Clinically active Crohn's disease in the presence of a low C-reactive protein

Emerging role of novel biomarkers in the diagnosis of inflammatory bowel disease

There is currently no gold standard test for the diagnosis of inflammatory bowel disease (IBD). Physicians must rely on a number of diagnostic tools including clinical and endoscopic evaluation as well as histologic, serologic and radiologic assessment. The real difficulty for physicians in both primary and secondary care is differentiating between patients suffering from functional symptoms and those with true underlying IBD. Alongside this, there is always concern regarding the possibility of a missed, or delayed diagnosis of ulcerative colitis (UC) or Crohn’s disease. Even once the diagnosis of IBD has been made, there is often uncertainty in distinguishing between cases of UC or Crohn’s. As a consequence, in cases of incorrect diagnosis, optimal treatment and management may be adversely affected. Endoscopic evaluation can be uncomfortable and inconvenient for patients. It carries significant risks including perforation and in terms of monetary cost, is expensive. The use of biomarkers to help in the diagnosis and differentiation of IBD has been increasing over time. However, there is not yet one biomarker, which is sensitive of specific enough to be used alone in diagnosing IBD. Current serum testing includes C-reactive protein and erythrocyte sedimentation rate, which are cheap, reliable but non-specific and thus not ideal. Stool based testing such as faecal calprotectin is a much more specific tool and is currently in widespread clinical use. Non-invasive sampling is of the greatest clinical value and with the recent advances in metabolomics, genetics and proteomics, there are now more tools available to develop sensitive and specific biomarkers to diagnose and differentiate between IBD. Many of these new advances are only in early stages of development but show great promise for future clinical use.

Use of blood based biomarkers in the evaluation of Crohn’s disease and ulcerative colitis

Despite significant improvements in our understanding of Crohn’s disease (CD) and ulcerative colitis (UC) in recent years, questions remain regarding the best approaches to assessment and management of these chronic diseases during periods of both relapse and remission. Various serologic biomarkers have been used in the evaluation of patients with both suspected and documented inflammatory bowel disease (IBD), and while each has potential utility in the assessment of patients with IBD, potential limitation remain with each method of assessment. Given these potential shortcomings, there has been increased interest in other means of evaluation of patients with IBD, including an expanding interest in the role of gene expression profiling. Among patients with IBD, gene expression profiles obtained from whole blood have been used to differentiate active from inactive CD, as well as to differentiate between CD, UC, and non-inflammatory diarrheal conditions. There are many opportunities for a non-invasive, blood based test to aid in the assessment of patients with IBD, particularly when considering more invasive means of evaluation including endoscopy with biopsy. Furthermore, as the emphasis on personalized medicine continues to increase, the potential ability of gene expression analysis to predict patient response to individual therapies offers great promise. While whole blood gene expression analysis may not completely replace more traditional means of evaluating patients with suspected or known IBD, it does offer significant potential to expand our knowledge of the underlying genes involved in the development of these diseases.

Platelet Activation Markers Are Associated with Crohn's Disease Activity in Patients with Low C-Reactive Protein

BACKGROUND

In assessing Crohn's disease (CD) activity, C-reactive protein (CRP) is an important indicator of inflammation; however, it is not necessarily associated with the Crohn's Disease Activity Index (CDAI), particularly in patients with low CRP. Recently, platelet activation factors have been recognized due to their importance in the inflammatory response. In this study, we examined associations between the CDAI and platelet factor 4 (PF-4), β-thromboglobulin (β-TG), and other coagulation and fibrinolysis factors.

AIMS

We aimed to find a new marker for evaluating disease activity in patients with CD and low CRP.

METHODS

Nine markers, including CRP, platelet count, white blood cell count, fibrin and fibrinogen degradation product, fibrinogen, thrombin-antithrombin complex, prothrombin fragments 1 + 2, PF-4, and β-TG were evaluated in 47 patients with CD and low CRP (<1.0 mg/dl). Patients were assigned to high or low disease activity groups, CDAI-H (CDAI ≥ 150) and CDAI-L (CDAI < 150), respectively.

RESULTS

CDAI-H exhibited significantly higher PF-4 and β-TG levels than CDAI-L (P < 0.01). Other markers were not significantly different between groups. CDAI was positively correlated with the levels of PF-4 and β-TG (P = 0.0033 and 0.0024; r = 0.4202 and 0.4321, respectively). Receiver operating characteristic curve analyses of PF-4 and β-TG showed high sensitivity (61.9 and 81%, respectively) and specificity (84.7 and 69.2%, respectively) for diagnosing active CD.

CONCLUSION

Among eight potential markers, PF-4 and β-TG were the most highly correlated with CDAI in patients with CD and low CRP. PF-4 and β-TG levels showed promise as new markers for assessing CD in patients with low CRP.

Usefulness of C-reactive protein as a disease activity marker in Crohn's disease according to the location of disease

Background/Aims

C-reactive protein (CRP) is a serologic activity marker in Crohn’s disease (CD), but it may be less useful in evaluating CD activity in ileal CD patients. We aimed to investigate the usefulness of CRP as a disease activity marker in CD according to disease location.

Methods

Korean CD patients in a single hospital were evaluated. Factors associated with elevated CRP concentration at the time of diagnosis of CD and the association between the physician’s prediction regarding upcoming surgery and the sites of the lesions directly related to surgery were analyzed.

Results

Of 435 CD patients, 25.7%, 6.9%, and 67.4% had ileal, colonic, and ileocolonic CD, respectively. Multivariate analysis revealed that an elevated erythrocyte sedimentation rate, reduced serum albumin, CD activity index (CDAI) >220, and ileocolonic/colonic location were associated with an elevated CRP level and that the CRP level was significantly correlated with the CDAI in all CD patients (γ=0.466, p<0.01). However, the correlation coefficient was dependent on the location, with values of 0.395, 0.456, and 0.527 in patients with an ileal, ileocolonic, and colonic disease location, respectively. Surgery for ileal lesions was less predictable than surgery for ileocolonic or colonic lesions during follow-up.

Conclusions

CRP is less useful as a disease activity marker in patients with ileal CD than those with ileocolonic or colonic CD.

Selecting Therapeutic Targets in Inflammatory Bowel Disease (STRIDE): Determining Therapeutic Goals for Treat-to-Target

OBJECTIVES

The Selecting Therapeutic Targets in Inflammatory Bowel Disease (STRIDE) program was initiated by the International Organization for the Study of Inflammatory Bowel Diseases (IOIBD). It examined potential treatment targets for inflammatory bowel disease (IBD) to be used for a "treat-to-target" clinical management strategy using an evidence-based expert consensus process.

METHODS

A Steering Committee of 28 IBD specialists developed recommendations based on a systematic literature review and expert opinion. Consensus was gained if ≥75% of participants scored the recommendation as 7-10 on a 10-point rating scale (where 10=agree completely).

