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

The effect of infliximab on circulating levels of leptin, adiponectin and resistin in patients with inflammatory bowel disease

BACKGROUND

Tumour necrosis factor alpha is a critical mediator of inflammation-related altered metabolism in inflammatory bowel disease (IBD), possibly through its interaction with adipokines, which play an important role in IBD. Infliximab is a well established antitumour necrosis factor alpha treatment in IBD.

AIM AND METHODS

We studied serum levels of leptin, adiponectin and resistin in 20 IBD patients before and after infliximab treatment using commercially available enzyme-linked immunosorbent assays. The results were correlated with alterations of disease activity, BMI and C-reactive protein.

RESULTS

Infliximab induced clinical response or remission in 18 out of 20 treated IBD patients. Mean serum-leptin levels were 4.6+/-0.5 and 5.1+/-0.5 ng/ml (P=0.41), mean serum-adiponectin levels were 10513.9+/-1216.9 and 9653.5+/-1031.5 ng/ml (P=0.36) and mean serum-resistin levels were 26.3+/-4.1 and 13.9+/-1.4 ng/ml (P=0.004), before and after infliximab treatment, respectively. No significant correlation between the changes of BMI, C-reactive protein or the clinical indices of activity and alterations of the examined adipokines was found.

CONCLUSIONS

Serum levels of leptin and adiponectin had no significant alterations, whereas serum-resistin levels are significantly decreased after infliximab therapy in IBD patients, suggesting a possible proinflammatory status for resistin in IBD and a role as a marker of successful therapy.

Infliximab in paediatric inflammatory bowel disease

Infliximab has been widely used in paediatric Crohn's disease, mainly in luminal and fistulous disease refractory to standard treatment and for extraintestinal manifestations. Moreover, there is growing experience with its use in refractory ulcerative colitis. Infliximab has shown similar efficacy and safety in children as in adult population. It is postulated that its early use in paediatric inflammatory bowel disease, as a bridging treatment until the onset of action of other immunomodulators, could reduce the use of steroids and change the natural history of the disease as well. The effect of infliximab on mucosal healing could also contribute to the normal growth and sexual maturation in these patients.

Review article: Reproduction in the patient with inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) affects mainly the young population. The effect of IBD and its treatment on fertility and pregnancy is therefore an important clinical consideration.

AIM

To review the best management of IBD in the reproductive and pregnant population.

METHODS

A MEDLINE and an EMBASE search were performed using mainly the search phrases 'pregnancy AND IBD,''sulphasalazine AND male fertility,''abdominal surgery AND female fertility,''AZA AND placenta' and 'infliximab AND pregnancy.' No language or date restrictions were placed. References of review articles were examined.

RESULTS

Overall male and female fertility are not affected by IBD. Sulphasalzine reduces male fertility. No other drugs used in IBD affect significantly fertility in humans. The risk of pregnancy-related complications and the disease behaviour during pregnancy depends mainly on disease activity at time of conception. Proactive treatment for maintenance of disease remission during gestation is recommended. Except for methotrexate, drugs used in IBD appear safe in pregnancy. Breast feeding should be encouraged.

CONCLUSION

The management of IBD in the young and pregnant population remains controversial because the literature comes mostly from retrospective studies. Further studies particularly large prospective trials are needed to guide clinicians in decision making.

Estado actual del tratamiento de la enfermedad inflamatoria intestinal

Treatment of inflammatory bowel disease should take some general considerations into account, standing out among them the importance of nutrition, antithrombotic prophylaxis in certain situations, prevention of osteoporosis and prevention of colorectal cancer by endoscopic screening in extensive ulcerous colitis or Crohn's colitis. Ulcerous colitis is still effectively treated with salicylates and steroids in its mild and moderate forms. Severe forms require parenteral steroids, cyclosporine or infliximab, and these are successfully used with immunosuppressants (azathioprine or mercaptopurine) in steroid dependence. Maintenance with salicylates, that should be adequately complied with, is an important point. Crohn's disease is treated with steroids in its mild and moderate forms, and again in corticodependent ones with immunosuppressants, which we are using increasingly sooner. Refractory forms or fistulous forms benefit from the use of biological treatments (infliximab) generally accompanied by immunosuppressants.

