Allelic variation at the interleukin 1beta gene is associated with decreased bone mass in patients with inflammatory bowel diseases

BACKGROUND: Interleukin 1beta (IL-1beta) and its natural antagonist have been implicated in the pathogenesis of inflammatory bowel disease (IBD). Both cytokines influence bone formation. IL-1beta stimulates osteoclast activity while interleukin 1 receptor antagonist (IL-1ra) enhances bone formation. AIMS: To determine whether the decreased bone mass in IBD is related to gene polymorphisms coding for IL-1beta and IL-1ra, and thus identify patients with an increased risk. METHODS: Bone mineral densitometry was performed at the femoral neck, lumbar spine, and the distal third of the radius in 75 IBD patients (34 men/41 women; 40.3 (1.6) years) and in 58 healthy controls (HC; 28 men/30 women; 32.4 (1.2) years). Values were correlated with the TaqI and AvaI gene polymorphisms in the IL1B and the variable number of tandem repeats gene polymorphism in the IL1RN gene. RESULTS: In IBD patients, but not in HC, carriers of allele 2 at the AvaI gene polymorphism (IL1B-511*2) had significantly lower Z scores at the lumbar spine (-0.82 (0.13) v -0.29 (0.21) p=0.03) and the femoral neck (-0.59 (0.14) v 0.15 (0.19); p=0.003) than non-carriers. These patients also had a higher risk for osteopenia or osteoporosis at the femoral neck (odds ratio 3.63 (95% confidence interval 0.95-13.93)). No association was found between bone mass and the other gene polymorphisms analysed in IBD patients or in HC. CONCLUSIONS: Our results suggest that genetic variability may be a major determinant of bone loss in IBD. Carriers of IL1B-511*2, who are hypersecretors of IL-1beta, have a higher risk of presenting with low bone mass in IBD. Screening for this allele may contribute to determination of the risk of bone loss at the time of disease onset.     

Diagnostic misclassification reduces the ability to detect linkage in inflammatory bowel disease genetic studies.

BACKGROUND: Linkage data have now identified several inflammatory bowel disease (IBD) susceptibility loci but these data have not been consistently replicated in independent studies. One potential explanation for this is the possibility that patients enrolled in such studies may have been erroneously classified with respect to their diagnosis. AIMS: To determine the rate and type of misclassification in a large population of individuals referred for participation in an IBD genetics study and to examine the effect of diagnostic misclassification on the power to detect linkage. METHODS: The medical records of 1096 patients entered into an IBD genetics programme were reviewed using standardised diagnostic criteria. The original patient reported diagnoses were changed, if necessary, based on review, and the reasons for the change in diagnosis were recorded. To evaluate the effect of misclassification on linkage results, simulations were created with Gensim and analysed using Genehunter to evaluate a model for IBD inheritance. RESULTS: Sixty eight of 1096 (6.2%) individuals had a change in diagnosis from that originally reported. The majority of changes were patients with either Crohn's disease or ulcerative colitis who were determined not to have IBD at all. The principal reasons for changes to the original diagnosis were discordance between the patients' subjective reports of diagnosis and actual clinical history, endoscopic, or pathological results; a change in disease pattern over time; and insufficient information available to confirm the original diagnosis. A 10% misclassification rate resulted in 28.4% and 40.2% loss of power to detect a true linkage when using a statistical model for a presumed IBD locus with lambda(s) values of 1.8 and 1.3, respectively. CONCLUSIONS: Diagnostic misclassification occurs in patients enrolled in IBD genetic studies and frequently involves assigning the diagnosis of IBD to non-affected individuals. Even low rates of diagnostic misclassification can lead to significant loss of power to detect a true linkage, particularly for loci with modest effects as are likely to be found in IBD.     

