Effects of cigarette smoking on the long-term course of Crohn's disease

Is the disease course predictable in inflammatory bowel diseases?

During the course of the disease, most patients with Crohn's disease (CD) may eventually develop a stricturing or a perforating complication, and a significant number of patients with both CD and ulcerative colitis will undergo surgery. In recent years, research has focused on the determination of factors important in the prediction of disease course in inflammatory bowel diseases to improve stratification of patients, identify individual patient profiles, including clinical, laboratory and molecular markers, which hopefully will allow physicians to choose the most appropriate management in terms of therapy and intensity of follow-up. This review summarizes the available evidence on clinical, endoscopic variables and biomarkers in the prediction of short and long-term outcome in patients with inflammatory bowel diseases.

Early azathioprine/biological therapy is associated with decreased risk for first surgery and delays time to surgery but not reoperation in both smokers and nonsmokers with Crohn's disease, while smoking decreases the risk of colectomy in ulcerative colitis

BACKGROUND/AIMS

Smoking may alter the natural course of Crohn's disease (CD). Smokers are more likely to develop complications, relapses and have a greater risk for surgery. In contrast, in ulcerative colitis (UC), smoking might improve the disease course. Our aim was to assess the combined effect of disease phenotype, smoking, and immunomodulator [azathioprine (AZA), AZA/biological] treatment on the risk of intestinal resection/reoperation in CD and colectomy in UC.

PATIENTS/METHODS

Six hundred and eighty-one inflammatory bowel disease patients were analyzed (CD: 340, male/female: 155/185, duration: 9.4+/-7.5 years; UC: 341, male/female: 174/164, duration: 11.5+/-9.7 years). Patients were interviewed on their smoking habits at the time of diagnosis and during the regular follow-up visits. Medical records were retrospectively analyzed.

RESULTS

Smoking was present in 45.5% in CD and 15.8% in UC. CD patients who underwent at least one bowel resection comprised 46.5%. In an univariate analysis, disease location, behavior, AZA, or AZA/biological use before surgery [odds ratio (OR): 0.26 and 0.22, P<0.001] and smoking (OR: 1.61, P = 0.03) were associated with risk for first surgery. Smoking, AZA, or AZA/biological (P<0.001) use before first surgery and disease behavior were independently associated with risk for surgery in a proportional Cox-regression analysis. Perianal disease (OR: 3.2, P = 0.001) and frequent relapses (OR: 4.8, P<0.001) but not smoking, AZA, or AZA/biological use after first surgery were predictive for reoperation. In UC, the rate of colectomy was 5.6%. Disease location (P = 0.001) and smoking status (P = 0.02) were independently associated with risk for colectomy in a proportional Cox-regression analysis.

CONCLUSION

Our data suggest that early AZA/biological therapy reduces the risk for first operation but not reoperation in CD, in both smokers and nonsmokers. In contrast, smoking was associated with a decreased need for colectomy in UC.

Self-reported antenatal adherence to medical treatment among pregnant women with Crohn's disease

BACKGROUND

Adherence to medical treatment among women with Crohn's disease (CD) prior to and during pregnancy has never been reported.

AIM

To examine both the predictors and prevalence rates of non-adherence to maintenance medical treatment among women with CD prior to and during pregnancy.

METHODS

Among a population of 1.6 million inhabitants, we identified a total of 132 women with CD who had given birth during 2000-2005. Questionnaires were used to investigate predictors and extent of adherence. The validity of self-reported use of medication was assessed using data from the Danish Prescription Database. We used logistic regression to estimate prevalence odds ratios for non-adherence according to smoking status and other predictors.

RESULTS

Eighty percent of the patients returned the questionnaire. A total of 58 (54%) women reported to have been on medical treatment, 50 of whom had fulfilled a prescription on relevant medication. Adherence to medical treatment was 72%. Fear of a negative effect on fertility/foetus was a reason for non-adherence by 18.8% prior to, and by 45.5% during, pregnancy. Among smokers, 30.8% were non-adherent compared with 11.5% among nonsmokers (prevalence odds ratio 3.41, 95% CI 0.8-14.7).