RESULTS

The group agreed upon 12 recommendations for ulcerative colitis (UC) and Crohn's disease (CD). The agreed target for UC was clinical/patient-reported outcome (PRO) remission (defined as resolution of rectal bleeding and diarrhea/altered bowel habit) and endoscopic remission (defined as a Mayo endoscopic subscore of 0-1). Histological remission was considered as an adjunctive goal. Clinical/PRO remission was also agreed upon as a target for CD and defined as resolution of abdominal pain and diarrhea/altered bowel habit; and endoscopic remission, defined as resolution of ulceration at ileocolonoscopy, or resolution of findings of inflammation on cross-sectional imaging in patients who cannot be adequately assessed with ileocolonoscopy. Biomarker remission (normal C-reactive protein (CRP) and calprotectin) was considered as an adjunctive target.

CONCLUSIONS

Evidence- and consensus-based recommendations for selecting the goals for treat-to-target strategies in patients with IBD are made available. Prospective studies are needed to determine how these targets will change disease course and patients' quality of life.

Monitoring disease activity and progression in Crohn's disease. A Swiss perspective on the IBD ahead 'optimised monitoring' recommendations

BACKGROUND AND AIMS

The structured IBD Ahead 'Optimised Monitoring' programme was designed to obtain the opinion, insight and advice of gastroenterologists on optimising the monitoring of Crohn's disease activity in four settings: (1) assessment at diagnosis, (2) monitoring in symptomatic patients, (3) monitoring in asymptomatic patients, and (4) the postoperative follow-up. For each of these settings, four monitoring methods were discussed: (a) symptom assessment, (b) endoscopy, (c) laboratory markers, and (d) imaging. Based on literature search and expert opinion compiled during an international consensus meeting, recommendations were given to answer the question 'which diagnostic method, when, and how often'. The International IBD Ahead Expert Panel advised to tailor this guidance to the healthcare system and the special prerequisites of each country. The IBD Ahead Swiss National Steering Committee proposes best-practice recommendations adapted for Switzerland.

METHODS

The IBD Ahead Steering Committee identified key questions and provided the Swiss Expert Panel with a structured literature research. The expert panel agreed on a set of statements. During an international expert meeting the consolidated outcome of the national meetings was merged into final statements agreed by the participating International and National Steering Committee members - the IBD Ahead 'Optimized Monitoring' Consensus.

RESULTS

A systematic assessment of symptoms, endoscopy findings, and laboratory markers with special emphasis on faecal calprotectin is deemed necessary even in symptom-free patients. The choice of recommended imaging methods is adapted to the specific situation in Switzerland and highlights the importance of ultrasonography and magnetic resonance imaging besides endoscopy.

CONCLUSION

The recommendations stress the importance of monitoring disease activity on a regular basis and by objective parameters, such as faecal calprotectin and endoscopy with detailed documentation of findings. Physicians should not rely on symptoms only and adapt the monitoring schedule and choice of options to individual situations.

Mongersen, an oral SMAD7 antisense oligonucleotide, and Crohn's disease

BACKGROUND

Crohn's disease-related inflammation is characterized by reduced activity of the immunosuppressive cytokine transforming growth factor β1 (TGF-β1) due to high levels of SMAD7, an inhibitor of TGF-β1 signaling. Preclinical studies and a phase 1 study have shown that an oral SMAD7 antisense oligonucleotide, mongersen, targets ileal and colonic SMAD7.

METHODS

In a double-blind, placebo-controlled, phase 2 trial, we evaluated the efficacy of mongersen for the treatment of persons with active Crohn's disease. Patients were randomly assigned to receive 10, 40, or 160 mg of mongersen or placebo per day for 2 weeks. The primary outcomes were clinical remission at day 15, defined as a Crohn's Disease Activity Index (CDAI) score of less than 150, with maintenance of remission for at least 2 weeks, and the safety of mongersen treatment. A secondary outcome was clinical response (defined as a reduction of 100 points or more in the CDAI score) at day 28.

RESULTS

The proportions of patients who reached the primary end point were 55% and 65% for the 40-mg and 160-mg mongersen groups, respectively, as compared with 10% for the placebo group (P<0.001). There was no significant difference in the percentage of participants reaching clinical remission between the 10-mg group (12%) and the placebo group. The rate of clinical response was significantly greater among patients receiving 10 mg (37%), 40 mg (58%), or 160 mg (72%) of mongersen than among those receiving placebo (17%) (P=0.04, P<0.001, and P<0.001, respectively). Most adverse events were related to complications and symptoms of Crohn's disease.

CONCLUSIONS

We found that study participants with Crohn's disease who received mongersen had significantly higher rates of remission and clinical response than those who received placebo. (Funded by Giuliani; EudraCT number, 2011-002640-27.).

Validation of gene expression biomarker analysis for biopsy-based clinical trials in Crohn's disease

BACKGROUND

The ability to measure the expression of proinflammatory cytokines from intestinal biopsies in patients with Crohn's disease in an accurate and reproducible way is critical for proof-of-concept and mechanism-of-action trials; however, the number of biopsies from a segment of the ileum or colon required to yield reproducible results has not been rigorously evaluated. We examined intestinal biopsies from patients with Crohn's disease to validate methods for detecting changes in inflammatory gene expression.

METHODS

To evaluate the reproducibility of gene expression measurements, intestinal biopsies were obtained from designated segments from 6 healthy controls, 6 patients with active Crohn's disease, and 6 patients with inactive Crohn's disease. Disease activity was based on the simple endoscopic score for Crohn's disease. Expression of 7 proinflammatory genes was measured from each biopsy using quantitative polymerase chain reaction. Using a linear mixed effects model, the power to detect transcriptional changes corresponding to active and inactive Crohn's disease was calculated.

RESULTS

Total simple endoscopic score for Crohn's disease score corresponds with expression of most inflammatory biomarkers. For most genes, 2 to 5 biopsies are needed to reduce sampling error to <25% for most genes. To measure changes in mRNA expression corresponding to active versus inactive Crohn's disease, 1 to 2 intestinal biopsies from 3 patients before and after treatment are needed to yield power of at least 80%.

CONCLUSIONS

Measuring proinflammatory gene expression from mucosal biopsies from patients with Crohn's disease is practicable and provides objective biomarkers that can be used in proof-of-concept and mechanism-of-action trials to assess response to therapy.

Adalimumab drug and antibody levels as predictors of clinical and laboratory response in patients with Crohn's disease

BACKGROUND

Adalimumab is an effective treatment for Crohn's disease (CD). Anti-adalimumab antibodies (AAA) and low trough serum drug concentrations have been implicated as pre-disposing factors for treatment failure.

