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The Asia-Pacific Working Group on Inflammatory Bowel Disease was established in Cebu, Philippines, under the auspices of the Asia-Pacific Association of Gastroenterology with the goal of improving inflammatory bowel disease care in Asia. This consensus is carried out in collaboration with Asian Organization for Crohn's and Colitis. With biologic agents and biosimilars becoming more established, it is necessary to conduct a review on existing literature and establish a consensus on when and how to introduce biologic agents and biosimilars in conjunction with conventional treatments for ulcerative colitis and Crohn's disease in Asia. These statements also address how pharmacogenetics influences the treatments of ulcerative colitis and Crohn's disease and provides guidance on response monitoring and strategies to restore loss of response. Finally, the review includes statements on how to manage treatment alongside possible hepatitis B and tuberculosis infections, both common in Asia. These statements have been prepared and voted upon by members of inflammatory bowel disease workgroup employing the modified Delphi process. These statements do not intend to be all-encompassing, and future revisions are likely as new data continue to emerge., (© 2019 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.)

Background: Randomized trials investigating the efficacy of aminosalicylates for the treatment of mildly to moderately active Crohn's disease have yielded conflicting results. A systematic review was conducted to critically examine current available data on the efficacy of sulfasalazine and mesalamine for inducing remission or clinical response in these patients., Objectives: To evaluate the efficacy of aminosalicylates compared to placebo, corticosteroids, and other aminosalicylates (alone or in combination with corticosteroids) for the treatment of mildly to moderately active Crohn's disease., Search Methods: We searched PubMed, EMBASE, MEDLINE and the Cochrane Central Library from inception to June 2015 to identify relevant studies. There were no language restrictions. We also searched reference lists from potentially relevant papers and review articles, as well as proceedings from annual meetings (1991-2015) of the American Gastroenterological Association and American College of Gastroenterology., Selection Criteria: Randomized controlled trials that evaluated the efficacy of sulfasalazine or mesalamine in the treatment of mildly to moderately active Crohn's disease compared to placebo, corticosteroids, and other aminosalicylates (alone or in combination with corticosteroids) were included., Data Collection and Analysis: Data extraction and assessment of methodological quality was independently performed by the investigators and any disagreement was resolved by discussion and consensus. We assessed methodological quality using the Cochrane risk of bias tool. The overall quality of the evidence supporting the outcomes was evaluated using the GRADE criteria. The primary outcome measure was a well defined clinical endpoint of induction of remission or response to treatment. Secondary outcomes included mean Crohn's disease activity index (CDAI) scores, adverse events, serious adverse events and withdrawal due to adverse events. For dichotomous outcomes we calculated the pooled risk ratio (RR) and corresponding 95% confidence interval (CI) using a random-effects model. For continuous outcomes we calculated the mean difference (MD) and 95% CI using a random-effects model. Sensitivity analyses based on a fixed-effect model and duration of therapy were conducted where appropriate., Main Results: Twenty studies (2367 patients) were included. Two studies were judged to be at high risk of bias due to lack of blinding. Eight studies were judged to be at high risk of bias due to incomplete outcomes data (high drop-out rates) and potential selective reporting. The other 10 studies were judged to be at low risk of bias. A non-significant trend in favour of sulfasalazine over placebo for inducing remission was observed, with benefit confined mainly to patients with Crohn's colitis. Forty-five per cent (63/141) of sulfasalazine patients entered remission at 17-18 weeks compared to 29% (43/148) of placebo patients (RR 1.38, 95% CI 1.00 to 1.89, 2 studies). A GRADE analysis rated the overall quality of the evidence supporting this outcome as moderate due to sparse data (106 events). There was no difference between sulfasalazine and placebo in