CONCLUSIONS

Despite fear of a negative effect on fertility/foetus, adherence to medical treatment is high in women with CD. There is no substantial variation in adherence prior to and during pregnancy. Smoking prior to pregnancy is a predictor of non-adherence.

Is the disease course predictable in inflammatory bowel diseases?

During the course of the disease, most patients with Crohn's disease (CD) may eventually develop a stricturing or a perforating complication, and a significant number of patients with both CD and ulcerative colitis will undergo surgery. In recent years, research has focused on the determination of factors important in the prediction of disease course in inflammatory bowel diseases to improve stratification of patients, identify individual patient profiles, including clinical, laboratory and molecular markers, which hopefully will allow physicians to choose the most appropriate management in terms of therapy and intensity of follow-up. This review summarizes the available evidence on clinical, endoscopic variables and biomarkers in the prediction of short and long-term outcome in patients with inflammatory bowel diseases.

Active and passive smoking behaviour and cessation plans of patients with Crohn's disease and ulcerative colitis

BACKGROUND

Smoking is a remarkable risk factor in inflammatory bowel disease (IBD), with negative effects on Crohn's disease (CD) and positive effects on ulcerative colitis (UC). This makes different changes in smoking behaviour after diagnosis between CD and UC likely. Changes in active smoking, cessation plans and passive smoking were studied in IBD patients.

METHODS

820 IBD patients were sent a questionnaire on active and passive smoking, and cessation plans. A total of 675 (82%) patients (380 CD and 295 UC) responded.

RESULTS

More ever smoking UC patients stopped smoking before diagnosis than CD patients (63% vs 22%; p<0.001), resulting in 30% former smokers at diagnosis in UC and 13% in CD (p<0.001). The smoking cessation rates at and after diagnosis are equal between CD and UC. Half of the CD patients stopped smoking after diagnosis leading to less present smokers in CD than in a control population (26% (95% confidence interval: 21.1%-29.9%) vs 33%). For both CD (22% vs 35%; p=0.044) and UC (24% vs 53%; p=0.024) continuing smokers after diagnosis were less often higher educated than quitters. Cessation plans (89%), passive smoking in childhood and present passive smoking were not different between CD and UC patients.

CONCLUSION

There are no differences in changes in smoking behaviour at and after diagnosis between CD and UC patients, suggesting a lack of knowledge in these patients about the link between their disease and smoking behaviour. However, CD patients seem less refractory to smoking cessation than the general population. Therefore it is worthwhile putting energy in helping CD patients stop smoking.

[Postoperative recurrence of Crohn's disease, and its prevention]

Crohn's disease is a chronic, progressive disabling condition ultimately leading to stricturing and/or penetrating complications. The need for surgery may be as high as 70% in patients with severe active disease or complications. However, relapse may develop in a significant proportion of the patients after surgery leading to frequent re-operations. Despite emerging data, postoperative prevention is still controversial. After careful evaluation of the individual risk a tailored therapy should be considered. In patients with small risk for relapse mesalazine or in selected cases no-treatment may be an option. In patients with a moderate-to-high risk azathioprine should be considered together with metronidazole in the three months. Follow-up ileocolonoscopy 6-12 months after the surgery is helpful in the determination of endoscopic severity and may assist in the optimization of the therapy. In most severe cases anti-TNF agents may be appropriate for postoperative prevention and therapy.

The impact of thiopurines on the risk of surgical recurrence in patients with Crohn's disease after first intestinal surgery

OBJECTIVES

Smoking and a lack of immunosuppressive (IS) therapy are considered risk factors for intestinal surgery in Crohn's disease (CD). Good evidence for the latter is lacking. The objective of this study was to evaluate the impact of thiopurine treatment on surgical recurrence in patients after first intestinal resection for CD and its possible interaction with smoking.

METHODS

Data on 326 patients after first intestinal resection were retrieved retrospectively, and subjects were grouped according to their postoperative exposure to thiopurines. Treatment with either azathioprine (AZA) or 6-mercaptopurine (6-MP) was recorded on 161 patients (49%). Smoking status was assessed by directly contacting the patients.