Association of the interleukin 1 receptor antagonist gene with ulcerative colitis in Northern European Caucasians

BACKGROUND AND AIMS: An association between the allele 2 of the interleukin 1 receptor antagonist gene variable number tandem repeats polymorphism in intron 2 and ulcerative colitis was first reported in 1994. Subsequent studies in Caucasian Northern European patients have not confirmed this, although trends towards an association were observed. The lack of statistical significance could reflect inadequate power. In this study the association was reassessed in a large independent set of well characterised Caucasian patients and a meta-analysis of reported patient series was performed. PATIENTS AND METHODS: A total of 320 patients with endoscopically and histologically confirmed ulcerative colitis (124 pancolitis, 196 left sided and distal disease) and 827 ethnically matched controls were genotyped at polymorphic sites in the interleukin 1 receptor antagonist gene. Carriage rates were compared using chi(2) statistics. A meta-analysis of this and seven previous studies in North European Caucasian patients was performed using the Mantel-Haenszel chi(2) test. RESULTS: Patients had a significantly increased carriage rate of allele 2 compared with controls (52% v 45%; odds ratio 1.3 (95% confidence interval (CI) 1.01-1.7); p=0.04). The allele 2 carriage rate was highest in extensive colitis (carriage rate 56%; odds ratio 1.5 (95% CI 1.1-2.3) p=0.02) and in individuals who had undergone colectomy (carriage rate 55%; odds ratio 1.5 (95% CI 0.95-2.4); p=0.08). Meta-analysis of all eight studies showed a significant association between carriage of allele 2 and ulcerative colitis (odds ratio 1.23 (95% CI 1.04-1.45); p=0.01). CONCLUSIONS: The association of the interleukin 1 receptor antagonist gene polymorphism with ulcerative colitis is confirmed. The association is minor and confers only a small risk to an individual but will contribute a high attributable risk in a population due to the high allelic frequency. Accurate phenotypic characterisation defines more homogeneous subsets of patients, such as those with extensive disease, in whom the association is greater.     

Visualising E-selectin in the detection and evaluation of inflammatory bowel disease

Background—Vascular endothelial E-selectin expression is induced by proinflammatory cytokines andcontributes to accumulation of leucocytes in tissues.
Aims—To investigate the role ofE-selectin in inflammatory bowel disease (IBD).
Methods—E-selectin expression wasassessed in patients with ulcerative colitis and Crohn's disease bymeasuring the concentration of circulating soluble E-selectin(sE-selectin) using ELISA, by immunohistochemistry of colonic biopsyspecimens, and by abdominal immunoscintigraphy after injectingradiolabelled F(ab')₂ fragment of a monoclonalanti-E-selectin antibody. The value of scintigraphy usinganti-E-selectin was judged by a prospective comparative study ofautologous leucocyte scanning and E-selectin antibody scanning in 17 patients with IBD.
Results—Circulating sE-selectin waselevated in patients with clinically active disease. Tissue expressionof E-selectin was enhanced in patients with active inflammation, withweak or absent expression in inactive disease and healthy controls.In-111 labelled anti-E-selectin scintiscans were compared with Tc-99mlabelled leucocyte scans performed 24 hours earlier. Twelve patientshad areas of active inflammation on leucocyte scan while 11 patients had positive E-selectin scans. The results of the two scans were concordant in 14 patients, with those positive for both (10/17) showingsimilar disease localisation and extent.
Conclusions—Tissue E-selectinand circulating sE-selectin are increased during active inflammatorybowel disease. Anti-E-selectin imaging with radiolabelled monoclonalantibody identified areas of inflammation in Crohn's disease andulcerative colitis. The technique should prove useful clinically foridentifying the site and extent of disease.

Keywords:E-selectin; inflammatory bowel disease; Crohn'sdisease; ulcerative colitis

     

Glucocorticoids in pediatric inflammatory bowel disease

Abstract

Children with moderate to severe inflammatory bowel disease (IBD) are treated with systemic glucocorticoids (GCs). The majority of the patients respond to the given treatment; however, steroid resistance and dependency are significant clinical problems. Also therapy-related side effects limit the use of GCs in the control of active inflammation. This review summarizes recent knowledge of GC treatment in pediatric patients with IBD.     

HLA-DR and -DQ phenotypes in inflammatory bowel disease: a meta-analysis.