adverse event outcomes. Sulfasalazine was significantly less effective than corticosteroids and inferior to combination therapy with corticosteroids (RR 0.64, 95% CI 0.47 to 0.86, 1 study, 110 patients). Forty-three per cent (55/128) of sulfasalazine patients entered remission at 17 to 18 weeks compared to 60% (79/132) of corticosteroid patients (RR 0.68, 95% CI 0.51 to 0.91; 2 studies, 260 patients). A GRADE analysis rated the overall quality of the evidence supporting this outcome as moderate due to sparse data (134 events). Sulfasalazine patients experienced significantly fewer adverse events than corticosteroid patients (RR 0.43, 95% CI 0.22 to 0.82; 1 study, 159 patients). There was no difference between sulfasalazine and corticosteroids in serious adverse events or withdrawal due to adverse events. Olsalazine was less effective than placebo in a single trial (RR 0.36, 95% CI 0.18 to 0.71; 91 patients). Low dose mesalamine (1 to 2 g/day) was not superior to placebo for induction of remission. Twenty-three per cent (43/185) of low dose mesalamine patients entered remission at week 6 compared to 15% (18/117) of placebo patients (RR = 1.46, 95% CI 0.89 to 2.40; n = 302). A GRADE analysis indicated that the overall quality of the evidence supporting this outcome was low due to risk of bias (incomplete outcome data) and sparse data (61 events). There was no difference between low dose mesalamine and placebo in the proportion of patients who had adverse events (RR 1.33, 95% CI 0.91 to 1.96; 3 studies, 342 patients) or withdrew due to adverse events (RR 1.21, 95% CI 0.75 to 1.95; 3 studies, 342 patients). High dose controlled-release mesalamine (4 g/day) was not superior to placebo, inducing a clinically non significant reduction in CDAI (MD -19.8 points, 95% CI -46.2 to 6.7; 3 studies, 615 patients), and was also inferior to budesonide (RR 0.56, 95% CI 0.40 to 0.78; 1 study, 182 patients, GRADE = low). While high dose delayed-release mesalamine (3 to 4.5 g/day) was not superior to placebo for induction of remission (RR 2.02, 95% CI 0.75 to 5.45; 1 study, 38 patients, GRADE = very low), no significant difference in efficacy was found when compared to conventional corticosteroids (RR 1.04, 95% CI 0.79 to 1.36; 3 studies, 178 patients, GRADE = moderate) or budesonide (RR 0.89, 95% CI 0.76 to 1.05; 1 study, 307 patients, GRADE = moderate). However, these trials were limited by risk of bias (incomplete outcome data) and sparse data (small numbers of events). There was a lack of good quality clinical trials comparing sulfasalazine with other mesalamine formulations. Adverse events that were commonly reported included headache, nausea, vomiting, abdominal pain and diarrhea., Authors' Conclusions: Sulfasalazine is only modestly effective with a trend towards benefit over placebo and is inferior to corticosteroids for the treatment of mildly to moderately active Crohn's disease. Olsalazine and low dose mesalamine (1 to 2 g/day) are not superior to placebo. High dose mesalamine (3.2 to 4 g/day) is not more effective than placebo for inducing response or remission. However, trials assessing the efficacy of high dose mesalamine (4 to 4.5 g/day) compared to budesonide yielded conflicting results and firm conclusions cannot be made. Future large randomized controlled trials are needed to provide definitive evidence on the efficacy of aminosalicylates in active Crohn's disease.

The Asia Pacific Working Group on Inflammatory Bowel Disease was established in Cebu, Philippines, at the Asia Pacific Digestive Week conference in 2006 under the auspices of the Asian Pacific Association of Gastroenterology (APAGE) with the goal of developing best management practices, coordinating research and raising awareness of IBD in the region. The consensus group previously published recommendations for the diagnosis and management of ulcerative colitis (UC) with specific relevance to the Asia-Pacific region. The present consensus statements were developed following a similar process to address the epidemiology, diagnosis and management of Crohn's disease (CD). The goals of these statements are to pool the pertinent literature specifically highlighting relevant data and conditions in the Asia-Pacific region relating to the economy, health systems, background infectious diseases, differential diagnoses and treatment availability. It does not intend to be all-comprehensive and future revisions are likely to be required in this ever-changing field., (© 2015 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.)