RESULTS

Surgical recurrence occurred in 151/326 (46.3%) patients after a median time of 71 (range 3-265) months. Cox regression revealed a significant reduction of re-operation rate in patients treated with AZA/6-MP for > or = 36 months as compared with patients treated for 3-35 months, for less than 3 months, and to those without postoperative treatment with AZA/6-MP (P=0.004). Cox regression analysis revealed treatment with thiopurines for > or = 36 months (hazard ratio (HR) 0.41; 95% confidence interval (CI) 0.23-0.76, P=0.004) and smoking (HR 1.6; 95% CI 1.14-2.4, P=0.008) as independent predictors for surgical recurrence. Furthermore, longer duration of disease tended to be protective (HR 0.99; 95% CI 0.99-1.0, P=0.067).

CONCLUSIONS

Long-term maintenance treatment with AZA/6-MP reduces the risk of surgical recurrence in patients with CD. We also identified smoking as a risk factor for surgical recurrence.

Current trends in inflammatory bowel disease: the natural history

The description of the prognosis of inflammatory bowel disease (IBD) is based on systematic follow-up of population-based cohorts. A steady increase in incidence of IBD has occurred. The distribution of ulcerative colitis (UC) is fairly uniform with a preponderance of left-sided disease. One-third of Crohn's disease (CD) patients present with colonic disease, one-third with ileocolonic disease and one-third with small bowel disease. IBD is associated with extra-intestinal manifestations (EIMs) in up to 36% of patients. Uveitis and episcleritis are the most common. The cumulative probability of a relapsing course in UC is 90% after 25 years. In CD disease behaviour varies substantially with time. At diagnosis behaviour is inflammatory in 70% of patients. At follow-up there is a change to either stricturing or penetrating disease. Most patients with CD will eventually require surgery. Risk factors for CD recurrence after surgery include penetrating/fistulizing disease behaviour, young age, short duration of disease before first surgery and ileocolonic disease. The incidence of colorectal cancer (CRC) in UC seems to be decreasing. The risk of CRC in CD seems to be equivalent to the risk in UC. Patients with small bowel CD are also at increased risk of small bowel adenocarcinoma. CD is associated with a mortality rate 20-70% higher than expected, whereas mortality in UC is equivalent to that of the general population. The improved prognosis of IBD, especially UC, could be due to a chemopreventive effect of the medications used. Further studies are needed to develop the best strategy for the reduction of mortality and cancer risk in IBD.

[Prediction of the disease course in inflammatory bowel diseases]

Clinical presentation at diagnosis and disease course of both Crohn's disease (CD) and ulcerative colitis (UC) are heterogeneous and variable over time. During follow up, intestinal strictures or perforation may eventually develop at most patients with CD, and significant number of patients will undergo surgery. Much emphasis was laid in recent years on the determination of important predictive factors. Since early introduction of immunomodulators and/or biologicals might be justified in patients at risk for disease progression, so it is important to identify these patients as soon as possible. This review article summarizes the available literature on important clinical, endoscopic, fecal, serological/routine laboratory and genetic factors and hopefully will assist clinicians in the decision making of daily practice when choosing the treatment strategy for their patients with inflammatory bowel diseases.

Evolving inflammatory bowel disease treatment paradigms: top-down versus step-up

Crohn disease (CD) and ulcerative colitis (UC) comprise a group of inflammatory disorders of the gastrointestinal tract that can vary in severity of disease, anatomic extent of inflammation, presence and nature of extraintestinal manifestations, and response to therapeutic approaches. There have been attempts to classify CD based on the location and behavior of disease. Advances in understanding of genetic susceptibility to inflammatory bowel disease (IBD) suggest that CD and UC may represent a continuum of overlapping disorders. This has led to an attempt to classify IBD on clinical, molecular, and serologic grounds. Differences in clinical, genetic, and immunologic profiles may require more targeted, refined treatment approaches to help clinicians make decisions regarding recently introduced biologic agents. This article provides an overview of the current approaches to therapy for CD and UC and focuses on the evidence supporting the rationale for changing paradigms in the management of IBD, including mucosal healing as an end point and earlier use of immunosuppressive and biologic agents, particularly in CD (so-called top-down therapy).

