The use of prognostic factors in inflammatory bowel diseases. Curr Gastroenterol Rep. 2014;16:416. [PMID: 25262067 DOI: 10.1007/s11894-014-0416-y]

How close are we to a success stratification tool for improving biological therapy in ulcerative colitis?

INTRODUCTION

Biological therapies have become the standard treatment for ulcerative colitis (UC). However, clinical remission rates post-induction therapy remain modest at 40-50%, with many initial responders losing response over time. Current treatment strategies frequently rely on a 'trial and error' approach, leading to prolonged periods of ineffective and costly therapies for patients, accompanied by associated treatment complications.

AREA COVERED

This review discusses current evidence on risk stratification tools for predicting therapeutic efficacy and minimizing adverse events in UC management. Recent studies have identified predictive factors for biologic therapy response. In the context of personalized medicine, the goal is to identify patients at high risk of progression and complications, as well as those likely to respond to specific therapies. Essential risk stratification tools include clinical decision-making aids, biomarkers, genomics, multi-omics factors, endoscopic, imaging, and histological assessments.

EXPERT OPINION

Employing risk stratification tools to predict therapeutic response and prevent treatment-related complications is essential for precision medicine in the biological management of UC. These tools are necessary to select the most suitable treatment for each individual patient, thereby enhancing efficacy and safety.

Predicting diagnostic biomarkers associated with immune infiltration in Crohn's disease based on machine learning and bioinformatics

OBJECTIVE

The objective of this study is to investigate potential biomarkers of Crohn's disease (CD) and the pathological importance of infiltration of associated immune cells in disease development using machine learning.

METHODS

Three publicly accessible CD gene expression profiles were obtained from the GEO database. Inflammatory tissue samples were selected and differentiated between colonic and ileal tissues. To determine the differentially expressed genes (DEGs) between CD and healthy controls, the larger sample size was merged as a training unit. The function of DEGs was comprehended through disease enrichment (DO) and gene set enrichment analysis (GSEA) on DEGs. Promising biomarkers were identified using the support vector machine-recursive feature elimination and lasso regression models. To further clarify the efficacy of potential biomarkers as diagnostic genes, the area under the ROC curve was observed in the validation group. Additionally, using the CIBERSORT approach, immune cell fractions from CD patients were examined and linked with potential biomarkers.

RESULTS

Thirty-four DEGs were identified in colon tissue, of which 26 were up-regulated and 8 were down-regulated. In ileal tissues, 50 up-regulated and 50 down-regulated DEGs were observed. Disease enrichment of colon and ileal DEGs primarily focused on immunity, inflammatory bowel disease, and related pathways. CXCL1, S100A8, REG3A, and DEFA6 in colon tissue and LCN2 and NAT8 in ileum tissue demonstrated excellent diagnostic value and could be employed as CD gene biomarkers using machine learning methods in conjunction with external dataset validation. In comparison to controls, antigen processing and presentation, chemokine signaling pathway, cytokine-cytokine receptor interactions, and natural killer cell-mediated cytotoxicity were activated in colonic tissues. Cytokine-cytokine receptor interactions, NOD-like receptor signaling pathways, and toll-like receptor signaling pathways were activated in ileal tissues. NAT8 was found to be associated with CD8 T cells, while CXCL1, S100A8, REG3A, LCN2, and DEFA6 were associated with neutrophils, indicating that immune cell infiltration in CD is closely connected.

CONCLUSION

CXCL1, S100A8, REG3A, and DEFA6 in colonic tissue and LCN2 and NAT8 in ileal tissue can be employed as CD biomarkers. Additionally, immune cell infiltration is crucial for CD development.

Recent Advances and Potential Multi-Omics Approaches in the Early Phases of Inflammatory Bowel Disease

Inflammatory bowel disease leads to debilitating gastrointestinal symptoms and reduced quality of life, resulting in a significant burden on healthcare utilization and costs. Despite substantial advancements in diagnosis and treatment, there may still be considerable delays in diagnosing some patients. To reduce disease progression before the full disease spectrum appears and improve prognostic outcomes, several strategies have concentrated on early intervention and prevention. Recent evidence shows that initial immune response changes and endoscopic lesions may exist for years before diagnosis, implying the existence of a preclinical phase of inflammatory bowel disease comparable to findings in other immune-mediated disorders. In this review, we highlight the most relevant findings regarding preclinical inflammatory bowel disease and the prospective role of novel omics techniques in this field.

