Factors predicting the therapeutic response to infliximab during maintenance therapy in Japanese patients with Crohn's disease

The Association between Genetics and Response to Treatment with Biologics in Patients with Psoriasis, Psoriatic Arthritis, Rheumatoid Arthritis, and Inflammatory Bowel Diseases: A Systematic Review and Meta-Analysis

Genetic biomarkers could potentially lower the risk of treatment failure in chronic inflammatory diseases (CID) like psoriasis, psoriatic arthritis (PsA), rheumatoid arthritis (RA), and inflammatory bowel disease (IBD). We performed a systematic review and meta-analysis assessing the association between single nucleotide polymorphisms (SNPs) and response to biologics. Odds ratio (OR) with 95% confidence interval (CI) meta-analyses were performed. In total, 185 studies examining 62,774 individuals were included. For the diseases combined, the minor allele of MYD88 (rs7744) was associated with good response to TNFi (OR: 1.24 [1.02-1.51], 6 studies, 3158 patients with psoriasis or RA) and the minor alleles of NLRP3 (rs4612666) (OR: 0.71 [0.58-0.87], 5 studies, 3819 patients with RA or IBD), TNF-308 (rs1800629) (OR: 0.71 [0.55-0.92], 25 studies, 4341 patients with psoriasis, RA, or IBD), FCGR3A (rs396991) (OR: 0.77 [0.65-0.93], 18 studies, 2562 patients with psoriasis, PsA, RA, or IBD), and TNF-238 (rs361525) (OR: 0.57 [0.34-0.96]), 7 studies, 818 patients with psoriasis, RA, or IBD) were associated with poor response to TNFi together or infliximab alone. Genetic variants in TNFα, NLRP3, MYD88, and FcRγ genes are associated with response to TNFi across several inflammatory diseases. Most other genetic variants associated with response were observed in a few studies, and further validation is needed.

Infliximab for maintenance of medically-induced remission in Crohn's disease

BACKGROUND

Infliximab is a monoclonal antibody that binds and neutralises tumour necrosis factor-alpha (TNF-α) which is present in high levels in the blood serum, mucosa and stool of patients with Crohn's disease.

OBJECTIVES

To determine the efficacy and safety of infliximab for maintaining remission in patients with Crohn's disease.

SEARCH METHODS

On 31 August, 2021 and 23 June, 2023, we searched CENTRAL, Embase, MEDLINE, ClinicalTrials.gov, and WHO ICTRP.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in which infliximab was compared to placebo or another active comparator for maintenance, remission, or response in patients with Crohn's disease.

DATA COLLECTION AND ANALYSIS

Pairs of review authors independently selected studies and conducted data extraction and risk of bias assessment. We expressed outcomes as risk ratios and mean differences with 95% confidence intervals. We assessed the certainty of the evidence using GRADE. Our primary outcome was clinical relapse. Secondary outcomes were loss of clinical response, endoscopic relapse, and withdrawal due to serious and adverse events.

