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Objective: There are scant data regarding outpatient adherence in quiescent ulcerative colitis aside from patients enrolled in controlled clinical trials. We conducted a prevalence study to determine the medication adherence rate of maintenance therapy and to identify possible risk factors for nonadherence., Methods: Outpatients with clinically quiescent ulcerative colitis for >6 months on maintenance mesalamine (Asacol, Procter and Gamble, Cincinnati, OH) were eligible. Patients were interviewed regarding disease history, and demographics were obtained from medical records. Refill information for at least 6 months was obtained from computerized pharmacy records. Adherence was defined as at least 80% consumption of supply dispensed. Using nonadherence as the outcome of interest, stratified analysis and regression modeling were used to identify significant associations., Results: Data were complete for the 94 patients recruited. The overall adherence rate was found to be 40%. The median amount of medication dispensed per patient was 71% (8-130%) of the prescribed regimen. Nonadherent patients were more likely to be male (67% vs 52%, p < 0.05), single (68% vs 53%, p = 0.04), and to have disease limited to the left side of the colon versus pancolitis (83% vs 51%, p < 0.01). Sixty-eight percent of patients who took more than four prescription medications were found to be nonadherent versus only 40% of those patients taking fewer medications (p = 0.05). Age, occupation, a family history of inflammatory bowel disease, length of remission, quality-of-life score, or method of recruitment (telephone interview vs clinical visit) were not associated with nonadherence. Logistic regression identified that a history of more than four prescriptions (odds ratio [OR] 2.5 [1.4-5.7]) and male gender (OR 2.06 [1.17-4.88]) increased the risk of nonadherence. Two statistically significant variables, which were protective against nonadherence, were endoscopy within the past 24 months (OR 0.96 [0.93-0.99]) and being married (OR 0.46 [0.39-0.57])., Conclusion: Nonadherence is associated with multiple concomitant medications, male gender, and single status. These patient characteristics may be helpful in targeting those patients at higher risk for nonadherence.

Crohn's disease is a chronic inflammatory disorder of the gastrointestinal tract, which is thought to result from the effect of environmental factors in a genetically predisposed host. A gene location in the pericentromeric region of chromosome 16, IBD1, that contributes to susceptibility to Crohn's disease has been established through multiple linkage studies, but the specific gene(s) has not been identified. NOD2, a gene that encodes a protein with homology to plant disease resistance gene products is located in the peak region of linkage on chromosome 16 (ref. 7). Here we show, by using the transmission disequilibium test and case-control analysis, that a frameshift mutation caused by a cytosine insertion, 3020insC, which is expected to encode a truncated NOD2 protein, is associated with Crohn's disease. Wild-type NOD2 activates nuclear factor NF-kappaB, making it responsive to bacterial lipopolysaccharides; however, this induction was deficient in mutant NOD2. These results implicate NOD2 in susceptibility to Crohn's disease, and suggest a link between an innate immune response to bacterial components and development of disease.

Background & Aims: We evaluated CDP571, a humanized antibody to tumor necrosis factor, for the treatment of active Crohn's disease., Methods: One hundred sixty-nine patients with moderate-to-severe Crohn's disease were enrolled in a 24-week placebo-controlled trial. Patients were initially randomized to a single dose of 10 or 20 mg/kg CDP571 or placebo to assess dose response. Patients were then retreated with 10 mg/kg CDP571 or placebo every 8 or 12 weeks to assess subsequent dosing intervals. The primary endpoint was clinical response at week 2, defined as a decrease in the Crohn's Disease Activity Index score > or = 70 points., Results: At week 2, clinical response occurred in 45% of CDP571-treated patients compared with 27% of patients in the placebo group (P = 0.023). Patients appeared to benefit from retreatment with CDP571 over 24 weeks, but not all of the results for secondary endpoints were statistically significant. The frequency of severe or serious adverse events was similar among all groups., Conclusions: CDP571 at an initial dose of 10 or 20 mg/kg is safe and effective for treatment of patients with moderate-to-severe Crohn's disease. Preliminary evidence suggests that retreatment with 10 mg/kg CDP571 at dose intervals of 8 or 12 weeks may also be beneficial, but additional studies are needed.

We report the experience of 11 patients (of 60 planned patients) enrolled in a double-blind, placebo-controlled clinical trial of infliximab in patients with severe, active steroid-refractory ulcerative colitis. The study was terminated prematurely because of slow enrollment. Patients having active disease for at least 2 weeks and receiving at least 5 days of intravenous corticosteroids were eligible to receive a single intravenous infusion of infliximab at 5, 10, or 20 mg/kg body weight. The primary endpoint used in this study was treatment failure at 2 weeks after infusion. Treatment failure was defined as 1) unachieved clinical response as defined by a modified Truelove and Witts severity score, 2) increase in corticosteroid dosage, 3) addition of immunosuppressants, 4) colectomy, or 5) death. Safety evaluations included physical examination, clinical chemistry and hematology laboratory tests, and occurrence of adverse experiences. Four of 8 patients (50%) who received infliximab were considered treatment successes at 2 weeks, compared with none of 3 patients who received placebo. Improvement in erythrocyte sedimentation rates and serum concentrations of C-reactive protein and interleukin-6 correlated with the clinical response observed in patients receiving infliximab. Infusion with infliximab produced no significant adverse events. Infliximab was well tolerated and may provide clinical benefit for some patients with steroid-refractory ulcerative colitis.

The role of biologics for peri-operative Crohn's disease will remain speculative until the accumulation of clinical trial data. The potential positioning of peri-operative biologic therapies includes the prevention of surgery, minimizing surgical morbidity or prevention or delaying post-operative disease recurrence. To date, there is limited, indirect data regarding the potential for infliximab to prevent surgery via the effective treatment of refractory disease and the improvement in fistulizing disease. Although there is no controlled data regarding the impact of biologics on surgical morbidity, patients with stricturing disease have undergone resection without added morbidity. Post-operative trials are certainly needed to ascertain the impact on the inevitability of disease recurrence.

In most Crohn's disease scenarios a step-up approach has been used to initiate therapy according to disease severity. However, this approach has ignored the concept of inductive therapy followed by maintenance treatment to prevent relapse. It is apparent from clinical trials that the success of maintenance approaches will depend upon the inductive therapy. Furthermore, the step-up approach often results in steroid-dependent or refractory disease. The potential of aggressive initial therapy followed by step-down maintenance therapy affords the potential to modify the disease course, a possibility that has not been accomplished by current therapeutic algorithims.

