A Novel 8-Predictors Signature to Predict Complicated Disease Course in Pediatric-onset Crohn's Disease: A Population-based Study

BACKGROUND

The identification of patients at high risk of a disabling disease course would be invaluable in guiding initial therapy in Crohn's disease (CD). Our objective was to evaluate a combination of clinical, serological, and genetic factors to predict complicated disease course in pediatric-onset CD.

METHODS

Data for pediatric-onset CD patients, diagnosed before 17 years of age between 1988 and 2004 and followed more than 5 years, were extracted from the population-based EPIMAD registry. The main outcome was defined by the occurrence of complicated behavior (stricturing or penetrating) and/or intestinal resection within the 5 years following diagnosis. Lasso logistic regression models were used to build a predictive model based on clinical data at diagnosis, serological data (ASCA, pANCA, anti-OmpC, anti-Cbir1, anti-Fla2, anti-Flax), and 369 candidate single nucleotide polymorphisms.

RESULTS

In total, 156 children with an inflammatory (B1) disease at diagnosis were included. Among them, 35% (n = 54) progressed to a complicated behavior or an intestinal resection within the 5 years following diagnosis. The best predictive model (PREDICT-EPIMAD) included the location at diagnosis, pANCA, and 6 single nucleotide polymorphisms. This model showed good discrimination and good calibration, with an area under the curve of 0.80 after correction for optimism bias (sensitivity, 79%, specificity, 74%, positive predictive value, 61%, negative predictive value, 87%). Decision curve analysis confirmed the clinical utility of the model.

CONCLUSIONS

A combination of clinical, serotypic, and genotypic variables can predict disease progression in this population-based pediatric-onset CD cohort. Independent validation is needed before it can be used in clinical practice.

Preclinical Serological Signatures are Associated With Complicated Crohn's Disease Phenotype at Diagnosis

BACKGROUND

At diagnosis, up to one-third of patients with Crohn's disease (CD) have a complicated phenotype with stricturing (B2) or penetrating (B3) behavior or require early surgery. We evaluated protein biomarkers and antimicrobial antibodies in serum archived years before CD diagnosis to assess whether complicated diagnoses were associated with a specific serological signature.

METHODS

Prediagnosis serum was obtained from 201 patients with CD and 201 healthy controls. Samples were evaluated with a comprehensive panel of 1129 proteomic markers (SomaLogic) and antimicrobial antibodies. CD diagnosis and complications were defined by the International Classification of Diseases-Ninth Revision and Current Procedural Terminology codes. Cox regression models were utilized to assess the association between markers and the subsequent risk of being diagnosed with complicated CD. In addition, biological pathway and network analyses were performed.

RESULTS

Forty-seven CD subjects (24%) had a B2 (n = 36) or B3 (n = 9) phenotype or CD-related surgery (n = 2) at diagnosis. Subjects presenting with complicated CD at diagnosis had higher levels of antimicrobial antibodies six years before diagnosis as compared with those diagnosed with noncomplicated CD. Twenty-two protein biomarkers (reflecting inflammatory, fibrosis, and tissue protection markers) were found to be associated with complicated CD. Pathway analysis of the altered protein biomarkers identified higher activation of the innate immune system and complement or coagulation cascades up to six years before diagnosis in complicated CD.

CONCLUSIONS

Proteins and antimicrobial antibodies associated with dysregulated innate immunity, excessive adaptive response to microbial antigens, and fibrosis precede and predict a complicated phenotype at the time of diagnosis in CD patients.

Crossover of the Patient Satisfaction Surveys, Adverse Events and Patient Complaints for Continuous Improvement in Radiotherapy Department

BACKGROUND

The patient's needs and expectations can be assessed through satisfaction surveys, adverse event declarations and records of complaints. However, by crossing individual complaints, satisfaction surveys in combination with adverse events received we could get valuable information. The objective is to identify common elements of work between these different sources to improve care.

METHODS

A retrospective analysis of patient's complaints, surveys and adverse events was carried out in order to highlight common improvement items between these 3 sources of information.

RESULTS

A satisfaction survey was given to the patients at the end of their treatment, who filled it out and left it in the "ad hoc" letterbox. At the end of December 2019, 4695 questionnaires had been collected (response rate 37%). In addition, since 2014, 1369 patients (approximately 20 patients per month) have been interviewed "face to face" by the research nurse who assesses their satisfaction using open questions. At the same time, a collection of complaints and adverse events was carried out. All this data has been analysed and cross-checked in order to highlight areas for improvement, in order to strengthen the safety and quality of care in our department.

CONCLUSIONS

Collecting and analysing satisfactions surveys, unexpected events and complaints constitute in our opinion, an effective tool to achieve patient empowerment. We aim for the patients to become a real player in their safety, involved in the overall effort to improve quality of their radiotherapy treatment by reporting what does not meet their expectations.

Anti-Microbial Antibody Response is Associated With Future Onset of Crohn's Disease Independent of Biomarkers of Altered Gut Barrier Function, Subclinical Inflammation, and Genetic Risk

BACKGROUND AND AIMS

Altered host immune reactivity to microbial antigens is hypothesized to trigger the onset of Crohn's disease (CD). We aimed to assess whether increased serum anti-microbial antibody response in asymptomatic first-degree relatives (FDRs) of CD patients is an independent risk factor for future CD development.