MAIN RESULTS

Nine RCTs with 1257 participants were included. They were conducted between 1999 and 2022; seven RCTs included biologically-naive patients, and the remaining two included a mix of naive/not naive patients. Three studies included patients in clinical remission, five included patients with a mix of activity scores, and one study included biologic responders with active disease at baseline. All studies allowed some form of concomitant medication during their duration. One study exclusively included patients with fistulating disease. The age of the participants ranged from 18 to 69 years old. All but one single-centre RCT were multicentre RCTs. Four studies were funded by pharmaceutical companies, two had a mix of commercial and public funding, and two had public funding. Infliximab is probably superior to placebo in preventing clinical relapse in patients who have mixed levels of clinical disease activity at baseline, and are not naive to biologics (56% vs 75%, RR 0.73, 95% CI 0.63 to 0.84, NNTB = 5, moderate-certainty evidence). We cannot draw any conclusions on loss of clinical response (RR 0.59, 95% CI 0.37 to 0.96), withdrawals due to adverse events (RR 0.66, 95% CI 0.37 to 1.19), or serious adverse events (RR 0.60, 95% CI 0.36 to 1.00) because the evidence is very low certainty. Infliximab combined with purine analogues is probably superior to purine analogues for clinical relapse (12% vs 59%, RR 0.20, 95% CI 0.10 to 0.42, NNTB = 2, moderate-certainty evidence), for patients in remission, and who are not naive to biologics. We cannot draw any conclusions on withdrawals due to adverse events (RR 0.47, 95% CI 0.15 to 1.49), and serious adverse events (RR 1.19, 95% CI 0.54 to 2.64) because the evidence is very low certainty. We cannot draw any conclusions about the effects of infliximab on serious adverse events compared to purine analogues (RR 0.79, 95% CI 0.37 to 1.68) for a population in remission at baseline because the evidence is very low certainty. There was no evidence available for the outcomes of clinical relapse, loss of clinical response, and withdrawal due to adverse events. Infliximab may be equivalent to biosimilar for clinical relapse (47% vs 40% RR 1.18, 95% CI 0.82 to 1.69), and it may be slightly less effective in averting loss of clinical response (49% vs 32%, RR 1.50, 95% CI 1.01 to 2.23, low-certainty evidence), for a population with mixed/low disease activity at baseline. Infliximab may be less effective than biosimilar in averting withdrawals due to adverse events (27% vs 0%, RR 20.73, 95% CI 2.86 to 150.33, low-certainty evidence). Infliximab may be equivalent to biosimilar for serious adverse events (10% vs 10%, RR 0.99, 95% CI 0.39 to 2.50, low-certainty evidence). We cannot draw any conclusions on the effects of subcutaneous biosimilar compared with intravenous biosimilar on clinical relapse (RR 1.01, 95% CI 0.65 to 1.57), loss of clinical response (RR 0.94, 95% CI 0.70 to 1.25), and withdrawals due to adverse events (RR 0.77, 95% CI 0.30 to 1.97) for an active disease population with clinical response at baseline because the evidence is of very low certainty. We cannot draw any conclusions on the effects of infliximab compared to adalimumab on loss of clinical response (RR 0.68, 95% CI 0.29 to 1.59), withdrawals due to adverse events (RR 0.10, 95% CI 0.01 to 0.72), serious adverse events (RR 0.09, 95% CI 0.01 to 1.54) for an active disease population with clinical response at baseline because the evidence is of very low certainty. There was no evidence available for the outcome of clinical relapse.

AUTHORS' CONCLUSIONS

Infliximab is probably more effective in preventing clinical relapse than placebo (moderate-certainty evidence). Infliximab in combination with purine analogues is probably more effective in preventing clinical and endoscopic relapse than purine analogues alone (moderate-certainty evidence). No conclusions can be drawn regarding prevention of loss of clinical response, occurrence of withdrawals due to adverse events, or total adverse events due to very low-certainty evidence for both of these comparisons. There may be little or no difference in prevention of clinical relapse, withdrawal due to adverse events or total adverse events between infliximab and a biosimilar (low-certainty evidence). Infliximab may lead to more loss of clinical response than a biosimilar (low-certainty evidence). We were unable to draw meaningful conclusions about other comparisons and outcomes related to missing data or very low-certainty evidence due to serious concerns about imprecision and risk of bias. Further research should focus on comparisons with other active therapies for maintaining remission, as well as ensuring adequate power calculations and reporting of methods.

Crohn's Patient Serum Proteomics Reveals Response Signature for Infliximab but not Vedolizumab

BACKGROUND

Crohn's disease is a chronic inflammatory bowel disease that affects the gastrointestinal tract. Common biologic families used to treat Crohn's are tumor necrosis factor (TNF)-α blockers (infliximab and adalimumab) and immune cell adhesion blockers (vedolizumab). Given their differing mechanisms of action, the ability to monitor response and predict treatment efficacy via easy-to-obtain blood draws remains an unmet need.

