Lymphoproliferative disorders in patients receiving thiopurines for inflammatory bowel disease: a prospective observational cohort study

Repeated enemas with hepatocyte growth factor selectively stimulate epithelial cell proliferation of injured mucosa in rats with experimental colitis

AIMS

Hepatocyte growth factor (HGF) modulates intestinal epithelial cell proliferation and migration. We previously reported that systemic administration of recombinant human HGF (rh-HGF) ameliorated experimental colitis. However, an increase in serum HGF concentrations may induce undesired systemic effects, limiting the use of rh-HGF. To avoid possible side effects, we investigated the safety and efficacy of rectally administered rh-HGF as a treatment for experimental colitis.

MAIN METHODS

We measured serum human HGF concentration following a single rectal enema of rh-HGF. Rats with 2,4,6-trinitrobenzene sulfonic acid (TNBS)- or dextran sulfate sodium (DSS)-induced colitis were treated with rectal enemas of rh-HGF once a day for seven days. The degree of mucosal injuries and the proliferative activity of the colon epithelium were examined.

KEY FINDINGS

Rats administered a rectal enema of rh-HGF at a dose of 0.1 mg/ml or less had no detectable rh-HGF in the serum. Repeated enemas of rh-HGF at this dose significantly reduced mucosal injuries, both with respect to lesion size and inflammatory cell infiltration. This regimen also stimulated proliferation of epithelial cells surrounding injured mucosa; however, the cell proliferation of uninjured mucosa was not affected by this local treatment.

SIGNIFICANCE

Rectally administered rh-HGF selectively accelerates the repair of injured mucosa in rat experimental colitis without systemic exposure to HGF. Rectal enemas of HGF are thus a potential novel and safe therapy for IBD.

Use of biological molecules in the treatment of inflammatory bowel disease

The introduction of biological agents (i.e. antitumour necrosis factor-α and anti-integrin treatments) for the treatment of inflammatory bowel disease (IBD) [i.e. Crohn's disease (CD) and ulcerative colitis] has led to a substantial change in the treatment algorithms and guidelines, especially in CD. However, many questions still remain about the true efficacy and the best treatment regimens. Thus, a need for further treatment options still exists as up to 40% of IBD patients treated with the presently available biologicals do not have positive clinical responses. Better patient selection might maximize the clinical benefit for those in most need of an effective therapy to avoid disabling disease whilst also minimizing the complications associated with therapy. Further, the 'trough-level strategy' may help clinicians to optimize therapy and to avoid loss of response and/or immunogenicity. The idea behind this dosage regimen is that correct dosing must ensure that the patient's lowest level of drug concentration (i.e. the trough level) occurring just before the next drug administration is high enough for the full effect to be seen. Controversy continues regarding the appropriate use of biologicals; therefore, in this review, we focus on considerations that might lead to a more rational strategy for antitumour necrosis factor-α agents in IBD, emphasizing the situations in which the risks may outweigh the benefits. Finally, the need for an appropriate strategy for stopping biological treatment is discussed.

Low prevalence of colonoscopic surveillance of inflammatory bowel disease patients with longstanding extensive colitis: a clinical practice survey nested in the CESAME cohort

BACKGROUND

Surveillance colonoscopy is recommended for inflammatory bowel disease (IBD) patients with longstanding extensive colitis (LEC).

AIMS

To assess modalities and results of colonoscopic surveillance in a subset of CESAME cohort patients at high risk of colorectal cancer (CRC) and followed in university French hospitals.

METHODS

Among 910 eligible patients with more than a 7-year history of extensive colitis at CESAME enrolment, 685 patients completed a questionnaire on surveillance colonoscopy and 102 were excluded because of prior proctocolectomy. Finally, 583 patients provided information spanning a median period of 41months (IQR 38-43) between cohort enrolment and the end of follow-up. Details of the colonoscopic procedures and histological findings were obtained for 440 colonoscopies in 270 patients.

RESULTS

Only 54% (n=312) of the patients with LEC had at least one surveillance colonoscopy during the study period, with marked variations across the nine participating centres (27% to 70%, P≤0.0001). Surveillance rate was significantly lower in Crohn's colitis than in ulcerative colitis (UC) (48% vs. 69%, P≤0.0001). Independent predictors of colonoscopic surveillance were male gender, UC IBD subtype, longer disease duration, previous history of CRC and disease management in a centre with large IBD population. Random biopsies, targeted biopsies and chromoendoscopy were performed during respectively 71%, 27 and 30% of surveillance colonoscopies. Two cases of high-grade dysplasia were detected in patients undergoing colonoscopic surveillance. Two advanced-stage CRC were diagnosed in patients who did not have colonosocopic surveillance.

CONCLUSIONS

Colonoscopic surveillance rate is low in IBD patients with longstanding extensive colitis.

Inflammatory bowel disease therapy: current state-of-the-art

PURPOSE OF REVIEW

The aim of this article is to review current evidence-based approaches to treatment of ulcerative colitis and Crohn's disease.

RECENT FINDINGS

The primary goal of treatment is to induce and to maintain remission in a safe and efficacious fashion. The 5-aminosalicylic acid (5-ASA) agents and oral steroids remain the first-line approach for the treatment of ulcerative colitis and Crohn's disease. The 'step-up' approach includes the use of immunomodulators [azathioprine (AZA), or 6-mercaptopurine (6-MP)] and newer biologic agents (infliximab, adalimumab, and natalizumab). The 'step-down' approach can also be considered individually on the basis of the severity of Crohn's disease.