AIMS

To assess adalimumab and AAA serum levels, and to examine their association and discriminatory ability with clinical response and serum C-reactive protein (CRP).

METHODS

We performed a cross-sectional study using trough sera from adalimumab-treated CD patients. Demographical data, Montreal classification, treatment regimen and clinical status were recorded. Serum adalimumab, AAA and CRP were measured. Receiver operating characteristic analysis and a multivariate regression model were performed to find drug and antibody thresholds for predicting disease activity at time of serum sampling.

RESULTS

One hundred and eighteen trough serum samples were included from 71 patients. High adalimumab trough serum concentration was associated with disease remission (Area Under Curve 0.748, P < 0.001). A cut-off drug level of 5.85 μg/mL yielded optimal sensitivity, specificity and positive likelihood ratio for remission prediction (68%, 70.6% and 2.3, respectively). AAA were inversely related with adalimumab drug levels (Spearman's r = -0.411, P < 0.001) and when subdivided into categorical values, positively related with disease activity (P < 0.001). High drug levels and stricturing vs. penetrating or inflammatory phenotype, but not AAA levels, independently predicted disease remission in a multivariate logistic regression model.

CONCLUSIONS

Adalimumab drug levels were inversely related to disease activity. High levels of anti-adalimumab antibodies were positively associated with disease activity, but this association was mediated mostly by adalimumab drug levels.

C-reactive protein in Crohn's disease: how informative is it?

C-reactive protein (CRP) is an important acute-phase marker, produced mainly in the liver. Its production by mesenteric adipocytes has been recently stressed in Crohn's disease (CD). There are many factors affecting CRP levels, both environmental and genetics. The short-life of this biomarker makes it of pertinent use in the assessment of inflammation. There are inconsistent results concerning the association of clinical activity indices, mucosal healing, histological activity and CRP. This review summarizes the role of CRP in CD, namely its importance in the differential diagnosis of CD; its relationship with clinical activity indices, other markers of inflammation and endoscopic and radiological cross sectional imaging; prediction of response to anti-TNF treatment and prediction of outcome.

Cryptogenia multifocal ulcerous stenosing enteritis: an entity on its own as a cause of abdominal pain, iron deficiency anemia and protein-losing enteropathy

We studied a patient with edema secondary to protein losing enteropathy, and recurrent bouts of bloating and abdominal pain secondary to intestinal subocclusion episodes. After the clinical study, the patient was diagnosed of cryptogenic multifocal ulcerous stenosing enteritis (CMUSE), that is a rare disease, probably caused by mutations in the gene PLA2G4A, and characterized by multiple short stenosis of the small bowel with superficial ulcers, which do not exceed the submucosa layer. Inflammatory bowel disease (Chron's disease), intestinal tuberculosis and intestinal ulcers secondary to non-steroidal anti-inflammatory drugs are the main differential diagnosis. To sum up, physicians should included CMUSE in the differential diagnosis of recurrent abdominal pain, iron deficiency anaemia, occult intestinal bleeding, edema and protein losing enteropathy.

Combined serological, genetic, and inflammatory markers differentiate non-IBD, Crohn's disease, and ulcerative colitis patients

BACKGROUND

Previous studies have demonstrated that serological markers can assist in diagnosing inflammatory bowel disease (IBD). In this study, we aim to build a diagnostic tool incorporating serological markers, genetic variants, and markers of inflammation into a computational algorithm to examine patterns of combinations of markers to (1) identify patients with IBD and (2) differentiate patients with Crohn's disease (CD) from ulcerative colitis (UC).

METHODS

In this cross-sectional study, patient blood samples from 572 CD, 328 UC, 437 non-IBD controls, and 183 healthy controls from academic and community centers were analyzed for 17 markers: 8 serological markers (ASCA-IgA, ASCA-IgG, ANCA, pANCA, OmpC, CBir1, A4-Fla2, and FlaX), 4 genetic markers (ATG16L1, NKX2-3, ECM1, and STAT3), and 5 inflammatory markers (CRP, SAA, ICAM-1, VCAM-1, and VEGF). A diagnostic Random Forest algorithm was constructed to classify IBD, CD, and UC.

RESULTS

Receiver operating characteristic analysis compared the diagnostic accuracy of using a panel of serological markers only (ASCA-IgA, ASCA-IgG, ANCA, pANCA, OmpC, and CBir1) versus using a marker panel that in addition to the serological markers mentioned above also included gene variants, inflammatory markers, and 2 additional serological markers (A4-Fla2 and FlaX). The extended marker panel increased the IBD versus non-IBD discrimination area under the curve from 0.80 (95% confidence interval [CI], ±0.05) to 0.87 (95% CI, ±0.04; P < 0.001). The CD versus UC discrimination increased from 0.78 (95% CI, ±0.06) to 0.93 (95% CI, ±0.04; P < 0.001).

CONCLUSIONS

Incorporating a combination of serological, genetic, and inflammation markers into a diagnostic algorithm improved the accuracy of identifying IBD and differentiating CD from UC versus using serological markers alone.

Neopterin concentration as an index of disease activity in Crohn's disease and ulcerative colitis

BACKGROUND

Neopterin, a pyrazino-[2,3-d]-pyrimidine compound, is a metabolite of cyclic guanosine monophosphate that is released by activated T lymphocytes and macrophages after induction by γ interferon. We sought to determine whether neopterin concentration in stool, serum, or urine is a useful marker of disease activity in patients with Crohn's disease or ulcerative colitis.

METHODS

We prospectively studied 70 outpatients (33 M, 37 F, aged 39.2 ± 14.0 y) with Crohn's disease (33 clinically in remission, 37 active), 52 outpatients (29 M, 23 F, aged 39.8 ± 12.2 y) with ulcerative colitis (29 clinically in remission, 23 active), and 141 healthy control subjects. Fecal, serum, and urine samples were analyzed for neopterin concentration and other analytes of interest. The following clinical indices were calculated at enrollment: for Crohn's disease, the Capetown Index and Harvey Bradshaw Index; for ulcerative colitis, Simple Clinical Colitis Activity Index, Disease Activity Index, and endoscopic disease severity (rated on a scale of 0 to 3). Crohn's disease was considered active if the Harvey Bradshaw Index was ≥ 5, and ulcerative colitis was considered active if the Simple Clinical Colitis Activity Index was >3.

RESULTS

Among Crohn's disease patients, fecal neopterin was higher in those with either clinically active (96.0 ng/g) or inactive (87.2 ng/g) disease than in control subjects (12.0 ng/g; P<0.05; inactive or active disease vs. controls). For ulcerative colitis patients, fecal neopterin concentration was higher in those with active (135.2 ng/g) disease than in those with inactive disease (62.7 ng/g; P<0.05) or healthy controls (12.0 ng/g; P<0.05). Neither serum nor urine neopterin concentrations were increased in patients with active inflammatory bowel disease. Nonsignificant trends toward greater fecal neopterin concentration were observed with increased colonic disease involvement, although not with endoscopic severity or clinical disease activity indices.