METHODS

To investigate these gaps in knowledge, we leveraged 2 prospective cohorts (LOVE-CD, TAILORIX) and profiled their serum using high-dimensional isobaric-labeled proteomics before treatment and 6 weeks after treatment initiation with either vedolizumab or infliximab.

RESULTS

The proportion of patients endoscopically responding to treatment was comparable among infliximab and vedolizumab cohorts; however, the impact of vedolizumab on patient sera was negligible. In contrast, infliximab treatment induced a robust response including increased blood-gas regulatory response proteins, and concomitant decreases in inflammation-related proteins. Further analysis comparing infliximab responders and nonresponders revealed a lingering innate immune enrichments in nonresponders and a unique protease regulation signature related to clotting cascades in responders. Lastly, using samples prior to infliximab treatment, we highlight serum protein biomarkers that potentially predict a positive response to infliximab treatment.

CONCLUSIONS

These results will positively impact the determination of appropriate patient treatment and inform the selection of clinical trial outcome metrics.

The importance of predicting patient responses to monoclonal antibodies for Crohn's disease

INTRODUCTION

Crohn's disease (CD) is a chronic immune-mediated inflammatory bowel disease that results in relapsing and remitting symptoms but progressive transmural bowel damage leading to significant morbidity. CD results from dysregulation of the immune system related to genetic and environmental factors. While the use of monoclonal antibodies targeting cytokines and adhesion molecules has been shown to improve outcomes in CD patients, their widespread use has been limited due to high costs as well as variable access. Here, we summarize the factors that have been shown to correlate with responsiveness to biologic agents for use in practice.

AREAS COVERED

We summarize the current literature regarding factors that have been shown to influence patient response to various biologic agents including: patient-related factors (e.g. age, gender, weight smoking history); disease-specific factors (e.g. disease duration, location/extension, behavior/phenotype, severity); genetic markers; transcription factors, and the gut microbiome. Finally, we review the utility of prediction models and present data supporting the use of recently developed decision support tools.

EXPERT OPINION

Clinical decision support tools developed by machine learning are currently available for the selection of biologic agents in CD patients. We expect these models to become an integral tool for clinicians in the treatment of CD in the coming years.

Association between genetic variants and development of antibodies to infliximab: A cross-sectional study in Chinese patients with Crohn's disease

Aims: Genetic variants increase the susceptibility to anti-drug antibodies (ADA) in response to anti-TNF therapy in chronic inflammatory diseases. However, little is known about genetic variants in Chinese populations. This study aimed to identify genetic variants contributing to the risk of the development of antibodies to infliximab (ATI) in Chinese patients with Crohn's disease (CD). Methods: CD patients (n = 104) treated with infliximab (IFX) during the maintenance therapy were enrolled in this cross-sectional study. ATI was assessed by an in-house developed drug-tolerant ELISA method. ATI titers of 1:20 and ≥1:60 were considered a low titer and a high titer, respectively. Thirteen types of single nucleotide polymorphisms (SNPs) within 13 genes involved in the immune process, the susceptibility to chronic inflammatory diseases, cytokines and apoptosis pathways were investigated. Results: The median trough levels of infliximab (TLI) in patients with clinical remission (CR) were higher than those in patients without CR (3.80 vs. 1.50 μg/mL, p < .001). The median TLI in patients with high-titer ATI was significantly lower than that in ATI-negative patients (1.15 vs. 4.48 μg/mL, p < .001) or those with low-titer ATI (1.15 vs. 2.95 μg/mL, p = .03). The HLA-DQA1*05 rs2097432 GG and GA genotypes were more frequent in patients with ATI (GG and AG vs. AA, 27/38 = 71.05% vs. 29/66 = 43.94%, OR 2.94, 95% CI 1.19-7.30, p = .02). Patients carrying the CC and AC genotypes of rs396991 in FCGR3A were associated with a higher frequency of ATI formation (CC and AC vs. AA, 37/57 = 64.91% vs. 19/47 = 40.43%, OR 2.94, 95% CI 1.24-6.96, p = .01). According to the number of variants in rs2097432 and rs393991, patients with two variants had a higher proportion of producing ATI (two variants vs. no variant, 17/21 = 80.95% vs. 9/30 = 30.00%, OR 9.92, 95% CI 2.59-37.87, p = .001; single variant vs. no variant, 30/53 = 56.60% vs. 9/30 = 30.00%, OR 3.04, 95% CI 1.18-7.88, p = .02). No association was found between other SNPs and ATI production. Conclusion: Rs2097432 in HLA-DQA1*05 and rs396991 in FCGR3A are associated with ATI production in Chinese patients with CD. A pharmacogenomic strategy could help with the clinical management of CD.