SUMMARY

Current treatment regimens still involve medications with well known efficacy and safety profiles and progress to more potent treatments such as immunomodulators and biologic agents. Adverse events of potent treatment with biologics and immunomodulators have been recognized. In some cases, aggressive approaches with the use of more potent agents as first-line therapy has been proposed, but they are still not considered a routine approach.

Management of inflammatory bowel disease with infliximab and other anti-tumor necrosis factor alpha therapies

Inflammatory bowel disease (IBD), most commonly referring to Crohn's disease and ulcerative colitis, is a chronic and disabling condition with an increasing incidence in southern Europe. The etiology of IBD remains unknown, but the characteristic disproportionate inflammatory response in the gut may develop through various mechanisms at the cellular and subcellular level. Tumor necrosis factor (TNF) alpha is one crucial mediator of this abnormal immune response, and in recent years, biological therapies targeting TNFα have significantly improved the management of IBD refractory to conventional therapies. Infliximab is the best studied anti-TNFα agent, and is currently approved in the European Union for adults and children with Crohn's disease and adults with ulcerative colitis; adalimumab is indicated for Crohn's disease in adults but not children, while certolizumab was not approved in the European Union for Crohn's disease. Infliximab has confirmed efficacy in adults with Crohn's disease (including fistulizing disease) and ulcerative colitis, with benefits observed in both clinical remission and mucosal healing, it is similarly effective in children with Crohn's disease. Evidence suggests that early treatment with infliximab may improve the natural course of the disease. Adalimumab showed efficacy in adults with Crohn's disease and more limited data suggest efficacy in children with Crohn's disease. Although certolizumab pegol has also shown promising data in adults with Crohn's disease, data in children are lacking. Anti-TNFα agents are generally well tolerated, although careful monitoring for adverse events such as infections, infusion reactions, lymphomas and demyelinating diseases is warranted. A definitive causal relationship between anti-TNFα agents and various adverse events is difficult to establish, as the underlying disease and concomitant immunosuppression also predispose patients to such events. Infliximab has not been associated with an increased incidence of serious events, and adalimumab and certolizumab are also generally well tolerated in clinical trials. Both adalimumab and certolizumab pegol are associated with lower levels of drug antibodies compared with infliximab. Reactivation of latent tuberculosis is a potential risk with any anti-TNFα agent, and identification and treatment is required before initiating therapy. Although causal relationships are difficult to establish, caution is advised with anti-TNFα compounds in patients developing neurological symptoms suggestive of demyelinating disease, or in those at high risk of malignancy. Infliximab is also generally well tolerated in children; however, data are scarce for the other compounds. No increased risks associated with pregnancy have been observed for infliximab or adalimumab, but caution in pregnancy and during breast-feeding is currently advocated. In terms of future research, more long-term data are needed for both certolizumab pegol in Crohn's disease and adalimumab in ulcerative colitis. More research on the benefits of early biological treatment on disease progression is needed. In summary, the anti-TNFα inhibitors represent a momentous advance in the treatment of Crohn's disease and ulcerative colitis refractory to conventional treatments. They offer significant benefits in quality of life and mucosal healing, and may have the potential to change the evolution of the disease when given early.

Clinical course of Crohn's disease following treatment of lymphoma

BACKGROUND

Crohn's disease (CD) patients may be at increased risk for the development of Hodgkin's lymphoma (HL) or non-Hodgkin's lymphoma (NHL), either through exposure to immunosuppressive medications or due to their underlying chronic inflammatory illness. There are limited data regarding the natural history of CD following treatment of lymphoma. We present a series of CD patients who were treated for lymphoma and describe the natural history of their CD following lymphoma treatment.

METHODS

Retrospective case series from three academic referral centers was used. All CD patients with a history of lymphoma were identified. Demographic data, CD medication exposure, and surgical procedures before and after lymphoma treatment were recorded.

RESULTS

Nine CD patients with a history of lymphoma were identified. Eight individuals received chemotherapy, while one patient was observed without treatment. Eight patients remained free of lymphoma for a mean of 72.8 months (range 1-276 months). The ninth patient had recurrence of his HL 3 years after lymphoma diagnosis. Following lymphoma treatment, two patients had quiescent CD with no specific therapy. Three patients demonstrated significant clinical relapse of their CD and a fourth patient developed CD after treatment of her lymphoma, which ultimately required long-term immunomodulator therapy with 6-mercaptopurine or methotrexate in the first three patients, and azathioprine in the fourth. Four patients required CD surgery after lymphoma treatment.

CONCLUSION

We report on the clinical course of CD in patients who develop lymphoma. Significant clinical relapse of CD following successful medical treatment of lymphoma occurred frequently in patients with a history of this neoplasm.

Optimizing thiopurine therapy in inflammatory bowel disease

Despite recent advances, the therapeutic armamentarium for inflammatory bowel disease (IBD) is still limited. In addition, a step-up approach is recommended for most IBD patients. Thus, optimizing each medical therapy before switching to another drug class is the rule in clinical practice. Conventional therapies for IBD have not received the same amount of attention as biologic therapies over the last decade. However, due to their efficacy, safety, and low cost the thiopurine drugs azathioprine and 6-mercaptopurine remain the backbone of therapy for IBD. Pharmacogenomic advances and increased knowledge of their metabolism are allowing dosage optimization. Herein, after describing the pharmacogenetics and pharmacokinetics of thiopurines, we will discuss how to optimize thiopurine therapy. We will then underscore the need to take into account safety issues when optimizing thiopurine treatment.