CONCLUSIONS

Fecal neopterin concentration is increased in patients with clinically active or inactive Crohn's disease and in patients with clinically active ulcerative colitis when compared with controls, and therefore represents a new biomarker for disease activity.

High-sensitivity C-reactive protein for identification of disease phenotype, active disease, and clinical relapses in Crohn's disease: a marker for patient classification?

BACKGROUND

C-reactive protein (CRP) is a traditional nonspecific marker of inflammation, with Crohn's disease (CD) being associated with a strong CRP response. Thus far, no clear cutoff values have been determined. The authors' aim was to investigate whether high-sensitivity (hs)-CRP is useful for the identification disease phenotype, active disease, and relapse during follow-up, using a classification based on the hs-CRP value at diagnosis.

METHODS

In all, 260 well-characterized, unrelated, consecutive CD patients (male/female: 120/140; duration: 7.0 ± 6.1 years), with a complete clinical follow-up, were included. Hs-CRP, clinical activity according to the Harvey-Bradshaw Index, and clinical data (disease phenotype according to the Montreal Classification, extraintestinal manifestations, smoking habits, medical therapy, and surgical events) were prospectively collected between January 1, 2008 and June 1, 2010. Medical records prior to the prospective follow-up period were analyzed retrospectively.

RESULTS

In all, 32.3% of CD patients had normal hs-CRP at diagnosis. Elevated hs-CRP at diagnosis was associated with disease location (P = 0.002), noninflammatory disease behavior (P = 0.058), and a subsequent need for later azathioprine/biological therapy (P < 0.001 and P = 0.024), respectively. The accuracy of hs-CRP for identifying patients with active disease during prospective follow-up was good (area under the curve [AUC]: 0.82, cutoff: 10.7 mg/L). AUC was better in patients with an elevated hs-CRP at diagnosis (AUC: 0.92, cutoff: 10.3 mg/L). In Kaplan-Meier and Cox-regression analyses, hs-CRP was an independent predictor of 3- (P = 0.007) or 12-month (P = 0.001) clinical relapses for patients in remission who had elevated hs-CRP at diagnosis. In addition, perianal involvement (P = 0.01) was associated with the 12-month relapse frequency.

CONCLUSIONS

Our data suggest that hs-CRP positivity at diagnosis is associated with disease location and behavior, and in patients who are hs-CRP positive at diagnosis, is an accurate marker of disease activity and a predictor of short- and medium-term clinical flare-ups during follow-up.

Soluble urokinase plasminogen activator receptor suPAR as a marker for inflammation in pediatric inflammatory bowel disease

OBJECTIVE

In inflammatory bowel disease (IBD), more means to monitor early therapeutic response are needed. In pediatric IBD, blood inflammatory markers erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) may be low in 10 to 20% of patients with severe disease. Recently, soluble urokinase plasminogen activator receptor (suPAR) was described as a potential blood inflammatory marker in adult IBD.

METHODS

We tested the performance of suPAR by the start of therapy with glucocorticoids (n = 19) or TNF-α-antagonist (n = 16) in pediatric IBD (Crohn's disease n = 19, ulcerative colitis (UC) n = 16).

RESULTS

The levels of suPAR were low in both patient groups studied. There was no difference in the values regarding the presence of Crohn's disease or ulcerative colitis. Thus, all analyses were performed on the entire sample set. Glucocorticoid therapy, however, resulted in a significant decline in suPAR levels from a median of 3.06 to 2.54 ng/ml (p < 0.01). In contrast, TNF-α-antagonist had no effect. The suPAR levels did not associate with ESR or CRP or fecal calprotectin (FC).

CONCLUSIONS

In pediatric IBD, the suPAR levels in blood are low and do not reflect the level of intestinal inflammation assessed with FC. The introduction of corticoids, however, results in a decline of suPAR levels in blood but not reflect therapeutic response to TNF-α-antagonist. Thus, suPAR is of limited value in assessing systemic inflammatory responses in pediatric IBD.

Biomarkers in inflammatory bowel disease: current practices and recent advances

Crohn's disease and ulcerative colitis represent the two main forms of the idiopathic chronic inflammatory bowel diseases (IBD). Currently available blood and stool based biomarkers provide reproducible, quantitative tools that can complement clinical assessment to aid clinicians in IBD diagnosis and management. C-reactive protein and fecal based leukocyte markers can help the clinician distinguish IBD from noninflammatory diarrhea and assess disease activity. The ability to differentiate between forms of IBD and predict risk for disease complications is specific to serologic tests including antibodies against Saccharomyces cerevisiae and perinuclear antineutrophil cytoplasmic proteins. Advances in genomic, proteomic, and metabolomic array based technologies are facilitating the development of new biomarkers for IBD. The discovery of novel biomarkers, which can correlate with mucosal healing or predict long-term disease course has the potential to significantly improve patient care. This article reviews the uses and limitations of currently available biomarkers and highlights recent advances in IBD biomarker discovery.

Differential effects of energy balance on experimentally-induced colitis

AIM: To characterize the influence of diet-induced changes in body fat on colitis severity in SMAD3-/- mice.

METHODS: SMAD3-/- mice (6-8 wk of age) were randomly assigned to receive a calorie restricted (30% of control; CR), control (CON), or high fat (HF) diet for 20 wk and were gavaged with sterile broth or with Helicobacter hepaticus (H. hepaticus) to induce colitis. Four weeks after infection, mice were sacrificed and the cecum and colons were processed for histological evaluation.

RESULTS: Dietary treatment significantly influenced body composition prior to infection (P < 0.05), with CR mice having less (14% ± 2%) and HF-fed mice more body fat (32% ± 7%) compared to controls (22% ± 4%). Differences in body composition were associated with alterations in plasma levels of leptin (HF > CON > CR) and adiponectin (CON > HF ≥ CR) (P < 0.05). There were no significant differences in colitis scores between CON and HF-fed mice 4 wk post-infection. Consistent with this, differences in proliferation and inflammation markers (COX-2, iNOS), and infiltrating cell types (CD3⁺ T lymphocytes, macrophages) were not observed. Unexpectedly, only 40% of CR mice survived infection with H. hepaticus, with mortality observed as early as 1 wk following induction of colitis.

CONCLUSION: Increased adiposity does not influence colitis severity in SMAD3-/- mice. Importantly, caloric restriction negatively impacts survival following pathogen challenge, potentially due to an impaired immune response.