METHODS

We measured host serum antibody response to 6 microbial antigens at enrollment (Prometheus enzyme-linked immunosorbent assay test: anti-Saccharomyces cerevisiae antibodies immunoglobulin A/immunoglobulin G, anti-OmpC, anti-A4-Fla2, anti-FlaX, anti-CBir1) and derived the sum of positive antibodies (AS). We used samples at enrollment of prospectively followed healthy FDRs from a nested case-control cohort of the Crohn's and Colitis Canada Genetics Environment Microbial Project. Those who later developed CD (n = 77) were matched 1:4 by age, sex, follow-up duration, and geographic location with control FDRs remaining healthy (n = 307). To address our research aims, we fitted a multivariable conditional logistic regression model and performed causal mediation analysis.

RESULTS

High baseline AS (≥2) (43% of cases, 11% of controls) was associated with higher risk of developing CD (adjusted odds ratio, 6.5; 95% confidence interval, 3.4-12.7; P < .001). Importantly, this association remained significant when adjusted for markers of gut barrier function, fecal calprotectin, C-reactive protein, and CD-polygenic risk score, and in subjects recruited more than 3 years before diagnosis. Causal mediation analysis showed that the effect of high AS on future CD development is partially mediated (42%) via preclinical gut inflammation.

CONCLUSIONS

Our results suggest that increased anti-microbial antibody responses are associated with risk of future development of CD, independent of biomarkers of abnormal gut barrier function, subclinical inflammation, and CD-related genetic risks. This suggests that anti-microbial antibody responses are an early predisease event in the development of CD.

Performance Characteristics of a Clinical Decision Support Tool for Disease Complications in Crohn's Disease

Background

Patients with Crohn's disease (CD) are at risk of complications. Performance characteristics of a decision support tool assessing the risk of CD complications were evaluated.

Methods

CDPATH (formerly called the Personalized Risk and Outcome Prediction Tool [PROSPECT]) was calibrated and validated in 2 cohorts. Tool prediction of disease characteristics was assessed using Cox regression and Harrell's C-statistic.

Results

All associations of CD complications and CDPATH components were significant except perianal location. There was a significant association between individualized risk assessment scores and CD complications in both cohorts.

Conclusion

CDPATH is validated as a clinical decision support tool for assessing the risk of CD complications.

Serum Biomarkers Identify Patients Who Will Develop Inflammatory Bowel Diseases Up to 5 Years Before Diagnosis

BACKGROUND & AIMS

Biomarkers are needed to identify patients at risk for development of inflammatory bowel diseases. We aimed to identify serum biomarkers of Crohn's disease and ulcerative colitis that can be detected and quantified before diagnosis.

METHODS

We obtained serum samples from patients archived before a diagnosis of Crohn's disease (n = 200) or ulcerative colitis (n = 199), as well as from 200 healthy individuals (controls), collected from 1998 through 2013 as part of the US Defense Medical Surveillance System. We measured levels of antibodies against microbes (anti-Saccharomyces cerevisiae IgA or IgG, anti-Escherichiacoli outer membrane porin C, anti-CBir1, anti-flagellin 2, anti-flagellin X, and perinuclear anti-neutrophil cytoplasmic antibodies) and 1129 proteins in each sample. We then used functional principal component analysis to derive the time-varying trajectory for each marker, which then was used in a multivariate model to predict disease status. Predictive performances at different prediagnosis timepoints were evaluated using area under the receiver operating characteristic curves (AUROCs). Biological pathways that were up-regulated in serum from patients with Crohn's disease were identified based on changes in protein abundance at different time periods preceding diagnosis.

RESULTS

We identified a panel of 51 protein biomarkers that were predictive of Crohn's disease within 5 years with an AUROC of 0.76 and a diagnosis within 1 year with an AUROC of 0.87. Based on the proteins included in the panel, imminent development of CD was associated with changes in the complement cascade, lysosomes, innate immune response, and glycosaminoglycan metabolism. Serum antibodies and proteins identified patients who received a diagnosis of ulcerative colitis within 5 years with an AUROC of only 0.56 and within 1 year with an AUROC of 0.72.

CONCLUSIONS

We identified a panel of serum antibodies and proteins that were predictive of patients who will receive a diagnosis of Crohn's disease within 5 years with high accuracy. By contrast we did not identify biomarkers associated with future diagnosis of ulcerative colitis.

Cohort profile of the PRoteomic Evaluation and Discovery in an IBD Cohort of Tri-service Subjects (PREDICTS) study: Rationale, organization, design, and baseline characteristics

Purpose

The etiology of Inflammatory Bowel Disease (IBD) remains currently unknown but evidence would suggest that it results from a complex interplay between genetic susceptibility genes, the intestinal microbiome and the environment, resulting in an increased response towards microbial and self-antigens, followed by the development of pre-clinical intestinal inflammation as a precursor to overt clinical disease. Efforts are needed to provide insights into the characterization of the disease, the possible prediction of complications, and the detection of a pre-clinical disease state where, through early screening and intervention, disease course can be reversed, attenuated or even prevented. A consortium of academic, industry and governmental organization investigators initiated this study to enable an assessment of pre-disease biomarkers in patients newly diagnosed with Crohn's disease (CD) and ulcerative colitis (UC).

Participants

A retrospective cohort of 1000 UC and 1000 CD cases with 500 matched controls was drawn from an active duty US military personnel population with relevant inclusion criteria with three associated pre-disease and a single disease-associated archived serum samples.