Medical and surgical therapy of inflammatory bowel disease in the elderly - prospects and complications

Population ageing is a global phenomenon. People aged 65 years and older comprise approximately 16% of the population of Europe. The medical management of elderly patients with inflammatory bowel disease (IBD) is challenging with respect to diagnosis, pharmaceutical and surgical treatment, and complications. IBD has a late onset in 10%-15% of patients, with the first flare occurring at 60 to 70 years of age; others suffer from the disease for several decades. Even though the natural course of the disease in geriatric populations and the diagnostic options may not differ much from those in younger patients, distinct problems exist in the choice of medical therapy. Recommended clinical practise has been rapidly evolving towards an intensified initial treatment in IBD. However, in patients older than 65 years, a gentler approach should be used, and a combination of immunosuppressive agents should be avoided because of increased risk of infectious and neoplastic complications. Furthermore, elderly patients with severe IBD show prolonged, complicated post-operative clinical courses with worse hospital outcomes, so early surgical intervention for elderly patients is recommended. This article provides an overview of elderly IBD patient care, including medical and surgical therapeutic considerations and emphasises the necessity of close collaborations between gastroenterologists and surgeons.

Inflammatory bowel disease

This review focuses on the prominent etiological and pathogenetic aspects of inflammatory bowel disease (IBD), with particular attention being paid to the mucosal immune response to commensal micro-organisms in health and disease. Pathogenetic implications for target therapy will also be discussed. The clinical presentation, diagnostic aspects, and currently recommended therapeutic options for the two main types of IBD are also taken into consideration, including manifestations of these conditions in the oral cavity.

Incidence and risk factors for lymphoma in a single-center inflammatory bowel disease population

AIMS

Previous studies on the risk of lymphoma in inflammatory bowel disease (IBD) have yielded conflicting results. We aim to determine the incidence and risk factors for lymphoma in a large IBD population.

METHODS

Patients with lymphoma were identified from a single-center IBD database. The standardized incidence ratio (SIR) of lymphoma was estimated using data from the Surveillance, Epidemiology and End Results (SEER) registry. Risk factors for lymphoma were determined by comparing cases with a matched IBD control group.

RESULTS

Eleven lymphomas were identified among 3,585 IBD patients during an average of 8.4 years of observation. Three patients were excluded. In the remaining eight, median age at diagnosis was 47 years and mean IBD duration was 20 years (range 7.5-45 years). The SIR for lymphoma was 1.6 [95% confidence interval (CI) 0.6-3.0], and for non-Hodgkin lymphoma (NHL), 1.5 (0.3-2.8). Three lymphoma patients (38%) received prior immunomodulators and two (25%) received biologics, versus 57% and 39% in the control group, respectively (P = 0.4). No correlation was seen with tobacco exposure, disease duration, use, or dose or duration of immunosuppressive therapy.

CONCLUSIONS

In this IBD cohort, risk of lymphoma was not increased compared with the general population. Risk of lymphoma was not associated with any demographic or therapy-related factors.

Role of conventional therapies in the era of biological treatment in Crohn’s disease

Outstanding progress regarding the pathophysiology of Crohn’s disease (CD) has led to the development of innovative therapeutic concepts. Numerous controlled trials have been performed in CD. This review concentrates on the results of randomized, placebo-controlled trials, and meta-analyses when available, that provide the highest degree of evidence. Current guidelines on the management of CD recommend a step-up approach to treatment involving the addition of more powerful therapies as the severity of disease and refractoriness to therapy increase. The advent of biological drugs has opened new therapeutic horizons for treating CD, modifying the treatment goals. However, the large majority of patients with CD will be managed through conventional therapy, even if they are a prelude to biological therapy.

Difficulties and possibilities with thiopurine therapy in inflammatory bowel disease--proceedings of the first Thiopurine Task Force meeting

BACKGROUND

Thiopurines, such as azathioprine and mercaptopurine, are of pivotal importance in the treatment of inflammatory bowel disease. Although these drugs have been used for several decades, still many questions remain unanswered.

AIM

To provide an overview of clinically and scientifically challenging topics concerning thiopurine therapy in inflammatory bowel disease treatment.

METHODS

The first meeting of the Thiopurine Task Force Interest Group was held during the 2009 United European Gastroenterology Week in London (GASTRO2009). The topics of this meeting were of particular clinical and scientific interest. Additional literature was identified by performing a Pubmed search using the search terms 'inflammatory bowel disease', 'azathioprine', '6-mercaptopurine' and 'thioguanine'.

RESULTS

The following topics were discussed: therapeutic drug monitoring; the synergy of thiopurines with aminosalicylates and allopurinol; serious adverse events such as opportunistic infections, hepatotoxicity, carcinogenicity and pancreatitis; prolongation of thiopurines during clinical remission; indications for thiopurines in the postoperative setting; and the potential use of thioguanine. Specific interesting and clinically relevant topics for potential future research are provided.

CONCLUSIONS

Thiopurines remain central to inflammatory bowel disease treatment, although future studies are required to substantiate a more personalised medicine approach to their use.

