Infliximab efficacy in pediatric ulcerative colitis

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.

A retrospective analysis of the efficacy and safety of infliximab as rescue therapy in acute severe ulcerative colitis

BACKGROUND

Forty per cent of patients with acute severe ulcerative colitis will not respond to intravenous corticosteroids and require second-line medical therapy or colectomy. A recent controlled trial has suggested that infliximab may be effective as rescue therapy.

AIM

To assess the value of infliximab as rescue therapy for acute severe colitis in a retrospective cohort of ulcerative colitis patients in Scotland.

METHODS

All patients satisfied Truelove and Witts criteria on admission, failed to respond to intravenous corticosteroids and received infliximab (5 mg/kg) as rescue therapy. Response was defined as need for colectomy at hospital discharge and by 90 days.

RESULTS

A total of 39 patients (median age 31.7 years) were treated. 26/39 (66%) responded, avoiding colectomy during the acute admission, and were followed up for a median of 203 days (Interquartile range = 135.5-328.5). Hypoalbuminaemia was a consistent predictor of non-response on univariate and multivariate analysis. At day 3 of intravenous steroids, 9/18 (50.0%) with serum albumin <34 g/L had urgent colectomy vs. 1/13 (7.7%) >or=34 g/L (P = 0.02, OR = 12.0, C.I. 1.28-112.7). Two serious adverse events occurred - one death due to Pseudomonas pneumonia, and one post-operative fungal septicaemia.

CONCLUSIONS

Infliximab represents a moderately effective rescue therapy for patients with acute severe ulcerative colitis. Serious adverse events, including death, do occur and should be discussed with patients prior to therapy.

Infliximab use in children and adolescents with inflammatory bowel disease

Infliximab is a chimeric monoclonal antibody (75% human, 25% murine) against tumor necrosis factor-alpha, a cytokine with a central role in the pathogenesis of inflammatory bowel disease. Large randomized controlled trials have shown the efficacy and safety of infliximab for the induction and maintenance of remission in adult patients with active Crohn disease (CD). In children and adolescents, mostly small, nonrandomized, non-placebo-controlled studies have supported the notion that infliximab is a potent drug in a population that does not respond to standard therapies. The safety of infliximab is of major concern, and the most frequent severe adverse events are related to severe infections and reactivation of tuberculosis. Non-life-threatening infusion reactions occur rather frequently and seem to be related to the formation of antibodies. The indications for infliximab treatment are therapy-resistant luminal CD (no efficacy or insufficient efficacy of conventional treatment) and therapy-resistant fistulas. An efficient remission induction strategy consists of 3 initial infliximab infusions at 0, 2, and 6 weeks in a dosage of 5 mg/kg to sustain remission. Patients needing maintenance therapy are subsequently treated with an infliximab infusion every 8 weeks. There are indications that the early stages of CD may be more susceptible to immunomodulation, and the natural history of CD may be altered by the introduction of infliximab early in the disease process instead of waiting until conventional therapy has failed. Major points of discussion are whether infliximab maintenance treatment should be episodic (on demand) or scheduled and when infliximab therapy can be discontinued.

Challenges and progress in pediatric inflammatory bowel disease

PURPOSE OF REVIEW

The induction and maintenance of disease remission and prevention of complications are primary goals in the management of inflammatory bowel disease. Recent research has added new insights into the pathogenesis, epidemiology, and treatment options for children with inflammatory bowel disease, and the findings will enable clinicians to develop a more rational approach to the diagnosis and treatment of pediatric patients with ulcerative colitis and Crohn's disease.

RECENT FINDINGS

Population-based studies have confirmed the increased incidence of inflammatory bowel disease in children. Previous medical history and serologies can be predictive of complications in Crohn's disease. Newer radiological and capsule endoscopic modalities have a potential future role in the diagnosis and interval assessment of patients with inflammatory bowel disease. Biological therapies play an increasingly prominent role in the management of children with ulcerative colitis and Crohn's disease. Studies of children with inflammatory bowel disease suggest that behavioral interventions may have a positive impact on morbidity and overall quality of life.

SUMMARY

New information concerning the natural history of Crohn's disease and ulcerative colitis and a better understanding of different treatment modalities will enable the development of increasingly effective and individualized pharmacological treatment plans for children with inflammatory bowel disease.

