pulmonary abnormalities are described in active IBD as well as in the stable situation. The aim of the present study is to evaluate whether eNO is increased in patients with active IBD and to investigate whether there exists a correlation between (1) the eNO levels and the disease activity, and (2) the spirometry and the disease activity in a subgroup of patients. In 31 patients with CD (mean age 36.8 +/- 12.9 years) and 24 patients with UC (mean age 38.0 +/- 14.7 years) the Crohn's Disease Activity Index (CDAI) and Colitis Activity Index (CAI) were measured, respectively. Exhaled NO was measured with a chemiluminescence analyzer, according to standardized criteria. In a subgroup of CD patients, spirometry was also performed according to standardized criteria. The mean CDAI in CD patients was 192.4 +/- 94.3 and their mean eNO value was 13.5 +/- 4.6 ppb. For UC the mean CAI was 6.2 +/- 4.8 and the mean eNO value was 15.8 +/- 6.2 ppb. In a matched control group of 27 healthy, non-smoking volunteers (mean age of 33.7 +/- 13.2 years) the eNO was 10.2 +/- 2.5 ppb (P < 0.05 compared to CD and P < 0.01 compared to UC). There was a disease-activity-related increase of the eNO level in patients with IBD. For patients with UC the correlation coefficient (r = 0.63, P < 0.001) was more pronounced than for CD (r = 0.39, P < 0.05). In 17 patients with CD, spirometry was available at the time of the eNO measurement. We found a significant negative correlation between the CDAI and the FEV1 and FVC in these patients (r = -0.559, P = 0.02 and r = -0.634, P = 0.006, respectively). We conclude that eNO is increased in active IBD and correlates with the activity of the disease; furthermore, we found a negative correlation between spirometry and disease activity in patients with CD. These observations strengthen the arguments that IBD is a systemic disease. Further research is needed to try to explain the significance of an increased eNO in IBD.

Intestinal permeation and gastrointestinal disease

The gastrointestinal tract constitutes one of the largest sites of exposure to the outside environment. The function of the gastrointestinal tract in monitoring and sealing the host interior from intruders is called the gut barrier. A variety of specific and nonspecific mechanisms are in operation to establish the host barrier; these include luminal mechanisms and digestive enzymes, the epithelial cells together with tight junctions in between them, and the gut immune system. Disruptions in the gut barrier follow injury from various causes including nonsteroidal anti-inflammatory drugs and oxidant stress, and involve mechanisms such as adenosine triphosphate depletion and damage to epithelial cell cytoskeletons that regulate tight junctions. Ample evidence links gut barrier dysfunction to multiorgan system failure in sepsis and immune dysregulation. Additionally, contribution of gut barrier dysfunction to gastrointestinal disease is an evolving concept and is the focus of this review. An overview of the evidence for the role of gut barrier dysfunction in disorders such as Crohn's disease, celiac disease, food allergy, acute pancreatitis, non-alcoholic fatty liver disease, and alcoholic liver disease is provided, together with critical insight into the implications of this evidence as a primary disease mechanism.

The role of epithelial cells in immune regulation in the gut

A variety of mechanisms contribute to the ability of the gut to either react or remain tolerant to antigens present in the intestinal lumen. Intestinal epithelial cells can control the uptake, transmission and presentation of luminal antigens through an astonishingly diverse set of pathways. Antigens can cross the epithelial barrier via non-specific pinocytotic, specific receptor mediated, or intracellular/paracellular bypass pathways. The differential processing and presentation by a variety of restriction elements may result in the activation of functionally distinct target cell populations which have the capacity to regulate the predominant trend of immune unresponsiveness within the gut.

Increased intestinal permeability to macromolecules and endotoxemia in patients with chronic alcohol abuse in different stages of alcohol-induced liver disease

BACKGROUND/AIMS

No information is yet available about the influence of alcohol abuse on the translocation of larger molecules (Mr>1200) through the intestinal mucosa in man. The present study aimed to determine the intestinal permeability to macromolecules in patients with chronic alcohol abuse and mild to more advanced stages of liver disease, and to measure the concentration of endotoxins in the plasma, as these compounds derive from the intestinal flora and are suspected to contribute to the development of alcoholic liver disease (ALD).

METHODS

The permeability to polyethylene glycol Mr 400, Mr 1500, Mr 4000, and Mr 10,000 and endotoxin plasma concentrations were measured in 54 patients with alcoholic liver disease, 19 of them with cirrhosis, and in 30 non-alcoholic healthy controls.

RESULTS

Permeability to polyethylene glycol Mr 400 was found to be unchanged in patients with ALD in comparison to healthy controls, whereas polyethylene glycol Mr 1500 and Mr 4000 were recovered in about twice as high concentrations in the urine of ALD patients (p<0.01). Polyethylene glycol Mr 10,000 was detected significantly less frequently in urine from healthy controls (0/30) than in urine of patients with alcoholic liver disease (20/54, p<0.01). Endotoxin concentrations in the plasma of alcoholics were increased more than 5-fold compared to healthy controls (p<0.01).

