Randomised controlled trial of azathioprine and 5-aminosalicylic acid for treatment of steroid dependent ulcerative colitis

Review article: interactions between genotype and response to therapy in inflammatory bowel diseases

BACKGROUND

More than half of the patients with inflammatory bowel diseases are candidates for immunosuppressive therapy. However, even the most effective drugs used in inflammatory bowel disease are only successful in about two-thirds of patients. Adverse events limit their use in a further substantial proportion of patients. Recent research has focussed on the possibility of predicting a drugs' efficacy and/or toxicity by identifying polymorphic variants in the genes encoding enzymes involved in metabolic pathways.

AIM

To highlight recent advances and limitations in the field of pharmacogenetics in inflammatory bowel disease.

RESULTS

Recent pharmacogenetic studies have mainly focussed on immunosuppressive agents including corticosteroids, azathioprine, methotrexate and infliximab. Several polymorphic genes encoding enzymes involved in the metabolism of these drugs have been identified including the inosine triphosphate pyrophosphatase in thiopurine therapy, the methylene tetrahydrofolate reductase in methotrexate therapy and polymorphisms in apoptosis genes in infliximab therapy. However, at the present time, genotyping for the variants of the thiopurine methyltransferase gene, an enzyme important for the metabolism of the thiopurine drugs, is the only useful test in clinical practice.

CONCLUSIONS

Although the field of pharmacogenetics in inflammatory bowel disease is promising most new targets have so far failed to translate into clinical practice. Future pharmaceutical trials should include pharmacogenetic research to test appropriate candidate genes in a prospective manner.

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.

Medical management of left-sided ulcerative colitis and ulcerative proctitis: critical evaluation of therapeutic trials

BACKGROUND

The goal of this work was to critically evaluate the published studies on the treatment of ulcerative proctitis (UP) and left-sided ulcerative colitis (L-UC). The results of this review provided the content for the accompanying treatment guidelines, Clinical Guidelines for the Medical Management of Left-sided Ulcerative Colitis and Ulcerative Proctitis: Summary Statement.

METHODS

All English language articles published between 1995 and September 2005 were identified through a comprehensive literature search using OVID and PubMed. The quality of the data supporting or rejecting the use of specific therapies was categorized by a data quality grading scale. An "A+" grade was assigned to treatment supported by multiple high-quality randomized controlled trials with consistent results, whereas a "D" grade was given to therapy supported only by expert opinion. The therapeutic efficacy of a treatment was defined by its success in treating UP and L-UC compared with placebo. A medication was ranked as "excellent" if it was specifically studied for UP and L-UC and had consistently positive results compared with placebo or another agent. Quality and efficacy scores were agreed on by author consensus.

RESULTS

For the acute treatment of UP or L-UC, the rectally administered corticosteroids and mesalazine (5-ASA), either alone or in combination with oral 5-ASAs, are the most effective therapy: evidence quality, A+; efficacy, excellent. Only rectally administered 5-ASA received an A+/excellent rating for maintenance of remission. Infliximab received an A+ grade for induction and maintenance of remission but only a "good" rating because the studies were performed in all UC, not specifically UP or L-UC.

CONCLUSIONS

This critical evaluation of treatment provides a "report card" on medications available for the management of patients with UP and L-UC. The guidelines should provide a useful reference and supplement for physicians treating UC patients.

Tacrolimus--finally!

Tacrolimus appears to be at least comparable to ciclosporin in refractory ulcerative colitis in terms of tolerability and efficacy but the oral route of administration and reliability of drug levels are advantageous

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.

The efficacy of corticosteroid therapy in inflammatory bowel disease: analysis of a 5-year UK inception cohort

BACKGROUND

Corticosteroids remain the mainstay of first-line therapy in active inflammatory bowel disease.

AIMS

To determine the clinical outcome after the first corticosteroid-therapy and to identify factors which predict response/failure.

METHODS

216 (136 ulcerative colitis and 80 Crohn's disease) patients were identified in this 5-year inception cohort. The outcomes of early (30 days) and late (1 year) responses were used. Multivariate analyses were performed to identify factors associated with outcome.

RESULTS

86 (63%) and 60 (75%) ulcerative colitis and Crohn's disease required corticosteroid therapy, respectively. In ulcerative colitis, at 30 days, 69 (51%), 42 (31%) and 25 (18%) patients demonstrated complete response, partial response and no response, respectively. For Crohn's disease, these outcomes were observed in 32 (40%), 28 (35%) and 20 (25%). After 1 year, 75 (55%), 23 (17%) and 29 (21%) patients with ulcerative colitis demonstrated prolonged response, corticosteroid-dependence or required surgery, respectively. For Crohn's disease, these outcomes were observed in 30 (38%), 19 (24%) and 27 (35%) patients. Extensive ulcerative colitis was a predictor of surgery (P = 0.001, OR: 15.2). In Crohn's disease, inflammatory disease behaviour was negatively associated with surgery (P = 0.02, OR: 0.13).

CONCLUSION

Although corticosteroids are effective, dependence/resistance remains common. Patients with extensive ulcerative colitis and fistulizing/stricturing Crohn's are most at risk of failing corticosteroid therapy.

Immunosuppressive drugs in ulcerative colitis: twisting facts to suit theories?

Immunosuppressive drugs have become a mainstay of therapy for the inflammatory bowel diseases. Although robust evidence exists in support of the use of these drugs in Crohn's disease, a close evaluation of the available data in ulcerative colitis reveals a much weaker evidence base. In particular, randomised controlled trials of azathioprine, the most commonly used immunosuppressive agent, do not provide rich evidence of efficacy whereas observational cohorts suggest this agent is effective, particularly in patients with relapsing disease who require corticosteroids. Ciclosporin is also effective in the most refractory cases but its efficacy needs to be carefully weighed against the possibility of rare but life threatening complications. Although the evidence base in support of immunosuppressive drugs in ulcerative colitis is not as strong as in Crohn's disease, these agents clearly have a role in the treatment of this disease.

Is thiopurine therapy in ulcerative colitis as effective as in Crohn's disease?

There is evidence in support of the use of azathioprine in steroid dependent ulcerative colitis patients, confirming the steroid sparing effect of azathioprine

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.