The alpha7 nicotinic acetylcholine receptor as a pharmacological target for inflammation

The physiological regulation of the immune system encompasses comprehensive anti-inflammatory mechanisms that can be harnessed for the treatment of infectious and inflammatory disorders. Recent studies indicate that the vagal nerve, involved in control of heart rate, hormone secretion and gastrointestinal motility, is also an immunomodulator. In experimental models of inflammatory diseases, vagal nerve stimulation attenuates the production of proinflammatory cytokines and inhibits the inflammatory process. Acetylcholine, the principal neurotransmitter of the vagal nerve, controls immune cell functions via the alpha7 nicotinic acetylcholine receptor (alpha7nAChR). From a pharmacological perspective, nicotinic agonists are more efficient than acetylcholine at inhibiting the inflammatory signaling and the production of proinflammatory cytokines. This 'nicotinic anti-inflammatory pathway' may have clinical implications as treatment with nicotinic agonists can modulate the production of proinflammatory cytokines from immune cells. Nicotine has been tested in clinical trials as a treatment for inflammatory diseases such as ulcerative colitis, but the therapeutic potential of this mechanism is limited by the collateral toxicity of nicotine. Here, we review the recent advances that support the design of more specific receptor-selective nicotinic agonists that have anti-inflammatory effects while eluding its collateral toxicity.

Management of inflammatory bowel disease in adults

Optimal care of the inflammatory bowel diseases, Crohn's disease and ulcerative colitis, requires a broad understanding of disease pathophysiology and therapeutic alternatives. The goals of therapy are accurate diagnosis and timely treatment to both induce and maintain a clinical remission and improve patient quality of life. Most patients can be adequately treated using a combination or aminosalicylates, antibiotics, and corticosteroids, though many patients with Crohn's disease will require immunomodulators, such as azathioprine or 6-mercaptopurine. The development of novel biologic therapies, particularly infliximab, have dramatically improved our ability to medically manage more severe Crohn's disease and ulcerative colitis patients. This review will focus on the medical management of inflammatory bowel disease in adults.

Fibrogenesis in Crohn's disease

INTRODUCTION

Over one-third of patients with Crohn's disease (CD) will develop an intestinal stricture and the great majority of these will require at least one surgical procedure. While the pathogenesis of inflammation in CD has been extensively investigated, knowledge of stricture pathogenesis remains limited. The aim of this review is to discuss the current understanding of fibrogenesis in CD and to outline potential directions in research and therapeutics.

METHODS

The electronic literature (January 1966 to May 2006) on CD-associated fibrosis was reviewed. Further references were obtained by cross-referencing from key articles.

RESULTS

CD-associated fibrosis results from chronic transmural inflammation and a complex interplay among intestinal mesenchymal cells, cytokines, and local inflammatory cells. The fibroblast is the key cell type mediating stricture formation. The cytoarchitecure of the bowel wall is altered with disruption of the muscularis mucosa, thickening of the muscularis propria, and deposition of collagen throughout. The cytokine TGF-beta appears critical in this process, acting to increase growth factor and extracellular matrix (ECM) production and dysregulate ECM turnover. Potential therapeutic interventions are likely to concentrate on modulating down-stream targets of TGF-beta.

CONCLUSIONS

Greater understanding of the biology of fibrostenosis is likely to yield significant advances in our ability to care for patients with stricturing CD. Potential dividends of this approach include identification of novel therapeutic targets and biomarkers useful for prognostication and therapeutic monitoring.

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.

Modulation by heme and zinc protoporphyrin of colonic heme oxygenase-1 and experimental inflammatory bowel disease in the rat

Reactive oxygen species, suggested to be involved in inflammatory bowel disease, may be modulated by endogenous anti-oxidant products of heme oxygenase-1 (HO-1). In the present work, HO-1 expression in trinitrobenzene sulphonic acid (TNBS)-induced colitis in the rat and the effects of HO-1 modulation, particularly by the HO-1 inducer, heme, were further evaluated. Colitis was induced by intracolonic challenge with TNBS and assessed macroscopically and by myeloperoxidase (MPO) assay. Heme oxygenase activity was determined by measurement of bilirubin formation and HO-1 protein expression was determined by Western blotting. TNBS challenge led to an early and substantial induction of HO-1 protein expression and heme oxygenase activity in the colon that peaked after 48-72 h and declined over 10 days. Heme (30 micromol/kg/day, s.c) increased colonic HO-1 protein expression and enzyme activity and decreased colonic damage and myeloperoxidase activity. Short-term administration of cadmium chloride (2 mg/kg, s.c.), another known HO-1 inducer, also reduced the colonic injury and myeloperoxidase levels. In contrast, the HO-1 inhibitor, zinc protoporphyrin (50 micromol/kg/day, s.c) significantly increased the colonic damage and myeloperoxidase activity over 10 days, as did tin protoporphyrin (30 micromol/kg/day, s.c). These results support the proposal that induction of HO-1 provides a protective mechanism in this model under both acute and more-chronic conditions, and that its selective up-regulation could thus be of therapeutic potential in colitis.

