Biomedical subjects

J K Macdonald

Publications and source records attributed to J K Macdonald.

6 recordsLinked to original sources

PubMed2006

Natalizumab for induction of remission in Crohn's disease.

BACKGROUND: The pathogenesis of Crohn's disease involves migration of leukocytes into gut tissue and subsequent inflammation. Natalizumab (Tysabri, Elan Pharmaceuticals and Biogen Idec) a recombinant humanized IgG4 monoclonal antibody that blocks adhesion and subsequent migration of leukocytes into the gut by binding the alpha4 integrin is a member of a new class of molecules known as selective adhesion molecule (SAM) inhibitors. The results of animal studies suggest that alpha4 integrin blockade could be a useful therapy for inflammatory bowel disease. The results of randomized controlled trials suggest that natalizumab may be an effective therapy for active Crohn's disease. This systematic review summarizes the current evidence on the use of natalizumab for the induction of remission in Crohn's disease. OBJECTIVES: To determine the efficacy and safety of natalizumab for induction of remission in Crohn's disease. SEARCH STRATEGY: A computer assisted search of the Cochrane Central Register of Controlled Trials, the Cochrane Inflammatory Bowel Disease and Functional Bowel Disorders Review Group Specialized Trials Register, MEDLINE and EMBASE was performed to identify relevant publications between 1966 and June 2005. The medical subject heading (MeSH) terms "Crohn disease" or "inflammatory bowel disease", "Natalizumab" or "Antegren" or "Tysabri" and "Antibodies, Monoclonal" were used to perform key word searches of each database. Manual searches of reference lists from potentially relevant papers were performed in order to identify additional studies that may have been missed using the computer-assisted search strategy. Abstracts from major gastroenterological meetings were searched to identify research submitted in abstract form only. Personal contacts, leaders in the field, and the manufacturers were contacted to identify other studies which may not be published. SELECTION CRITERIA: We included only randomized controlled trials comparing natalizumab to a placebo or control therapy for the induction of remission in Crohn's disease. DATA COLLECTION AND ANALYSIS: Data were analyzed using Review Manager (RevMan 4.2.8). All data were analyzed on an intention-to-treat basis. For pooled data, summary test statistics were derived using the relative risk and 95% confidence intervals. Fixed and random effects models were used where appropriate. The definitions of treatment success, remission and clinical improvement were set by the authors of each paper, and the data were combined for analysis only if these definitions were sufficiently similar. MAIN RESULTS: Pooled data from the three included studies suggest that natalizumab (3 to 4 mg/kg) may be effective for induction of clinical response and remission in patients with moderately to severely active Crohn's disease. This benefit is statistically significant for one, two and three infusion treatments. There was a trend toward increased benefit with additional infusions of natalizumab. Natalizumab appears to provide greater benefit for patient subgroups characterized by objective confirmation of active inflammation or chronically active disease despite conventional therapies. These subgroup analyses demonstrated significantly greater clinical response and remission rates for natalizumab compared with placebo in patients with elevated C-reactive protein levels, active disease despite the use of immunosuppressants, or prior anti-tumor necrosis factor therapy. These benefits were apparent for both short term (one infusion) and longer term treatment (two or three infusions). Natalizumab was generally well tolerated and the safety profile observed in the three included studies was similar. Adverse events occurred infrequently and were experienced by a similar proportion of natalizumab and placebo treated patients. There were no statistically significant differences between natalizumab and placebo treated patients in the proportions of patients who withdrew due to adverse events or those who experienced serious adverse events. The included trials lacked adequate power to detect serious adverse events that occur infrequently. Recently, two patients with multiple sclerosis treated with natalizumab in combination with interferon beta-1a and one patient with Crohn's disease treated with natalizumab in combination with azathioprine developed progressive multifocal leukoencephalopathy (PML) resulting in two patient deaths. As a result all dosing in clinical trials and commercial use of natalizumab has been suspended. A retrospective investigation was conducted to assess the risk of PML in natalizumab treated patients and no new cases were identified. AUTHORS' CONCLUSIONS: Pooled data and the results of an ongoing study suggest that natalizumab may be effective for induction of clinical response and remission in patients with moderately to severely active Crohn's disease. The clinical benefit of induction therapy with natalizumab in Crohn's disease should be weighed against the potential risk of serious adverse events. Currently natalizumab is not available on the market for routine clinical use as a consequence of the unexpected association with PML. However, preliminary data from the retrospective investigation of adverse events associated with natalizumab suggest that it may be possible to identify patients at risk for PML by testing for the appearance of JC virus in plasma.

