Infliximab in the treatment of Crohn's disease: predictors of response in an Italian multicentric open study

Use of methotrexate in refractory Crohn's disease: the Edinburgh experience

BACKGROUND

In the two benchmark controlled trials in Crohn's disease (CD) supporting its use, methotrexate (MTX) was used as the immunosuppressant of choice in immunomodulatory-naive patients. However, in daily clinical practice MTX is used generally after thiopurine analogs have failed.

METHODS

The data are reported using intramuscular (IM) MTX (25 mg/week) in the induction of remission and oral MTX (15 mg/week) in 39 CD patients with a median age of 32 years, assessed retrospectively. In all, 97% patients had failed azathioprine and/or mercaptopurine therapy due to lack of efficacy in 14 (36%) and side effects in 24 (61%) patients; 21 patients (53%) were steroid-dependent with a median dose of 27.5 mg prednisolone/day for over a year.

RESULTS

In all, 72% of patients tolerated an induction regimen of 25 mg/week of IM MTX; 10% managed a reduced dose and 18% were intolerant. Remission was achieved in 71% of patients at 16 weeks. In the patients taking corticosteroids, withdrawal was achieved in 26% of patients and reduction in 47% at 16 weeks. Oral MTX therapy was continued in 22 patients after induction. In this group the probability of relapse was 78% at 50 weeks of oral therapy.

CONCLUSIONS

Parenteral MTX therapy is efficacious in inducing remission in steroid-dependent CD patients, although its use is limited by side effects in approximately 30% of patients. Low-dose oral therapy does not maintain long-term remission and is not a suitable alternative.

Therapeutic efficacy of infliximab on patients with short duration of Crohn's disease: a Japanese multicenter survey

PURPOSE

This study was designed to evaluate the efficacy of infliximab in patients with Crohn's disease of durations less than one year.

METHODS

Two nationwide surveys of 35 Japanese institutions majoring in inflammatory bowel disease identified 41 patients with active Crohn's disease who were treated by infliximab within 12 months after the diagnosis (E-group) and 97 patients treated later during their clinical course (L-group). Clinical features, responses to infliximab, and accompanying medications were compared between the two groups. A decrease in Crohn's disease activity index > or = 70 or the index < 150 two weeks after infliximab was regarded to be efficacious.

RESULTS

The age was younger (24 vs. 33 years, median, P < 0.0001) and intestinal stricture (12 vs. 49 percent, P < 0.0001), internal fistula (0 vs. 26 percent, P = 0.0003), and previous intestinal resection (7 vs. 57 percent, P < 0.0001) were less frequent in the E-group than in the L-group. The efficacy of infliximab was different between the two groups with a significantly higher value in the E-group than in the L-group (90 vs. 61 percent, P = 0.0012). A multivariate logistic regression analysis revealed nonstricturing intestinal lesion to be a significant factor related to the efficacy of infliximab.

CONCLUSION

Infliximab is more efficacious in Crohn's disease with short duration, probably because of less frequent stenosis.

Imaging of perianal Crohn's disease

Perianal fistulas and abscesses are common complications of Crohn's disease, affecting up to 50% of patients during their disease course. Accurate diagnosis and classification of perianal disease is crucial before and during treatment to plan an adequate approach for each patient and to avoid irreversible functional consequences. Although examination under anaesthesia has been considered the gold standard for diagnosis and classification of Crohn's disease perianal fistulas, taken alone it does not have perfect accuracy, stressing the need for concomitant or alternative, non-invasive, methods of evaluation. In this context, imaging modalities assessed for diagnosis, classification and monitoring of Crohn's disease perianal fistulas include pelvic magnetic resonance imaging, anorectal endoscopic ultrasonography, transcutaneous perianal ultrasound, fistulography and computed tomography. In particular, magnetic resonance imaging and endoscopic ultrasonography findings have shown the best accuracy, and the ability to influence therapeutic management of these patients. For transcutaneous perianal ultrasound too, good preliminary data have been reported. This paper reviews the available data on imaging methods for the management of perianal Crohn's disease.

Mode of function of biological anti-TNF agents in the treatment of inflammatory bowel diseases

TNF-alpha has been identified as a major mediator in the pathophysiology of inflammation. Anti-TNF agents, either as a neutralising antibody or a soluble TNF receptor, have markedly influenced the clinical management of several chronic inflammatory disorders. Whereas it seems likely that neutralisation of soluble and membrane-bound TNF might be a key mechanism of any anti-TNF agent, the potential of the anti-TNF antibody infliximab to induce lymphocyte/monocyte apoptosis in Crohn's disease has been considered an additional important mechanism. Other potential mode of actions include induction of the anti-inflammatory cytokines IL-10 or TGF-beta via retrograde signalling or induction of a certain subset of regulatory T cells. Certolizumab, a pegylated fully human anti-TNF monoclonal antibody also effective in Crohn's disease, lacks the capacity to induce apoptosis. Therefore, the capacity to induce apoptosis and neutralisation of TNF alone are insufficient to explain clinical efficacy of anti-TNF agents in human inflammatory bowel diseases.