Significant advances have been made regarding our understanding of the etiopathogenesis of inflammatory bowel disease. This review focuses on the most recent applications of medical therapy for ulcerative colitis. Therapeutic approaches continue to evolve regarding inductive and maintenance strategies with oral and topical aminosalicylates, systemic and non-systemic corticosteroids, and cyclosporine and alternative immunomodulators. As further investigations continue to discern microbiological and immunoinflammatory targets, future therapies may include both probiotics and novel biological agents.

Crohn's disease and ulcerative colitis are idiopathic inflammatory bowel diseases characterized by dysregulated intestinal immune responses in genetically susceptible hosts. Conventional approaches to the medical therapy of ulcerative colitis and Crohn's disease can now be directed at either induction or maintenance of remission to improve therapeutic efficacy while minimizing complications. Newer approaches have expanded the utility of conventional therapies by improving both safety and efficacy and highlight the importance of specific targets along the immunoinflammatory pathways. The combination of conventional and novel approaches now offers the potential of modifying the natural history of these diseases.

Background & Aims: There is evidence for the IBD1 Crohn's disease (CD) susceptibility locus on chromosome 16 in several but not all populations studied. Genetic and phenotypic heterogeneity may underlie ability to replicate IBD1. We determined if age and severity stratification could identify a clinical subgroup at risk for IBD1., Methods: Linkage analysis at microsatellites spanning chromosome 16 was performed in 2 groups of CD pedigrees: group 1, 57 pedigrees with at least one affected relative classified as having "severe" disease, by history of surgical resection or immunomodulator therapy, and with disease diagnosed before age 22; and group 2, 33 pedigrees with no history of early-onset, severe CD., Results: Group 1 pedigrees demonstrated genomewide significant linkage evidence for the IBD1 locus (nonparametric multipoint logarithm of the odds [Mlod], 3.84; P = 1.3 x 10(-5)) with linkage evidence greater than all 90 pedigrees (Mlod, 2.12; P = 9.0 x 10(-4)). Group 2 pedigrees had near zero nonparametric 2-point and Mlod scores for the IBD1 region. Heterogeneity between groups 1 and 2 was significant (P = 0.002)., Conclusions: Presence of early-onset, more severe CD identifies pedigrees at high risk for IBD1. These pedigrees will have more power to refine the IBD1 locus and identify the causative gene.

Background & Aims: Interleukin (IL)-10 is a cytokine with potent anti-inflammatory properties. We investigated the safety and efficacy of different doses of human recombinant (rhu)IL-10 in patients with Crohn's disease (CD)., Methods: A prospective, multicenter, double-blind, placebo-controlled study was conducted in 329 therapy-refractory patients with CD. Clinical improvement was defined by a reduction of the Crohn's Disease Activity Index (CDAI) by 100 points or more and clinical remission by a decrease of the CDAI to <150 points. At selected centers, patients underwent ileocolonoscopies and activation of the nuclear factor-kappa B (NF-kappa B) system was assessed in biopsy specimens., Results: Subcutaneous treatment with rhuIL-10 over 28 days induced a fully reversible, dose-dependent decrease in hemoglobin and thrombocyte counts but no clinically significant side effects. No differences in the induction of remission were observed between rhuIL-10 groups (1 microg, 18% [9.6-29.2]; 4 microg, 20% [11.3-32.2]; 8 microg, 20% [11.1-31.8]; 20 microg, 28% [18-40.7]; and placebo, 18% [9.6-29.6]). Clinical improvement was observed in 46% (33.7-59) in the 8-microg/kg rhuIL-10 group in comparison with 27% (17-39.6) in patients taking placebo. Responders to rhuIL-10 showed inhibition of NF-kappaB p65 activation in contrast to nonresponders., Conclusions: Up to 8 microg/kg of rhuIL-10 was well tolerated. A tendency toward clinical improvement but not remission was observed in the 8-microg/kg dose group. Further studies should delineate which subgroups of patients with CD benefit from rhuIL-10 therapy.

Background & Aims: Interleukin 10 (IL-10) is an anti-inflammatory, immunomodulatory cytokine that regulates mucosal inflammation. This study evaluated the safety, tolerance, and efficacy of recombinant human IL-10 (rhuIL-10) for mild to moderately active Crohn's disease., Methods: We conducted a 24-week multicenter, prospective, randomized, double-blind, placebo-controlled, and sequential-escalating-dose study. Ninety-five patients with Crohn's Disease Activity Index of 200-350, not presently undergoing corticosteroid, mesalamine, or immunosuppressive therapy, were treated with subcutaneous rhuIL-10 (1, 5, 10, or 20 microg/kg) or placebo once daily for 28 consecutive days. Patients were followed up for 20 weeks after treatment. Evaluation of safety and tolerance was the first objective, and efficacy was the second objective., Results: Adverse effects were dose-related, mild-to-moderate in severity, and reversible. Asymptomatic and reversible anemia and thrombocytopenia were observed at higher doses. No withdrawal or delayed adverse effects were evident during 20 weeks of follow-up. At the end of treatment (day 29), intent-to-treat analysis showed that 23.5% (confidence interval [CI], 6.8%-49.9%) of patients receiving 5 micro/kg rhuIL-10 experienced clinical remission and endoscopic improvement; 0% (CI, 0%-14.8%) of patients in the placebo group did. Higher doses of recombinant human IL-10 were less effective than 5 microg/kg. No rhuIL-10 serum accumulation and no antibody against IL-10 were detected after 4 weeks., Conclusions: Subcutaneous rhuIL-10 administered daily for 28 days to patients with mild to moderately active Crohn's disease is safe, well-tolerated, and shows clinical and endoscopic improvement.

Objective: The aim of this study is to report on the first year experience with infliximab for Crohn's disease., Methods: All Crohn's patients receiving infliximab at our institution in the first year of release were prospectively registered. Disease activity was scored at initial infusion, and at 1, 3, 7, and 12 wk. Results were tabulated separately for patients with luminal (L) or fistulous (F) Crohn's disease. Steroid withdrawal and adverse events were tabulated., Results: One hundred twenty-nine patients were treated (81 L, 48 F). Mean number of infusions/patient were 2.38 L, 3.23 F. Median time to response and remission was 8 and 9 days L; 9 and 10 days F, respectively. Initial infusion course response and remission rates at 3 wk were 65% and 31% L; 78% and 24% F, respectively. Rates were higher if concurrently treated with 6-mercaptopurine or azathioprine and improved with subsequent infusions. Relapse occurred in 78% at a mean 8.5 wk L and in 71% at a mean of 12.2 wk F. Steroid tapering was seen in >90%, with 54% completely off steroids after a second infusion. Infusion-related reactions were seen in up to 24% of patients. The incidence of side effects did not differ if on concurrent immunomodulatory therapy., Conclusions: Clinical experience with infliximab closely parallels the results of the controlled clinical trials, and includes steroid-sparing effects.