Antibodies, Monoclonal↗

PubMed2006

Oral 5-aminosalicylic acid for induction of remission in ulcerative colitis.

BACKGROUND: The newer 5-ASA preparations were intended to avoid the adverse effects of SASP while maintaining its therapeutic benefits. The efficacy and safety of 5-ASA preparations have been evaluated in numerous clinical trials that have often lacked sufficient statistical power to arrive at definitive conclusions. Previously, it was found that newer 5-ASA drugs in doses of at least 2 g/day, were more effective than placebo but no more effective than SASP in inducing remission in ulcerative colitis. This updated review includes more recent studies and evaluates the effectiveness, dose-responsiveness, and safety of 5-ASA preparations in terms of more precise outcome measures. OBJECTIVES: To assess the efficacy, dose-responsiveness and safety of the newer release formulations of 5-aminosalicylic acid (5-ASA) compared to placebo or sulfasalazine (SASP) for the induction of remission in active ulcerative colitis. SEARCH STRATEGY: A computer-assisted literature search for relevant studies (1981-2005) was performed using MEDLINE, BIOS, the Cochrane Controlled Trials Register, the Cochrane IBD/FBD group specialized trials register and the Science Citation Index, followed by a manual search of reference lists from previously retrieved articles, review articles, symposia proceedings, and abstracts from major gastrointestinal conferences. SELECTION CRITERIA: Studies were accepted for analysis if they were randomized, double-blinded, and controlled clinical trials of parallel design, with treatment durations of a minimum of four weeks. DATA COLLECTION AND ANALYSIS: Based on an intention to treat principle, the outcomes of interest in the treatment of active disease were the failure to induce global/clinical remission, global/clinical improvement, endoscopic remission, or endoscopic improvement. MAIN RESULTS: 5-ASA was superior to placebo with regard to all measured outcome variables. For the failure to induce global/clinical improvement or remission, the pooled Peto odds ratio was 0.40 (95% CI, 0.30 to 0.53). A dose-response trend for 5-ASA was also observed. When 5-ASA was compared to SASP, the pooled Peto odds ratio was 0.83 (95% CI 0.60 to 1.13) for the failure to induce global/clinical improvement or remission, and 0.66 (95% CI 0.42 to 1.04) for the failure to induce endoscopic improvement. SASP was not as well tolerated as 5-ASA. AUTHORS' CONCLUSIONS: The newer 5-ASA preparations were superior to placebo and tended towards therapeutic benefit over SASP. However, considering their relative costs, a clinical advantage to using the newer 5-ASA preparations in place of SASP appears unlikely. This review updates the existing review of oral 5-aminosalicylic acid for induction of remission in ulcerative colitis which was published in the Cochrane Library (Issue 1, 2006).

Administration, Oral↗

PubMed2006

Oral 5-aminosalicylic acid for maintenance of remission in ulcerative colitis.