BACKGROUND: Susceptibility to inflammatory bowel disease (IBD) is partially genetically determined and the HLA class II genes are candidates for a role in genetic susceptibility to IBD, because their products play a central role in the immune response. Multiple studies have reported associations between HLA-DR or -DQ phenotypes and either ulcerative colitis or Crohn's disease, but much of the data are still controversial. AIMS: To estimate overall associations between HLA class II phenotypes and IBD, and to establish the relative risk conferred by HLA-DR and -DQ phenotypes by meta-analysis. METHODS: Medline was searched for publications reporting on the relation between IBD and HLA class II phenotypes. Raw data were extracted by recalculating the number of phenotypes or the number of alleles of the main antigens. Odds ratios and confidence intervals were calculated according to the Mantel-Haenszel method. RESULTS: DR2, DR9, and DRB1*0103 were positively associated with ulcerative colitis, and a negative association was found for DR4 and ulcerative colitis. For Crohn's disease a positive association was found with DR7, DRB3*0301, and DQ4 and a negative association with DR2 and DR3. CONCLUSIONS: Both ulcerative colitis and Crohn's disease are associated with specific HLA class II phenotypes. Further analysis of these phenotypes and subgroup analysis may elucidate how these alleles contribute to susceptibility to IBD.     

Thiol methyltransferase activity in inflammatory bowel disease

BACKGROUND: Luminal anionic sulphide may contribute to epithelial damage in ulcerative colitis. Thiol methyltransferase (TMT) governs sulphide detoxification by the colonic mucosa and circulating erythrocytes. AIMS: To measure levels of TMT activity in erythrocytes of surgically treated cases of colitis or in rectal biopsies of defined groups of colitis. PATIENTS: Venepuncture blood was obtained from 37 blood donors and 27 subjects who had previously undergone a proctocolectomy for colitis: 18 for ulcerative colitis and nine for Crohn's colitis. Rectal biopsies from 122 cases were obtained: 47 without mucosal disease, 33 post-colon resection for cancer, 14 with moderate to severe ulcerative colitis, 15 with quiescent ulcerative colitis, seven with acute Crohn's colitis, and six with radiation proctitis. METHODS: TMT activity was measured by high performance liquid chromatography with radioactive detection to measure (14)C methylmercaptoethanol formation, the reaction product of cell extracts incubated with mercaptoethanol and (14)C S-adenosylmethionine. RESULTS: Erythrocyte TMT activity of surgically treated cases of colitis was significantly elevated (p<0. 001) compared with control cases. TMT activity of rectal biopsies was significantly decreased (p<0.02) in acute but not quiescent ulcerative colitis, Crohn's colitis, or radiation colitis. CONCLUSIONS: Erythrocyte TMT activity was persistently elevated after proctocolectomy for Crohn's disease and ulcerative colitis. No primary defect of TMT activity was found in any case of unoperated colitis but mucosal activity was diminished with disease progression of ulcerative colitis. Studies of genetic control of TMT activity of erythrocytes in inflammatory bowel disease appear worthwhile.     

Advances in the management of inflammatory bowel disease

Our understanding of inflammatory bowel diseases (IBD) is constantly evolving, and many new treatment options have emerged recently. This review critically examines the evidence for these new developments and aims to provide an overview for medical professionals involved in the care of patients with IBD. Proposed changes in the use of aminosalicylates, immunosuppressants and biological agents are described, and the evidence for several promising novel agents is reviewed.     

Management of inflammatory bowel disease in adults

Optimal care of the inflammatory bowel diseases, Crohn's disease and ulcerative colitis, requires a broad understanding of disease pathophysiology and therapeutic alternatives. The goals of therapy are accurate diagnosis and timely treatment to both induce and maintain a clinical remission and improve patient quality of life. Most patients can be adequately treated using a combination or aminosalicylates, antibiotics, and corticosteroids, though many patients with Crohn's disease will require immunomodulators, such as azathioprine or 6-mercaptopurine. The development of novel biologic therapies, particularly infliximab, have dramatically improved our ability to medically manage more severe Crohn's disease and ulcerative colitis patients. This review will focus on the medical management of inflammatory bowel disease in adults.     