Despite limited understanding of therapeutic aetiopathogenesis of ulcerative colitis and Crohn's disease, there is a strong evidence base for the efficacy of pharmacological and biological therapies. It is equally important to recognise toxicity of the medical armamentarium for inflammatory bowel disease (IBD). Sulfasalazine consists of sulfapyridine linked to 5-aminosalicylic acid (5-ASA) via an azo bond. Common adverse effects related to sulfapyridine 'intolerance' include headache, nausea, anorexia, and malaise. Other allergic or toxic adverse effects include fever, rash, haemolytic anaemia, hepatitis, pancreatitis, paradoxical worsening of colitis, and reversible sperm abnormalities. The newer 5-ASA agents were developed to deliver the active ingredient of sulfasalazine while minimising adverse effects. Adverse effects are infrequent but may include nausea, dyspepsia and headache. Olsalazine may cause a secretory diarrhoea. Uncommon hypersensitivity reactions, including worsening of colitis, pancreatitis, pericarditis and nephritis, have also been reported. Corticosteroids are commonly prescribed for treatment of moderate to severe IBD. Despite short term efficacy, corticosteroids have numerous adverse effects that preclude their long term use. Adverse effects include acne, fluid retention, fat redistribution, hypertension, hyperglycaemia, psycho-neurological disturbances, cataracts, adrenal suppression, growth failure in children, and osteonecrosis. Newer corticosteroid preparations offer potential for targeted therapy and less corticosteroid-related adverse effects. Azathioprine and mercaptopurine are associated with pancreatitis in 3 to 15% of patients that resolves upon drug cessation. Bone marrow suppression is dose related and may be delayed. The adverse effects of methotrexate include nausea, leucopenia and, rarely, hypersensitivity pneumonia or hepatic fibrosis. Common adverse effects of cyclosporin include nephrotoxicity, hypertension, headache, gingival hyperplasia, hyperkalaemia, paresthesias, and tremors. These adverse effects usually abate with dose reduction or cessation of therapy. Seizures and opportunistic infections have also been reported. Antibacterials are commonly employed as primary therapy for Crohn's disease. Common adverse effects of metronidazole include nausea and a metallic taste. Peripheral neuropathy can occur with prolonged administration. Ciprofloxacin and other antibacterials may be beneficial in those intolerant to metronidazole. Newer immunosuppressive agents previously reserved for transplant recipients are under investigation for IBD. Tacrolimus has an adverse effect profile similar to cyclosporin, and may cause renal insufficiency. Mycophenolate mofetil, a purine synthesis inhibitor, has primarily gastrointestinal adverse effects. Biological agents targeting specific sites in the immunoinflammatory cascade are now available to treat IBD. Infliximab, a chimeric antibody targeting tumour necrosis factor-or has been well tolerated in clinical trials and early postmarketing experience. Additional trials are needed to assess long term adverse effects.

Objective: Methotrexate is currently used as a treatment for refractory inflammatory bowel disease. This study sought to evaluate the hepatic effects of long-term methotrexate therapy in patients with inflammatory bowel disease and to determine whether the established guidelines for monitoring methotrexate-related hepatotoxicity with surveillance liver biopsy in patients with psoriasis or rheumatoid arthritis are applicable to these patients., Methods: Thirty-two patients with inflammatory bowel disease receiving cumulative methotrexate doses of > or = 1500 mg were studied. Liver chemistry tests were obtained before and during therapy. Twenty patients underwent liver biopsies as recommended for methotrexate-treated patients with psoriasis; the biopsies were reviewed and graded according to Roenigk's criteria for methotrexate-induced hepatotoxicity (a grading system for methotrexate hepatotoxicity in psoriasis patients) by a liver pathologist blinded to the methotrexate dose., Results: In patients who had liver biopsies, the mean cumulative methotrexate dose was 2633 mg (range, 1500-5410 mg), given for a mean of 131.7 wk (range, 66-281 wk). Nineteen of 20 patients (95%) had mild histological abnormalities (Roenigk's grade I and II), and one patient had hepatic fibrosis (Roenigk's grade IIIB). Abnormal liver chemistry tests, present in 6 of 20 (30%) patients, did not identify the patient with Roenigk's grade IIIB hepatotoxicity., Conclusions: Cumulative methotrexate doses up to 5410 mg given up to 281 wk in patients with inflammatory bowel disease are associated with little hepatotoxicity. Surveillance liver biopsies based on cumulative methotrexate doses are not warranted in these patients.

Objective: To report on the results of a prospective longitudinal study of a new bowel-sparing procedure (side-to-side isoperistaltic strictureplasty [SSIS]) in patients with extensive Crohn's disease., Methods: Between January 1992 and April 1999, the authors operated on 469 consecutive patients for Crohn's disease of the small bowel. Seventy-one patients (15.1%) underwent at least one strictureplasty; of these, 21 (4.5%; 12 men, 9 women; mean age 39) underwent an SSIS. The long-term changes occurring in the SSIS were studied radiographically, endoscopically, and histopathologically., Results: The indication for surgical intervention was symptomatic partial intestinal obstruction in each of the 21 patients. Fourteen SSISs were constructed in the jejunum, four in the ileum, and three with ileum overlapping colon. The average length of the SSIS was 24 cm. Performance of an SSIS instead of a resection resulted in preservation of an average of 17% of small bowel length. One patient suffered a postoperative gastrointestinal hemorrhage. All patients were discharged on oral feedings after a mean of 8 days. In all cases, SSIS resulted in resolution of the preoperative symptoms. With follow-up extending to 7.5 years in 20 patients (one patient died of unrelated causes), radiographic, endoscopic, and histopathologic examination of the SSIS suggests regression of previously active Crohn's disease., Conclusions: SSIS is a safe and effective procedure in patients with extensive Crohn's disease. The authors' results provide radiographic, endoscopic, and histopathologic evidence that active Crohn's disease regresses at the site of the SSIS.