Inflammatory bowel disease (IBD) was previously thought to be rare in Asia, but emerging data indicate rising incidence and prevalence of IBD in the region. The Asia Pacific Working Group on Inflammatory Bowel Disease was established in Cebu, Philippines, at the Asia Pacific Digestive Week conference in 2006 under the auspices of the Asian Pacific Association of Gastroenterology with the goal of developing best management practices, coordinating research, and raising awareness of IBD in the region. The consensus group previously published recommendations for the diagnosis and management of ulcerative colitis with specific relevance to the Asia-Pacific region. The present consensus statements were developed following a similar process to address the epidemiology, diagnosis, and management of Crohn's disease. The goals of these statements are to pool the pertinent literature specifically highlighting relevant data and conditions in the Asia-Pacific region relating to the economy, health systems, background infectious diseases, differential diagnoses, and treatment availability. It does not intend to be all comprehensive and future revisions are likely to be required in this ever-changing field., (© 2015 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.)

Background: Crohn's disease (CD) is increasing in incidence and prevalence in Asia, but there is a paucity of population-based studies on risk factors for surgery in Asian patients with CD. This will be useful to identify patients who may benefit from top-down treatment. This study describes the rates of abdominal surgery and identifies associated risk factors in Singaporean patients with CD., Methods: This was a retrospective observational study. The medical records of Singaporeans diagnosed with CD from 1970 to 2013 were reviewed from 8 different hospitals in Singapore. The cumulative probability of CD-related abdominal surgery was estimated using the Kaplan-Meier method. The logistic regression model was used to assess associations between independent risk factors and surgery., Results: The cohort of 430 Singaporean patients with CD included 63.5% Chinese, 11.9% Malay, and 24.7% Indians, with a male to female ratio of 1.6; median follow-up was 7.3 years (range, 2.9-13.0 yr) and median age at diagnosis 30.5 years (range, 19.5-43.7 yr). One hundred twelve patients (26.0%) required major abdominal surgery: the cumulative risk of surgery was 14.9% at 90 days, 21.2% at 5 years, 28.8% at 10 years, 38.3% at 20 years, and 50.6% at 30 years from diagnosis. Of the surgical patients, 75.0% were Chinese, 10.7% Malays, and 14.3% Indians; 21.4% underwent surgery for inflammatory disease, 40.2% for stricturing disease, and 38.4% for penetrating disease. Age at diagnosis (A2 17-40 yr, OR: 2.75, 95% confidence interval [CI], 1.14-7.76), ileal disease (L1 location, OR: 2.35, 95% CI, 1.14-5.0), stricturing (B2 OR: 6.09, 95% CI, 3.20-11.8), and penetrating behavior (B3 OR: 21.6, 95% CI, 9.0-58.8) were independent risk factors for CD-related abdominal surgery. Indian patients were less likely to require surgery (OR: 0.40, 95% CI, 0.19-0.78)., Conclusions: Age at diagnosis, L1 location, B2, and B3 disease behavior are independent risk factors for abdominal surgery. Interestingly, despite a higher prevalence of CD in Indians, a smaller proportion of Indian patients required surgery. These findings suggest that both environmental and genetic factors contribute to the risk of surgery in Asian patients with CD.