Progression of inflammatory bowel disease in China

The epidemiology and phenotype of inflammatory bowel disease (IBD) in the Chinese population is not well-known. We performed a comprehensive search of the Chinese biomedical literature database from 1989 to 2007 using the following key words: inflammatory bowel disease (IBD), ulcerative colitis (UC), Crohn's disease (CD). The investigation of hospitalized IBD patients from 1990 to 2003 was also carried out in 23 medical centers of 11 cities over China. There are some notable epidemiological and phenotypical differences between Chinese IBD and Caucasian IBD, including a lack of familial clustering, male predominance, a relatively later onset of the illness with no second peak age occurrence after 50 years old, a milder clinical course, less extra-intestinal manifestations and complications, and less fistulous and peri-anal complications in Chinese CD. The data indicate an increased incidence of IBD in China with many complicated clinical problems, which offers potential opportunities to study the disease prospectively and identify the etiological factors, leading also to the better management of this disease in China.     

Imbalance of the interleukin 1 system in colonic mucosa—association with intestinal inflammation and interleukin 1 receptor agonist genotype 2

Background—Interleukin 1 (IL-1) α and β arepotent cytokines which play key roles in inflammation. They arecontrolled by IL-1 receptor antagonist (IL-1ra).
Aims—To investigate the influence of mucosalinflammation and IL-1ra genotype on the IL-1ra:IL-1 balance.
Patients and methods—IL-1α, IL-1β, and IL-1rawere measured by enzyme linked immunosorbent assay (ELISA) in biopsyspecimens taken from inflamed and non-inflamed colon of 60 patientswith Crohn's disease (CD), 34 with ulcerative colitis (UC), 15 inflammatory controls, and 103 non-inflamed controls. IL-1ra genotypewas determined by polymerase chain reaction and gel electrophoresis.
Results—IL-1α and IL-1β were significantlyincreased in inflamed mucosa in inflammatory bowel disease (IBD) (CD:53.5 (22.4) and 409.9 (118.7) pg/mg protein, respectively; UC: 18.9 (6.8) and 214.5 (78.2) pg/mg, respectively) and non-IBD patients (19.2(7.4) and 281.4 (121.0) pg/mg, respectively; p<0.0001) compared withnormal controls (2.8 (0.6) and 30.6 (5.6) pg/mg, respectively). In CDIL-1α and β were also significantly increased in non-inflamed mucosa (6.1 (1.3) pg/mg and 88.7 (17.4) pg/mg, respectively;p<0.0012). IL-1ra:(IL-1α+β) ratios were significantly decreased ininflamed mucosa of patients with CD (182 (45); p<0.0001), UC (425 (136); p=0.0018) and without IBD (221 (76); p<0.0001), and innon-inflamed mucosa in CD (369 (149); p<0.0001) compared with normalcontrols (1307 (245); p<0.0001). Patients with IL-1ra genotype 2 hadslightly but significantly reduced mucosal IL-1ra concentrations(p=0.003). The greatest difference was seen in colonic biopsy specimensfrom patients with inflamed Crohn's disease.
Conclusion—Mucosal inflammation can modulate thebalance of the IL-1:IL-1ra system in colonic mucosa.

Keywords:interleukin 1; interleukin 1 receptor antagonist; inflammatory bowel disease; Crohn's disease; mucosal inflammation; genotype

     

Collagenase-3 (MMP-13) expression by inflamed mucosa in inflammatory bowel disease

Objective. To determine whether the expression of collagenase-3 (MMP-13) in biopsies from patients with inflammatory bowel disease is correlated with histological inflammation parameters. Material and methods. Fifty-nine patients with inflammatory bowel disease were included in the study. The control group comprised 20 patients free of inflammatory disease and ten patients with acute diverticulitis. MMP-13 expression was determined by immunohistochemical staining and the specimens were assigned a histological inflammation score. Results. It was found that 62.8% of patients with ulcerative colitis (UC) and 54.1% of patients with Crohn's disease (CD) showed MMP-13-positive immunostaining in biopsies from affected areas. MMP-13-positive staining was more intense in ulcerated colonic mucosa. A positive and significant correlation was found between MMP-13 expression and the histological inflammation scores in mucosal samples from patients with CD (r=0.74, p<0.0001) or UC (r=0.62, p<0.0001). However, no MMP-13-positive immunostaining was found in either the biopsy specimens of the control group or those biopsies taken from patients with UC or CD in microscopically confirmed non-affected areas of the colonic mucosa. Similarly, colonic mucosa samples of the 10 patients with acute diverticulitis did not show immunostaining for MMP-13. Conclusions. Our findings demonstrating the absence of MMP-13 expression in non-inflamed colonic mucosa or in acute diverticulitis, as well as a positive correlation between elevated MMP-13 expression and histological criteria of inflammation in patients with inflammatory bowel diseases (CD and UC) suggest a role of the protease in the pathogenesis of these latter processes.     