Background: Patients with Crohn's disease often have relapses. Better treatments are needed for the maintenance of remission. Although methotrexate is an effective short-term treatment for Crohn's disease, its role in maintaining remissions is not known., Methods: We conducted a double-blind, placebo-controlled, multicenter study of patients with chronically active Crohn's disease who had entered remission after 16 to 24 weeks of treatment with 25 mg of methotrexate given intramuscularly once weekly. Patients were randomly assigned to receive either methotrexate at a dose of 15 mg intramuscularly once weekly or placebo for 40 weeks. No other treatments for Crohn's disease were permitted. We compared the efficacy of treatment by analyzing the proportion of patients who remained in remission at week 40. Remission was defined as a score of 150 or less on the Crohn's Disease Activity Index., Results: Forty patients received methotrexate, and 36 received placebo. At week 40, 26 patients (65 percent) were in remission in the methotrexate group, as compared with 14 (39 percent) in the placebo group (P=0.04; absolute reduction in the risk of relapse, 26.1 percent; 95 percent confidence interval, 4.4 percent to 47.8 percent). Fewer patients in the methotrexate group than in the placebo group required prednisone for relapse (11 of 40 [28 percent] vs. 21 of 36 [58 percent], P=0.01). None of the patients who received methotrexate had a severe adverse event; one patient in this group withdrew because of nausea., Conclusions: In patients with Crohn's disease who enter remission after treatment with methotrexate, a low dose of methotrexate maintains remission.

The idiopathic inflammatory bowel diseases (IBDs), consisting of Crohn's disease and ulcerative colitis, are complex genetic disorders involving chronic inflammation of the intestines. Multiple genetic loci have been implicated through genome-wide searches, but refinement of localization sufficient to undertake positional cloning efforts has been problematic. This difficulty can be obviated through identification of ancestrally shared regions in genetic isolates, such as the Chaldean population, a Roman Catholic group from Iraq. We analyzed four multiply affected American Chaldean families with inflammatory bowel disease not known to be related. We observed evidence for linkage and linkage disequilibrium in precisely the same region of chromosome band 1p36 reported previously in an outbred population. Maximal evidence for linkage was observed near D1S1597 by multipoint analysis (MLOD = 3.01, P = 6.1 x 10(-5)). A shared haplotype (D1S507 to D1S1628) was observed over 27 cM between two families. There was homozygous sharing of a 5 cM portion of that haplotype in one family and over a <1 cM region in the second family. Homozygous sharing of this haplotype near D1S2697 and D1S3669 was observed in one individual in a third multiply affected family, with heterozygous sharing in a fourth family. Linkage in outbred families as well as in this genetic isolate indicates that a pathophysiologically crucial IBD susceptibility gene is located in 1p36. These findings provide a unique opportunity to refine the localization and identify a major susceptibility gene for a complex genetic disorder.

Clinical recurrence of Crohn's disease after surgical resection is a significant problem, with reported rates as high as 55% at 5 yr and 76% at 15 yr. Specific factors that predispose to postoperative recurrence of Crohn's disease have not been well defined. In addition, the underlying pathophysiology of recurrent disease and the reason for its localization to the neoterminal ileum are not well understood. Various operative techniques have been evaluated but none, aside from formation of an ostomy, has been shown to reduce the risk of recurrence. In contrast, there is increasing evidence that postoperative medical therapy has the potential to decrease the risk of postoperative recurrence. Historically, sulfasalazine may have a modest effect on reducing postoperative recurrence of ileal or ileocolonic disease. However, 5-ASA preparations that can selectively deliver mesalamine to the small bowel or anastomotic margin should be more effective. Indeed, in several studies and as confirmed by a meta-analysis, mesalamine has been demonstrated to reduce significantly postoperative recurrence of Crohn's disease. Metronidazole and 6-mercaptopurine or azathioprine also seem to be of benefit in postoperative prophylaxis of disease recurrence, but additional controlled studies are required to define better the efficacy and dose-response of these agents. Corticosteroids are ineffective at reducing postoperative recurrence.

Objectives: Therapeutic trials in left-sided ulcerative colitis (L-UC) and ulcerative proctitis (UP) have lacked control for medication type, dose, delivery, and duration of therapy., Methods: All published therapeutic articles and abstracts in L-UC or UP from 1958-1997 were reviewed. Improvement, remission rates, and adverse events were recorded for all (ALL), placebo-controlled (PC) studies, and for PC studies passing quality assessment (QA) scoring. Meta-analysis was used where appropriate., Results: Left-sided UC: For active disease, 67 studies (17 PC; 10 QA) were identified. Mesalamine enemas achieved remission in a duration but not a dose response (QA), with higher remission rates than steroid enemas (ALL) and clinical improvement rates superior to oral therapies (QA, ALL). Remission maintenance: 17 (six PC, six QA) studies were identified. Mesalamine therapies had comparable remission rates at 6 months, with a possible dose but not delivery effect. Mesalamine enema dosing intervals between QHS to Q3 days maintained efficacy. Reported adverse events were most common with oral sulfasalazine and dose-independent for mesalamine. Withdrawals from therapy were less than placebo, or < or =3%. Ulcerative proctitis: For active disease, 18 (nine PC, three QA) studies were identified. Mesalamine suppositories achieved clinical improvement and remission in a duration but not dose response, with higher rates of remission than topical steroids (ALL). Remission maintenance: three (three PC, two QA) studies were identified. Remission ranged from 75% to 90% (6 months) and 61-90% (12 months) for mesalamine agents. Reported adverse events were most common for mesalamine foam (8%). Withdrawals from therapy were <2%., Conclusions: In L-UC and UP, the efficacy and side-effect profile of topical mesalamine are dose independent and superior to oral therapies and topical steroids. Economic analysis suggests that use of these agents will also result in an overall decrease in patient costs.

Background & Aims: Inhibition of tumor necrosis factor is a proposed mechanism for the anti-inflammatory properties of thalidomide. We performed an open-label trial of thalidomide in refractory Crohn's disease., Methods: Twenty-two patients with refractory Crohn's disease (Crohn's Disease Activity Index [CDAI] > 200 and/or draining perianal disease) initiated therapy with thalidomide, 200 mg at bedtime (18 patients), or 300 mg at bedtime (4 patients). CDAI and goal interval scores (GIS) were assessed at weeks 0, 4, and 12. Clinical response for patients with luminal disease was defined as reduction in CDAI score of >150 points and for fistula patients was 2 scores of >/=1+ in 3 parameters of the GIS. Clinical remission was defined as a total CDAI < 150 (luminal patients) or >/=2+ for all parameters of the GIS (fistula patients)., Results: Nine patients with luminal disease and 13 with fistulas (16 male, 6 female) were enrolled. The median CDAI score at entry was 371 (95-468). Sixteen patients completed 4 weeks of treatment (12 clinical responses, 4 clinical remissions). All 14 patients completing 12 weeks met criteria for clinical response. Nine achieved clinical remission (3 luminal, 6 fistula patients). The median CDAI score was 175 (30-468; P < 0.001 vs. baseline)., Conclusions: Thalidomide is efficacious in some patients with refractory Crohn's disease.