Findings to date

The PREDICTS study has been established as a biorepository platform study to perform novel discovery and analysis efforts in the field of IBD and proteomic systems biology.

Future plans

This study is poised to enable the assessment of novel biomarkers within the serum compartment to be analyzed with the goal of identifying pre-disease signals that ultimately predict disease risk, and further elucidate disease pathogenesis in the early stages of the disease process, and identify novel exposures that increase disease risk.

Anti-TNF Therapeutic Drug Monitoring in Postoperative Crohn's Disease

BACKGROUND

Anti-TNF prevents postoperative Crohn's disease recurrence in most patients but not all. This study aimed to define the relationship between adalimumab pharmacokinetics, maintenance of remission and recurrence.

METHODS

As part of a study of postoperative Crohn's disease management, some patients undergoing resection received prophylactic postoperative adalimumab. In these patients, serum and fecal adalimumab concentration and serum anti-adalimumab antibodies [AAAs] were measured at 6, 12 and 18 months postoperatively. Levels of Crohn's disease activity index [CDAI], C-reactive protein [CRP] and fecal calprotectin [FC] were assessed at 6 and 18 months postoperatively. Body mass index and smoking status were recorded. A colonoscopy was performed at 6 and/or 18 months.

RESULTS

Fifty-two patients [32 on monotherapy and 20 on combination therapy with thiopurine] were studied. Adalimumab concentration did not differ significantly between patients in endoscopic remission vs recurrence [Rutgeerts ≥ i2] [9.98µg/mL vs 8.43 µg/mL, p = 0.387]. Patients on adalimumab monotherapy had a significantly lower adalimumab concentration [7.89 µg/mL] than patients on combination therapy [11.725 µg/mL] [p = 0.001], and were significantly more likely to have measurable AAA [31% vs 17%, p = 0.001]. Adalimumab concentrations were lower in patients with detectable AAA compared with those without [3.59 µg/mL vs 12.0 µg/mL, p < 0.001]. Adalimumab was not detected in fecal samples. Adalimumab serum concentrations were lower in obese patients compared with in non-obese patients [p = 0.046].

CONCLUSION

Adalimumab concentration in patients treated with adalimumab to prevent symptomatic endoscopic recurrence postoperatively is, for most patients, well within the therapeutic window, and is not significantly lower in patients who develop recurrence compared with in those who remain in remission. Mechanisms of anti-TNF failure to prevent postoperative recurrence remain to be determined in these patients.

Evolution of cytokines and inflammatory biomarkers during infliximab induction therapy and the impact of inflammatory burden on primary response in patients with Crohn's disease

OBJECTIVE

Primary non-response to infliximab in Crohn's disease is still incompletely understood. Our aim was to further characterize the role of inflammatory burden during infliximab induction therapy.

MATERIALS AND METHODS

We studied a well-characterized cohort of 201 anti-TNF naive Crohn's disease patients treated with infliximab 5mg/kg at week 0, 2, 6 and 14 who had serum samples drawn just before every infusion. All serum samples were analyzed for CRP, albumin, TNF, IFN-γ, IL-6, IL-8, IL-10, infliximab trough concentrations (in-house-developed ELISA) and antibodies to infliximab (HMSA, Prometheus Laboratories Inc., San Diego, CA). Primary non-response was defined as the absence of clinical improvement at week 14.

RESULTS

The incidence of primary non-response to infliximab was 8% (n = 16). IL-8 concentrations at baseline were higher (p = .01) and albumin at week 6 was lower in primary non-responders (p = .01) compared to responders. During induction, IFN-γ and IL-6 concentrations decreased significantly at week 2 and week 6 in responders compared to primary non-responders (p < .05). Serum TNF increased significantly after each infliximab infusion and this increase from week 0 to week 14 was more pronounced in responders (p = .03). Multiple logistic regression identified TNF/CRP ratio at baseline as predictive for primary non-response to infliximab at week 14 (OR 2.8 (95% CI 1.4-5.5; p = .003)).

CONCLUSIONS

In this intensively sampled cohort of Crohn's disease patients, we demonstrate that inflammatory burden is more determining for primary non-response than drug exposure or immunogenicity. Our findings furthermore suggest that the contribution of TNF in inflammation might be higher in primary non-response, contradicting the non-TNF-driven concept.

Serologic antibodies in relation to outcome in postoperative Crohn's disease

BACKGROUND AND AIM

Disease recurs frequently after Crohn's disease resection. The role of serological antimicrobial antibodies in predicting recurrence or as a marker of recurrence has not been well defined.

METHODS

A total of 169 patients (523 samples) were prospectively studied, with testing peri-operatively, and 6, 12 and 18 months postoperatively. Colonoscopy was performed at 18 months postoperatively. Serologic antibody presence (perinuclear anti-neutrophil cytoplasmic antibody [pANCA], anti-Saccharomyces cerevisiae antibodies [ASCA] IgA/IgG, anti-OmpC, anti-CBir1, anti-A4-Fla2, anti-Fla-X) and titer were tested. Quartile sum score (range 6-24), logistic regression analysis, and correlation with phenotype, smoking status, and endoscopic outcome were assessed.