Evaluating the clinical application of the immune cells' ratios and inflammatory markers in the diagnosis of inflammatory bowel disease

Objective

Inflammatory Bowel Diseases (IBDs) are chronic inflammatory conditions of the gastrointestinal tract, including Crohn's disease (CD) and ulcerative colitis (UC). Developing methods for effective screening and diagnosis is extremely needed. Accordingly, this study aims to evaluate the potential of immune cells ratios in the diagnosis of IBD.

Methods

This case-control study includes data from Jordan University Hospital (JUH) medical records for IBD patients with age- and gender-matched healthy controls.

Results

This study included 46 participants, of which 56.52% had IBD, 54.35% were males, with insignificant differences in sex, age, and body mass index (BMI) between IBD patients and controls (p>0.05). In the CD group, the variables with the highest sensitivity and specificity (HSS) were neutrophil-to-lymphocyte (NLR) (75%, 80%) and platelet-to-lymphocytes (PLR) (75%, 90%), in UC group; mean corpuscular hemoglobin (MCH) (80%, 80%). In CD group, the combinations giving the HSS were PLR+NLR (76%, 90.9%), C-reactive protein (CRP)+PLR (76%, 90.9%), and CRP+NLR (73.07%, 90%). In UC group, the combinations giving the HSS were erythrocyte sedimentation rate (ESR)+PLR (76.9%, 100%), PLR+MCH (74.07%, 100%), PLR+CRP (71.42%, 100%), and PLR+NLR (71.42%, 100%). Regression analysis identified five different combinations of significance in the diagnosis of CD and UC. Higher Youden's index was used and defined the most beneficial clinical combinations as NLR+PLR and CRP+PLR for CD, whereas ESR+PLR for UC.

Conclusion

Implications to our study include the clinical application of immune cell ratios, inflammatory markers, and their different combinations along with patients' history and physical examination findings for easier, faster, and more cost-effective diagnosis of IBDs.

Variables associated with progression of moderate-to-severe Crohn’s disease

Objective

Determine the variables associated with hospitalisations in patients with Crohn’s disease and those associated with surgery, intestinal resection, hospital readmission, need for multiple operations and immunobiological agent use.

Design

A cross-sectional study was conducted from 2019 to 2021, using two centres for inflammatory bowel diseases in the Brazilian Public Health System.

Results

This study included 220 patients. Only perianal disease was associated with hospitalisation (31.6% vs 13.0%, p=0.012). Stricturing or penetrating behaviour (35.8% vs 12.6%, p<0.001) and perianal disease (45.9% vs 9.9%, p<0.001) were associated with surgery. Ileal or ileocolonic location (80.0% vs 46.5%, p=0.044) and stricturing or penetrating behaviour (68.0% vs 11.2%, p<0.001) were associated with intestinal resection. Steroids use at first Crohn’s disease occurrence and postoperative complications were associated with hospital readmission and need for multiple operations, respectively. Age below 40 years at diagnosis (81.3% vs 62.0%, p=0.004), upper gastrointestinal tract involvement (21.8% vs 10.3%, p=0.040) and perianal disease (35.9% vs 16.3%, p<0.001) were associated with immunobiological agent use.

Conclusion

Perianal disease and stricturing or penetrating behaviour were associated with more than one significant outcome. Other variables related to Crohn’s disease progression were age below 40 years at diagnosis, an ileal or ileocolonic disease localisation, an upper gastrointestinal tract involvement, the use of steroids at the first Crohn’s disease occurrence and history of postoperative complications. These findings are similar to those in the countries with a high prevalence of Crohn’s disease.

Predictor of primary response to antitumor necrosis factor-α therapy for inflammatory bowel disease: a single-center observational study

BACKGROUND

It is necessary to find reliable and appropriate predictors of primary response to anti-TNFα therapy (infliximab and adalimumab) in inflammatory bowel disease (IBD) so as to avoid treatment failure and select optimal treatment. The aim of this study is to reveal useful predictors of the response to anti-TNFα treatment from baseline to 2 months after initial administration of anti-TNFα for individual IBD patients using our pharmacokinetic and pharmacodynamic (PK/PD) model at the time of second administration.