The role of TNFalpha in ulcerative colitis

Standard of care for ulcerative colitis involves long-term pharmacotherapy or colectomy. Approximately 20% to 30% of patients eventually require a colectomy because patients either do not respond or cannot tolerate the currently available pharmacotherapies. Advances in our knowledge of the pathophysiology of ulcerative colitis have highlighted the importance of cytokines such as tumor necrosis factor alpha (TNFalpha) in the inflammatory process. TNFalpha is a proinflammatory mediator that plays an integral role in the pathogenesis of inflammatory bowel disease. In addition, mounting evidence indicates a genetic association between TNFalpha and ulcerative colitis. Furthermore, increased TNFalpha levels have been demonstrated in studies of patients with ulcerative colitis. TNFalpha is likely an important component in the pathophysiology of ulcerative colitis, and thus agents targeting TNFalpha in ulcerative colitis have been studied. Recent randomized controlled trials have confirmed that biologic anti-TNFalpha therapy is effective in ulcerative colitis. Soluble TNFalpha receptors or biologic agents that suppress or inhibit TNFalpha production may also show therapeutic promise.

Short- and long-term response to and weaning from infliximab therapy in pediatric ulcerative colitis

OBJECTIVES

We evaluated the response to infliximab in pediatric patients with ulcerative colitis (UC) and their long-term follow-up. We expanded our previous study of 14 patients and furthermore evaluated the success of weaning patients from infliximab.

PATIENTS AND METHODS

We reviewed the charts of 27 pediatric patients with UC who were treated with infliximab instead of undergoing a colectomy. Patients with new-onset UC refractory to intravenous steroids for 5 to 10 days and patients with non-steroid-dependent UC with an acute exacerbation were classified as acutely ill (n = 16); patients with chronic steroid-dependent UC were classified as chronically ill (n = 11). The Lichtiger Colitis Activity Index (LCAI) was measured for all patients at baseline and at 1 and 2 months after treatment with infliximab was initiated. Patients were regarded as successfully treated if they remained off steroids and avoided colectomy.

RESULTS

The acutely ill group had a mean LCAI score of 11.4 at induction and 0.3 after 2 months. The chronically ill group had a mean LCAI score of 11.2 at induction and 5.5 after 2 months. Treatment with infliximab was successful in 75% of acutely ill patients and in 27% of chronically ill patients. Infliximab was discontinued in 80% of successfully treated patients (83% of acutely ill, 67% of chronically ill). These patients had an average of 10 infusions and a mean follow-up time of 10 months from their last infliximab infusion.

CONCLUSIONS

Our results suggest that infliximab is more effective in acutely ill UC patients than in patients with chronic steroid-dependent UC. In addition, some patients treated with infliximab can be weaned from infliximab and maintain remission.

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.

Update in the treatment of paediatric ulcerative colitis

Ulcerative colitis is an important disease in the paediatric population. Ulcerative colitis is one of the chronic inflammatory bowel diseases, and is medically incurable. However, the arsenal of medications has grown as knowledge of the pathogenesis of this disease advances. This review looks at the classical treatments for children with ulcerative colitis, including the 5-aminosalicylates, corticosteroids and imunomodulators, as well as biological therapy and other, newer modalities.

Contemporary morphologic definition of backwash ileitis in ulcerative colitis and features that distinguish it from Crohn disease

Terminal ileum (TI) sections from 250 ulcerative colitis (UC) total colectomy specimens resected during 3 periods and endoscopic TI biopsy specimens from 100 contemporary chronic UC and 100 Crohn disease (CD) patients were reviewed. The respective proportions of cases resected during the 3 periods with moderately or markedly active cecal UC were 72%, 34%, and 2% and with moderate or marked backwash ileitis (BWI), 21%, 18%, and 0%. The activity level of BWI correlated with level of cecal UC. In contemporary initial endoscopic TI biopsy specimens, 6% of chronic UC patients had BWI, all with moderately to markedly active cecal chronic UC. In CD cases, 75% had chronic or active enteritis, consisting of patchy lamina propria edema containing mildly active inflammation, crypt disarray, and focally blunted or flattened villi. Mucous gland metaplasia was present in 27% of CD biopsy specimens. BWI should be restricted to active enteritis that involves the ileum in a contiguous pattern from the cecum that has a similar or greater degree of active inflammation. Mild BWI predominantly involves the superficial mucosa in a contiguous pattern. Focal isolated ileal erosions, mucous gland metaplasia, or patchy edema with mild active inflammation are features of CD.