Background & Aims: Infliximab, an anti-tumor necrosis factor monoclonal antibody, rapidly reduces signs and symptoms of active Crohn's disease. The aim of this study was to determine whether repeated infusions of infliximab would effectively and safely maintain the remitting benefit., Methods: The efficacy, safety, pharmacokinetics, and immunogenicity of 4 repeated treatments with 10 mg/kg infliximab given every 8 weeks were compared with the effects of placebo in a randomized, double-blind, placebo-controlled, parallel group trial. Seventy-three patients with active Crohn's disease who had not adequately responded to conventional therapies and then had demonstrated a clinical response (>/=70-point decrease in the Crohn's Disease Activity Index) to an initial infusion of infliximab (or placebo) were studied., Results: Retreatment with infliximab maintained the clinical benefit through the retreatment period and 8 weeks after the last infusion in nearly all patients retreated with infliximab. Median values for Crohn's Disease Activity Index, inflammatory bowel disease questionnaire (a quality of life measurement), and serum C-reactive protein concentration were maintained at remission levels with infliximab retreatment, but not with placebo retreatment. Retreatment with infliximab every 8 weeks maintained serum infliximab concentration and was well tolerated with a low incidence of immunogenicity. One case of lymphoma and 1 case of suspected lupus were reported; the complete long-term safety profile of infliximab requires additional clinical investigation., Conclusions: Long-term treatment with infliximab showed efficacy and tolerability in managing symptoms of patients with active Crohn's disease not responding to conventional treatments.

Background & Aims: Azathioprine is effective for Crohn's disease but acts slowly. A loading dose may decrease the time to response., Methods: A placebo-controlled study was conducted in patients with active Crohn's disease despite prednisone treatment. Patients were randomized to a 36-hour infusion of azathioprine, 40 mg/kg (51 patients), or placebo (45 patients) followed by oral azathioprine, 2 mg/kg, for 16 weeks. Prednisone was tapered over 5 weeks. The primary outcome measure was complete remission at week 8, defined by discontinuation of prednisone and a Crohn's Disease Activity Index of

Recognizing clinical and pathologic scenarios, rather than ordering definitive tests, is still the basis for diagnosis of Crohn's disease. Steroids, salicylates, immunomodulating agents, and surgery remain the focus of treatment. The advent of infliximab, however, offers a new therapeutic option for patients with refractory disease.

Background & Aims: Recombinant human interleukin 11 (rhIL-11) is a cytokine with thrombocytopoietic activity and anti-inflammatory and mucosal protective effects. The objectives of this study were to investigate the safety and tolerability of rhIL-11 in patients with Crohn's disease and to explore the effects of dose and schedule on platelet count and Crohn's disease activity., Methods: A multicenter, double-masked, placebo-controlled, dose-escalation study of 76 patients with active Crohn's disease was performed. Patients were randomized to receive subcutaneous placebo or rhIL-11 at doses of 5, 16, or 40 microgram. kg-1. wk-1 given 2 or 5 times weekly for 3 weeks. Clinical and laboratory safety data were recorded, and disease activity was measured at each visit., Results: Subcutaneous injection of rhIL-11 generally was well tolerated. Significantly greater increases in platelet counts were found among patients receiving rhIL-11 40 microgram. kg-1. wk-1 as 2 or 5 weekly doses and 16 microgram. kg-1. week-1 as 5 weekly doses compared with patients receiving placebo (P < 0.05). Patients receiving 16 microgram. kg-1. wk-1 had the highest clinical response rates, with a response seen in 42% of patients (5/12) receiving 5 weekly doses and 33% of patients (4/12) receiving 2 weekly doses, compared with 7% of patients (1/15) receiving placebo., Conclusions: Short-term treatment with rhIL-11 is well tolerated in patients with active Crohn's disease. The thrombocytopoietic effect of rhIL-11 seems to be both dose and schedule dependent and may be minimized with retained clinical benefit in Crohn's disease at 16 microgram. kg-1. wk-1 given in 2 equal doses.

The past year's literature pertaining to the medical treatment of Crohn's disease was highlighted by the US Food and Drug Administration's approval of infliximab. Other developments of interest include more evolutionary (in contrast to revolutionary) clinical data regarding aminosalicylates, antibiotics, and steroids as inductive agents and use of immunomodulatory agents as maintenance therapies. Comparative trials continue to demonstrate that steroids, including budesonide, have a greater acute benefit than aminosalicylates, but this benefit does not translate into long-term efficacy. Azathioprine and 6-mercaptopurine are the standard maintenance therapies for steroid-dependent Crohn's disease, and long-term safety data continue to accumulate regarding these agents in adults and children. Several novel approaches have been reported in preliminary fashion that will require much more extensive clinical experience and controlled-trial evidence.

CD and UC represent a spectrum of chronic IBD that present in protean ways and are accompanied by a variety of systemic sequelae. Sulfasalazine and the newer 5-aminosalicylates are important in the management of mild-to-moderate disease, whereas corticosteroids remain the primary therapy for most patients with moderate-to-severe disease (Tables 2-5). The toxicities associated with long-term steroid therapy, combined with their ineffectiveness as maintenance medications, have led to increased use of immunomodulators, such as azathioprine and 6-MP, for the treatment of steroid-dependent and steroid-resistant IBD. Infliximab is a novel therapeutic adjunct for chronically active and fistulizing CD that will herald a new era of biologic therapy for IBD. Meanwhile, CSA remains an alternative to urgent colectomy in severe UC unresponsive to corticosteroids and also for CD patients with severe disease or refractory fistulas. Finally, continued insights into the etiopathogenic pathways in IBD will provide evolving and innovative approaches until the eventual causes and cures are elucidated. In the meantime, clinicians should remain optimistic regarding current ability to reduce the morbidity and maintain the quality of life for patients suffering with these frustrating diseases.