METHODS

We retrospectively analyzed 26 IBD patients who received anti-TNFα. In the PK/PD model, inflammation was assumed to be suppressed based on the action of anti-TNFα at the rate constant of Kanti-TNFα (day-1). Kanti-TNFα0 (day-1) is Kanti-TNFα in the absence of anti-TNFα. We expressed inflammation caused by factors not affected by the action of anti-TNFα using the rate constant Kelse (day-1). Using univariate and multivariate linear regressions, we statistically analyzed factors related to the improvement of disease activity index.

RESULTS

The significant correlation between Kanti-TNFα0/Kelse and the improvement of disease activity index was shown in Crohn's disease patients (univariate: estimated value 2.4; P = 0.003; and multivariate: 1.8; P = 0.012) and ulcerative colitis patients (univariate: 0.12; P = 0.011), and no other factors were significant.

CONCLUSION

This is the first study to present a useful predictor of primary response to anti-TNFα of individual IBD patients at second administration. The Kanti-TNFα0/Kelse ratio may help to select the optimal therapeutic drug and avoid the improper continuous administration of anti-TNFα in the induction phase.

Early Intervention in Ulcerative Colitis: Ready for Prime Time?

Growing evidence shows that ulcerative colitis (UC) is a progressive disease similar to Crohn’s disease (CD). The UC-related burden is often underestimated by physicians and a standard step-up therapeutic approach is preferred. However, in many patients with UC the disease activity is not adequately controlled by current management, leading to poor long-term prognosis. Data from both randomized controlled trials and real-world studies support early intervention in CD in order to prevent disease progression and irreversible bowel damage. Similarly, an early disease intervention during the so-called “window of opportunity” could lead to better outcomes in UC. Here, we summarize the literature evidence on early intervention in patients with UC, highlighting strengths and limitations of this approach.

The Role of Early Biologic Therapy in Inflammatory Bowel Disease

The goals for treatment of inflammatory bowel diseases (IBDs) are changing from elimination of symptoms toward complete disease control-a process that demands both clinical and endoscopic remission. This new IBD treatment paradigm has been shifting from a conventional "step-up" approach toward a more "top-down" early intervention treatment strategy. Recent studies suggest that the use of biologic agents, specifically those targeting tumor necrosis factor alpha, earlier in the treatment course improves patient outcomes and can prevent progression to irreversible bowel damage. Although the strategy of early intervention has accumulating evidence in Crohn's disease, there is less evidence supporting its impact in ulcerative colitis.

Predictive parameters for the clinical course of Crohn's disease: development of a simple and reliable risk model

PURPOSE

The aim of our study was to identify clinical parameters in recently diagnosed Crohn's disease (CD) patients for prediction of their disease course.

METHODS

EPIC (Early Predictive parameters of Immunosuppressive therapy in Crohn's disease) is a prospective, observational study in 341 patients with a recent CD diagnosis (≤ 6 months), and naïve to immunosuppressants (IS) and anti-tumor necrosis factor α (TNF) agents. Patient characteristics were documented up to 2 years. In line with national and international guidelines, a complicated disease course was defined as need for immunosuppressants and/or anti-TNF agents, and CD-related hospitalization with or without immunosuppressants and/or anti-TNF agents.

RESULTS

A total of 212 CD patients were analyzed of whom 57 (27%) had an uncomplicated disease within 24 months, while 155 (73%) had a complicated disease course: need for IS and/or anti-TNF agents (N = 115), CD-related hospitalization with or without IS/anti-TNF agents (N = 40). Identified risk predictors for a complicated disease were as follows: age at onset < 40 years (OR 2.3; 95% CI 1.2-4.5), anemia (OR 2.1; 95% CI 1.1-4.2), and treatment with systemic corticosteroids at first flare (OR 2.2; 95% CI 1.1-4.7). These three parameters were used to develop a risk model allowing prediction of the future disease course.

CONCLUSION

Our three-parameter model enables an assessment of each CD patient's risk to develop a complicated disease course. Due to the easy accessibility of these parameters, this model can be utilized in daily clinical care to assist selecting the initial treatment for each individual patient.

De-escalation of IBD Therapy: When, Who, and How?