Pharmacogenetics of Biological Agents Used in Inflammatory Bowel Disease: A Systematic Review

Inflammatory Bowel Disease (IBD) comprises a group of disorders, in particular Crohn's disease (CD) and ulcerative colitis (UC), characterized by chronic inflammation affecting the gastrointestinal tract. The treatment of these conditions is primarily based on anti-inflammatory drugs, although the use of biological drugs with lower side effects quickly increased in the last decade. However, the presence of certain polymorphisms in the population may determine a different outcome in response to therapy, reflecting the heterogeneity of the efficacy in patients. Considering that several studies showed important correlations between genetic polymorphisms and response to biological treatments in IBD patients, this systematic review aims to summarize the pharmacogenetics of biologicals approved for IBD, thus highlighting a possible association between some polymorphisms and drug response. With this purpose, we reviewed PubMed papers published over the past 21 years (2000-2021), using as the search term "drug name and IBD or CD or UC and polymorphisms" to underline the role of pharmacogenetic tests in approaching the disease with a targeted therapy.

Deep learning vs conventional learning algorithms for clinical prediction in Crohn's disease: A proof-of-concept study

BACKGROUND

Traditional methods of developing predictive models in inflammatory bowel diseases (IBD) rely on using statistical regression approaches to deriving clinical scores such as the Crohn's disease (CD) activity index. However, traditional approaches are unable to take advantage of more complex data structures such as repeated measurements. Deep learning methods have the potential ability to automatically find and learn complex, hidden relationships between predictive markers and outcomes, but their application to clinical prediction in CD and IBD has not been explored previously.

AIM

To determine and compare the utility of deep learning with conventional algorithms in predicting response to anti-tumor necrosis factor (anti-TNF) therapy in CD.

METHODS

This was a retrospective single-center cohort study of all CD patients who commenced anti-TNF therapy (either adalimumab or infliximab) from January 1, 2010 to December 31, 2015. Remission was defined as a C-reactive protein (CRP) < 5 mg/L at 12 mo after anti-TNF commencement. Three supervised learning algorithms were compared: (1) A conventional statistical learning algorithm using multivariable logistic regression on baseline data only; (2) A deep learning algorithm using a feed-forward artificial neural network on baseline data only; and (3) A deep learning algorithm using a recurrent neural network on repeated data. Predictive performance was assessed using area under the receiver operator characteristic curve (AUC) after 10× repeated 5-fold cross-validation.

RESULTS

A total of 146 patients were included (median age 36 years, 48% male). Concomitant therapy at anti-TNF commencement included thiopurines (68%), methotrexate (18%), corticosteroids (44%) and aminosalicylates (33%). After 12 mo, 64% had CRP < 5 mg/L. The conventional learning algorithm selected the following baseline variables for the predictive model: Complex disease behavior, albumin, monocytes, lymphocytes, mean corpuscular hemoglobin concentration and gamma-glutamyl transferase, and had a cross-validated AUC of 0.659, 95% confidence interval (CI): 0.562-0.756. A feed-forward artificial neural network using only baseline data demonstrated an AUC of 0.710 (95%CI: 0.622-0.799; P = 0.25 vs conventional). A recurrent neural network using repeated biomarker measurements demonstrated significantly higher AUC compared to the conventional algorithm (0.754, 95%CI: 0.674-0.834; P = 0.036).