Objective: Cyclosporin (CSA) is a promising alternative for patients with severe steroid-refractory ulcerative colitis (UC) previously facing only surgical options. Concerns over the long term efficacy and side effects resulted in this investigation of the University of Chicago's 5-yr CSA experience in these patients., Methods: All steroid-refractory severe ulcerative colitis (UC) patients treated with IV CSA from 1991 to 1995 were identified by using the university's IBD database, with additional information from patient charts and physician files., Results: A total of 42 patients with severe UC unresponsive to IV steroids were treated with IV CSA (4 mg/kg/day). Of 42 patients, 36 (86%) responded; 31 were continued on oral CSA (8 mg/kg/day) for an overall mean of 20 wk. Ten initial CSA responders had colectomies after a mean of 6 months. Of the 36 initial responders, 25 (69%) also received 6-mercaptopurine (6-MP) or azathioprine (aza), and CSA and steroids were tapered. A total of 20% required colectomy, vs 45% of those not receiving 6MP/aza. In all, 62% of all patients, 72% of initial CSA responders, and 80% of initial CSA responders receiving 6MP/aza have avoided colectomy, with a life table analysis of "noncolectomy survival" of 58%, 70%, and 71%, respectively, at 5.5 yr. All colectomies occurred within 18 months of CSA initiation. Complications, resulting in CSA discontinuation in six patients, were all reversible, with complete recovery., Conclusions: CSA successfully allows most severe steroid resistant UC patients to retain their colons, and provides time for "elective" colectomy in others, especially if 6MP/aza are also given. Careful monitoring for side effects, including PCP prophylaxis, should be part of the treatment protocol.

Background: Enterocutaneous fistulas are a serious complication of Crohn's disease and are difficult to treat. Infliximab, a chimeric monoclonal antibody to tumor necrosis factor alpha, has recently been developed as a treatment for Crohn's disease. We conducted a randomized, multicenter, double-blind, placebo-controlled trial of infliximab for the treatment of fistulas in patients with Crohn's disease., Methods: The study included 94 adult patients who had draining abdominal or perianal fistulas of at least three months' duration as a complication of Crohn's disease. Patients were randomly assigned to receive one of three treatments: placebo (31 patients), 5 mg of infliximab per kilogram of body weight (31 patients), or 10 mg of infliximab per kilogram (32 patients); all three were to be administered intravenously at weeks 0, 2, and 6. The primary end point was a reduction of 50 percent or more from base line in the number of draining fistulas observed at two or more consecutive study visits. A secondary end point was the closure of all fistulas., Results: Sixty-eight percent of the patients who received 5 mg of infliximab per kilogram and 56 percent of those who received 10 mg per kilogram achieved the primary end point, as compared with 26 percent of the patients in the placebo group (P=0.002 and P=0.02, respectively). In addition, 55 percent of the patients assigned to receive 5 mg of infliximab per kilogram and 38 percent of those assigned to 10 mg per kilogram had closure of all fistulas, as compared with 13 percent of the patients assigned to placebo (P=0.001 and P=0.04, respectively). The median length of time during which the fistulas remained closed was three months. More than 60 percent of patients in all the groups had adverse events. For patients treated with infliximab, the most common were headache, abscess, upper respiratory tract infection, and fatigue., Conclusions: Infliximab is an efficacious treatment for fistulas in patients with Crohn's disease.

Tumor necrosis factor-alpha (TNFalpha), a proinflammatory cytokine, plays an important role in the pathogenesis of inflammatory bowel disease (IBD). Biotechnology agents including a chimeric monoclonal anti-TNF antibody (infliximab), a humanized monoclonal anti-TNF antibody (CDP571), and a recombinant TNF receptor fusion protein (etanercept) have been used to inhibit TNFalpha activity. Controlled trials have demonstrated efficacy for infliximab in moderately to severely active Crohn's disease (CD) and fistulizing CD sufficient to justify recent U.S. Food and Drug Administration (FDA) approval. Additional trials have been completed in rheumatoid arthritis (RA). Similarly, preliminary controlled trials have suggested efficacy for CDP571 in active CD and RA. Larger controlled trials have demonstrated efficacy for etanercept in RA patients who have failed disease modifying antirheumatic drug (DMARD) therapy leading to FDA approval for RA. Toxicities observed with anti-TNF therapies have included formation of human antichimeric antibodies (HACA) with associated acute and delayed hypersensitivity infusion reactions, human antihuman antibodies (HAHAs), and formation of autoantibodies with rare instances of drug-induced lupus. Several cases of non-Hodgkin's lymphoma also has been described. Future studies should evaluate optimal timing and duration of anti-TNF therapy, the utility of adjuvant medical treatments during anti-TNF therapy, and evaluate long-term safety and efficacy of the various anti-TNF agents.

Cyclosporin (CSA) has emerged as a medical alternative to colectomy in severe, steroid-refractory ulcerative colitis (UC) patients. This is the first formal quality-of-life study comparing such patients treated with intravenously administered cyclosporin with those treated surgically with colectomy. Quality-of-life analyses were conducted in all patients who underwent colectomy or received intravenous CSA for severe UC from 1991 to 1995 using the Inflammatory Bowel Disease Questionnaire, a visual-analog scale (VAS), and the Oresland scale, with additional questions regarding health care utilization and medication use. The 18 CSA-treated patients reported a better ability to sleep (p = 0.002; VAS), better stool consistency (p < 0.001; VAS), less abdominal or rectal pain (p = 0.009, VAS), and fewer daytime (p < 0.001; Oresland), nighttime (p = 0.006; Oresland), and daily trips to the toilet (p < 0.001; VAS) than the 46 surgical patients. The mean number and rate of hospitalizations within the first year was also lower in the CSA patients (p < 0.001 for both). The surgical patients reported fewer initial visits to their specialist (p < 0.001) and less medication use (p < 0.001; Oresland). Patients with severe steroid-refractory UC treated with intravenously administered CSA scored as well as or better than their surgical counterparts. The use of CSA in selected patients is substantiated both by clinical results and quality-of-life analysis.

Background & Aims: Two European genome-wide screens for inflammatory bowel disease have identified two significant regions of linkage on chromosomes 16 (IBD1) and 12 (IBD2) and two regions with suggestive levels of significance (chromosomes 3p and 7q). The aim of this study was to determine if there was evidence for linkage to these regions in non-Jewish and Ashkenazi Jewish families multiplex for Crohn's disease from the United States., Methods: One hundred forty-eight affected relative pairs, 34% Ashkenazim, were genotyped with 10-14 highly polymorphic markers overlying each candidate region. Nonparametric multipoint and two-point linkage analyses were performed., Results: Significant evidence for replication of linkage was found only for the chromosome 16 locus, IBD1, maximal at D16S769 (nonparametric linkage score [NPL], 2.49; P = 0.007). Analysis by ethnicity showed stronger evidence for Ashkenazim (D16S769; NPL = 2. 52; P = 0.007) than for non-Jewish white populations (D16S401; NPL = 1.40; P = 0.082). There was no significant evidence for replication on chromosome 12 (IBD2). Minimal evidence for extension of linkage evidence was observed for the chromosomes 3p and 7q regions., Conclusions: American families, particularly Ashkenazim, have significant evidence for the Crohn's disease susceptibility locus, IBD1, on chromosome 16, but not for IBD2 on chromosome 12.