Pediatric inflammatory bowel disease

Inflammatory bowel disease is an important cause of gastrointestinal pathology in children and adolescents. The incidence of pediatric inflammatory bowel disease is increasing; therefore, it is important for the clinician to be aware of the presentation of this disease in the pediatric population. Laboratory tests, radiology studies, and endoscopic procedures are helpful in diagnosing inflammatory bowel disease and differentiating between Crohn’s disease and ulcerative colitis. Once diagnosed, the goal of medical management is to induce remission of disease while minimizing the side effects of the medication. Specific attention needs to be paid to achieving normal growth in this susceptible population. Surgical management is usually indicated for failure of medical management, complication, or malignancy. Algorithms for diagnostic evaluation and treatment of pediatric inflammatory bowel disease are presented. The specific psychosocial issues facing these patients are also discussed in this review as are the future goals of research in the complex problem of pediatric inflammatory bowel disease.

Infliximab and ulcerative colitis

Tumour necrosis factor (TNF)-alpha is an inflammatory cytokine that plays a main role in the inflammatory process underlying inflammatory bowel disease (IBD). Despite the fact that the cytokine profiles associated with ulcerative colitis (UC) and Crohn's disease (CD) are classically considered different (a Th2 pattern in UC and a Th1 pattern in CD), there are several evidences in vitro and in vivo that TNF-alpha has an important role in UC. For this reason, infliximab, the chimeric monoclonal antibody to TNF-alpha, has been evaluated in the therapy of UC. The drug has been evaluated in different clinical settings both in adults and in children: in moderate-severe steroid-dependent UC, in severe refractory UC as rescue therapy, in active non-steroid-refractory UC, in resistant pouchitis and in maintenance of moderate-severe UC responsive to infliximab. On the basis of the randomised controlled trials (RCTs), it is possible to draw the following conclusions for adults: infliximab seems active in severe steroid-refractory UC, allowing colectomy to be spared even if further controlled trials are needed with a larger sample of patients adopting strict and well-defined inclusion criteria. The drug seems active in inducing remission after 8 weeks in steroid-refractory patients, in patients taking steroids (even if it is not clear at which dosage of steroid dependence the drug is more active) and also in patients failing aminosalicylates therapy. The long-term response of infliximab in comparison to placebo in these subgroups of patients is not clinically impressive even if it is statistically significant. Further trials are warranted in order to establish the role of infliximab in steroid-dependent UC (defined with clear criteria), in maintaining remission after severe UC, in non-steroid-dependent moderate-severe UC and in refractory pouchitis. For children it is not possible to draw the same conclusions, due to a lack of RCTs, despite the encouraging data coming from open studies, mainly in steroid-refractory UC.

Defects in mucosal immunity leading to ulcerative colitis

Evidence accumulated over the last decade demonstrates that what we call 'ulcerative colitis' is actually a heterogeneous group of diseases resulting from different pathogenic mechanisms with a common symptomatic expression. Subgroups of patients with ulcerative colitis can be stratified by presence or absence of serum autoantibodies, which are thought not to be pathogenic but to mark for a distinct disease phenotype. In recent years, animal-based experimental systems have emerged that reflect human ulcerative colitis and have potential to accelerate our understanding of its pathogenesis. Genetic and immunological data from human studies in combination with results from animal model systems are the foundation of a hypothesis, which includes a role for microbial antigen exposure in the initiation, perpetuation, and amplification of the disease. In ulcerative colitis, it appears as though the T-cell response to the antigens is not T-helper (Th) 1 dominant as in the case of Crohn's disease but rather is either Th2 [interleukin (IL)-4, IL-13] or is mediated by specialized cells such as natural killer (NK) T cells (IL-13). Lamina propria T cells from ulcerative colitis patients produce significantly greater amounts of IL-13. Ulcerative colitis is associated with an atypical Th2 response mediated by a distinct subset of NK T cells that produce IL-13 and are cytotoxic for epithelial cells. The way in which this response affects the ultimate cascade of inflammatory events has yet to be determined.