When patients with inflammatory bowel disease reach clinical remission with biologic therapy, a question that often comes up is, “when can I stop my biologic medication?” This is a question fraught with challenges for both physicians and patients. For physicians, there are valid concerns that stepping down from a successful therapy will lead to relapse and disease exacerbation, and that stepping down could lead to anti-biologic antibodies. For patients, the question is often driven by concerns about long-term side effects and costs of biologics. This review provides an overview of the rationale for, and risks of, withdrawal of IBD therapy. Selected studies have shown how to identify subsets of patients in whom de-escalation can be performed with low risk of relapse. Practical guidance on when and how to de-escalate IBD therapy is provided.

Intestinal T Cell Profiling in Inflammatory Bowel Disease: Linking T Cell Subsets to Disease Activity and Disease Course

INTRODUCTION

A dysregulated intestinal T cell response is presumed in patients with inflammatory bowel disease [IBD]. In this longitudinal study, we investigated the changes in intestinal T lymphocyte subsets in IBD at first presentation and over time during endoscopic active or inactive disease, and relate them to disease activity and outcome.

METHODS

We included 129 newly diagnosed patients (87 Crohn's disease [CD], 42 ulcerative colitis [UC]) and 19 healthy controls [HC]. Follow-up biopsy specimens were analysed from 70 IBD patients. Immunophenotyping of specimens was performed by flow cytometry identifying lymphocyte subpopulations.

RESULTS

IBD patients at diagnosis displayed higher percentages of CD4 T+ cells, Tregs, and central memory T cells [TCM] and with lower percentages of CD8 and CD103 T lymphocytes than HC. Follow-up specimens of patients with endoscopic inactive disease showed T cell subset recovery comparable to HC. Endoscopic active disease at follow-up coincided with T cell subsets similar to those at diagnosis. In UC, lower baseline percentages of CD3 cells was associated with milder disease course without the need of an immunomodulator, whereas in CD, higher baseline percentages of CD4 and Tregs were associated with complicated disease course.

CONCLUSIONS

The intestinal T cell infiltrate in IBD patients with active endoscopic disease is composed of increased percentages of CD4+ T cells, Tregs, and TCM, with lower percentages of CD8+ T cells and CD103+ T cells, compared with HC and endoscopic inactive IBD. Baseline percentages of CD3, CD4, and Tregs were associated with disease outcome. Further research is needed to demonstrate the predictive value of these lymphocyte subsets.

Association of miR-146 rs2910164, miR-196a rs11614913, miR-221 rs113054794 and miR-224 rs188519172 polymorphisms with anti-TNF treatment response in a Greek population with Crohn’s disease

AIM

To investigate the correlation between rs2910164, rs11 614913, rs113054794, and rs188519172 polymorphisms and response to anti-TNF treatment in patients with Crohn’s disease (CD).

METHODS

One hundred seven patients with CD based on standard clinical, endoscopic, radiological, and pathological criteria were included in the study. They all received infliximab or adalimumab intravenously or subcutaneously at standard induction doses as per international guidelines. Clinical and biochemical response was assessed using the Harvey-Bradshaw index and CRP levels respectively. Endoscopic response was evaluated by ileocolonoscopy at week 12-20 of therapy. The changes in endoscopic appearance compared to baseline were classified into four categories, and patients were classified as responders and non-responders. Whole peripheral blood was extracted and genotyping was performed by PCR.

RESULTS

One hundred and seven patients were included in the study. Seventy two (67.3%) patients were classified as complete responders, 22 (20.5%) as partial while 13 (12.1%) were primary non-responders. No correlation was detected between response to anti-TNF agents and patients’ characteristics such as gender, age and disease duration while clinical and biochemical indexes used were associated with endoscopic response. Concerning prevalence of rs2910164, rs11614913, and rs188519172 polymorphisms of miR-146, miR-196a and miR-224 respectively no statistically important difference was found between complete, partial, and non-responders to anti-TNF treatment. Actually CC genotype of rs2910164 was not detected in any patient. Regarding rs113054794 of miR-221, normal CC genotype was the only one detected in all studied patients, suggesting this polymorphism is highly rare in the studied population.

CONCLUSION

No correlation is detected between studied polymorphisms and patients’ response to anti-TNF treatment. Polymorphism rs113054794 is not detected in our population.