Genes of intestinal Escherichia coli and their relation to the inflammatory activity in patients with ulcerative colitis and Crohn's disease

Escherichia coli gene fimA was the most frequent gene that occurred in the intestine of all investigated groups. All subjects with fimA gene had significantly higher values of tumor necrosis factor alpha (TNF-α) and CRP than those with other E. coli genes. There was also a tendency to increased serum interleukin (IL)-6 levels in patients carrying the fimA gene; however, no relation was observed to serum IL-8 and IL-10. Patients with Crohn's disease had significantly higher IL-6 than those with ulcerative colitis (UC) and controls. The highest levels of TNF-α were detected in the UC group. There were no significant differences in serum IL-8 and IL-10 between all three groups. The presence of E. coli gene fimA in the large bowel of patients with IBD is related to the immunological activity of the disease which may be important from the aspect of therapeutical strategy.

Use of C-reactive protein in children with newly diagnosed inflammatory bowel disease

C-reactive protein (CRP), a marker for inflammation, was evaluated with other routine blood tests in children with newly diagnosed inflammatory bowel disease. Evaluation of CRP level helped identify additional patients found to have inflammatory bowel disease at endoscopy, although a sizeable number of patients with mild ulcerative colitis had a normal CRP level.

Using metabolomic analysis to understand inflammatory bowel diseases

Crohn's disease (CD) and ulcerative colitis (UC) are inflammatory bowel diseases (IBD) attributed to a dysregulated immune response towards intestinal microbiota. Although various susceptibility genes have been identified for CD and UC, the exact disease etiology is unclear and complicated by the influence of environmental factors. Metabolomic analysis enables high sample throughput measurements of multiple metabolites in biological samples. The use of metabolomic analysis in medical sciences has revealed metabolite perturbations associated with diseases. This article provides a summary of the current understanding of IBD, and describes potential applications and previous metabolomic analysis in IBD research to understand IBD pathogenesis and improve IBD therapy.

Serum immune-activation potency and response to anti-TNF-α therapy in Crohn's disease

AIM: To study whether immune-activation stage in serum of adult Crohn’s disease (CD) patients correlates with disease activity and with treatment response to anti-tumor necrosis factor-α (TNF-α) therapy.

METHODS: Serum samples were obtained from 15 adult CD patients introduced to anti-TNF-α therapy. The individual stage of immune activation was studied applying our new in vitro assay, in which target cells (donor derived peripheral blood mononuclear cells) were cultured with patient serum and the T-cell activation induced by the patient serum was studied using a panel of markers for effector [interferon γ (IFNγ), interleukin (IL)-5] and regulatory T-cells [forkhead transcription factor 3 (FOXP3) and glucocorticoid-induced tumour necrosis factor receptor (GITR)]. The endoscopic disease activity was assessed with the Crohn’s disease endoscopic index of severity (CDEIS) before and 3 mo after therapy with an anti-TNF-α agent.

RESULTS: Low induction of FOXP3 and GITR in target cells cultured in the presence of patient serum was associated with high disease activity i.e. CDEIS assessed before therapy (r = -0.621, P = 0.013 and r = -0.625, P = 0.013, respectively). FOXP3 expression correlated inversely with pre-treatment erythrocyte sedimentation rate (r = -0.548, P = 0.034). Low serum induced FOXP3 (r = -0.600, P = 0.018) and GITR (r = -0.589, P = 0.021) expression and low IFNγ secretion from target cells (r = -0.538, P = 0.039) associated with treatment response detected as a decrease in CDEIS.

CONCLUSION: The immune-activation potency in the patient serum prior to anti-TNF-α therapy reflected intestinal inflammation and the therapeutic response.

Is the disease course predictable in inflammatory bowel diseases?

During the course of the disease, most patients with Crohn's disease (CD) may eventually develop a stricturing or a perforating complication, and a significant number of patients with both CD and ulcerative colitis will undergo surgery. In recent years, research has focused on the determination of factors important in the prediction of disease course in inflammatory bowel diseases to improve stratification of patients, identify individual patient profiles, including clinical, laboratory and molecular markers, which hopefully will allow physicians to choose the most appropriate management in terms of therapy and intensity of follow-up. This review summarizes the available evidence on clinical, endoscopic variables and biomarkers in the prediction of short and long-term outcome in patients with inflammatory bowel diseases.

High-sensitivity C-reactive protein in paediatric inflammatory bowel disease

AIM: To study whether high-sensitivity C-reactive protein (hs-CRP) measurement can aid the assessment of disease activity and glucocorticoid treatment in paediatric inflammatory bowel disease (IBD).

METHODS: CRP levels were measured in 39 children with IBD undergoing colonoscopy [median age 12.8 years, Crohn’s disease (CD) n = 20], in 22 other children with IBD followed for acute response to glucocorticoids, and in 33 paediatric non-IBD patients. When standard CRP level was below detection limit (< 5 mg/L), hs-CRP was analyzed.

RESULTS: Sixty-four percent (25/39) of the children with IBD undergoing colonoscopy displayed undetectable (< 5 mg/L) standard CRP levels. Of these, the hs-CRP measurement could not differentiate between active (median, 0.2 mg/L, range, 0.007-1.37, n = 17) or quiescent (0.1 mg/L, 0.01-1.89, n = 8, P = NS) disease. Patients with ileocolonic CD had higher CRP levels (14 mg/L, 0.06-45, n = 13) than patients with no ileal involvement (0.18 mg/L, 0.01-9, n = 7, P < 0.01) or ulcerative colitis (UC) (0.13 mg/L, 0.007-23, P < 0.05). In children with active IBD treated with systemic glucocorticoids, the standard CRP was undetectable in 59% of the patients. The hs-CRP levels did not differ between patients that responded to steroid therapy and in non-responders.

CONCLUSION: The measurement of hs-CRP did not prove useful in the assessment of disease activity or glucocorticoid treatment in paediatric IBD patients that had undetectable standard CRP.

Is the disease course predictable in inflammatory bowel diseases?

During the course of the disease, most patients with Crohn’s disease (CD) may eventually develop a stricturing or a perforating complication, and a significant number of patients with both CD and ulcerative colitis will undergo surgery. In recent years, research has focused on the determination of factors important in the prediction of disease course in inflammatory bowel diseases to improve stratification of patients, identify individual patient profiles, including clinical, laboratory and molecular markers, which hopefully will allow physicians to choose the most appropriate management in terms of therapy and intensity of follow-up. This review summarizes the available evidence on clinical, endoscopic variables and biomarkers in the prediction of short and long-term outcome in patients with inflammatory bowel diseases.