Microbiome and metabolome in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic gastrointestinal disease of unknown etiology, involving complex interactions between the gut microbiome and host immune response. The microbial dysbiosis is well documented in IBD and significantly influences the host metabolic pathways. Thus, a metabolomic fingerprint resulting from the influence of gut dysbiosis in IBD could aid in assessing the disease activity. PubMed, Medline, Science Direct, and Web of Science were searched for studies exploring the association between microbiome and metabolome in IBD patients in the last 5 years. Additionally, references of cited original articles and reviews were further assessed for relevant work. We provide a literature overview of the recent metabolomic studies performed on patients with IBD. The findings report alterations in the metabolite levels of these patients. We also discuss the gut dysbiosis observed in IBD and its influence on host metabolic pathways such as lipids, amino acids, short-chain fatty acids, and others. IBD, being a chronic idiopathic disease, requires routine monitoring. The available non-invasive markers have their limitations. The metabolite changes account for both dysbiosis and its influence on the host's immune response and metabolism. A metabolome approach would thus facilitate the identification of surrogate metabolite markers reflecting the disease activity.     

Peripheral arthropathies in inflammatory bowel disease: their articular distribution and natural history

Background—Peripheral arthropathy is a well-recognised complication of inflammatory bowel disease (IBD). Little is known of its natural history, but a variety of joint involvement has been described, from large joint pauciarticular arthropathy to a rheumatoid pattern polyarthropathy.
Aims—To classify the peripheral arthropathies according to pattern of articular involvement, and study their natural history and clinical associations.
Methods—The case notes of all patients attending the Oxford IBD clinic were reviewed, and information on general disease characteristics, extraintestinal features, and arthropathy extracted. This was confirmed by direct patient interview using questionnaires at routine follow up. Patients with recorded joint swelling or effusion were classified as type 1 (pauciarticular) if less than five joints were involved and type 2 (polyarticular) if five or more were involved. Patients without evidence of swelling were classified as arthralgia.
Results—In total, 976 patients with ulcerative colitis (UC) and 483 with Crohn''s disease (CD) were reviewed. Type 1 occurred in 3.6% of patients with UC (83% acute and self-limiting) and in 6.0% of those with CD (79% self-limiting); 83% and 76%, respectively, were associated with relapsing IBD. Type 2 occurred in 2.5% of patients with UC and 4.0% of those with CD; 87% and 89%, respectively, caused persistent symptoms whereas only 29% and 42%, respectively, were associated with relapsing IBD.
Conclusion—Enteropathic peripheral arthropathy without axial involvement can be subdivided into a pauciarticular, large joint arthropathy, and a bilateral symmetrical polyarthropathy, each being distinguished by its articular distribution and natural history.

     

Why children with inflammatory bowel disease are diagnosed at a younger age than their affected parent

BACKGROUND: Genetic anticipation has been proposed to explain observed age differences at diagnosis of Crohn's disease in affected parents and offspring. AIMS: To compare affected parent-child pairs with Crohn's disease and ulcerative colitis with a control group of non-familial patients with inflammatory bowel disease (IBD) in order to quantify whether ascertainment bias could account for this effect. METHODS: 137 affected parent-child pairs from 96 families and 214 patients with sporadic IBD were studied. Age at onset of symptoms and diagnosis were ascertained by interview and disease confirmed from clinical records. RESULTS: Of the 137 affected parent-child pairs, 50 had Crohn's disease only, 51 had ulcerative colitis only, and in 36, one had Crohn's disease and the other ulcerative colitis. The median age of parents at diagnosis was 17.5 years older, 16 years older, and 18 years older in the Crohn's disease, ulcerative colitis, and mixed disease families respectively (p<0.001 in each case). These observed age differences were compatible with those predicted from the regression lines of years of birth against age at diagnosis for the non-familial IBD patients. No evidence was found for an effect of parental sex on age at diagnosis or disease extent in offspring. CONCLUSIONS: There was no evidence of genetic anticipation or genomic imprinting of age at diagnosis in this sample of IBD families. Ascertainment bias is responsible for the age differences at diagnosis between affected parents and children.     