BACKGROUND: The newer 5-ASA preparations were intended to avoid the adverse effects of SASP while maintaining its therapeutic benefits. The efficacy and safety of 5-ASA preparations have been evaluated in numerous clinical trials that have often lacked sufficient statistical power to arrive at definitive conclusions. Previously, it was found that newer 5-ASA drugs were more effective than placebo but no more effective than SASP in inducing remission in ulcerative colitis. This updated review includes more recent studies and evaluates the effectiveness, dose-responsiveness, and safety of 5-ASA preparations in terms of more precise outcome measures. OBJECTIVES: To assess the efficacy, dose-responsiveness and safety of the newer release formulations of 5-aminosalicylic acid (5-ASA) compared to placebo or sulfasalazine (SASP) in the maintenance of remission in ulcerative colitis. SEARCH STRATEGY: A computer-assisted literature search for relevant studies (1981-2005) was performed using MEDLINE, BIOS, the Cochrane Controlled Trials Register, the Cochrane IBD/FBD Group Specialized Trials Register, and the Science Citation Index, followed by a manual search of reference lists from previously retrieved articles, review articles, symposia proceedings, and abstracts from major gastrointestinal conferences. SELECTION CRITERIA: Studies were accepted for analysis if they were prospective, randomized, double-blinded, and placebo- or SASP-controlled clinical trials of parallel design with treatment duration of at least six months. DATA COLLECTION AND ANALYSIS: Based on an intention to treat principle, the primary outcome was the failure to maintain clinical or endoscopic remission. Secondary outcomes were the number of patients experiencing adverse events, the number of patients withdrawn due to adverse events, and exclusions or withdrawals after entry into the study (not due to relapse). All data were analyzed using the Peto odds ratio and corresponding 95% confidence intervals (CI). MAIN RESULTS: The Peto odds ratio for the failure to maintain clinical or endoscopic remission (withdrawals and relapses) for 5-ASA versus placebo was 0.47 (95% CI, 0.36 to 0.62) with an NNT of 6. These values were also calculated for the trials in which SASP and 5-ASA were compared, revealing an odds ratio of 1.29 (95% CI, 1.05 to 1.57), with a negative NNT value (-19), suggesting a higher degree of therapeutic effectiveness for SASP.SASP and 5-ASA had similar adverse event profiles, with odds ratios of 1.16(0.62 to 2.16), and 1.31(0.86 to 1.99), respectively. The NNH values were determined to be 171 and 78 respectively. AUTHORS' CONCLUSIONS: The newer 5-ASA preparations were superior to placebo in maintenance therapy. However, the newer preparations had a statistically significant therapeutic inferiority relative to SASP. This review updates the existing review of oral 5-aminosalicylic acid for maintenance of remission in ulcerative colitis which was published in the Cochrane Library (Issue 1, 2006).

Administration, Oral↗

PubMed2005

Interventions for treating collagenous colitis.

BACKGROUND: Collagenous colitis is a disorder that is recognized as a cause of chronic diarrhea. Treatment has been based mainly on anecdotal evidence. This review was performed to identify therapies for collagenous colitis that have been proven in randomized trials. OBJECTIVES: To determine effective treatments for patients with clinically active collagenous colitis. SEARCH STRATEGY: Relevant papers published between 1970 and June 2005 were identified via the MEDLINE and PUBMED databases. Manual searches from the references of identified papers, as well as review papers on collagenous or microscopic colitis were performed to identify additional studies. Abstracts from major gastroenterological meetings were searched to identify research submitted in abstract form only. Finally, the Cochrane Controlled Trials Register and the Cochrane Inflammatory Bowel Disease and Functional Bowel Disorders Group Specialized Trials Register were searched for other studies. SELECTION CRITERIA: Six randomized trials were identified. One trial studied bismuth subsalicylate (published in abstract form only), one trial studied Boswellia serrata extract (published in abstract form only), one trial studied prednisolone, and 3 trials studied budesonide in the therapy of collagenous colitis. DATA COLLECTION AND ANALYSIS: Data were extracted independently by each author onto 2x2 tables (treatment versus placebo and response versus no response). For therapies assessed in one trial only, p-values were derived using the chi-square test. For therapies assessed in more than one trial, summary test statistics were derived using the Peto odds ratio and 95% confidence intervals. Data were combined for analysis only if the outcomes were sufficiently similar in definition. MAIN RESULTS: There were 9 patients with collagenous colitis in the trial studying bismuth subsalicylate (nine 262 mg tablets daily for 8 weeks). Those randomized to active drug were more likely to have clinical (p = 0.003) and histological (p = 0.003) improvement than those assigned to placebo. Eleven patients were enrolled in the trial studying prednisolone (50 mg daily for 2 weeks). There was a trend towards clinical response in patients on active medication compared to placebo (p = 0.064). The effect of prednisolone on histologic improvement was not studied. Thirty-one patients were enrolled in the Boswellia serrata extract trial. Clinical improvement was noted in 44% of patients who received active treatment compared to 27% of patients who received placebo (p = 0.32). A total of 94 patients were enrolled in 3 trials studying budesonide (9 mg daily or in a tapering schedule for 6 to 8 weeks). The pooled odds ratio for clinical response to treatment with budesonide was 12.32 (95% CI 5.53 - 27.46), with a number needed to treat of 2 patients. There was significant histological improvement with treatment in all 3 trials studying budesonide therapy. Budesonide also appears to improve patients' quality of life. AUTHORS' CONCLUSIONS: Budesonide is effective for the treatment of collagenous colitis. The evidence for benefit with bismuth subsalicylate is weaker. The effectiveness of prednisolone and Boswellia serrata extract and other therapies for induction or maintenance of remission of collagenous colitis is unknown and requires further study.