RESULTS

Patients with ≥ 2 previous resections were more likely to be anti-OmpC positive (94% vs 55%, ≥ 2 vs < 2, P = 0.001). Recurrence at 18 months was associated with anti-Fla-X positivity at baseline (49% vs 29%; positive vs negative, P = 0.033) and 12 months (52% vs 31%, P = 0.04). Patients positive (n = 28) for all four antibacterial antibodies (anti-CBir1, anti-OmpC, anti-A4-Fla2, and anti-Fla-X) at baseline were more likely to experience recurrence at 18 months than patients negative (n = 32) for all four antibodies (82% vs 18%, P = 0.034; odds ratio 6.4, 95% confidence interval 1.16-34.9). The baseline quartile sum score for all six antimicrobial antibodies was higher in patients with severe recurrence (Rutgeert's i3-i4) at 18 months, adjusted for clinical risk factors (odds ratio 1.16, 95% confidence interval 1.01-1.34, P = 0.039). Smoking affected antibody status.

CONCLUSIONS

Anti-Fla-X and presence of all anti-bacterial antibodies identifies patients at higher risk of early postoperative Crohn's disease recurrence. Serologic screening pre-operatively may help identify patients at increased risk of recurrence.

Serologic microbial associated markers can predict Crohn's disease behaviour years before disease diagnosis

BACKGROUND

Patients with Crohn's disease (CD) have serologic responses to various microbial antigens. Serologic markers are associated with aggressive forms of disease and can be detected before onset of symptoms. Their utility in pre-clinical disease or prediction of complicated disease course before diagnosis is unclear.

AIM

To evaluate the pattern of serologic anti-microbial antibodies long prior to diagnosis and the subsequent risk of complicated Crohn's disease at diagnosis.

METHODS

Sera from 100 US military personnel with Crohn's disease were obtained from the Department of Defense Serum Repository. For each patient, four samples were obtained at different time points before and around diagnosis, and were tested for 6 microbiota-directed antibodies (ASCA-IgA, ASCA-IgG, anti-OmpC, anti-CBir1, anti-A4-Fla2 and anti-FlaX). Associations between the presence and accumulation of Crohn's disease anti-microbial antibodies before diagnosis and with the later development of complications were evaluated.

RESULTS

Overall, 65 patients were positive for at least one Crohn's disease associated anti-microbial antibody in the earliest available sample, at a median of 6 years before Crohn's disease diagnosis (interquartile range, 5.6-8.2). The number of positive anti-microbial antibodies increased up to the time of Crohn's disease diagnosis. Complicated disease developed around the time of diagnosis in 24 patients. The proportion of positive antimicrobial antibodies before diagnosis was higher in patients with complicated vs. noncomplicated Crohn's disease. There was an inverse relationship between the time to first complication and the magnitude of serologic response before diagnosis.

CONCLUSION

The presence and accumulation of circulating anti-microbial antibodies years before Crohn's disease diagnosis was associated with complicated Crohn's disease at or shortly after diagnosis.

The association of tissue anti-TNF drug levels with serological and endoscopic disease activity in inflammatory bowel disease: the ATLAS study

OBJECTIVE

The aim of this study was to assess the correlation between serum and intestinal anti-tumour necrosis factor (TNF) levels, and their relationship to endoscopic disease activity and levels of TNF.

DESIGN

Cross-sectional study of 30 patients receiving treatment with infliximab or adalimumab for Crohn's disease or UC. For each patient, a sample of serum was matched to tissue biopsies. Endoscopic and histological disease activity was recorded for each tissue sample.

RESULTS

There was a significant positive correlation between anti-TNF in serum and tissue (r=0.3920, p=0.002), especially in uninflamed tissue (r=0.50, p<0.001), but not with those samples that had inflammation (r=0.19, p=0.54). Anti-TNF concentration in tissue correlated with degree of endoscopic inflammation, except for tissue with severe inflammation in which anti-TNF levels were again lower (mean normalised anti-TNF in tissue: uninflamed=0.93, mild=2.17, moderate=13.71, severe=2.2 inflammation (p=0.0042)). The ratio of anti-TNF-to-TNF in tissue was highest in uninflamed areas and lowest in severely inflamed areas. Patients with active mucosal disease had a higher rate of serum to tissue drug level mismatch when compared to those in remission (73.3% vs 33.3%, respectively; p=0.03).

CONCLUSIONS

Our data suggest that local tissue inflammation characterised by high levels of TNF serves as a sink for anti-TNF. We further postulate that some patients with high serum anti-TNF levels have active disease because tissue levels of anti-TNF are insufficient to neutralise local TNF production.

A Matrix-based Model Predicts Primary Response to Infliximab in Crohn's Disease

BACKGROUND

Prediction of primary non-response [PNR] to anti-tumour necrosis factors [TNFs] in inflammatory bowel disease [IBD] is direly needed to select the optimal therapeutic class for a given patient. We developed a matrix-based prediction tool to predict response to infliximab [IFX] in Crohn's disease [CD] patients.

METHODS

This retrospective single-centre study included 201 anti-TNF naïve CD patients who started with IFX induction therapy. PNR occurred in 16 [8%] patients. Clinical, biological [including serum TNF and the IBD serology 6 panel and genetic [the 163 validated IBD risk loci] markers were collected before start. Based on the best fitted regression model, probabilities of primary response to IFX were calculated and arranged in a prediction matrix tool.