IBD-related carcinoma and lymphoma

Patients with inflammatory bowel disease (IBD) have an increased risk of developing colorectal cancer (CRC). Risk factors are extent and severity of colonic inflammation, concurrent primary sclerosing cholangitis, and a positive family history of sporadic CRC. The chromosomal instability, microsatellite instability and hypermethylation pathways form the molecular background of IBD-related carcinogenesis, which is not different from sporadic CRC. The dysplasia-carcinoma sequence of IBD-related colorectal carcinogenesis makes patients suitable for endoscopic surveillance. In the future, new molecular biomarkers and endoscopic techniques may improve early detection of precursor lesions of IBD-related CRC. The potential of aminosalicylates and ursodeoxycholic acid as chemopreventive agents needs to be studied in randomized clinical trials. Patients with IBD who are being treated with thiopurines have a slightly increased risk of developing lymphoproliferative disorders, whereas patients with small bowel Crohn's disease have a high relative risk and a small absolute risk of developing small bowel adenocarcinoma.

Infliximab induces clonal expansion of γδ-T cells in Crohn's disease: a predictor of lymphoma risk?

Background

Concominant with the widespread use of combined immunotherapy in the management of Crohn's disease (CD), the incidence of hepato-splenic gamma-delta (γδ)-T cell lymphoma has increased sharply in CD patients. Malignant transformation of lymphocytes is believed to be a multistep process resulting in the selection of malignant γδ-T cell clones. We hypothesised that repeated infusion of anti-TNF-α agents may induce clonal selection and that concurrent treatment with immunomodulators further predisposes patients to γδ-T cell expansion.

Methodology/Principal Findings

We investigated dynamic changes in the γδ-T cells of patient with CD following treatment with infliximab (Remicade®; n = 20) or adalimumab (Humira®; n = 26) using flow cytometry. In patients with a high γδ-T cell level, the γδ-T cells were assessed for clonality. Of these 46 CD patients, 35 had a γδ-T cells level (mean 1.6%) comparable to healthy individuals (mean 2.2%), and 11 CD patients (24%) exhibited an increased level of γδ-T cells (5–15%). In the 18 patients also receiving thiopurines or methotrexate, the average baseline γδ-T cell level was 4.4%. In three male CD patients with a high baseline value, the γδ-T cell population increased dramatically following infliximab therapy. A fourth male patient also on infliximab monotherapy presented with 20% γδ-T cells, which increased to 25% shortly after treatment and was 36% between infusions. Clonality studies revealed an oligoclonal γδ-T cell pattern with dominant γδ-T cell clones. In support of our clinical findings, in vitro experiments showed a dose-dependent proliferative effect of anti-TNF-α agents on γδ-T cells.

Conclusion/Significance

CD patients treated with immunomodulators had constitutively high levels of γδ-T cells. Infliximab exacerbated clonal γδ-T cell expansion in vivo and induced γδ-T cell proliferation in vitro. Overall, young, male CD patients with high baseline γδ-T cell levels may be at an increased risk of developing malignant γδ-T cell lymphomas following treatment with anti-TNF-α agents.

Mucosal healing in inflammatory bowel disease: where do we stand?

The definition of remission in Crohn's disease and ulcerative colitis has evolved to include mucosal healing as a measure of treatment efficacy. Randomized, controlled trials have demonstrated mucosal healing is attainable with the current arsenal of therapies available to treat inflammatory bowel disease. Mucosal healing has been shown to reduce the likelihood of clinical relapse, reduce the risk of future surgeries, and reduce hospitalizations. This review focuses on the latest studies addressing clinical outcomes of mucosal healing in the clinical trial and practice setting.

The homologous recombination protein RAD51D mediates the processing of 6-thioguanine lesions downstream of mismatch repair

Thiopurines are extensively used as immunosuppressants and in the treatment of childhood cancers, even though there is concern about therapy-induced leukemias and myelodysplastic syndromes resulting from thiopurine use. Following metabolic activation, thiopurines are incorporated into DNA and invoke mismatch repair (MMR). Recognition of 6-thioguanine (6-thioG) in DNA by key MMR proteins results in cell death rather than repair. There are suggestions that homologous recombination (HR) is involved downstream of MMR following thiopurine treatment, but the precise role of HR is poorly understood. In this study, we demonstrate that cells deficient in RAD51D (a RAD51 paralogue) are extremely sensitive to 6-thioG. This sensitivity is almost completely rescued by the deletion of Mlh1, which suggests that HR is involved in the repair of the 6-thioG-induced recombinogenic lesions generated by MMR. Furthermore, 6-thioG induces chromosome aberrations in the Rad51d-deficient cells. Interestingly, Rad51d-deficient cells show a striking increase in the frequency of triradial and quadriradial chromosomes in response to 6-thioG therapy. The presence of these chromatid exchange-type aberrations indicates that the deficiency in RAD51D-dependent HR results in profound chromosomal damage precipitated by the processing of 6-thioG by MMR. The radials are notable as an important source of chromosomal translocations, which are the most common class of mutations found in hematologic malignancies. This study thus suggests that HR insufficiency could be a potential risk factor for the development of secondary cancers that result from long-term use of thiopurines in patients.