Objective: Female patients with bowel disease commonly report worsening symptoms in relation to the menstrual cycle. Our aim was to determine the nature of gastrointestinal symptoms correlating with the menstrual cycle in women with inflammatory and irritable bowel disease., Methods: This was a retrospective study involving 49 women with ulcerative colitis (UC), 49 women with Crohn's disease (CD), 46 women with irritable bowel syndrome (IBS), and 90 healthy community controls. Participants were interviewed using a questionnaire including information regarding general health, medication history, pregnancy, as well as premenstrual and menstrual symptoms. Chi2 testing and logistic regression modeling were used to test for differences in frequencies between groups and for risk analysis., Results: Premenstrual symptoms were reported by 93% of all women but statistically more often by patients with CD (p < 0.01). CD patients were also more likely to report increased gastrointestinal symptoms during menstruation ( < 0.01), diarrhea being the symptom reported most often. All disease groups had a cyclical pattern to their bowel habits significantly more than controls (p=0.01). Cyclical symptoms included diarrhea, abdominal pain, and constipation. Logistic regression revealed an odds ratio (OR) of 1.1 (95% CI 0.9-1.2) for experiencing bowel symptoms during the premenstrual and menstrual phases and an OR of 2.0 (95% CI 1.2-3.2) for experiencing a cyclical pattern in bowel habit changes in women with bowel disease., Conclusion: The prevalence of menstrually related symptoms is high, and appears to affect bowel patterns. The physiological and clinical effects of the menstrual cycle should be taken into consideration when assessing for disease activity.

Background & Aims: Budesonide is a highly potent topical glucocorticosteroid that is characterized by low systemic availability as a result of high first-pass hepatic metabolism. The aim of this study was to evaluate the efficacy and safety of three doses of an enema preparation of budesonide in patients with active distal ulcerative colitis/proctitis., Methods: In a double-blind multicenter trial, 233 patients were randomized to receive either a placebo enema or budesonide enema at a dose of 0.5 mg/100 mL, 2.0 mg/100 mL, or 8.0 mg/100 mL. The primary efficacy variables were an improvement of sigmoidoscopic inflammation grade, total histopathology score, and remission rates. Effects on cortisol concentrations were also assessed., Results: After 6 weeks of treatment, there was significant improvement in sigmoidoscopy and histopathology scores in the budesonide 2.0-mg and 8.0-mg dose groups compared with placebo. Remission was achieved in 19% of patients in the 2.0-mg budesonide group (P

The idiopathic inflammatory bowel diseases, Crohn's disease (CD) and ulcerative colitis (UC), are chronic, frequently disabling diseases of the intestines. Segregation analyses, twin concordance, and ethnic differences in familial risks have established that CD and UC are complex, non-Mendelian, related genetic disorders. We performed a genome-wide screen using 377 autosomal markers, on 297 CD, UC, or mixed relative pairs from 174 families, 37% Ashkenazim. We observed evidence for linkage at 3q for all families (multipoint logarithm of the odds score (MLod) = 2.29, P = 5.7 x 10(-4)), with greatest significance for non-Ashkenazim Caucasians (MLod = 3.39, P = 3.92 x 10(-5)), and at chromosome 1p (MLod = 2.65, P = 2.4 x 10(-4)) for all families. In a limited subset of mixed families (containing one member with CD and another with UC), evidence for linkage was observed on chromosome 4q (MLod = 2.76, P = 1.9 x 10(-4)), especially among Ashkenazim. There was confirmatory evidence for a CD locus, overlapping IBD1, in the pericentromeric region of chromosome 16 (MLod = 1.69, P = 2.6 x 10(-3)), particularly among Ashkenazim (MLod = 1.51, P = 7.8 x 10(-3)); however, positive MLod scores were observed over a very broad region of chromosome 16. Furthermore, evidence for epistasis between IBD1 and chromosome 1p was observed. Thirteen additional loci demonstrated nominal (MLod > 1.0, P < 0.016) evidence for linkage. This screen provides strong evidence that there are several major susceptibility loci contributing to the genetic risk for CD and UC.

Crohn's disease is a chronic inflammatory bowel disease of unknown etiology. Sulfasalazine and the newer 5-aminosalicylates remain the first agents of choice to treat mild to moderate disease and often are effective at high doses as maintenance therapies. Corticosteroids are often required to treat more moderate to severe disease activity, although approximately one-third of patients become steroid-dependent after a steroid-induced remission. Corticosteroids have proven ineffective in maintaining remission and side effects resulting from prolonged exposure preclude their long-term use. Azathioprine and 6-mercaptopurine are effective in the setting of steroid dependence and steroid resistance, as well as for the treatment of perianal and fistulizing complications unresponsive to antibiotics. Crohn's disease commonly recurs following surgical resection, and there is expanding evidence that postoperative prophylaxis with certain antibiotics (e.g., metronidazole), aminosalicylates or immunomodulators may be beneficial in the prevention of disease recurrence following resection. Cyclosporin may benefit patients with severe Crohn's disease or refractory fistulas. Recent trials of newer immunosuppressive agents commonly employed in transplant recipients and ongoing development of a new class of "biologic" agents targeting specific sites in the immunoinflammatory cascade, are expanding the pharmacological armamentarium available to treat certain patients.

The safety and efficacy of mesalamine enemas were determined ina dose-ranging study enrolling 287 patients with ulcerative proctitis and proctosigmoiditis in a double-blind, placebo-controlled, multicenter trial. Patients were randomized to receive placebo, 1, 2, or 4 g in 100 ml mesalamine (PENTASA) enemas h.s. for 8 weeks. Efficacy was assessed by clinical, sigmoidoscopic, and histologic improvement, as well as by induction of remission. Sixty-seven percent, 65%, and 75% of patients receiving 1-, 2-, and 4-g enemas were markedly improved according to the physician's global assessment compared with 27% of patients treated with placebo. The mean improvement in sigmoidoscopic index was 5.8, 5.9, and 6.4 points (on a 15-point scale) for the 1-, 2-, and 4-g enema groups compared with a decrease of 1.8 points for the placebo group. Improvement in biopsy scores was observed in 47, 55, and 59% of 1-, 2-, and 4-g groups contrasted with 27% of the placebo-treated patients. All three doses were significantly more effective than placebo in reducing symptoms and trips to the toilet compared with placebo. No dose-response relation was demonstrated. The safety profile was similar to that of placebo. In conclusion, mesalamine enemas are effective as a single agent in the short-term treatment of distal ulcerative colitis without an apparent dose response between 1 and 4 g nightly.