RESULTS

Multiple logistic regression withheld three final independent predictors [p < 0.05] for PNR: age at first IFX, {odds ratio (OR) (95% confidence interval [CI] of 1.1 (1.0-1.1)}, body mass index [BMI] (0.86 [0.7-1.0]), and previous surgery (4.4 [1.2-16.5]). The accuracy of this prediction model did not improve when the genetic markers were added (area under the curve [AUC] from 0.80 [0.67-0.93] to 0.78 [0.65-0.91]). The predicted probabilities for PNR to IFX increased from 1% to 53% depending on the combination of final predictors.

CONCLUSIONS

Readily available clinical factors [age at first IFX, BMI, and previous surgery] outperform serological and IBD risk loci in prediction of primary response to infliximab in this real-life cohort of CD patients. This matrix tool could be useful for guiding physicians and may avoid unnecessary or inappropriate exposure to IFX in IBD patients unlikely to benefit.

Long-term outcome of patients with Crohn's disease who discontinued infliximab therapy upon clinical remission

BACKGROUND & AIMS

There are limited data on the effects of discontinuing infliximab therapy for Crohn's disease (CD). We investigated the long-term outcome of patients with CD who discontinued infliximab while in clinical remission, and searched for prognostic markers of continued remission after infliximab cessation.

METHODS

We performed a retrospective, single-center study of 100 patients with CD who discontinued infliximab upon achieving clinical remission; 84 patients continued immunomodulator therapy. Clinical and endoscopic data were retrieved from a medical database in Belgium, and patients were followed up through April 2013 (median, 9.7 y; interquartile range, 8-11.5 y). Sustained clinical remission (SCR) was defined as maintenance of disease remission, without escalation in medical therapy or CD-related surgeries, until the end of the follow-up period. We measured trough concentrations of infliximab, antibodies to microbial antigens, and circulating inflammatory markers in serum samples collected before treatment and at the time of infliximab discontinuation.

RESULTS

At the end of the follow-up period, 52 patients had SCR. Univariate (log-rank) analysis associated SCR with patient age at diagnosis (≥25 y; P = .012) and disease duration (<1 y; P = .017). Among factors evaluated at the time of infliximab discontinuation, infliximab trough concentrations (<6 μg/mL; P = .031), complete mucosal healing (P = .046), and serum positivity for vascular cell adhesion molecule-1 (>0.67 μg/mL; P = .024) were associated with SCR. In multiple Cox proportional hazards regression analysis, only age at diagnosis of 25 years and older was associated independently with SCR (hazard ratio, 1.83; 95% confidence interval, 1.03-3.25; P = .04).

CONCLUSIONS

In a large, real-life study, 52% of patients with CD who discontinued infliximab upon achieving clinical remission remained in SCR after a median period of approximately 10 years; Most patients remained on immunomodulator therapy. Although patients with CD have variable responses to infliximab, a subgroup achieved long-term remission after infliximab discontinuation.

[Which is the place of the human being inside the recommendations, multidisciplinary oncological meetings, and treatment plan?]

Nowadays, the cancer patient has access to a highly technical, more and more targeted and increasingly individualized medicine. And the human being in that matter ? Numerous tools have been developed to help physicians and caregivers to reconcile contemporary medicine and the rights of the patient. Among these are multidisciplinary oncology meetings and treatment guidelines published by national and international scientific societies. The patients care must be cross-disciplinary and evidence-based. This shared decision-making process should at the end be in accordance with the wishes of the patient. This approach should allow him/her to maintain autonomy and be the main actor in the decision-making process.

Combination of genetic and quantitative serological immune markers are associated with complicated Crohn's disease behavior

BACKGROUND

Treatment of Crohn's disease (CD) with biologics may alter disease progression, leading to fewer disease-related complications, but cost and adverse event profiles often limit their effective use. Tools identifying patients at high risk of complications, who would benefit the most from biologics, would be valuable. Previous studies suggest that biomarkers may aid in determining the course of CD. We aimed to determine if combined serologic immune responses and NOD2 genetic markers are associated with CD complications.

METHODS

In this cross-sectional study, banked blood from well-characterized CD patients (n = 593; mean follow-up: 12 years) from tertiary and community centers was analyzed for six serological biomarkers (ASCA-IgA, ASCA-IgG, anti-OmpC, anti-CBir1, anti-I2, pANCA). In a patient subset (n = 385), NOD2 (SNP8, SNP12, SNP13) genotyping was performed. Complications included stricturing and penetrating disease behaviors. A logistic regression model for the risk of complications over time was constructed and evaluated by cross-validation.

RESULTS

For each serologic marker, complication rates were stratified by quartile. Complication frequency was significantly different across quartiles for each marker (P trend ≤ 0.001). Patients with SNP13 NOD2 risk alleles experienced increased complications versus patients without NOD2 mutations (P ≤ 0.001). A calibration plot of modeled versus observed complication rates demonstrated good agreement (R = 0.973). Performance of the model integrating serologic and genetic markers was demonstrated by area under the receiver operating characteristic curve (AUC = 0.801; 95% confidence interval: 0.757-0.846).

CONCLUSIONS

This model combining serologic and NOD2 genetic markers may provide physicians with a tool to assess the probability of patients developing a complication over the course of CD.

A flow cytometric application for screening of new anti-inflammatory compounds (42.18)

Septic shock is a major public health problem. Organ failure during sepsis has been attributed to an extensive inflammatory response. Consequently, inflammatory reactions are important targets for drug development.