Candidate Serum Markers in Early Crohn's Disease: Predictors of Disease Course

BACKGROUND AND AIMS

More than half of patients with Crohn's disease [CD] develop disease complications requiring aggressive medical therapy or surgery over time. However, predicting disease course and treatment response remains difficult. We therefore identified distinctive serum analytes associated with disease activity and course in newly diagnosed, untreated patients at presentation and during their follow-up.

METHODS

In a pilot study, a multiplex immunoassay analysis on 36 markers was performed on serum from 20 CD patients at the time of primary diagnosis following endoscopic evaluation. The 12 most potent markers associated with disease activity, phenotype and course were analysed in a consecutive cohort of 66 CD patients at diagnosis and follow-up [n = 39]. A healthy control group [n = 20] was included as a reference.

RESULTS

CD patients had higher baseline levels of sTNF-R2 [p = 0.001], sIL-2R [p = 0.0001], and MMP-1 [p = 0.001] compared with healthy controls. Serial measurements revealed that these three analytes dropped statistically significantly from baseline level during remission and were high during exacerbation. Great decline of sTNF-R1 levels was found during remission, with 6.7-fold lower levels than in healthy controls [p = 0.015]. Patients who did not respond to initial prednisone treatment had higher baseline levels of sTNF-R2 [p = 0.001]. Patients experiencing relapses during follow-up had lower baseline sTNF-R2 and VCAM levels compared with patients with long-lasting remission.

CONCLUSIONS

In a large cohort of newly diagnosed untreated CD patients, we identified candidate serum markers [sTNF-R1, sTNF-R2, sIL-2R, and MMP-1] associated with disease activity. Furthermore, sTNF-R2 was associated with prednisone response and, together with VCAM, with long-lasting remission.

Autoantibodies Against Glycoprotein 2 Isoforms in Pediatric Patients with Inflammatory Bowel Disease

BACKGROUND

Anti-Glycoprotein 2 (GP2) antibodies are associated with a more complicated course of Crohn's disease (CD) in adults. Four different GP2 isoforms with different length and antibody-binding sites have been identified so far but not been explored in serological studies. We aimed to investigate the diagnostic utility of autoantibodies against all 4 isoforms of GP2 in an exclusively pediatric population for the first time.

METHODS

We included 278 children and adolescents with inflammatory bowel disease: 164 with CD, 114 with ulcerative colitis, 83 disease controls (acute gastrointestinal infection, nonspecific gastrointestinal functional disorders), and 219 healthy controls. Sera were tested for anti-GP2 antibodies using 4 different isoforms of GP2 for anti-Saccharomyces cerevisiae antibodies, antineutrophil cytoplasmic antibodies, and pancreatic antibodies.

RESULTS

Anti-GP2 antibodies were significantly more prevalent in patients with CD than in ulcerative colitis and controls. We found a sensitivity of 38% (with a specificity of 95%) for anti-GP2 IgG against isoform 4 in CD. Anti-GP2 IgA against isoform 1 and anti-GP2 IgG against isoform 4 possessed the best diagnostic values for identification of CD. For the differentiation of CD from ulcerative colitis anti-GP2 IgG against isoforms 3 and 4 proved to be most accurate markers. Anti-GP2 antibodies were associated with a more complicated disease behavior and bowel surgery in CD. In a subgroup of patients with CD, anti-GP2 IgG against isoform 4 proved to be a relatively stable marker over time independent of disease activity.

CONCLUSIONS

Anti-GP2 antibodies against different isoforms are specific markers for CD and for different phenotypes in pediatric inflammatory bowel disease.

Incidence and Clinical Outcomes of Inflammatory Bowel Disease in South Korea, 2011-2014: A Nationwide Population-Based Study

BACKGROUND

The incidence of inflammatory bowel disease (IBD) is increasing in East Asia; however, population-based data from this region are lacking.

AIM

We conducted a nationwide, population-based study to examine the incidence and disease course of IBD in South Korea.

METHODS

Using the National Health Insurance claims data, we collected data on patients diagnosed with IBD [10,049 with ulcerative colitis (UC) and 5595 with Crohn's disease (CD)] from 2011 to 2014.