Anti-Inflammatory Agents↗

PubMed2005

Cyclosporine for induction of remission in Crohn's disease.

BACKGROUND: Cyclosporine was first found to be an effective and well-tolerated immunosuppressive agent in organ transplant recipients, and subsequently in several autoimmune diseases. It was reported in open studies that cyclosporine is effective for induction of remission in Crohn's disease. Four randomized controlled trials have been performed to determine whether the results observed in these open studies were valid. This systematic review summarizes the evidence on the use of oral cyclosporine for the induction of remission in Crohn's disease. OBJECTIVES: To evaluate the effectiveness of oral cyclosporine for induction of remission in patients with active Crohn's disease in the presence and absence of concomitant steroid therapy. Secondary objectives were to evaluate clinical response rates and adverse events associated with cyclosporine. SEARCH STRATEGY: Computer-assisted searches of the on-line bibliographic databases MEDLINE and EMBASE were performed to identify potentially relevant publications between 1980 and July 2004. The MeSH terms "Crohn Disease" or "Inflammatory Bowel disease" and "Cyclosporin" (exploded) were used to perform key word searches of the databases. Manual searches of reference lists from potentially relevant papers were performed in order to identify additional studies that may have been missed. Abstracts from major gastroenterological meetings, The Cochrane Central Register of Controlled Trials and the Cochrane Inflammatory Bowel Disease Group Specialized Trials Register were also searched for relevant studies. Appropriate officials at Sandoz Corporation were contacted to seek information on any unpublished trials. SELECTION CRITERIA: Prospective, randomized, double-blinded, placebo-controlled trials of parallel design with treatment duration of a minimum 12 weeks comparing oral cyclosporine therapy with placebo for treatment of patients with active Crohn's disease were eligible for inclusion. DATA COLLECTION AND ANALYSIS: All data were analyzed on an intention-to-treat basis. Data were extracted from the original research articles and converted into 2x2 tables (cyclosporine vs. placebo). Where available, individual 2x2 tables for strata within studies were also used. Heterogeneity was assessed using the chi-square test (p < 0.10 was regarded as statistically significant). For non-pooled data, p-values were derived using the chi-square test. For pooled data, summary test statistics were derived using the Peto odds ratio and 95% confidence intervals. A fixed effects model was used for pooling of data. For continuous data, summary test statistics were derived using the weighted mean difference and 95% confidence intervals. The definitions of treatment success, remission and clinical improvement were set by the authors of each paper, and the data were combined for analysis only if these definitions were sufficiently similar. MAIN RESULTS: Brynskov 1989a found that patients receiving high dose cyclosporine (median 7.6 mg/kg/day) had statistically significant clinical improvement at 12 weeks compared to placebo patients. None of the other studies found any statistically significant benefit for clinical improvement or induction of remission for low dose cyclosporine treatment (5 mg/kg/day) used by itself or in combination with corticosteroids compared to placebo. Cyclosporine was associated with a significantly higher proportion of adverse events and withdrawals due to adverse events relative to placebo. AUTHORS' CONCLUSIONS: Brynskov 1989a enrolled a small number of patients and the modified clinical grading scale used in the study has not been validated in other studies. Furthermore, statistically significant clinical improvement does not imply induction of clinical remission. Indeed, Brynskov 1989a found no statistically significant differences in the mean Crohn's Disease Activity Index score at 12 weeks indicating that cyclosporine was no more effective than placebo for induction of remission in Crohn's disease. The results of this review demonstrate that low dose (5 mg/kg/day) oral cyclosporine is not effective for the induction of remission in Crohn's disease. Patients treated with low dose oral cyclosporine are more likely than placebo treated patients to experience adverse events including renal dysfunction. The use of low dose oral cyclosporine for the treatment of chronic active Crohn's disease does not appear to be justified. Oral dosing at higher levels or parenteral administration of cyclosporine have not been adequately evaluated in controlled clinical trials. Higher doses of cyclosporine are not likely to be useful for the long-term management of Crohn's disease because of the risk of nephrotoxicity and the availability of other proven interventions.