Inflammatory cytokine production is the result of the activation of signaling pathways. The Toll-Like receptor (TLR) family can recognize every known human pathogen. They trigger the host defense by activating signaling pathway such as NF-kB, MAPK, AKT and JAK/STAT. The stimulation of these pathways by pathogens will lead to an activation of transcription factors and the release of cytokines that can positively or negatively influence innate and adaptive immunity. Therefore, there is great interest in developing cell signaling inhibitors as new classes of anti-inflammatory and immuno-regulatory compounds.

We have used BD Cytometric Bead Array and BD Phosflow technologies to propose a flexible application that will facilitate the screening of compound libraries to find new anti-inflammatory drug candidates. To test this approach, we used well-characterized MAPK and PI3K/AKT inhibitors in an in vitro sepsis model. Our results demonstrated that we can simultaneously monitor the effect of a given compound on cell signaling molecules and on the inflammatory cytokines released. Moreover, we were able to specifically identify the cell population involved in the process.

In conclusion, this screening approach allows researchers to quantitatively assess and correlate the release of inflammatory cytokines with the signaling state of the cell.

Role of Gab2 in mammary tumorigenesis and metastasis

Overexpression of the adaptor/scaffolding protein Gab2 has been detected in primary human breast cancer cells and cell lines, although its functional significance in breast carcinogenesis is not fully understood. Here, we show a requirement for Gab2 in promoting mammary tumor metastasis. Although Gab2 expression levels were elevated in mammary tumors induced by the Neu (ErbB-2) oncogene, homozygous deletion of Gab2 in mice had only a modest effect on the initiation of Neu-induced mammary tumors. Notably, ablation of Gab2 severely suppressed lung metastasis. Gab2-deficient cancer cells displayed normal Akt activities, and their proliferative rate in vitro was similar to control cells. However, Gab2(-/-) cancer cells exhibited decreased migration and impaired Erk activation, and the defects were rescued by re-introduction of Gab2 into Gab2(-/-) cells. These findings suggest that although Gab2 overexpression may confer growth advantage to tumor cells, the functional requirement for Gab2 in mammary tumor initiation/growth may be dispensable, and that Gab2 may have a prominent role in promoting mammary tumor metastasis.

Rat gap junction connexin-30 inhibits proliferation of glioma cell lines

Connexins, the structural components of gap junctions, control cell growth and differentiation and are believed to belong to a family of tumour suppressor genes. Studies on connexin localization in brain showed that several of these proteins were expressed in distinct compartments of the brain in a cell-type specific manner, indicating that different gap junctions play specific roles in the physiology of the mammalian brain. In this report, we first cloned rat connexin-30 cDNA from brain and showed that it was expressed in long-term primary culture of rat astrocytes. In order to examine the potential role of connexin-30 in tumour cell proliferation, we transfected the connexin-30 cDNA into two rat glioma cell lines (9L and C6) which have lost its expression. Transfected clones adequately expressed membrane-bound connexin-30 protein. Connexin-30-expressing clones showed slower growth, lower DNA synthesis and reduced proliferation in soft agar as compared with the parental and control cells. We concluded that connexin-30 may also probably be considered as a tumour suppressor in rat gliomas.

Similar efficiency of DNA-liposome complexes and retrovirus-producing cells for HSV-tk suicide gene therapy of peritoneal carcinomatosis

Several experimental approaches have been tested for suicide gene delivery into tumor cells, including viral and non-viral vectors. In this study, we compared the efficiency of Herpes Simplex Virus type 1 thymidine kinase gene (HSV-tk) delivery by retrovirus-producing cells and DNA/liposome complexes for the treatment of peritoneal carcinomatosis induced in syngeneic rats by DHD/K12 colorectal adenocarcinoma cells. After in vitro determination of the best transduction conditions, rats were treated with multiple intraperitoneal injections of plasmid DNA containing one or two copies of CMV-driven HSV-tk gene (pCMV-TK and p(CMV-TK)2, respectively) associated with LipofectAMINE, each injection being followed by a Ganciclovir (GCV) course. Animals treated by DNA/liposome complexes and GCV or with retrovirus-producing cells and GCV showed a similar increase of survival as compared to the control group. After DNA/ liposome injections, expression of the tk transgene was detected in tumor nodes (epiploon) and also in liver, lung, spleen, bowels and brain. The expression was not homogeneous throughout the different organs and most likely reflected the transfection of only a limited number of cells.

Combined suicide and cytokine gene therapy for peritoneal carcinomatosis

BACKGROUND

Gene therapy is a novel approach for the treatment of cancers, and tumours disseminated in the peritoneal cavity are suitable for in situ delivery of a therapeutic gene.

AIMS

The efficacy of a therapy combining a suicide gene (herpes simplex virus type I thymidine kinase (HSV-TK)) and cytokine genes was investigated in a model of peritoneal carcinomatosis induced by colon carcinoma cells in syngeneic rats.

MATERIAL AND METHODS

Pre-established macroscopic tumours in BDIX rats were treated by intraperitoneal injections of retrovirus producing cells (FLYA13 TK, FLYA13 granulocyte macrophage-colony stimulating factor (GM-CSF), FLYA13 interleukin 12 (IL-12)) and ganciclovir (GCV).