Influenza vaccination coverage in children with inflammatory bowel disease

The aim of this study was to evaluate the influenza vaccination status among paediatric patients with inflammatory bowel disease (IBD) in Poland. This was a questionnaire‐based study. 242 patients with IBD and 142 controls were enrolled in the study. Of patients with IBD, 7·8% received an influenza vaccine, compared to 18·3% of controls (P = 0·0013). There were no statistically significant differences in time from IBD diagnosis, disease activity and in drugs, between vaccinated and non‐vaccinated IBD children. In conclusion, the data of our study demonstrate an alarmingly poor influenza vaccination status in the majority of children with IBD. Therefore, there is an unmet need to implement better influenza vaccination strategies for this group of patients.     

Faecal calprotectin in children with clinically quiescent inflammatory bowel disease

Abstract

Objective. The use of faecal calprotectin as a surrogate marker for intestinal inflammation is emerging. However, the data on faecal calprotectin during maintenance therapy in children with inflammatory bowel disease, IBD, are sparse. Our aim was to study faecal calprotectin levels in paediatric IBD during clinically quiescent disease and to investigate if high levels were associated with a flare-up of the disease. Subjects and methods. Faecal calprotectin level was measured in 72 children with paediatric IBD in clinical remission (median age 13 years). Of these, 37 children had been in clinical remission for more than a year, 20 for 6–12 months and 15 for 3 to <6 months. The clinical outcome of the patients was followed up to the first relapse or up to 12 months. Results. When in clinical remission, 35% (25/72) of the children had normal faecal calprotectin (<100 μg/g) and 13% (9/72) a very high level (>1000 μg/g) while not reporting symptoms. A clinical relapse occurred in 35% (25/72) during the subsequent 12 months. When in clinical remission, the predictive value of faecal calprotectin for an overt relapse was low ranging from 0.396 to 0.429 for faecal calprotectin values >100 μg/g or >1000 μg/g, respectively. The negative predictive value was 0.75 for values <100 μg/g. Conclusions. In paediatric IBD, subjective symptoms and clinical assessment associate poorly with the levels of faecal calprotectin. During maintenance medication in colonic disease, the probability of staying in clinical remission for a subsequent year is high if faecal calprotectin value is low.     

Secretion imbalance between tumour necrosis factor and its inhibitor in inflammatory bowel disease

BACKGROUND: Tumour necrosis factor (TNF) alpha and TNF-beta are soluble ligands binding to TNF receptors with similar activities; soluble TNF receptors neutralise TNF activity by acting as inhibitors. Little is known about the cytokine/soluble receptor role in inflammatory bowel disease (IBD). AIMS: To test the hypothesis that an imbalance in secretion between TNF and TNF inhibitors plays a role in gut inflammation in patients with IBD. METHODS: The secretion of TNF-alpha, TNF-beta, and soluble TNF receptors was compared in the culture supernatants of colonic biopsy specimens and isolated lamina propria mononuclear cells from patients with active colonic IBD. RESULTS: Spontaneous secretion of TNF-alpha in involved IBD mucosa was higher than in normal control and self limited colitis mucosa. Secretion of TNF-beta was higher in patients with Crohn's disease than in those with ulcerative colitis. Soluble TNF receptor in IBD mucosa inhibited TNF activity. Type 2 soluble receptor release from IBD mucosa was increased in active inflammation; release from lamina propria cells was not increased. Mucosal TNF-alpha production correlated with severity of disease. CONCLUSIONS: Results showed enhanced secretion of TNF-alpha but failure to release enhanced amounts of soluble TNF receptor in lamina propria mononuclear cells of patients with IBD. An imbalance in secretion between TNF and TNF inhibitor may be implicated in the pathogenesis of IBD.