CONCLUSIONS

The results of this study indicate that alcohol abuse impairs the function of the intestinal barrier, which might enhance the translocation of bacterial toxins, thereby contributing to inflammatory processes in alcoholic liver disease.

Bronchial hyperresponsiveness in children and adolescents with Crohn's disease

Pulmonary manifestations have been described in Crohn's disease (CD). Bronchial responsiveness to methacholine (MCh) was evaluated in 14 children with CD with no evidence of airway disease, 10 asthmatics, and 10 healthy subjects. In patients with CD total blood eosinophils and serum IgE were 0.20 x 10(9) x L(-1) (95% CI -1.68 to 2.08) and 138.4 kU x L(-)(1) (95% CI 18.84 to 257.96), respectively. Three patients with CD had positive prick tests. Bronchial hyperresponsiveness (BHR) was demonstrated in 10 patients with CD (71%) and in the asthmatics, but not in control subjects. In patients with CD PD(20) appeared significantly greater than in asthmatics (699 microg [95% CI 238 to 1,115] versus 104 microg [95% CI 37.35 to 293]; p < 0.05), and was not related either to baseline FEV(1) or IgE or eosinophils (r = 0.32; r = -0.5; r = -0.15, p = NS, respectively). Neither activity nor treatment or duration of CD affected BHR. Five nonatopic CD patients underwent a second MCh challenge over a 25-mo period: the PD(20) appeared significantly greater than basal PD(20) (1,941 microg versus 575 microg, p < 0.05, respectively), in the absence of significant changes of disease activity. BHR might be the expression of subclinical airway inflammation, a phenomenon which can be responsible for the development of various pulmonary manifestations in CD.

[Bronchopulmonary manifestations of gastroenterologic and hepatic diseases]

Topics of this review are the bronchopulmonary manifestations of gastroesophageal reflux disease, cirrhosis of the liver and chronic inflammatory bowel diseases. About 20% of patients with chronic obstructive airway disease show evidence of gastroesophageal reflux disease. Reflux bronchoconstriction seems to be of greater importance than microaspiration. First studies show the positive effects of acid inhibition by proton pump inhibitors on pulmonary symptoms. Hepatorenal syndrome is characterized by arterial hypoxemia with PaO2-values < 70 mm Hg. Different mediators (endotoxins, amines, polypeptides or allergens) are discussed. Furthermore, elevated levels of prostacycline, atrial natriuretic factor and platelet activating factor have been described. Recently published studies focused on the role of nitric oxide (NO). Patients with cirrhosis of the liver show a higher rate of a pathologically elevated airway resistance which might be induced by a reduced histamine clearance. Ascites leads to reversible restrictive airway disease. Bronchopulmonary manifestations in chronic inflammatory bowel diseases include obstructive and restrictive airway diseases, vascular or serosal changes and show low clinical evidence. In contrast, pathological changes of the common function tests were found in 30 to 50%. These findings may be induced by circulating immune complexes, vasculitis, increased permeability or a combined immune reaction of both, the bronchial and intestinal mucosa. Undesired effects of salicylates should be taken into account. This review shows that bronchopulmonary manifestations in diseases of the Gl-tract or the liver are more common than usually known and should be taken into clinical consideration.

Number, fixation properties, dye-binding and protease expression of duodenal mast cells: comparisons between healthy subjects and patients with gastritis or Crohn's disease

There is an accumulation of evidence to suggest that mast cells may play a key role in gastrointestinal inflammation. We have investigated the numbers and heterogeneity in staining properties of mast cells in biopsies of the duodenum of normal subjects (n = 10), and of normal duodenum from patients with Crohn's disease of the ileum and/or colon (n = 7) or with Helicobacter-associated gastritis of the antrum/corpus (n = 6). In normal donors, two subsets of mast cells, one located in the duodenal mucosa and the other in the submucosa, were clearly distinguished by their morphology and dye-binding properties. Whereas submucosal mast cells stained metachromatically with Toluidine Blue after neutral formalin fixation and emitted a yellow fluorescence after staining with Berberine sulphate, those in the mucosa were invisible using these stains. In patients with gastritis or Crohn's disease, there were marked changes in the numbers of mucosal mast cells compared with control subjects even though the duodenal biopsies were from apparently uninvolved tissue. Gastritis was associated with increased mucosal mast cell numbers (controls: 187 +/- 23 cells mm-2; gastritis: 413 +/- 139 cells mm-2; p = 0.0004), but mean mucosal mast cell counts in the uninvolved duodenum of Crohn's patients were actually decreased (34 +/- 30 cells mm-2, p = 0.0147). The clear differentiation between mucosal and submucosal mast cells on the basis of metachromasia with Toluidine Blue was not seen in biopsies from the patients with gastritis or Crohn's disease. Previous studies which have suggested that there are no distinct mucosal and submucosal mast cell subsets in the human intestine may, therefore, have been affected by the use of tissue from diseased subjects. Heterogeneity in the expression of mast cell tryptase and chymase was seen by immunohistochemistry using specific antibodies, but the relative numbers of mast cell subsets were critically dependent on the methods used. Using a sensitive staining procedure, the majority of mucosal mast cells stained positively for chymase as well as for tryptase, an observation confirmed by immunoelectron microscopy and immunoabsorption studies. Our findings suggest that early stages in intestinal inflammation may be reflected in changes in mast cell numbers and in their staining properties, and call for a reappraisal of mast cell heterogeneity in the human intestinal tract.