RESULTS

TK/GCV treated animals showed a slight increase in survival time (72 days) compared with the control group (63 days) while the association of cytokine and TK/GCV gene therapy resulted in significantly improved survival, with a large proportion of animals remaining tumour free on day 480 (60% and 40% for TK/GCV/GM-CSF and TK/GCV/IL-12 treated animals, respectively). Histological analysis of treated animals showed that the remaining tumour nodes were infiltrated by mononuclear cells but no major differences were observed between the various treatments. Immunohistochemical analysis revealed that lymphoid CD4(+) and CD8(+) T cells as well as macrophages accumulated outside untreated tumour nodes while CD8(+) and CD25(+) activated T cells and macrophages heavily infiltrated the tumours after the different treatments.

CONCLUSIONS

Our data indicate that combined suicide and cytokine gene therapy is a powerful approach for the treatment of macroscopic peritoneal carcinomatosis.

Pharmacological modulation of the bystander effect in the herpes simplex virus thymidine kinase/ganciclovir gene therapy system: effects of dibutyryl adenosine 3',5'-cyclic monophosphate, alpha-glycyrrhetinic acid, and cytosine arabinoside

The herpes simplex virus type 1 thymidine kinase (HSV1-tk) suicide gene/ganciclovir system was first applied to the treatment of glioblastoma tumors, but was hampered by the low gene transfection yield. Fortunately, the gap junction-dependent diffusion of phosphorylated ganciclovir metabolites from transfected cells to their neighbors proved to enhance the overall benefit of this strategy. However, as tumor cells are often gap junction-deficient, we sought to restore this property pharmacologically and hence to improve the efficacy of the treatment. We demonstrated that this approach was feasible in glioblastoma cells using dibutyryl adenosine 3',5'-cyclic monophosphate (cAMP) (100 microM) as a pharmacological inducer of gap junctions. alpha-Glycyrrhetinic acid (25 microM), on the other hand, strongly inhibited both gap junction-mediated intercellular communication and the bystander effect, thus confirming the role of gap junctions in HSV-tk-mediated bystander killing. Using cytosine arabinoside as a growth inhibitor, we underlined the role of tumor cell proliferation in the sensitivity of HSV-tk-transfected cells to ganciclovir and demonstrated its correlation with the importance of the bystander effect.

Antitumoral vaccination with granulocyte-macrophage colony-stimulating factor or interleukin-12-expressing DHD/K12 colon adenocarcinoma cells

Immunomodulating gene therapy for the treatment of malignant diseases is under extensive investigation. In this study, we induced an antitumoral immune response with murine interleukin-12 (mIL-12) and murine granulocyte-macrophage colony-stimulating factor (GM-CSF)-secreting tumor cells in a model of peritoneal carcinomatosis. Intraperitoneal injection of DHD/K12 tumoral cells engineered to produce IL-12 or GM-CSF did not generate any tumors, whereas untransduced DHD/K12 cells gave rise to peritoneal carcinomatosis. IL-12-expressing DHD/K12 cells also protected against tumors derived from coinjected parental cells. To test whether cytokine-producing cells could elicit a memory antitumoral immune response, animals received a challenge with parental DHD/K12 cells 35 days after the injection of proliferating or irradiated DHD/K12 engineered cells. Under our experimental conditions, irradiated tumor cells did not generate any antitumoral immunity. In contrast, tumor development was delayed and survival increased in the animals vaccinated with cytokine-secreting proliferating cells. A specific cytotoxic T-lymphocyte response against DHD/K12 parental cells was observed after vaccination with GM-CSF-expressing cells. Our results demonstrated that intraperitoneal vaccination with IL-12- or GM-CSF-expressing adenocarcinoma cells induced a systemic immune antitumoral response that may be useful as an adjuvant therapy after surgical resection of colorectal cancer.

Cytosine deaminase suicide gene therapy for peritoneal carcinomatosis

Gene therapy is a novel therapeutic approach that might soon improve the prognosis of some cancers. We investigated the feasibility of cytosine deaminase (CD) suicide gene therapy in a model of peritoneal carcinomatosis. DHD/K12 colorectal adenocarcinoma cells transfected in vitro with the CD gene were highly sensitive to 5-fluorocytosine (5-FC), and a bystander effect could also be observed. Treating CD+ cells with 5-FC resulted in apoptosis as detected by terminal deoxynucleotidyltransferase-mediated deoxyuridine triphosphate nick-end labeling. In vitro, several human cell lines derived from ovarian or colorectal carcinomas, as well as the rat glioblastoma 9 L cell line, responded to CD/5-FC and showed a very strong bystander effect. 5-FC treatment of peritoneal carcinomatosis generated in syngeneic BDIX rats by CD-expressing DHD/K12 cells led to a complete and prolonged response and to prolonged survival. Our study thus demonstrated the efficacy of CD suicide gene therapy for the treatment of peritoneal carcinomatosis.