Infliximab Therapy in Children and Adolescents with Inflammatory Bowel Disease

This review summarises the present knowledge of infliximab therapy in children with inflammatory bowel disease (IBD) based on the available published literature. Infliximab, the chimeric monoclonal IgG(1) antibody to tumour necrosis factor-alpha, is indicated for medically refractory luminal and fistulising paediatric Crohn's disease. Recently, ulcerative colitis case series in children and adolescents suggested that infliximab might also be effective for treatment of ulcerative colitis resistant to standard medical therapy. Induction therapy with infliximab 5 mg/kg at weeks 0, 2 and 6 is routinely used. Since the majority of patients will relapse if not re-treated, a long-term approach with systematic re-treatment with 5 mg/kg every 8-12 weeks is recommended. Maintenance therapy every 8 weeks was superior to 12 weeks' administration in maintaining response and remission in the largest-to-date paediatric randomised trial. Concomitant immunosuppressive therapy reduces the risk of infliximab antibody formation and infusion reactions, and prolongs the duration of treatment success. Severe reactions may not be an absolute contraindication to future infliximab therapy. Premedication does not prevent the development of infusion reactions; however, it is indicated for prevention of subsequent infusion reactions. Adverse events and safety findings in children are comparable to those observed in adults. Latent tuberculosis needs to be screened for. Malignancy rates in paediatric patients treated with infliximab do not seem to be increased. However, newly reported cases of hepatosplenic T-cell lymphoma in young patients with IBD treated with infliximab and mercaptopurine therapy raise concern, and long-term follow-up studies are necessary to determine the true malignancy risk.

Systematic review: Infliximab therapy in ulcerative colitis

AIM

To perform a systematic review and meta-analysis on the efficacy and tolerance of infliximab in ulcerative colitis.

SELECTION OF STUDIES

evaluating efficacy of infliximab in ulcerative colitis. For the meta-analysis, randomized clinical trials comparing infliximab vs. placebo/steroids.

SEARCH STRATEGY

electronic and manual. Study quality: independently assessed by two reviewers.

DATA SYNTHESIS

meta-analysis combining the odds ratios (OR).

RESULTS

Thirty-four studies (896 patients) evaluated infliximab therapy in UC, with heterogeneous results. Mean short-term (2.3 weeks) response and remission with infliximab was 68% (95% CI 65-71%) and 40% (36-44%). Mean long-term (8.9 months) response and remission was 53% (49-56%) and 39% (35-42%). Five randomized double-blind studies compared infliximab with placebo, the meta-analysis showing an advantage (P < 0.001) of infliximab in all endpoints (short-/long-term response/remission): ORs from 2.7 to 4.6, and number-needed-to-treat (NNT) from 3 to 5. Similar infliximab response was calculated independently of the indication (steroid-refractory/non-steroid-refractory) or the dose (5/10 mg/kg). Adverse effects were reported in 83% and 75% of the infliximab and placebo-treated patients (OR = 1.52; 95% CI 1.03-2.24; number-needed-to-harm (NNH) was 14).

CONCLUSION

Infliximab is more effective than placebo, with an NNT from 3 to 5, for the treatment of moderate-to-severe UC, achieving clinical remission in 40% of the patients at approximately 9 months of follow-up. Further studies are necessary to confirm the long-term efficacy of infliximab in ulcerative colitis.

The role of anti-tumor necrosis factor-alpha therapy in Pyoderma gangrenosum associated with inflammatory bowel disease

Pyoderma gangrenosum (PG) is an ulcerative neutrophilic dermatosis seen in 1-5% of patients with inflammatory bowel disease (IBD). The pathogenesis of PG remains unclear, but may be related to abnormal T-cell responses and production of tumor necrosis factor (TNF)-alpha, a powerful proinflammatory cytokine. Although their use is not supported by appropriately controlled trials, corticosteroids and systemic immunosuppressants are the classical cornerstones of treatment of PG, against which they have a nonspecific effect. Successful curative or symptomatic treatment of associated disorders may lead to an improvement in PG. A new era for the management of chronic inflammatory disease began with the advent of biotherapies and particularly anti-TNFalpha therapy, which allows for a specific intervention in the immune cascade. Anti-TNFalpha therapy has improved and broadened the therapeutic options for IBD and, therefore, has brought new perspectives to management of the extra-intestinal manifestations of this disorder, including PG. To date, infliximab, etanercept, and adalimumab have been used in the treatment of PG. Published data have demonstrated that infliximab is highly effective in the treatment of PG, whether associated with IBD or not. This treatment is generally well tolerated, even as long-term therapy. However, rare and serious complications have been reported. Although infliximab is a costly drug, its use should be considered for patients with PG and particularly with corticosteroid-refractory PG associated with IBD. Additional comparative long-term studies are needed to determine the long-term efficacy and safety of anti-TNFalpha therapy and define its role in the management of PG, with or without accompanying IBD.