Increased intestinal permeability in bronchial asthma

T lymphocytes are a major component of bronchial inflammatory processes in asthma. Because lymphocytes have the ability to migrate from one mucosal site to another, we initiated this prospective study to demonstrate mucosal abnormalities of the digestive barrier in asthma. To establish this we studied intestinal permeability in a group of 37 patients with asthma (21 allergic and 16 nonallergic) by measuring chromium 51-labeled ethylenediaminetetraacetatic acid (CrEDTA) urinary recovery. The results were compared with those obtained in a group of 13 nonasthmatic patients with chronic obstructive pulmonary disease and 26 healthy control subjects. Urinary recovery of CrEDTA was significantly higher in patients with asthma (2.5% +/- 1.95%) than in patients with chronic obstructive pulmonary disease (1.16% +/- 0.48%) and healthy control subjects (1.36% +/- 0.14%). There was no significant difference in intestinal permeability between patients with allergic asthma (2.94% +/- 2.4%) and those with nonallergic asthma (1.92% +/- 0.9%). Intestinal permeability was not correlated with the severity of asthma as measured by FEV1. Similarly, intestinal permeability did not significantly vary according to Aas score or steroid treatment. Serum IgE values and eosinophil blood count were not correlated with intestinal permeability. Intestinal permeability was evaluated sequentially in seven patients with asthma (4 allergic and 3 nonallergic) with a mean interval of 7.6 months (range, 2 to 13 months) and did not significantly change. Our results support the hypothesis that a general defect of the whole mucosal system is present as a cause or a consequence of bronchial asthma.

[Sarcoidosis in children with digestive manifestations]

BACKGROUND

Gastric involvement is the least rare among digestive localizations of sarcoidosis, as well in adults as in children. When it is to be seen at the beginning of the disease, it may cause difficulties in the diagnostic, especially with Crohn's disease.

CASE REPORT

Gastric ulcers were detected in a 12 year-old girl, of African origin, who complained about epigastric pain. Eighteen months later, diarrhea, poor growing, uveitis and inflammatory biological signs led to a probable diagnostic of Crohn's disease. Endoscopy seemed to confirm this diagnostic with granulomatous lesions on gastric biopsies. The absence of radiological anomalies of the digestive tract and the poor efficiency of the medical treatment led to question this diagnosis and to assert that of sarcoidosis.

CONCLUSIONS

This case allows to emphasize the rare involvement of the digestive tract in sarcoidosis and the aspects common both to Crohn's disease and sarcoidosis.

Association between inflammatory bowel disease and sarcoidosis. Report of two cases and review of the literature

BACKGROUND

Common etiopathogenic factors may explain the association of systemic sarcoidosis with inflammatory bowel disease.

METHODS

We report two cases of such an association: one of sarcoidosis that developed 2 years after proctocolectomy for ulcerative colitis and one of sarcoidosis and Crohn's colitis. Factors like increased cellular immunity or circulating immunocomplexes or autoantibodies may have a role. Exogenous agents or familiarity may also be involved.

CONCLUSIONS

It is postulated that the association between sarcoidosis and inflammatory bowel disease (both ulcerative colitis and Crohn's disease) does not occur by chance alone and that the two conditions may share some genetic or immunologic alterations. The two diseases, however, follow an independent clinical course.

Ileal and colonic fatty acid profiles in patients with active Crohn's disease

In patients with active Crohn's disease and in a control group the fatty acid profiles in the whole lipid fraction of ileal and colonic mucosal biopsy specimens were determined by capillary gas chromatography. The biopsy specimens in Crohn's disease patients were taken from the inflamed terminal ileum as well as from the inflamed and macroscopically normal colon. Compared with controls the fatty acid distribution in the inflamed ileal mucosa was significantly characterised by (a) a decrease of 18:2 n6 and 18:3 n3 accompanied by a substantial increase of the highly polyunsaturated fatty acids 20:4 n6, 22:4 n6, and 22:6 n3 and (b) a higher unsaturation index of total fatty acids compared with controls. These changes were similar in the inflamed colon. Additionally, both the inflamed and the macroscopically normal colonic mucosa showed an increase of saturated (18:0) and a decrease of monounsaturated fatty acids (18:1 n9). Fatty acid profiles of ileum and colon showed side variations in controls, but not in the Crohn's disease group. These data suggest that in Crohn's disease changes in the distribution of polyunsaturated fatty acids seem to be the general feature of inflamed mucosa in small and large intestine. Results further suggest that colonic fatty acid metabolism in Crohn's disease is altered by degrees, showing changes in saturated and monounsaturated fatty acids as an additional, primary event.