The patient with persistent perianal fistulae

The management of patients with persistent perianal fistulae depends on thorough evaluation by clinical history and examination, assessment of intestinal disease and assessment of perianal disease. The main therapeutic options are medical and surgical treatment and their appropriate integration is essential for the optimal management of the patients. Medical treatment includes antibiotics, azathioprine or 6-mercaptopurine, infliximab and tacrolimus or cyclosporine. Surgical treatment includes fistulotomy, placement of setons, endorectal advancement flaps, fecal diversion and proctectomy. Fistula recurrence often occurs, possibly due to early discontinuation of medication or premature removal of setons. Using anorectal endoscopic ultrasound or magnetic resonance imaging to guide therapy, the healing rates of perianal fistula can be increased. In persistent complex perianal fistulae where medical treatment initially fails, examination under anaesthesia and placement of non-cutting setons, when necessary, combined with medical treatment results in higher healing rates.

Does cigarette smoking influence the phenotype of Crohn's disease? Analysis using the Montreal classification

OBJECTIVES

The clinical subclassification of Crohn's disease by phenotype has recently been reevaluated. We have investigated the relationships between smoking habit, age at diagnosis, disease location, and progression to stricturing or penetrating complications using the Montreal classification.

METHODS

408 patients (157 male, median age 29.4 yr) were assessed. Data were collected on smoking habit, age at diagnosis, anatomical distribution, and disease behavior. Follow-up data were available on all patients (median 10 yr).

RESULTS

At diagnosis, ex-smokers (N = 53) were older than nonsmokers (N = 177) or current smokers (N = 178, medians 43.2 vs 28.3 or 28.9 yr, respectively, P < 0.001). Disease location differed according to smoking habit at diagnosis (chi(2)= 24.1, P= 0.02) as current smokers had less colonic (L2) disease than nonsmokers or ex-smokers (30%vs 45%, 50%, respectively). In univariate Kaplan-Meier survival analysis, smoking habit at diagnosis was not associated with time to development of stricturing disease, internal penetrating disease, perianal penetrating disease, or time to first surgery. Patients with isolated colonic (L2) disease were slower to develop strictures (P < 0.001) or internal penetrating disease (P= 0.001) and to require surgery (P < 0.001). Cox models with smoking habit as time-dependent covariates showed that, relative to ileal (L1) location of disease, progression to stricturing disease was less rapid for patients with colonic (L2) disease (HR 0.140, P < 0.001), but not independently affected by smoking habit. Progression to surgery was also slower for colonic (L2) than ileal (L1) disease location (HR 0.273, P < 0.001), but was independent of smoking habit.

CONCLUSIONS

Smoking habit was associated with age at diagnosis and disease location in Crohn's disease, while disease location was associated with the rate of development of stricturing complications and requirement for surgery. The pathogenic basis of these observations needs to be explained.

Treatment with biologic therapies and the risk of cancer in patients with IBD

The proven involvement of cytokines in the pathophysiology of IBD has led to the development of powerful, selective, anticytokine drugs--so-called biologics--as a therapy for IBD. Although the efficacy of infliximab, a chimeric monoclonal IgG1 antibody directed against tumor necrosis factor, is proven and the use of biologic agents is growing worldwide, there is concern about their long-term safety, which includes the risk of developing cancer. An increased risk of malignancies, particularly lymphoma, has been reported in some studies of infliximab-treated patients with IBD; however, the increased risk could be caused by the underlying chronic disease, severity of the disease, concomitant medications (e.g. conventional immunomodulators), infliximab itself, or all of these variables. At present, the data do not provide clear evidence for a causal association between infliximab and the increased cancer risk. In appropriately selected patients with severe, refractory Crohn's disease, the benefits of biologic therapy seem to outweigh the cancer risk. Multicenter, case-control studies in large populations, with a long-term follow-up are needed to define the outcome of patients with IBD treated with biologic therapies.

Cytokine network in chronic perianal Crohn's disease and indeterminate colitis after colectomy

Antitumor necrosis factor alpha (anti-TNF-alpha) therapy in perianal Crohn's disease (CD) is widely established but recent studies suggest that the underlying fistula tract and inflammation may persist. Treatment with a monoclonal antibody against interleukin (IL)-12 was reported to induce clinical responses and remissions in patients with active CD. The aim of our study was to analyze the cytokine network (TNF-alpha, IL-12, IL-1beta, and IL-6) in 12 patients with chronic perianal CD and a Crohn's disease activity index (CDAI) score <150 to exclude active intestinal disease, in 7 patients with indeterminate colitis (IC) after restorative proctocolectomy with perianal complications, in 7 patients with active intestinal CD without perianal manifestations, and in 19 healthy controls. Nonparametric Mann-Whitney U test and Spearman's rank correlation test were used. Serum TNF-alpha levels were significantly higher in patients with IC than perianal CD patients and healthy controls. Serum TNF-alpha levels significantly correlated with perianal CDAI score and with the presence of anal fistulas. Serum IL-12 levels correlated with the presence of anal strictures and were similar in all groups. Serum IL-6 levels were significantly higher in the presence of perianal fistulas and lower in the presence of anal strictures. Our study confirmed that TNF-alpha plays a major role in the perianal and intestinal CD. Furthermore, the significantly higher TNF-alpha serum levels in patients with IC suggest the use of anti-TNF-alpha in such patients. On the contrary, according to our results the efficacy of anti-IL-12 antibodies appears doubtful in chronic perianal CD or IC without anal strictures. The role of IL-6 as a systemic mediator for active chronic inflammation was confirmed and a possible role for its monoclonal antibody was suggested.