EBV-associated colitis mimicking IBD in an immunocompetent individual

BACKGROUND

A 30-year-old immunocompetent male with an unremarkable medical history presented with 2 months of lower abdominal bloating and loose, bloody, mucoid bowel movements. He was clinically suspected to have IBD. Due to the progression of his symptoms, he ultimately required hospitalization for further investigation and care.

INVESTIGATIONS

Full medical history and physical examination, routine blood analyses, stool studies, hepatitis serologic tests, abdominal CT, colonoscopy, PCR analysis and light microscopy and immunoperoxidase staining of colonic biopsy samples.

DIAGNOSIS

Epstein-Barr virus (EBV)-associated lymphoproliferative disorder with diffuse colonic involvement (EBV colitis) in an immunocompetent adult.

MANAGEMENT

Inpatient supportive care.

Review article: explaining risks of inflammatory bowel disease therapy to patients

BACKGROUND

Medical treatment for inflammatory bowel disease (IBD) has advanced significantly over the past decade, but it is important to communicate effectively the balance of benefits and risks of therapy to patients to facilitate informed medical decisions.

AIM

To review the available data describing the risk of side effects of IBD medications and to describe effective methods for communicating risk.

METHODS

To identify relevant articles for this review, a PubMed search was conducted using relevant key words and phrases. In addition, reference lists from identified manuscripts were searched and recent abstracts from National meetings were reviewed.

RESULTS

The steroid-sparing medications used for the treatment of IBD all carry risks of both common and rare adverse events. Trade-offs need to be made between the risks of these medications vs. the risks of poorly treated disease and corticosteroids. There has been significant research on how best to present risk data to patients, which is summarized in this review.

CONCLUSIONS

To ensure that our patients understand their choices and feel comfortable with their treatment, we need to communicate risk data to patients clearly. Patients comprehend absolute numbers better than relative risk, and when available, pictorial representations of data are preferred over solely presenting numerical outcomes.

A systematic review of factors that contribute to hepatosplenic T-cell lymphoma in patients with inflammatory bowel disease

BACKGROUND & AIMS

Hepatosplenic T-cell lymphoma (HSTCL) is a rare and usually fatal lymphoma that primarily affects men younger than 35 years old. Treatment of patients with inflammatory bowel disease (IBD) using antibodies to tumor necrosis factor (anti-TNFs) and thiopurines has been associated with HSTCL. We investigated the medications, duration of therapy, and ages of patients associated with HSTCL.

METHODS

We collected and analyzed data on the association between HSTCL, and anti-TNF and thiopurine therapies in patients with IBD from published reports and the MedWatch reporting system of the US Food and Drug Administration.

RESULTS

Of 36 patients with HSTCL, 20 received therapy with infliximab and a thiopurine and 16 received a thiopurine as monotherapy for IBD. Four patients who had been treated with infliximab and a thiopurine also received adalimumab. One of these patients had been given infliximab, adalimumab, and natalizumab. Of 31 patients of known gender, only 2 were female. Twenty-seven of the 30 patients of known age were younger than 35 years old.

CONCLUSIONS

Most patients with HSTCL who received long-term therapy (at least 2 y) with thiopurines for IBD were men younger than 35 years old. There were no reported cases of HSTCL in patients with IBD who received only anti-TNF therapy. Physicians should consider giving thiopurines and anti-TNF agents to young male patients with IBD only in cases in which a clear benefit is expected, such as in early stage disease in untreated patients or possibly in very severe cases.

Inflammatory bowel disease and colitis: new concepts from the bench and the clinic

PURPOSE OF REVIEW

The previous 18 months have shown important progress in unravelling the causes of inflammatory bowel disease (IBD) and in improving its management for the patients.

RECENT FINDINGS

More genome-wide association studies and meta-analyses of these have been published and have identified more than 100 confirmed genes for IBD, and highlighted a number of novel pathways. Two of the genes, NOD2/CARD15 and the autophagy gene ATG16L1 have recently been linked into one functional pathway of bacterial sensing, invasion and elimination. From the clinical side, the previous year has been dominated mainly by the results of the SONIC study, comparing efficacy and safety of azathioprine, infliximab and the combination of azathioprine and infliximab, in patients with active Crohn's disease, naive to these drugs. International consensus guidelines on infection prevention were released last year by the European Crohn's and Colitis Organisation.

SUMMARY

The recent findings in IBD include the increasing number of IBD susceptibility genes, the demonstration that NOD2 and ATG16L1 are linked in one functional pathway and the role of IL-33/ST2 in colitis. From the bedside, the novelties have been the results of SONIC and selecting the right patient for intensified treatment with immunomodulators and anti-tumor necrosis factor, and appropriate counselling regarding risk of infections and vaccinations.