CONCLUSION

Deep learning methods are feasible and have the potential for stronger predictive performance compared to conventional model building methods when applied to predicting remission after anti-TNF therapy in CD.

Association of polymorphisms in promoter region of TNF-α -238 and -308 with clinical outcomes in patients with immune-mediated inflammatory diseases on anti-TNF therapy

The hypothesis of the study was that polymorphisms in promoter regions -238 and -308 of TNF-α could be associated with different clinical outcomes in inflammatory bowel diseases (IBD) and immune-mediated rheumatic diseases (IMRD). The aim was to examine the possible association of both polymorphisms with concentration of C-reactive protein (CRP) and fecal calprotectin (fCAL), onset of the remission and development of the ADA in patients on therapy with anti-TNF inhibitors. The prospective study was done in patients with IBD and IMRD on infliximab (IFX) or adalimumab (ADM). Patients were genotyped for TNF-α -238 and -308 polymorphisms. The concentration of CRP, fCAL, IFX or ADM and antibodies to drugs were measured according to manufacturer's instructions and followed-up for 6 or 12 months. Out of all patients (N = 112), number of patients in remission did not differ according to genotypes (for IBD patients P = 0.509 vs 0.223; for IMRD patients P = 0.541 vs 0.132 for TNF-α -238 and -308, respectively). Initial CRP concentration was higher in IBD patients with TNF-α -308 GG than GA/AA genotypes in patients who failed to achieve remission [11.8 (4.4-39.6) vs 3.1 (1.5-6.5), P = 0.033]. In IBD patients with remission, fCAL concentration after at least 6 months of therapy was higher in TNF-α-308 GG than in GA genotype [52 (25-552) vs 20 (20-20) µg/g, P = 0.041]. Our results showed the association of TNF-α -308 GG genotype with a higher concentration of CRP and fecal calprotectin in patients with inflammatory bowel diseases on IFX or ADM therapy. Clinical remission and development of antibodies to anti-TNF drugs were not associated with TNF-α -238 and -308 polymorphisms.

Bioelectrical impedance analysis-based nomogram construction for predicting secondary loss of response to infliximab in bio-naïve Crohn's disease patients

BACKGROUND

Infliximab is emerging as the first-line therapy for Crohn's disease (CD); however, the rate of secondary loss of response (SLR) can exceed 50%. This study aimed to construct a nomogram based on bioelectrical impedance analysis (BIA) indexes and laboratory markers to predict SLR to infliximab in biologically naïve CD patients.

METHODS

Data of 136 biologically naïve CD patients treated between September 2019 and March 2021 were retrospectively retrieved. BIA-based body composition parameters and laboratory markers were obtained before the infliximab therapy. Predictor selection was conducted using the least absolute shrinkage and selection operator (LASSO) and univariate logistic regression. The nomogram was developed using multivariable logistic regression, and internal validation was made by ten-fold cross-validation.

RESULTS

SLR occurred in 51% of the CD patients during 54 weeks. The nomogram predictors included hemoglobin, albumin, serum iron, and BIA scores. The nomogram showed significant discrimination (area under the curve [AUC], 0.920; 95% confidence interval, 0.873-0.967) and calibration (mean error = 0.012). Decision curve analysis (DCA) indicated that the nomogram provided net clinical benefit when the risk probability was between 2% and 83%. Internal validation assessment of the nomogram robustness found an AUC of 0.904 and an accuracy of 0.841.

CONCLUSIONS

This BIA-based body composition parameters- and laboratory markers-based novel nomogram could act as a predictive tool to evaluate SLR to infliximab therapy, crucial for optimizing treatment strategies and switching biologics in CD.