Role of diet in the development of inflammatory bowel disease

The inflammatory bowel diseases (IBDs) are a group of heterogeneous disorders characterized by acute and chronic inflammatory changes in the small or large bowel, or in both. Increasing incidence and prevalence figures for IBD both in the developed and developing world indicate that environmental factors are at least as significant in IBD as genetic susceptibility. Of these, diet and the host microbiota are likely to play important but as yet poorly defined roles. The major constituents of a standard "Western" diet may contribute to, or protect against, intestinal inflammation via several mechanisms. These include the effects of insulin resistance and short-chain fatty acids such as butyrate, modification of intestinal permeability, the antiinflammatory role of polyunsaturated fatty acids, and the effect of sulfur compounds from protein on host microbiota. This detailed review critically assesses the evidence for the role of diet in the development of IBD and examines the evidence for obesity as a contributing factor to IBD pathogenesis. Particular attention is focused on methodological issues including suitability of cases and controls, confounders such as smoking, and total energy expenditure.

C-reactive protein and disease activity in children with Crohn's disease

BACKGROUND AND AIMS

Various markers are used to monitor disease activity in paediatric Crohn's disease (CD). We sought to determine whether C-reactive protein measurement was useful in the assessment of disease activity in children with CD, with comparison to the other markers of disease activity.

METHODS

Details of disease activity, C-reactive protein and inflammatory markers were obtained retrospectively from the records of 100 outpatient visits by 63 children with CD.

RESULTS

The children were 12.6 (+/-3.4) years of age. C-reactive protein values correlated positively with disease activity (P < 0.0001). Children with inactive disease (according to pediatric CD activity index scores) had significantly lower C-reactive protein values compared to children with mild disease (P < 0.001). In addition, C-reactive protein values correlated well with ESR (P < 0.0001). Conclusions C-reactive protein measurements provided useful information in assessing children with CD and correlated well with a validated measure of disease activity.

Clinical significance of inflammatory markers

Inflammatory markers play a key role in the evaluation of patients with gastrointestinal symptoms. For patients presenting with nonspecific symptoms of abdominal pain and diarrhea, distinguishing inflammatory bowel disease from other disorders can be difficult, and invasive diagnostic procedures may be required. Inflammatory markers can be useful to differentiate patients who may require further workup from those who do not. Several serum, fecal, and other markers are reviewed for their use in clinical practice. Although no single ideal marker exists, a few show promise in diagnosing inflammatory disease, monitoring disease activity, and predicting relapse.

Relationship of C-reactive protein with clinical response after therapy with ustekinumab in Crohn's disease

OBJECTIVES

Ustekinumab induction therapy was studied in a placebo-controlled trial of patients with Crohn's disease (CD; n=104). In patients receiving ustekinumab, 49% achieved clinical response at week 8 vs. 40% for placebo (P=0.34). In a subgroup of patients previously treated with infliximab (n=49), 59% receiving ustekinumab responded vs. 26% receiving placebo (P=0.02).

METHODS

C-reactive protein (CRP) concentrations were analyzed from serum collected at baseline and at week 8. Change from baseline CRP concentration after treatment, the relationship between baseline CRP concentration and clinical response, and the relationship between baseline CRP concentration and disease location were investigated.

RESULTS

Mean changes from baseline CRP at week 8 in the primary group were -0.3 and -3.1 mg/l after treatments with placebo (n=43) and ustekinumab (n=46), respectively (P=0.074). In the infliximab-experienced subgroup, the mean changes were +2.0 (placebo, n=23) and -2.6 mg/l (ustekinumab, n=20) (P=0.004). Patients with baseline CRP >or=10 mg/l tended to have lower placebo and a higher ustekinumab response. In addition, more extensive diseases associated with CD in the colon and ileum were reflected by higher CRP concentrations.

CONCLUSIONS

The potential benefit of ustekinumab in CD is supported by serum CRP reductions. Evidence suggests that increased systemic inflammation as manifested by higher baseline CRP values leads to larger treatment effects with ustekinumab, especially in infliximab-experienced patients.

Correlation of serum-soluble triggering receptor expressed on myeloid cells-1 with clinical disease activity in inflammatory bowel disease

Although triggering receptor expressed on myeloid cells-1 (TREM-1) has recently been shown to be upregulated in the intestines of patients with inflammatory bowel disease (IBD), it remains unclear whether serum-soluble TREM-1 (sTREM-1) level reflects disease activity in patients with IBD. This study aimed to evaluate the correlation of sTREM-1 level with disease activity in IBD. We prospectively enrolled consecutive patients with IBD and assessed their clinical disease activity using the guidelines of the American College of Gastroenterology. At the time that disease activity was assessed, sTREM-1 level (using an enzyme-linked immunosorbent assay method) and other laboratory findings including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were also measured. A total of 31 patients with ulcerative colitis (UC) and 22 with Crohn's disease (CD) were enrolled. The mean sTREM-1 level in patients with either UC (60.4 +/- 41.8 pg/ml) or CD (66.5 +/- 42.4 pg/ml) was significantly higher than in healthy controls (0.6 +/- 1.4 pg/ml) (P = 0.003 and P = 0.002, respectively). In patients with UC, sTREM-1 level was more highly correlated with disease activity (r = 0.849) than was ESR (r = 0.619) or CRP level (r = 0.546). Moreover, sTREM-1 level correlated well with disease activity irrespective of disease extent. In patients with CD, sTREM-1 level was lower in those with remission compared with those without (46.8 +/- 35.3 pg/ml versus 77.8 +/- 43.1 pg/ml), but this trend did not reach statistical significance (P = 0.100). The results of our study suggest that sTREM-1 could be a potential marker for disease activity in IBD patients, especially those with UC.

Urinary neopterin is a valuable tool in monitoring Crohn's disease activity

BACKGROUND

The aim was to investigate the relation between urinary neopterin and the Crohn's Disease Activity Index (CDAI) and to compare its ability to discriminate active versus inactive CD with serum C-reactive protein (CRP).

METHODS

In all, 217 urinary samples for neopterin measurement were obtained in a cohort of 93 consecutive patients with CD and 66 samples in 33 healthy volunteers. Clinical parameters were recorded and blood samples for CRP were collected as well.

RESULTS

Whereas patients with inactive CD showed similar levels of urinary neopterin excretion than healthy volunteers (163 +/- 8 versus 142 +/- 7 nmol/mol of creatinine, respectively; P = 0.1), urinary neopterin excretion from mild to severe active CD was significantly higher (302 +/- 15 nmol/mol of creatinine; P < 0.001). Serum CRP levels were higher in active CD (14.8 +/- 2.1 mg/L) compared with inactive CD (5.6 +/- 0.8 mg/L; P < 0.001). Urinary neopterin excretion, and to a lesser degree CRP, were positively and significantly correlated with CDAI (r = 0.64 and 0.43, respectively, P < 0.001). Based on the cutoff of 183 nmol/mol of creatinine for urinary neopterin, the sensitivity and specificity of urinary neopterin to discriminate between active and inactive CD were 73% and 82%, respectively, and the positive and negative predictive values were 80% and 78%, respectively.