Perianal disease is a frequent complication necessitating both medical and surgical management in Crohn's disease. Fissures, fistulae, or abscesses are found in approximately 36% of patients; occur more often in the ileocolonic and colonic disease; and may precede the onset of intestinal symptoms (Farmer et al, Gastroenterology 68:627-635, 1975; Rankin et al, Gastroenterology 77:914-920, 1979; Gray et al, Gut 6:515-524, 1965; and Homan et al, Arch Surg 111:1333-1335, 1976). To approach perianal manifestations, the physician must identify the anatomic location of the disease, treat the suppurative complications, and consider a long-term approach to palliation of chronic inflammatory sequelae. This article will review the medical management of perianal Crohn's disease and indications for surgery.

Background: Studies in animals and an open-label trial have suggested a role for antibodies to tumor necrosis factor alpha, specifically chimeric monoclonal antibody cA2, in the treatment of Crohn's disease., Methods: We conducted a 12-week multicenter, double-blind, placebo-controlled trial of cA2 in 108 patients with moderate-to-severe Crohn's disease that was resistant to treatment. All had scores on the Crohn's Disease Activity Index between 220 and 400 (scores can range from 0 to about 600, with higher scores indicating more severe illness). Patients were randomly assigned to receive a single two-hour intravenous infusion of either placebo or cA2 in a dose of 5 mg per kilogram of body weight, 10 mg per kilogram, or 20 mg per kilogram. Clinical response, the primary end point, was defined as a reduction of 70 or more points in the score on the Crohn's Disease Activity Index at four weeks that was not accompanied by a change in any concomitant medications., Results: At four weeks, 81 percent of the patients given 5 mg of cA2 per kilogram (22 of 27 patients), 50 percent of those given 10 mg of cA2 per kilogram (14 of 28), and 64 percent of those given 20 mg of cA2 per kilogram (18 of 28) had had a clinical response, as compared with 17 percent of patients in the placebo group (4 of 24) (p<0.001 for the comparison of the cA2 group as a whole with placebo). Thirty-three percent of the patients given cA2 went into remission (defined as a score below 150 on the Crohn's Disease Activity Index), as compared with 4 percent of the patients given placebo (P=0.005). At 12 weeks, 41 percent of the cA2-treated patients (34 of 83) had had a clinical response, as compared with 12 percent of the patients in the placebo group (3 of 25) (P=0.008). The rates of adverse effects were similar in the groups., Conclusions: A single infusion of cA2 was an effective short-term treatment in many patients with moderate-to-severe, treatment-resistant Crohn's disease.

Summary: : Crohn's disease and ulcerative colitis are related complex genetic disorders producing chronic intestinal inflammation. A susceptibility locus for Crohn's disease, IBDI (inflammatory bowel disease), has been implicated on chromosome 16. To evaluate IBDI in a different population using alternative methodology, we tested markers in the region of IBDI. Seventy-two relative pairs with Crohn's disease only, 23 mixed relative pairs (one relative having Crohn's disease, the other, ulcerative colitis), and 5 relative pairs with ulcerative colitis were genotyped in the region of IBDI. Our population consisted of white Americans, with 29% of families of Ashkenazi Jewish descent. Among the Crohn's disease pairs, we found evidence for linkage at IBDI using multipoint analysis, p = 0.0082. Negative linkage scores were obtained for mixed and ulcerative colitis-only relative pairs. For the entire data set, including mixed relative pairs and relative pairs with ulcerative colitis, there was no significant evidence of linkage. No difference was observed in the evidence of linkage between Jewish and non-Jewish families. Our studies confirm that IBDI represents a susceptibility locus for Crohn's disease, but not ulcerative colitis.

Guidelines for clinical practice are intended to suggest preferable approaches to particular medical problems as established by interpretation and collation of scientifically valid research, derived from extensive review of published literature. When data are not available that will withstand objective scrutiny, a recommendation may be made based on a consensus of experts. Guidelines are intended to apply to the clinical situation for all physicians without regard to specialty. Guidelines are intended to be flexible, not necessarily indicating the only acceptable approach, and should be distinguished from standards of care that are inflexible and rarely violated. Given the wide range of choices in any health care problem, the physician should select the course best suited to the individual patient and the clinical situation presented. These guidelines are developed under the auspices of the American College of Gastroenterology and its Practice Parameters Committee. Expert opinion is solicited from the outset for the document. Guidelines are reviewed in depth by the Committee, with participation from experienced clinicians and others in related fields. The final recommendations are based on the data available at the time of the production of the document and may be updated with pertinent scientific developments at a later time.

Background & Aims: Leukotrienes (LTs) are believed to be important in the pathogenesis of ulcerative colitis (UC). The aim of this study was to determine whether inhibition of LT biosynthesis with a 5-lipoxygenase inhibitor (MK-591) induces remission in patients with mild to moderate UC., Methods: One hundred eighty-three patients with mild to moderately active UC enrolled in this randomized parallel group, double-blind study. Patients received placebo or MK-591 at a dose of 12.5, 50, or 100 mg twice daily for 8 weeks. A subset of patients underwent rectal dialysis to determine LTB4 concentration., Results: MK-591 reduced LTB4 concentrations in rectal dialysate at the final determination. The median percent of baseline LTB4 concentration for 100 mg taken twice daily was 1.4% (n = 4); for 50 mg taken twice daily, 16.5% (n = 6); for 12.5 mg taken twice daily, 12% (n = 6); and for placebo, 78% (n = 6). There was no correlation between reduction of LTB4 and remission. Patients in remission at week 8 were as follows: placebo, 9 of 44 (20.5%); 100 mg taken twice daily, 11 of 43 (25.6%); 50 mg taken twice daily, 8 of 49 (16.3%); and 12.5 mg taken twice daily, 4 of 47 (8.5%) (P > 0.10)., Conclusions: MK-591 markedly inhibited LT biosynthesis, but it did not differ significantly from placebo in clinical efficacy. Inhibition of LT biosynthesis was not effective as a single therapeutic modality in active UC.