A Novel Radiomics Nomogram for the Prediction of Secondary Loss of Response to Infliximab in Crohn's Disease

Purpose

The prediction of the loss of response (LOR) to infliximab (IFX) is crucial for optimizing treatment strategies and shifting biologics. However, a secondary LOR is difficult to predict by endoscopy due to the intestinal stricture, perforation, and fistulas. This study aimed to develop and validate a radiomic nomogram for the prediction of secondary LOR to IFX in patients with Crohn’s disease (CD).

Patients and Methods

A total of 186 biologic-naive patients diagnosed with CD between September 2016 and June 2019 were enrolled. Secondary LOR was determined during week 54. Computed tomography enterography (CTE) texture analysis (TA) features were extracted from lesions and analyzed using LIFEx software. Feature selection was performed by least absolute shrinkage and selection operator (LASSO) and ten-fold cross validation. A nomogram was constructed using multivariable logistic regression, and the internal validation was approached by ten-fold cross validation.

Results

Predictors contained in the radiomics nomogram included three first-order and five second-order signatures. The prediction model presented significant discrimination (AUC, 0.880; 95% CI, 0.816–0.944) and high calibration (mean absolute error of = 0.028). Decision curve analysis (DCA) indicated that the nomogram provided clinical net benefit. Ten-fold cross validation assessed the stability of the nomogram with an AUC of 0.817 and an accuracy of 0.819.

Conclusion

This novel radiomics nomogram provides a predictive tool to assess secondary LOR to IFX in patients with Crohn’s disease. This tool will help physicians decide when to switch therapy.

Development and Validation of an Interleukin-6 Nomogram to Predict Primary Non-response to Infliximab in Crohn's Disease Patients

Background: The primary non-response (PNR) rate of infliximab (IFX) varies from 20 to 46% for the treatment of Crohn’s disease (CD). Detected PNR reduces the improper use of specific treatments. To date, there is hardly any knowledge regarding early markers of PNR. The aim of this study was to evaluate the role of Interleukin-6 (IL-6) as an early predictor of PNR of IFX for the treatment of CD.

Methods: We enrolled 322 bio-naïve patients diagnosed with CD from January 2016 to May 2020. Primary response was determined at week 14. Multivariable logistic regression was used to construct prediction models. Area under the curve (AUC), calibration and decision curve analyses (DCA) were assessed in the validation cohort. GEO data were analyzed to identify potential mechanisms of IL-6 in IFX therapy for CD.

Results: PNR occurred in 31.06% (100 of 322) patients who were assessable at week 14. IL-6 levels significantly decreased after IFX therapy (p < 0.001). The validation model containing IL-6 presented enhanced discrimination with an AUC of 0.908 and high calibration. Decision curve analysis (DCA) indicated that the model added extra predictive value. GEO data confirmed the IL-6 levels were increased in the PNR group and IL-6-related differentially expressed genes (DEGs) were enriched in the inflammatory response.

Conclusions: We concluded that IL-6 may be used as a predictive factor to assess the risk of PNR to IFX therapy.

Development of a Simple, Serum Biomarker-based Model Predictive of the Need for Early Biologic Therapy in Crohn's Disease

BACKGROUND

Early or first-line treatment with biologics, as opposed to conventional immunomodulators, is not always necessary to achieve remission in Crohn's disease [CD] and may not be cost-effective. This study aimed to develop a simple model to predict the need for early biologic therapy, in order to risk-stratify CD patients and guide initial treatment selection.

METHODS

A model-building study using supervised statistical learning methods was conducted using a retrospective cohort across two tertiary centres. All biologic-naïve CD patients who commenced an immunomodulator between January 1, 2004 and December 31, 2016, were included. A predictive score was derived using Cox regression modelling of immunomodulator failure, and was internally validated using bootstrap resampling.