CONCLUSIONS

Urinary neopterin excretion is an objective, valuable, simple, and noninvasive biomarker to detect and follow fluctuations of CD activity. Further work is warranted to study its clinical value and relation to mucosal healing.

C-reactive protein levels during a relapse of Crohn’s disease are associated with the clinical course of the disease

AIM: To explore if C-reactive protein (CRP) levels might serve as a prognostic factor with respect to the clinical course of Crohn’s disease and might be useful for classification.

METHODS: In this retrospective cohort study we enrolled 94 patients from the inflammatory bowel disease (IBD) database of the University Medical Centre Utrecht. CRP levels during relapse were correlated with the number of relapses per year. Severity of relapses was based on endoscopic reports and prednisone use. Furthermore, patients were categorized in a low or high CRP group based on their CRP response during relapse and demographic and clinical features were compared.

RESULTS: Overall, a positive correlation between CRP levels, number of relapses, and severity of relapse was found (respectively r_s = 0.31, P < 0.01 and r_s = 0.50, P < 0.001). Employing a cut-off level of 15 mg/L, the index CRP level was found to discriminate patients with respect to the number of relapses per year, as well as for severity of relapses (respectively 0.25 ± 0.16 vs 0.36 ± 0.24, P < 0.05 and 4.4 ± 1.2 vs 3.2 ± 1.1 on a 10-point visual analogue scale, P < 0.001 for the high CRP and low CRP groups respectively). In addition, the high CRP group showed more cumulative days of prednisone use per year (107 ± 95 vs 58 ± 48, P < 0.05), as well as a better response to infliximab (93 % vs 33 %, P = 0.06).

CONCLUSION: A higher CRP level during relapse seems to be associated with a more severe clinical course of disease.

Current and future diagnostic approaches: from serologies to imaging

Advances in serologic markers and imaging modalities continue to revolutionize diagnostic approaches to inflammatory bowel disease (IBD). Autoimmune and antimicrobial antibodies demonstrate diagnostic value in those patients with a moderate pretest probability of disease. Emerging data also support the use of antimicrobial antibody levels as a predictive tool for small bowel complications and the need for future surgery. In addition to being a prognostic marker in patients with acute severe colitis, serum C-reactive protein has been shown to correlate with clinical, endoscopic, and radiologic measures of disease activity. Capsule endoscopy and double-balloon endoscopy allow for visualization of the entire small bowel, and double-balloon endoscopy also has the capability to treat lesions. CT enterography is beginning to replace small bowel follow-through because of its high sensitivity and specificity for disease of the small intestine. Both CT and magnetic resonance enterography detect luminal and extraluminal abnormalities, with MRI serving as a safe imaging option in cases of pregnancy and renal insufficiency. These newer modalities add to the armamentarium clinicians can use for evaluation of IBD.

Correlation between levels of C-reactive protein and clinical activity in Crohn's disease

AIMS

To determine the factors associated with an increased C-reactive protein level in Crohn's disease patients and to seek a correlation between the C-reactive protein value and the Crohn's disease activity index.

METHODS

We prospectively studied 103 Crohn's disease patients, 76% of whose disease was active at the time of inclusion. C-reactive protein measurement was carried out on all patients. An increased C-reactive protein level was defined as >/=10mg/L.

RESULTS

The median C-reactive protein rate was 53.9mg/L (ranging from 1 to 228mg/L). An increased C-reactive protein was found in 77 patients (75%). By univariate analysis, ileocolic localization, severity of the flare, erythrocyte sedimentation rate, leukocyte and platelet count, fibrinogen, albumin, serum calcium and Crohn's disease activity index were found to be associated to elevated C-reactive protein values. By multivariate analysis, independent factors associated with an increased C-reactive protein level were: ileocolic localization (p=0.02; OR [95% CI]: 2.84 [1.25-9.52]) and moderate or severe disease activity (p=0.001; OR [95% CI]: 4.20 [1.92-8.64]). A statistically significant association between the Crohn's disease activity index score and the C-reactive protein level was found in our study (r=0.302; p=0.001). The optimal C-reactive protein threshold value that separates patients with moderate to severe disease (Crohn's disease activity index>220) from the others was calculated to be 19mg/L with a sensitivity of 76.4% and a specificity of 56.2%.

CONCLUSION

The C-reactive protein level is correlated to disease activity in Crohn's disease. Its role seems to be essential in predicting moderate and severe disease activity.

CRP correlates with clinical score in ulcerative colitis but not in Crohn's disease

The aim of this study was to prospectively evaluate the correlation between clinical scoring systems and C-reactive protein (CRP) in inflammatory bowel disease. The modified Harvey-Bradshaw index was used in 40 patients (58 assessments) with Crohn's disease, and the Lichtiger score in 29 patients (36 assessments) with ulcerative colitis. In ulcerative colitis, CRP was elevated in 14%, 42%, 64%, and 83%, respectively, of subjects with quiescent, mild, moderate, and severe disease. There was a linear correlation of log(CRP) with clinical score except for proctitis. In Crohn's disease, CRP was elevated in 54%, 70%, 75%, and 100%, respectively, of subjects with quiescent, mild, moderate, and severe disease. We conclude that the clinical score has a good correlation with CRP in ulcerative colitis except for proctitis, whereas clinical score has a poor correlation with CRP in Crohn's disease, particularly in those with clinically quiescent, fibrostenotic, and ileal disease.

Assessment of endoscopic activity index and biological inflammatory markers in clinically active Crohn's disease with normal C-reactive protein serum level

BACKGROUND

Patients with clinically active Crohn's disease (CD), defined by a Crohn's Disease Activity Index (CDAI)>150, may have normal C-reactive protein (CRP) serum levels. In such cases, it is difficult to know whether these patients have really active disease or rather functional symptoms. This distinction is important to decide the most appropriate treatment. The aim of our work was to assess intestinal and colonic lesions in such patients and to look for biological markers potentially associated with endoscopic activity of the disease.

METHODS

We included 28 consecutive CD patients with CDAI>150 and a normal CRP level. These patients underwent a full colonoscopy with Crohn's Disease Endoscopy Index of Severity (CDEIS) calculation, fecal calprotectin, blood fibrinogen, acid alpha-1 glycoprotein, and erythrocyte sedimentation rate measurement. The Harvey-Bradshaw score was also calculated. Serum IL1 beta, IL6, IL8, sIL2R, and sTNFR2 were measured.

RESULTS

The median CDAI was 181 (151-485). Almost all (92.9%) these patients had endoscopic lesions, but the majority had only mild lesions (CDEIS<or=6). No correlation was found between CDEIS and any of the clinical or biological markers. However, all the patients with significant endoscopic lesions (defined by a CDEIS>6) had previous surgical intestinal resection and lesions involving the anastomosis.