News from the "5th International Meeting on Inflammatory Bowel Diseases" CAPRI 2010

At the "5th International Meeting on Inflammatory Bowel Diseases selected topics of inflammatory bowel disease (IBD), including the environment, genetics, the gut flora, the cell response and immunomodulation were discussed in order to better understand specific clinical and therapeutic aspects. The incidence of IBD continues to rise, both in low and in high-incidence areas. It is believed that factors associated with 'Westernization' may be conditioning the expression of these disorders. The increased incidence of IBD among migrants from low-incidence to high-incidence areas within the same generation suggests a strong environmental influence. The development of genome-wide association scanning (GWAS) technologies has lead to the discovery of more than 100 IBD loci. Some, as the Th 17 pathway genes, are shared between Crohn's disease (CD) and ulcerative colitis (UC), while other are IBD subtype-specific (autophagy genes, epithelial barrier genes). Disease-specific therapies targeting these pathways should be developed. Epigenetic regulation of the inflammatory response also appears to play an important role in the pathogenesis of IBD. The importance of gut flora in intestinal homeostasis and inflammation was reinforced, the concepts of eubiosis and dysbiosis were introduced, and some strategies for reverting dysbiosis to a homeostatic state of eubiosis were proposed. The current status of studies on the human gut microbiota metagenome, metaprotome, and metabolome was also presented. The cell response in inflammation, including endoplasmic reticulum (ER) stress responses, autophagy and inflammasome-dependent events were related to IBD pathogenesis. It was suggested that inflammation-associated ER stress responses may be a common trait in the pathogenesis of various chronic immune and metabolic diseases. How innate and adaptive immunity signaling events can perpetuate chronic inflammation was discussed extensively. Signal transduction pathways provide intracellular mechanisms by which cells respond and adapt to multiple environmental stresses. The identification of these signals has led to a greater mechanistic understanding of IBD pathogenesis and pointed to potentially new therapeutic targets. A critical analysis of clinical trials and of risk-benefit of biological therapy was presented. The problem of Epstein-Barr virus (EBV) and lymphoma in IBD was extensively discussed. Lymphomas can develop in intestinal segments affected by IBD and are in most cases associated with EBV. The reasons of treatment failure were also analyzed both from basic and clinical points of view. Two very interesting presentations on the integration of research and clinical care in the near future closed the meeting. These presentations were focused on macrotrends affecting healthcare delivery and research, and the need to innovate traditional infrastructures to deal with these changing trends as well as new opportunities to accelerate scientific knowledge.

Rectal non-Hodgkin's lymphoma in an infliximab treated patient with ulcerative colitis and primary sclerosing cholangitis

A 20-year old man with ulcerative colitis (UC) and primary sclerosing cholangitis (PSC) was diagnosed with a rectal non-Hodgkin's lymphoma (NHL) at surveillance endoscopy while being in remission on infliximab therapy. Further staging identified a diffuse large B-cell NHL, EBV negative restricted to the rectal submucosa (stage IA). Until now, there has not been any evidence of an increased risk of NHL in patients with UC nor of an increased risk of lymphoproliferative disorders in IBD patients. Hence, the role of concomitant PSC in the pathogenesis of intestinal NHL is unclear. However, IBD patients treated with purine analogues and with anti-TNF are at risk of NHL, especially hepatosplenic T-cell lymphoma. The management of this particular young patient is further complicated by the possibility of a future colectomy due to intractable disease which compromises the use of radiotherapy for this localized disease.

Thiopurines in Crohn's disease, is there something new?

IMPORTANCE OF THE FIELD

traditional immunosuppressants, including azathioprine, remain the mainstay of therapy in steroid dependent/refractory patients with inflammatory bowel diseases (IBD). The main limitations of its use are its side effects appearing in about a fifth of the patients, including myelosuppression and liver toxicity. Major complications occur in patients with low thiopurine-S-methyltransferase (TPMT) enzyme activity; however, the clinical relevance of these tests remains conflictive.

AREAS COVERED IN THIS REVIEW

in this review, the authors aim to summarize the new data regarding the relationship between the pharmacology of thiopurines and pathogenesis of adverse events.

WHAT THE READER WILL GAIN

readers will gain an understanding of the metabolism of thiopurines, side effect profile, pharmacological background of side effects, importance of metabolite monitoring, clinical relevance of inherited differences in drug metabolism and other conditions (e.g., concomitant use of allopurinol) which can modify enzyme activity. By gaining an understanding of the pharmacology and metabolism of thiopurines, clinicians will be able to optimize thiopurine therapy in IBD.

TAKE HOME MESSAGE

TPMT testing and metabolite monitoring are still not considered the standard of care, and clinicians will continue to choose the approach that best suits their clinical practice and patient needs. Regardless of what strategy is chosen, patients need to be carefully monitored and well informed about the potential risks.

[What has been confirmed in the treatment of inflammatory bowel disease?]

The therapy of inflammatory bowel diseases is currently guided by clinical variables. An escalation of immunosuppressive therapy is required in case of treatment failure. However, clinical remission does not necessarily imply mucosal healing. In parallel to the treatment of rheumatoid arthritis a novel concept is emerging suggesting that an early anti-inflammatory treatment can reduce structural changes in inflammatory bowel diseases. The studies supporting this novel therapeutic strategy that mucosal healing might build the future therapeutic goal will be discussed. In order to adjust the therapy, risk factors indicating a complicated disease course will be identified, resulting in the development of an individual disease course. The benefit of these strategies will be discussed together with therapy-associated complications.

Update on the risk of lymphoma following immunosuppressive therapy for inflammatory bowel disease

The care of inflammatory bowel disease has changed considerably with the introduction of a number of immunosuppressants including anti-metabolite and anti-TNF therapies. While efficacious, these medications also carry important risks, notably the potential risk of lymphoma. This risk is one of the most worrisome for both patients and physicians. Our current knowledge is still evolving; however, our understanding of what risks these drugs carry, both individually and synergistically, is critical in allowing informed decision making. In this article, we will describe the known lymphoma risks of commonly used immunosuppressant medications in inflammatory bowel disease, with an emphasis on non-Hodgkin's lymphoma and hepatosplenic T-cell lymphoma.