RESULTS

Of 410 patients [median age 37 years, 47% male, median disease duration 4.7 years], 229 [56%] experienced immunomodulator failure [39 required surgery, 24 experienced a new stricture, 44 experienced a new fistula/abscess, 122 required biologic escalation] with a median time to failure of 16 months. Independent predictors of treatment failure included raised C-reactive protein [CRP], low albumin, complex disease behaviour, younger age, and baseline steroids. Highest CRP and lowest albumin measured within the 3 months preceding immunomodulator initiation outperformed baseline measurements. After model selection, only highest CRP and lowest albumin remained and the resultant Crohn's Immunomodulator CRP-Albumin [CICA] index demonstrated robust optimism-corrected discriminative performance at 12, 24, and 36 months (area under the curve [AUC] 0.84, 0.83, 0.81, respectively).

CONCLUSIONS

The derived CICA index based on simple, widely available markers is feasible, internally valid, and has a high utility in predicting immunomodulator failure. This requires external, prospective validation.

Development of a clinical model to predict secondary non-response of infliximab treatment in Crohn's disease

PURPOSE

Secondary non-response to infliximab (IFX) in patients with Crohn's disease (CD) is so common that prediction of non-response is required to adopt the optimal therapy for an individual patient.

METHODS

The clinical model was constructed in a training cohort. Clinical features, serological parameters, and genetic biomarkers at week 14 IFX therapy were obtained as predictors. Secondary non-response was defined at week 54. Univariate analysis was first performed to eliminate irrelevant predictors with non-response. Then, a logistic regression model was developed by using predictors with P < 0.1 in a univariate analysis. Finally, the model was validated with reference to its discrimination, calibration, and decision curve analysis (DCA).

RESULTS

In a univariate analysis, erythrocyte sedimentation rate (ESR), the previous surgery, disease location, C-reactive protein (CRP), and TNFRSF1B (676 T>G) were found associated with secondary non-response to IFX. Logistic regression analysis with stepwise backward selection P < 0.05 then identified that ESR, the previous surgery, CRP, and TNFRSF1B (676 T>G) could serve as independent predictors, and a clinical model was developed based on the above predictors. Model 2 with TNFRSF1B (676 T>G) incorporated demonstrated more satisfactory discrimination (P = 0.029), better calibration (U P2 > 0.05), and higher clinical value in the validation cohort.

CONCLUSIONS

The study presents a model to predict non-response to IFX in CD, which incorporates previous surgery, ESR, CRP, and TNFRSF1B (676 T>G). This model can be used to help clinicians adjust the therapeutic strategy and CD patients avoid unnecessary exposure to IFX.

Diet Recommendations for Hospitalized Patients With Inflammatory Bowel Disease: Better Options Than Nil Per Os

Hospitalizations are a time when providers often have uncertainty about what to feed patients with inflammatory bowel disease (IBD). While there are many trials evaluating the role of diet in the management of IBD, the role of diet for the hospitalized patient is less clear. The hospitalization may serve as an opportunity to educate patients about the role of diet, try different diets, and develop dietary recommendations for after discharge. Here, we review the literature for dietary considerations during hospitalizations and acute settings, as well as upon discharge. Patients with IBD benefit from screening and nutritional support for malnutrition and nutritional deficiencies. Enteral nutrition and exclusion diets are promising as induction and maintenance therapies, but no specific recommendations during hospitalization for adult patients are available currently. There are very few reasons to enforce bowel rest or clear liquids other than bowel obstruction, uncontrolled sepsis, or need for urgent or emergent surgery; most patients - including many with penetrating or stricturing disease - benefit from feeding in whichever capacity is tolerated, with enteral and parenteral nutrition used as needed to reach nutritional goals. Future studies are needed to define how the use of different diets can influence the outcomes of patients hospitalized for IBD.