RESULTS

During the study period, the average annual incidence of UC was 5.0 per 10⁵, while that of CD was 2.8 per 10⁵. Among patients with UC, the cumulative rates of surgery 1 and 4 years after diagnosis were 1.0 and 2.0%; those among patients with CD were 9.0 and 13.9%, respectively. The 1- and 4-year cumulative rates of moderate- to high-dose corticosteroid use were, respectively, 26.6 and 45.2% among patients with UC, and 29.9 and 50.8% among those with CD. Similarly, the 1- and 4-year cumulative rates of immunomodulator use were 14.1 and 26.4% among patients with UC, and 58.3 and 76.1% among those with CD, respectively. With regard to biologic use, the 1- and 4-year cumulative rates were 3.0 and 9.0% among patients with UC, and 11.1 and 31.7% among those with CD, respectively.

CONCLUSIONS

The recent incidence of IBD in South Korea has been the highest in East Asia. Patients who had been diagnosed recently with IBD showed lower rates of surgery and higher rates of immunomodulator and biologic use compared to those reported ever in South Korea.

Predicting Outcomes to Optimize Disease Management in Inflammatory Bowel Diseases

BACKGROUND AND AIMS

Efforts to slow or prevent the progressive course of inflammatory bowel diseases [IBD] include early and intensive monitoring and treatment of patients at higher risk for complications. It is therefore essential to identify high-risk patients - both at diagnosis and throughout disease course.

METHODS

As a part of an IBD Ahead initiative, we conducted a comprehensive literature review to identify predictors of long-term IBD prognosis and generate draft expert summary statements. Statements were refined at national meetings of IBD experts in 32 countries and were finalized at an international meeting in November 2014.

RESULTS

Patients with Crohn's disease presenting at a young age or with extensive anatomical involvement, deep ulcerations, ileal/ileocolonic involvement, perianal and/or severe rectal disease or penetrating/stenosing behaviour should be regarded as high risk for complications. Patients with ulcerative colitis presenting at young age, with extensive colitis and frequent flare-ups needing steroids or hospitalization present increased risk for colectomy or future hospitalization. Smoking status, concurrent primary sclerosing cholangitis and concurrent infections may impact the course of disease. Current genetic and serological markers lack accuracy for clinical use.

CONCLUSIONS

Simple demographic and clinical features can guide the clinician in identifying patients at higher risk for disease complications at diagnosis and throughout disease course. However, many of these risk factors have been identified retrospectively and lack validation. Appropriately powered prospective studies are required to inform algorithms that can truly predict the risk for disease progression in the individual patient.

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.

Contribution of susceptibility variants at FCGR2A and 13q12 to the risk of relapse among Japanese patients with ulcerative colitis

BACKGROUND

Recent genome-wide association studies have identified nearly 100 susceptibility genes for ulcerative colitis (UC). However, the contribution of susceptibility variants for UC to clinical outcome has scarcely been reported. The aim of this study was to investigate whether UC-associated genetic variants confer a risk of clinical relapse.

METHODS

One hundred and nine consecutive Japanese subjects with quiescent UC were recruited. Four genetic variants of HLA-DRB1*1502, rs6671847 at FCGR2A, rs17085007 at 13q12, and rs2108225 at SLC26A3 were genotyped by Invader assay. The clinical courses were followed after blood sampling, and the risk of relapse according to these genotypes was calculated by Cox proportional hazard model.

RESULTS

During the mean follow-up period of 35 months (range 1-81 months), 49 of 109 subjects (45 %) relapsed. Carriers of the G allele of rs6671847 showed an increased risk of relapse compared with non-carriers [adjusted hazard ratio (HR), 2.27; 95 % confidence interval (CI), 1.20-4.32; p = 0.01]. Patients with the CT or TT genotypes of rs17085007 also had an increased risk of relapse compared to subjects with the CC genotype (for CT: adjusted HR, 2.16; 95 % CI, 1.10-4.23; p = 0.03; for TT: adjusted HR, 3.25; 95 % CI, 1.18-8.95; p = 0.02). These two risk variants multiplied the risk of relapse by 2.74 times (95 % CI, 1.10-4.23; p = 0.01) in patients with one risk genotype and 5.40 times (95 % CI, 2.06-14.13; p = 0.0006) in patients with both risk genotypes.

CONCLUSIONS

Genetic variants of rs6671847 at FCGR2A and rs17085007 at 13q12 conferred a risk of relapse in patients with UC.