Thiopurine therapy in inflammatory bowel disease

The thiopurines azathioprine and 6-mercaptopurine have been used in the treatment of Crohn's disease and ulcerative colitis for over 40 years. Randomized controlled trials have supported their use in the treatment of active disease, as well as for the maintenance of disease remission. Presently, the most debated issues surrounding the thiopurines include: the role of thiopurine methyltransferase and metabolite-adjusted dosing in enhancing efficacy and minimizing toxicity; the timing of thiopurine use, that is, earlier versus later use during the course of the disease; the selection of thiopurine monotherapy versus combination therapy with an anti-TNF-α; agent; and the safety profile of thiopurines. Accumulated evidence has supported the safety of 6-mercaptopurine/azathioprine use in pregnancy and lactation. Thiopurine therapy in inflammatory bowel diseases is associated with an increased risk of lymphoproliferative disorders. Factoring their proven efficacy over a broad range of clinical scenarios within Crohn's disease and ulcerative colitis together with their overall safety profile and convenient and inexpensive once-daily oral administration, azathioprine and 6-mercaptopurine remain among the mainstays of Crohn's disease and ulcerative colitis therapy.

Gastric ulcers and swollen kidneys: a rare diagnosis complicating Crohn's disease

We present a case of a 48-year-old woman with Crohn's colitis admitted with abdominal pain and fever. She had been started on azathioprine 6 months before presentation and had received three doses of infliximab. Abdominal CT scan revealed a liver abscess. Azathioprine was stopped and antibiotics started. She was subsequently discharged with follow-up imaging planned. She presented 3 weeks later with haematemesis. Gastroscopy revealed multiple gastric ulcers. A repeat CT scan showed bilateral renal masses and a renal biopsy was arranged. Gastric and renal biopsies were consistent with B cell lymphoma. Chemotherapy was started and resulted in improvement in CT scan findings as well as ulcer healing.

Review article: malignancy on thiopurine treatment with special reference to inflammatory bowel disease

BACKGROUND

Immunosuppression is a risk factor for carcinogenesis. Thiopurines specifically contribute to this. As thiopurines are used more aggressively in the treatment of IBD, it is likely that we will see more thiopurine-related malignancy.

AIM

To review the literature, exploring how immunosuppression, thiopurines specifically, might cause cancer and which malignancies occur in practice, placing specific emphasis on IBD cohorts.

METHODS

Search terms included 'malignancy' 'cancer' 'azathioprine' 'mercaptopurine' 'tioguanine (thioguanine)' 'thiopurine' and 'inflammatory bowel disease' 'Crohn's disease' 'ulcerative colitis'. We also searched for specific cancers (lymphoma, colorectal cancer, skin cancer, cervical cancer) and reviewed the reference lists of the articles detected.

RESULTS

Immunosuppression is associated with an increased risk of cancer. Thiopurines are associated with specific additional risks. In IBD cohorts, very few thiopurine-related malignancies have been reported. However, studies suggest a relative risk of 4-5 for lymphoma. This still translates into a low actual risk, (one extra lymphoma in every 300-1400 years of thiopurine treatment).

CONCLUSIONS

Whilst we must be aware of this risk and counsel our patients appropriately, thiopurines remain a mainstay of IBD therapy. We present practical advice aimed at minimizing our patients' risk of developing malignancy, whilst optimizing the benefits that thiopurines can provide.

Risk of cancer in inflammatory bowel disease treated with azathioprine: a UK population-based case-control study

OBJECTIVES

Azathioprine is an accepted treatment of inflammatory bowel disease (IBD), but concerns exist regarding its carcinogenic potential. Studies in renal transplant and rheumatology patients have reported an increased cancer risk. In IBD, studies suggest a small increased risk of lymphoma and protection against colorectal cancer, but the overall risk of malignancy has not been established.

METHODS

We conducted a nested case-control study using the General Practice Research Database. Records of IBD patients were examined for azathioprine prescriptions and cancers. Prescriptions per year of follow-up were grouped for analysis. Azathioprine use was compared between IBD cases (with a diagnosed cancer) and IBD controls (without).

RESULTS

Overall, 15,471 patients with IBD and over 1 year of appropriate data were identified. Among these, 392 developed cancer, of whom 10.5% received at least one prescription for azathioprine, compared with 1,914 (12.7%) of the controls. Analyzing the occurrence of any cancer against azathioprine prescription showed a nonsignificant protective effect (odds ratio (OR)=0.92, 95% confidence interval (CI)=0.79-1.06). Correction for the effects of age and smoking removed this effect (OR=1.04, 95% CI=0.89-1.21). Diagnosis of lymphoma was associated with ever use of azathioprine with OR of 3.22, CI=1.01-10.18.

CONCLUSIONS

We found evidence of an increased risk of lymphoma, which is consistent with previous studies. We found no overall increase in risk of cancer in individuals with IBD who had taken azathioprine. Our study does not show a need for azathioprine cessation in the medium term in IBD because of the risk of malignancy.