A cell type-specific and gap junction-independent mechanism for the herpes simplex virus-1 thymidine kinase gene/ganciclovir-mediated bystander effect

Tumor cells expressing the herpes simplex virus type 1 thymidine kinase (HSV-tk) gene are killed by nucleoside analogues such as ganciclovir (GCV). GCV affects not only the cells expressing HSV-tk but also neighboring cells that do not express the gene; this phenomenon commonly is called "bystander effect." GCV metabolites transfer via gap junctional intercellular communication (GJIC) accounts for the bystander effect in different cell lines, but other mechanisms have also been described. In this study, we analyzed the mechanisms of the bystander effect in two cell lines exhibiting different capacities of communication (DHD/K12 and 9L). The 9L cells exhibited a very good bystander effect, which was completely blocked by a long-term inhibitor of GJIC, 18 alpha-glycyrrhetinic acid. DHD/K12 cells exhibited a moderate bystander effect that was not abolished by 18 alpha-glycyrrhetinic acid or 1-octanol, another strong inhibitor of GJIC. Interestingly, we also observed a bystander effect in cultures where HSV-tk-expressing DHD/K12 cells were physically separated from their untransfected counterparts but grown in the same medium. Moreover, the transfer of filtered conditioned medium from GCV-treated HSV-tk-expressing DHD/K12 cells to DHD/K12 parental cells induced a decrease of survival in a concentration-dependent manner, suggesting that the bystander effect in this cell line was mediated by a soluble factor.

IkappaB-alpha enhances transactivation by the HOXB7 homeodomain-containing protein

Combinatorial interactions between distinct transcription factors generate specificity in the controlled expression of target genes. In this report, we demonstrated that the HOXB7 homeodomain-containing protein, which plays a key role in development and differentiation, physically interacted in vitro with IkappaB-alpha, an inhibitor of NF-kappaB activity. This interaction was mediated by the IkappaB-alpha ankyrin repeats and C-terminal domain as well as by the HOXB7 N-terminal domain. In transient transfection experiments, IkappaB-alpha markedly increased HOXB7-dependent transcription from a reporter plasmid containing a homeodomain consensus-binding sequence. This report therefore showed a novel function for IkappaB-alpha, namely a positive regulation of transcriptional activation by homeodomain-containing proteins.

Repeated cycles of retrovirus-mediated HSVtk gene transfer plus ganciclovir increase survival of rats with peritoneal carcinomatosis

Peritoneal carcinomatosis is a common clinical situation that requires novel therapeutic approaches. We investigated the efficiency of an HSVtk gene therapy for the treatment of peritoneal carcinomatosis induced in syngeneic rats by DHD/K12 colon carcinoma cells. In this setting, the efficiency of two different retrovirus producing cell lines (GP+AmEnv12 and FLYA13) was compared. Rats treated with a single injection of retrovirus producing cells followed by a 5-day course of ganciclovir treatment showed an increased survival as compared with control animals. Animals treated with three injections of producing cells, each followed by a 4-5-day course of ganciclovir treatment, showed an increased survival as compared with control rats and with those treated with a single cycle of retrovirus producing cells plus ganciclovir. However, only a few animals remained tumor-free after day 180. There was no difference between the two producing cell lines in any of the experiments. RT-PCR demonstrated a faint expression of the tk transgene in the liver, spleen, epiploon, bowels and the lung of the animals injected with the HSVtk producing cells, reflecting most likely the transduction of only a limited number of cells.

HSV-1 thymidine kinase gene therapy for colorectal adenocarcinoma-derived peritoneal carcinomatosis

Peritoneal carcinomatosis is a common clinical situation which, in most cases, cannot be eradicated by surgery or chemotherapy. The feasibility of an HSV-TK-based suicide gene therapy for peritoneal carcinomatosis induced by DHD/K12 colon carcinoma cells was investigated. DHD/K12 cells stably expressing the tk gene were killed in vitro in the presence of low concentrations of ganciclovir, they exhibited a 'bystander effect' when mixed with TK-negative cells. BD-IX rats injected intraperitoneally, either directly or after surgical peritoneal irritations, with DHD/K12 cells developed peritoneal carcinomatosis within 2 weeks. Ganciclovir treatment of animals injected with DHD/K12-TK cells allowed a significant reduction of the tumor volume as well as a prolonged survival. Of these animals 35-40% showed a long-term disease-free survival after ganciclovir therapy. Residual or relapsing tumors could be explained by a low expression of the transgene as demonstrated by RT-PCR.

Seventeen copies of the human 37 kDa laminin receptor precursor/p40 ribosome-associated protein gene are processed pseudogenes arisen from retropositional events

A cDNA coding for a 37 kDa polypeptide has been identified in several species as both the potential precursor of the 67 kDa laminin receptor (37LRP) and a putative ribosome-associated protein (p40). Interestingly, increased expression of this polypeptide (37LRP/p40) is consistently observed in invasive and metastatic cancer cells and is associated with poor prognosis. Southern-blot analysis of human genomic DNA predicted multiple copies of the 37LRP/p40 gene. In this study, we report that the number of copies of this sequence in the human genome is 26 +/- 2. We have sequenced and analyzed 19 genomic clones corresponding to the 37LRP/p40 gene and found that they were all processed pseudogenes. They all lack intronic sequences and show multiple genetic alterations leading in some cases to the appearance of stop codons. Moreover, they all bear characteristic features of retroposons as the presence of a poly(A)-tail at their 3' end and short direct repeated flanking DNA sequences. None of the pseudogenes analyzed present cis-elements in their 5' flanking region such as TATA or GC boxes. Our date reveal that over 50% of the 37LRP/p40 gene copies are pseudogenes most probably generated by retropositional events. The finding of multiple pseudogenes for the 37LRP/p40 suggests that the accumulation of several copies of this gene might have given a survival advantage to the cell in the course of evolution.