Background: Controlled clinical trials investigating the efficacy of aminosalicylates for the treatment of mildly to moderately active Crohn's disease have yielded conflicting results. A systematic review was conducted to critically examine current available data on the efficacy of sulfasalazine and mesalamine for inducing remission or clinical response in patients with mildly to moderately active Crohn's disease., Objectives: To evaluate the efficacy of aminosalicylates compared to placebo, corticosteroids, and other aminosalicylates (alone or in combination with corticosteroids) for the treatment of mildly to moderately active Crohn's disease., Search Strategy: Separate MEDLINE (1966-July 2010), Cochrane Central Register of Controlled Trials (CENTRAL; Issue 3, 2010) and EMBASE database searches (1985-July 2010) of all relevant English and non-English language articles were performed, followed by manual searches of the reference list from potentially relevant papers and review articles, as well as proceedings from annual meetings (1991-2010) of the American Gastroenterological Association (AGA) and American College of Gastroenterology (ACG)., Selection Criteria: Randomized controlled trials that evaluated the efficacy of sulfasalazine or mesalamine in the treatment of mildly to moderately active Crohn's disease compared to placebo, corticosteroids, and other aminosalicylates (alone or in combination with corticosteroids) were included., Data Collection and Analysis: Data extraction and assessment of methodological quality of each selected study was independently performed by the investigators and any disagreement was resolved by discussion and consensus. The primary outcome measure was a well defined clinical endpoint of induction of remission or response to treatment. Nineteen studies met the inclusion criteria and were analyzed. Pooled relative risks (RR) for inducing remission or clinical response and their 95% confidence intervals were calculated (random effects model) where appropriate., Main Results: Sulfasalazine was more likely to induce remission (RR 1.38; 95% CI 1.02 to 1.87; n = 263) compared to placebo with benefit confined mainly to patients with colitis. Sulfasalazine was less effective than corticosteroids (RR 0.66; 95% CI 0.53 to 0.81; n = 260). Olsalazine was less effective than placebo in a single trial. Low dose mesalamine (1 to 2 g/day) was not superior to placebo (RR = 1.46, 95% CI 0.89-2.40; n = 302) and was less effective than corticosteroids. High dose mesalamine (3 to 4.5 g/day) was not superior to placebo for induction of remission (RR 2.02; 95% CI 0.75 to 5.45) or response (Weighted Mean Difference -19.8 points; 95% CI -46.2 to 6.7; n = 615). In a single randomized controlled trial, 5-ASA was inferior to budesonide (RR 0.56; 95% CI 0.40 to 0.78). No statistically significant difference was found between high dose mesalamine and conventional corticosteroids (RR 1.04; 95% CI 0.79 to 1.36; n = 178). However, relatively few patients were available for analysis. There was a lack of good quality clinical trials comparing sulfasalazine with other mesalamine formulations., Authors' Conclusions: Sulfasalazine has modest efficacy compared to placebo and is inferior to corticosteroids for the treatment of mild to moderately active Crohn's disease. Olsalazine and low dose mesalamine (1 to 2 g/day) are not superior to placebo. High dose mesalamine (3 to 4.5 g/day) is not more effective than placebo for inducing response or remission. High dose mesalamine was inferior to budesonide for inducing remission in a single trial. In conclusion, sulfasalazine shows modest efficacy for the treatment of active Crohn's disease. However, the existing data show little benefit for 5-aminosalicylates.

Aminosalicylates have been shown to exhibit a wide range of anti-inflammatory and immunomodulatory properties. Since the discovery of sulfasalazine's efficacy in ulcerative colitis and the subsequent development of sulfa-free mesalamine delivery systems, aminosalicylates have evolved to become an integral part of our therapeutic armamentarium and are now first-line therapies for the treatment of mildly to moderately active inflammatory bowel disease and for maintenance of remissions after successful induction therapy. Despite the substantial body of evidence supporting the use of aminosalicylates in ulcerative colitis and Crohn's disease, gaps in our evidence base and controversies surrounding aminosalicylates clinical application have emerged. In this review, issues of dose response and optimization of the treatment regimen in ulcerative colitis, the discrimination between oral mesalamine formulations in left-sided colitis, and their efficacy in active and quiescent Crohn's disease are discussed.

Ulcerative colitis and Crohn's disease, the idiopathic inflammatory bowel diseases (IBD), are thought to represent genetically determined, dysregulated immune responses to otherwise innocuous luminal antigens. Although progress in research has advanced our understanding of the immunopathogenesis and begun to elucidate genetic contributions toward susceptibility, limitations of current medical approaches continue to drive the search for better therapeutic agents. Most recently, the introduction of infliximab has heralded a new era of evolving biologically targeted treatments for IBD. Infliximab is currently the only biologic agent approved for the treatment of inflammatory and fistulizing Crohn's disease, but ongoing research continues to generate new biologic agents targeted at specific pathogenic mechanisms involved in the inflammatory process. Undoubtedly, with the success of infliximab, the role of biologic therapy will continue to expand in the future treatment of IBD.