Emerging drugs to treat Crohn's disease

IMPORTANCE OF THE FIELD

Inflammatory bowel diseases are chronic inflammatory diseases that comprise of two forms - Crohn's disease (CD) and ulcerative colitis (UC) - characterized by aberrant responses to luminal bacteria in genetically susceptible individuals. Whereas inflammation is limited to the large intestine in patients with UC, CD can affect all parts of the gastrointestinal tract. During disease exacerbations, pharmacological or surgical intervention is usually needed to re-establish remission; however, current therapeutic interventions cannot cure CD. As a subgroup of patients with CD will not be able to remain in remission with available drugs or suffer from side effects, new therapeutic strategies are needed.

AREAS COVERED IN THIS REVIEW

This review focuses on emerging drugs in the treatment of CD and reviews data on their efficacy and safety. An extensive review of the available literature was undertaken using MEDLINE to identify relevant studies.

WHAT THE READER WILL GAIN

The reader will learn about current therapeutic strategies in patients with CD and gain insights into emerging new drugs.

TAKE HOME MESSAGE

As modification of the clinical course of CD becomes the therapeutic paradigm, potential future treatments have to induce mucosal healing in order to prevent long-term complications. New biologics show promising results.

Inflammatory bowel disease and intestinal cancer: a paradigm of the Yin-Yang interplay between inflammation and cancer

Colon cancer represents a paradigm for the connection between inflammation and cancer in terms of epidemiology and mechanistic studies in preclinical models. Key components of cancer promoting inflammation include master transcription factors (for example, nuclear factor kappaB, STAT3), proinflammatory cytokines (for example, tumor necrosis factor, interleukin-6 (IL-6)), cyclooxygenase-2 and selected chemokines (for example, CCL2). Of no less importance are mediators that keep inflammation in check, including IL-10, transforming growth factorbeta, toll-like receptor and the IL-1 receptor inhibitor TIR8/SIGIRR, and the chemokine decoy and scavenger receptor D6. Dissection of molecular pathways involved in colitis-associated cancer may offer opportunities for innovative therapeutic strategies.

Decision-making in ileocecal Crohn's disease management: surgery versus pharmacotherapy

Ileocecal Crohn's disease (CD) can be treated medically as well as surgically. Both treatment modalities have been improved markedly in the last two decades, making CD more manageable. However, multidisciplinary research, addressing issues such as timing of surgery or medical treatment versus surgery, is scarce. Particularly in limited ileocecal CD, ileocolic resection might be a good alternative to long-term medical therapy. This review discusses the evidence on medical and surgical treatment options for ileocecal CD. It provides an aid in decision-making by discussing a treatment algorithm that can be used until further evidence on treatment is available.

Optimising use of thiopurines in inflammatory bowel disease

Azathioprine (AZA) and 6-mercaptopurine (6-MP) are the most widely used immunosuppressive therapies in inflammatory bowel disease. Pretreatment measurement of thiopurine methyltransferase (TPMT) activity is recommended and although conventional practice is to use a dose of 2 mg/kg AZA (1 mg/kg 6-MP), higher doses of 2.5 mg/kg AZA or more may be required in some patients, particularly if TPMT activity is high. Dose raising is limited by toxicity, and a robust monitoring system is mandatory. Patients with side effects to AZA may tolerate 6-MP but pancreatitis is a contraindication to switching. Metabolite monitoring is not widely available but may be useful, particularly if non-compliance is possible or where metabolite shunting to 6-methylmercaptopurine is suspected, on the basis of non-response or toxicity. It may allow dose optimisation before switching to alternative immunosuppressants. The drug appears safe in pregnancy and breast feeding. Long term duration of therapy is a balance between benefits in relation to the underlying disease extent, activity and aggressiveness, and the risk of neoplasia, particularly lymphoma.

Optimizing the safety of biologic therapy for IBD

The introduction of biologic therapy for the treatment of IBD has substantially changed its management. The safety concerns associated with biologic therapies include the increased risk of infection, autoimmunity, development of lymphoma and demyelinating disease, and the risk of worsening heart failure. There are several strategies for minimizing the risks associated with biologic therapies. Pretreatment strategies include taking a proper history from the patient, physical examination of the patient, screening for latent tuberculosis and ruling out sepsis. Vaccination of patients against vaccine preventable diseases is also recommended. During treatment, patients should be closely monitored and any symptoms that develop should be dealt with early. Education of physicians and patients is also important to allow the early detection of any adverse events.

Top-down therapy for IBD: rationale and requisite evidence

Several trials have shown that early treatment of Crohn's disease with immunomodulators and anti-TNF agents leads to a superior clinical outcome, including healing of the mucosa, compared with standard therapy alone. Mounting evidence indicates that mucosal healing is associated with a reduced risk of complications, and a reduced need for surgeries and hospitalizations. In the SONIC trial, a combination of the standard azathioprine immunomodulator therapy and infliximab, an anti-TNF agent, had more potent anti-inflammatory effects than either drug alone in patients with Crohn's disease who had evidence of active inflammation. These findings and those from rheumatoid arthritis trials have prompted the investigation of early initiation of immunomodulator (standard or anti-TNF) therapy for Crohn's disease, in suitable patients, which has led to substantial improvements in disease management. Careful selection of patients is, however, essential given the potential risk of toxic effects from these therapies and the fact that some patients with IBD will have a favorable disease course without them. Identification of suitable patients, however, remains a challenge, as genetic, phenotypic and environmental factors have not yet been identified that can be used for routine assessment and selection is mainly based on clinical criteria.