Infliximab in ulcerative colitis

Infliximab is effective for treatment of moderate-to-severe UC and is recommended for patients who have had an inadequate response to medical therapy or who are intolerant of or do not desire to take the potential risk of using specific agents including immunomodulators (cyclosporine A, azathioprine, or 6-mercaptopurine), corticosteroids, and, potentially, mesalamine. Future trials are needed to assess the efficacy of infliximab with immunomodulators to see if additional benefit is achieved so that the risk-benefit ratio is positive. Based on the favorable efficacy of infliximab for UC therapy, the ground work has been established for evaluating infliximab and addressing some of the many unanswered questions and also for assessing other anti-TNF agents and streamlining the anti-TNG antibody to improve efficacy, reduce side effects, and ease administration.

Drug therapy of inflammatory bowel disease in fertile women

Inflammatory bowel disease (IBD) is a disease that affects women of childbearing age. Active disease at conception increases the risk for adverse outcomes and thus postponement of pregnancy until the disease is in remission is the best advice that physicians can give their IBD patients. The majority of medications used to treat IBD are safe in pregnancy and breastfeeding; active, untreated, or undertreated disease is more deleterious than active therapy.

Quality of life after proctocolectomy with ileoanal anastomosis for patients with ulcerative colitis

Ulcerative colitis, a chronic inflammatory disease of the rectal and colonic mucosa, affects approximately 250,000 to 500,000 people in the United States, with 30% to 40% of patients requiring some form of surgical intervention during the course of their disease. The predominant reason for total proctocolectomy is for symptoms refractory to currently available medical therapy. Less common reasons are dysplasia or cancer. The goal of colectomy is to prevent recurrence of systemic inflammatory disease. Consequently, surgery with total proctocolectomy and creation of an ileal J-pouch-anal anastomosis has become the procedure of choice for many patients without other therapeutic options. Health-related quality of life (QOL) in patients with severe ulcerative colitis is so poor that, after ileal J-pouch-anal anastomosis, QOL is considered to improve in most clinical studies (8 studies, improved QOL; 1 study, no change; 1 study, QOL worse than general population). However, QOL and bowel function after such surgery cannot be considered "normal" in all patients, because a substantial number still have problems with urgency, leakage, nocturnal soiling, sexual dysfunction, and pouchitis, and some require conversion to a permanent ileostomy after ileal J-pouch-anal anastomosis failure. Thus, despite the availability of ileal J-pouch-anal anastomosis, surgery does not always restore all aspects of QOL to normal.

Reactive hemophagocytic syndrome complicating the treatment of inflammatory bowel disease

BACKGROUND AND AIMS

Reactive hemophagocytic syndrome (RHS) is a rare disease in which inappropriately activated macrophages consume bone marrow-derived cells. Most cases are associated with infection in the setting of immunodeficiency. The widespread use of immunosuppressive therapy in the treatment of inflammatory bowel disease (IBD) places patients with Crohn's disease and ulcerative colitis at risk of this complication. No concerted effort has been made to alert gastroenterologists of this condition, and treatment recommendations are lacking. The aims of this study were to describe the clinical and laboratory features of RHS associated with IBD and to review diagnostic criteria, treatment options, and pathogenesis.

MATERIALS AND METHODS

Clinical and laboratory data were pooled from the clinical practice of the investigators and from published cases. Descriptive statistics were performed.

RESULTS AND CONCLUSIONS

Seven cases of RHS complicating the treatment of IBD were identified. All patients were on immunosuppressive therapy, with nearly half taking >1 agent. All patients presented with fever, leukopenia, anemia, and hyperferritinemia. Infection by a member of the herpesvirus family or an intracellular pathogen precipitated RHS in 6 of 7 patients. The mortality rate was 29%. The diagnosis of RHS should be considered in patients with IBD taking immunosuppressive therapy who present with fever and cytopenia. Evaluation should begin with a serum ferritin. In patients with a serum ferritin > or =10,000 ng/mL, a bone marrow biopsy should be performed to confirm hemophagocytosis. If the initial evaluation is negative, then clinical suspicion should be maintained until the episode resolves.