Controversies in the treatment of common anal problems

Treating common benign anal diseases has evolved towards more outpatient procedures with better outcome. However, minimizing post-procedure morbidities such as pain and the avoidance incontinence remain the most significant concerns. We introduce some controversies and highlight the developments in current surgical practice for the treatment of common anal problems.

Review article: Infliximab therapy for inflammatory bowel disease--seven years on

Infliximab, the chimeric monoclonal IgG1 antibody to tumour necrosis factor, is indicated for refractory luminal and fistulizing Crohn's disease and extra-intestinal manifestations of inflammatory bowel disease. Recently, the active ulcerative colitis trials (ACT) studies have shown that infliximab is also efficacious to treat ulcerative colitis resistant to standard therapy. Induction with 5 mg/kg infliximab at weeks 0, 2 and 6 is advocated. The response to infliximab is improved when concomitant immunosuppressive therapy is given. As the majority of patients will relapse if not retreated, a long-term strategy is necessary. Although episodic therapy can be used, the optimal strategy is systematic maintenance treatment with 5 mg/kg intravenous (i.v.) every 8 weeks. Long-term maintenance therapy with infliximab results in a reduction of the rate of complications, hospitalizations and surgeries associated with Crohn's disease. Safety problems with the monoclonal antibody infliximab treatment mainly concern the formation of antibodies to infliximab, which may lead to infusion reactions, loss of response and serum sickness-like delayed infusion reactions. Latent tuberculosis needs to be screened for. The rate of other opportunistic infections is slightly increased mainly in patients treated concomitantly with immunosuppression. There is no evidence that malignancy rates in patients treated with antitumour necrosis factor strategies are increased.

Biologic Therapy for Inflammatory Bowel Disease

Despite all of the advances in our understanding of the pathophysiology of inflammatory bowel disease (IBD), we still do not know its cause. Some of the most recently available data are discussed in this review; however, this field is changing rapidly and it is increasingly becoming accepted that immunogenetics play an important role in the predisposition, modulation and perpetuation of IBD. The role of intestinal milieu, and enteric flora in particular, appears to be of greater significance than previously thought. This complex interplay of genetic, microbial and environmental factors culminates in a sustained activation of the mucosal immune and non-immune response, probably facilitated by defects in the intestinal epithelial barrier and mucosal immune system, resulting in active inflammation and tissue destruction. Under normal situations, the intestinal mucosa is in a state of 'controlled' inflammation regulated by a delicate balance of proinflammatory (tumour necrosis factor [TNF]-alpha, interferon [IFN]-gamma, interleukin [IL]-1, IL-6, IL-12) and anti-inflammatory cytokines (IL-4, IL-10, IL-11). The mucosal immune system is the central effector of intestinal inflammation and injury, with cytokines playing a central role in modulating inflammation. Cytokines may, therefore, be a logical target for IBD therapy using specific cytokine inhibitors. Biotechnology agents targeted against TNF, leukocyte adhesion, T-helper cell (T(h))-1 polarisation, T-cell activation or nuclear factor (NF)-kappaB, and other miscellaneous therapies are being evaluated as potential therapies for IBD. In this context, infliximab is currently the only biologic agent approved for the treatment of inflammatory and fistulising Crohn's disease. Other anti-TNF biologic agents have emerged, including CDP 571, certolizumab pegol (CDP 870), etanercept, onercept and adalimumab. However, ongoing research continues to generate new biologic agents targeted at specific pathogenic mechanisms involved in the inflammatory process. Lymphocyte-endothelial interactions mediated by adhesion molecules are important in leukocyte migration and recruitment to sites of inflammation, and selective blockade of these adhesion molecules is a novel and promising strategy to treat Crohn's disease. Therapeutic agents that inhibit leukocyte trafficking include natalizumab, MLN-02 and alicaforsen (ISIS 2302). Other agents being investigated for the treatment of Crohn's disease include inhibitors of T-cell activation, peroxisome proliferator-activated receptors, proinflammatory cytokine receptors and T(h)1 polarisation, and growth hormone and growth factors. Agents being investigated for treatment of ulcerative colitis include many of those mentioned for Crohn's disease. More controlled clinical trials are currently being conducted, exploring the safety and efficacy of old and new biologic agents, and the search certainly will open new and exciting perspectives on the development of therapies for IBD.