Crohn Disease↗

PubMed2004

Transdermal nicotine for induction of remission in ulcerative colitis.

BACKGROUND: Ulcerative colitis is largely a disease of nonsmokers. Intermittent smokers often experience improvement in their symptoms while smoking. Nonsmokers with ulcerative colitis who begin smoking may go into remission. Randomized controlled trials were developed to test the efficacy of transdermal nicotine for the induction of remission in ulcerative colitis. OBJECTIVES: (1) To determine the efficacy of transdermal nicotine for induction of remission in ulcerative colitis. (2) To assess adverse events associated with transdermal nicotine therapy for ulcerative colitis SEARCH STRATEGY: The MEDLINE (via PubMed) and EMBASE databases were searched using the search criteria "ulcerative colitis" and "transdermal nicotine" or "nicotine" to identify relevant papers published between 1970 and December 2003. Manual searches of reference lists from potentially relevant papers were performed to identify additional studies. Abstracts from major gastroenterological meetings were searched to identify research submitted in abstract form only. The Cochrane Central Register of Controlled Trials and the Cochrane Inflammatory Bowel Disease Group Specialized Trials Register were also searched. SELECTION CRITERIA: We included only randomized controlled trials in which patients with active mild to moderate ulcerative colitis were randomly allocated to receive transdermal nicotine (15 to 25 mg/day) or a placebo or another treatment (corticosteroids or mesalamine). DATA COLLECTION AND ANALYSIS: Data extraction and assessment of the methodological quality of each trial were independently performed by each author. Any disagreement among reviewers was resolved by consensus. The primary outcome measure was the number of patients achieving clinical or sigmoidoscopic remission as defined by the primary studies (e.g. no symptoms of ulcerative colitis), and expressed as a percentage of the patients randomized (intention to treat analysis). Secondary outcomes included clinical response, adverse events and withdrawal because of adverse events. MAIN RESULTS: Seven studies were identified, five of which met the inclusion criteria. A meta-analysis of two trials in which 71 patients were randomized to nicotine and 70 to placebo showed a statistically significant benefit for nicotine treatment. After four to six weeks of treatment 19 of 71 patients treated with transdermal nicotine were in clinical remission compared to 9 of 70 treated with placebo (OR=2.56, 95% CI 1.02-6.45). In the same group of patients improvement or remission was noted in 29 of the 71 patients assigned to nicotine compared to 14 of 70 patients assigned to placebo (OR=2.72, 95% CI 1.28 - 5.81). For patients with left sided colitis the odds ratio was 2.31 (95% CI 1.05-5.10). When transdermal nicotine was compared to standard medical therapy no significant benefit for nicotine was observed. After four to six weeks of standard therapy (oral prednisone or mesalamine), 34 of 63 patients were in clinical or sigmoidoscopic remission compared to 33 of 66 patients treated with transdermal nicotine (OR=0.77, 95% CI 0.37-1.60). A meta-analysis of all five studies which included 137 patients treated with transdermal nicotine and 133 patients treated with a placebo or standard therapy demonstrated no statistically significant benefit of nicotine therapy (OR=1.23; 95% CI 0.71-2.14). Patients treated with transdermal nicotine were significantly more likely to withdrawal due to adverse events than patients treated with placebo or standard medical therapy (OR=5.82, 95% CI, 1.66 - 20.47) and were significantly more likely to suffer from an adverse event than patients treated with placebo or standard medical therapy (OR=3.54, 95% CI, 2.07 - 6.08). REVIEWERS' CONCLUSIONS: The results of this review provide evidence that transdermal nicotine is superior to placebo for the induction of remission in patient's with ulcerative colitis. The review did not identify any significant advantage for transdermal nicotine therapy compared to standard medical therapy. Adverse events associated with transdermal nicotine are significant and limit its use in some patients.

Administration, Cutaneous↗