CONCLUSIONS

Patients with elevated CDAI and normal CRP have only mild mucosal lesions of CD. Most significant lesions may be observed at the anastomosis and proximal to it in previously operated patients. None of the biological markers tested was associated with these endoscopic lesions.

[Role of biological markers in inflammatory bowel disease]

The role played by the distinct biological markers in chronic inflammatory bowel disease (IBD) remains insufficiently characterized. C-reactive protein (CRP) has a short half-life and consequently it is elevated early after the onset of the inflammatory process and rapidly decreases after its resolution, making it an attractive marker of disease activity. Moreover, this test is inexpensive and easy to perform and is unaffected by medication. While Crohn's disease is associated with a marked CRP response, there is little or no elevation in the synthesis of this protein in ulcerative colitis. Erythrocyte sedimentation rate provides some advantages such as its ease of determination, availability, and reduced cost. Nevertheless, it also has several disadvantages, notably the fact that its concentration depends on age, the presence of anemia, smoking, and the use of certain drugs. Moreover, its utility is limited by its long half life and consequent prolonged latency period after changes in chronic IBD activity. In theory, fecal markers have the advantages of showing greater specificity in the diagnosis of chronic IBD. Several gastrointestinal diseases, including chronic IBD, show greater leukocyte elimination in feces and a close correlation has been described between fecal calprotectin concentration and leukocyte excretion quantified by 111indium. Advantages of this fecal marker are that it can be detected through a simple and inexpensive technique and also shows excellent stability in feces for prolonged periods. Like calprotectin, fecal lactoferrin is also quantified by a simple and inexpensive ELISA method, although there is considerably less experience with this latter marker.

Review article: biological activity markers in inflammatory bowel disease

BACKGROUND

Traditionally, inflammatory bowel disease activity is assessed by clinical activity indices that measure clinical symptoms and endoscopic indices that measure endoscopic inflammation. Biological markers are a non-invasive way of objectively measuring inflammation and can play an adjunctive or primary role in the assessment of disease activity.

AIM

To review the data on biological markers for assessment of disease activity and prediction of relapse in inflammatory bowel disease.

METHODS

To collect relevant articles, a PubMed search was performed from 1980 to 2006 using following search terms in combination: inflammatory bowel disease, biomarkers, inflammation, disease activity, relapse, acute phase reactants cytokines, interleukins, adhesion molecules, integrins, calprotectin and lactoferrin.

RESULTS

Biological activity markers can be classified into serological, faecal and miscellaneous categories. Acute phase reactants levels correlate with disease activity and some can be used to help predict relapse. Cytokines and adhesion molecules are elevated in active disease inconsistently. Faecal markers are useful in assessment of disease activity and relapse.

CONCLUSIONS

Acute phase reactants and faecal markers are useful to assess the disease activity in clinical practice. More data are required on cytokines and adhesion molecules. C-reactive protein, erythrocyte sedimentation rate, interleukins and faecal markers may be useful in predicting a relapse.

Evolving diagnostic strategies for inflammatory bowel disease

Advances in serologic markers, endoscopy, and radiology have led to rapid expansion of diagnosis and disease activity assessment of inflammatory bowel disease (IBD). Serologic markers may have diagnostic value in patients with an intermediate pretest probability of IBD, but these serology tests lack complete sensitivity, and a negative serology result does not exclude the possibility of IBD. Several recent studies have confirmed the utility of serologies in predicting intestinal complications and need for surgery in Crohn's disease. Serum C-reactive protein concentrations correlate with clinical, endoscopic, and radiologic measures of disease activity and appear to have prognostic value in acute severe colitis. Capsule and double balloon endoscopy allow visual inspection of previously inaccessible areas of the small intestine and are useful for patients with suspected small bowel involvement but negative results on conventional testing. CT enterography, which entails oral ingestion of a large volume of a neutral or negative contrast agent and scanning that highlights differences in contrast between the lumen and the bowel wall, appears to be more sensitive than small bowel follow-through for detecting small bowel Crohn's disease and provides extraluminal information. Magnetic resonance enterography uses principles similar to those for CT enterography, and early results are encouraging.

Associations between NOD2/CARD15 genotype and phenotype in Crohn’s disease-Are we there yet?

There have been multiple NOD2/CARD15 genotype-phenotype analyses undertaken in patients with Crohn's disease since the gene’s discovery in 2001. This review focuses on the major published series based upon their size and on the presence of specific clinical and genetic information provided in the published material from 2001 to 2005. Twelve studies provided raw data to carry out comparisons of disease location while ten studies included analysis of NOD2/CARD15 genotypes. NOD2/CARD15 variant frequency in ileal disease did not differ significantly among studies, whereas a comparison of disease location demonstrated highly significant differences among studies. Meta-analysis confirmed significant associations between NOD2/CARD15 variants and both ileal and ileocolonic disease locations, and with both stricturing and penetrating forms of disease behavior. This review underlines the significant phenotypic differences that exist among populations, including similar ethnic groups, and has demonstrated the need for further studies of patients with long-term “inflammatory” Crohn’s disease.

The +1059G/C polymorphism in the C-reactive protein (CRP) gene is associated with involvement of the terminal ileum and decreased serum CRP levels in patients with Crohn's disease

BACKGROUND

Serum C-reactive protein (CRP) levels influence the response to anti-tumour necrosis factor (TNF) therapies.

AIM

To analyse the influence of the +1059G/C CRP polymorphism on CRP serum levels and disease susceptibility in patients with Crohn's disease (CD).

METHODS

Using restriction fragment length polymorphism (RFLP) analysis, genomic DNA from 241 CD patients and 199 unrelated controls was analysed for the +1059G/C substitution in the CRP gene and the common caspase-activation recruitment domain 15 (CARD15) variants.

RESULTS

Homozygous C/C carriers were detected only among CD patients (P = 0.066). Patients with ileal involvement (L1 and L3 phenotype) were found in only 58.4% of patients with the wildtype G/G genotype but in 88.2% of the heterozygous G/C carriers (OR 5.26; 95% CI 1.19-23.92) and four of the five C/C homozygous carriers (80%; OR 4.55; 95% CI 1.64-16.67; P = 0.008 for hetero- and homozygous carriers vs. wildtype) which was independent of the presence of CARD15 variants. Increased CD activity was associated with increased CRP serum levels (P < 0.005). For Crohn's disease activity index (CDAI) < 150, C/C homozygosity for the +1059 G/C polymorphism was associated with significantly lower CRP serum levels (P < 0.01).

CONCLUSIONS

The C allele of the CRP +1059G/C polymorphism is associated with decreased serum CRP levels and increased likelihood of disease involvement of the terminal ileum in CD patients.