Long-term effect of NUDT15 R139C on hematologic indices in inflammatory bowel disease patients treated with thiopurine

BACKGROUND AND AIM

A missense variant of the nucleoside diphosphate-linked moiety X-type motif 15 (NUDT15) gene (R139C) predisposes Asian patients with inflammatory bowel disease (IBD) to thiopurine-induced leukopenia. This study evaluates the long-term effect of NUDT15 R139C heterozygosity on hematological parameters during thiopurine administration.

METHODS

We enrolled 83 Japanese IBD patients who were on anti-tumor necrosis factor-α agents and had used thiopurine. NUDT15 R139C was genotyped by polymerase chain reaction. We retrospectively reviewed patient clinical charts to collect data on white blood cell (WBC) count, mean corpuscular volume (MCV), hemoglobin, and platelet count during the 24 months following thiopurine initiation.

RESULTS

The included patients had either Crohn's disease (54; 65.1%) or ulcerative colitis (29; 34.9%). Genotyping of NUDT15 R139C identified 62 patients (74.7%) of genotype C/C and 21 (25.3%) of genotype C/T. The median dose of thiopurine was lower in the C/T group than in the C/C group after starting thiopurine. At 6 months, the mean WBC count of the C/T group became significantly lower than that of the C/C group (P = 0.008) and remained lower through the 24 months. The C/T group developed grade 2-4 leukopenia by 6 months, which persisted through 12-24 months. The mean MCV in the C/T group became higher than that of the C/C group after 3 months.

CONCLUSIONS

NUDT15 R139C heterozygosity affected the WBC count and MCV for 24 months after thiopurine administration. Our results indicate that careful monitoring of leukopenia and dose adjustment are necessary throughout treatment in IBD patients heterozygous for the NUDT15 R139C.

Pre-Treatment Biomarkers of Anti-Tumour Necrosis Factor Therapy Response in Crohn's Disease-A Systematic Review and Gene Ontology Analysis

The most prominent treatment for the serious cases of Crohn’s disease (CD) are biological tumour necrosis factor (TNF) inhibitors. Unfortunately, therapy nonresponse is still a serious issue in ~1/3 of CD patients. Accurate prediction of responsiveness prior to therapy start would therefore be of great value. Clinical predictors have, however, proved insufficient. Here, we integrate genomic and expression data on potential pre-treatment biomarkers of anti-TNF nonresponse. We show that there is almost no overlap between genomic (annotated with tissue-specific expression quantitative trait loci data) and transcription (RNA and protein data) biomarkers. Furthermore, using interaction networks we demonstrate there is little direct interaction between the proposed biomarkers, though a majority do have common interactors connecting them into networks. Our gene ontology analysis shows that these networks have roles in apoptotic signalling, response to oxidative stress and inflammation pathways. We conclude that a more systematic approach with genome-wide search of genomic and expression biomarkers in the same patients is needed in future studies.

Genetic Studies of Inflammatory Bowel Disease-Focusing on Asian Patients

The pathogenesis of inflammatory bowel disease (IBD) is not well-understood; however, increased and persistent intestinal inflammation, due to inappropriate immune responses that are caused by interactions between genetic factors, gut microbiota, and environmental factors, are thought to lead to IBD. Various studies have identified more than 240 genetic variants related to IBD. These genetic variants are involved in innate and adaptive immunity, autophagy, defective bacterial handing, interleukin-23 and 10 signaling, and so on. According to several epidemiological and clinical studies, the phenotypes and clinical course of IBD differ between Asians and Europeans. Although the risk loci for IBD typically overlap between Asians and Westerners, genetic heterogeneity has been detected in many loci/genes, such as NOD2/CARD15, TNFSF15 and human leukocyte antigen, contributing to the risk of IBD. Thus, although common pathways exist between Westerners and Asians in the development of IBD, their significance may differ for individual pathways. Although genetic studies are not universally applicable in the clinical field, they may be useful for diagnosing and categorizing IBD, predicting therapeutic responses and toxicity to drugs, and assessing prognosis by risk modeling, thereby enabling precision medicine for individual patients.