Postoperative management of Crohn disease

Crohn disease often recurs after surgical resection. Despite extensive research in the prevention of postoperative Crohn disease, optimal management strategies have yet to be defined. Risk of disease recurrence needs to be carefully balanced against potential risks associated with treatment. Patients with low risk of postoperative recurrence may not require medication, whereas those at moderate risk may benefit from antibiotics or immunomodulators. Those at highest risk of recurrence may benefit from biologic therapy for maintenance of surgical remission. Postoperative colonoscopy within 1 year of resective surgery is important for identification of disease recurrence and modification of medications.

Evolving inflammatory bowel disease treatment paradigms: top-down versus step-up

Crohn disease (CD) and ulcerative colitis (UC) comprise a group of inflammatory disorders of the gastrointestinal tract that can vary in severity of disease, anatomic extent of inflammation, presence and nature of extraintestinal manifestations, and response to therapeutic approaches. There have been attempts to classify CD based on the location and behavior of disease. Advances in understanding of genetic susceptibility to inflammatory bowel disease (IBD) suggest that CD and UC may represent a continuum of overlapping disorders. This has led to an attempt to classify IBD on clinical, molecular, and serologic grounds. Differences in clinical, genetic, and immunologic profiles may require more targeted, refined treatment approaches to help clinicians make decisions regarding recently introduced biologic agents. This article provides an overview of the current approaches to therapy for CD and UC and focuses on the evidence supporting the rationale for changing paradigms in the management of IBD, including mucosal healing as an end point and earlier use of immunosuppressive and biologic agents, particularly in CD (so-called top-down therapy).

Postoperative management of crohn disease

Crohn disease often recurs after surgical resection. Despite extensive research in the prevention of postoperative Crohn disease, optimal management strategies have yet to be defined. Risk of disease recurrence needs to be carefully balanced against potential risks associated with treatment. Patients with low risk of postoperative recurrence may not require medication, whereas those at moderate risk may benefit from antibiotics or immunomodulators. Those at highest risk of recurrence may benefit from biologic therapy for maintenance of surgical remission. Postoperative colonoscopy within 1 year of resective surgery is important for identification of disease recurrence and modification of medications.

[Risks related to tobacco use in general and intestinal surgery]

Peri-operative smoking history is an important risk factor, which is often under-appreciated by surgeons. In the first place, tobacco use predisposes patients to specific pathologies, which may require surgical intervention. Secondarily, smoking has been shown to increase surgical risks of mortality, morbidity and length of hospital stay. Of particular importance in general surgery is the increased risk of anastomotic leak with fistula formation, of deep infections, and of abdominal wall complications (infection and ventral hernia). If the patient can stop smoking prior to surgery, there is a concomitant decrease in post-operative complications. Surgeons should be familiar with the pharmacologic and behavioral interventions, which may help the patient with smoking cessation and should not hesitate to defer elective surgery for four to eight weeks so that the patient may have the full benefit of smoking cessation.

Immunomodulators are associated with a lower risk of first surgery among patients with non-penetrating non-stricturing Crohn's disease

OBJECTIVES

Early immunomodulator therapy may alter the natural history of Crohn's disease in certain patients. We determined whether immunomodulator use was associated with a lower risk of first surgery among patients with non-stricturing non-penetrating Crohn's disease.

METHODS

A total of 159 consecutive patients with non-penetrating non-stricturing Crohn's disease from 1994 to 2005 were retrospectively identified and followed from diagnosis to either first surgery (surgery group) or last clinic follow-up (medication group) in a historical cohort analysis. Immunomodulator use, duration, disease location, age at diagnosis, smoking, family history, and decade of diagnosis were compared. Cox proportional hazards models were adjusted for propensity score to determine whether immunomodulator use lasting >6 months decreased the risk of first surgery and whether duration of therapy affected risk.

RESULTS

The median duration of follow-up was similar (6.0 vs. 5.5 years), age at diagnosis 10 years earlier, and isolated colonic disease three times less common (18 vs. 49%) in the surgery group as compared with the medication group. Immunomodulator use increased with time but overall was less common in the surgical group (24 vs. 48%). In the multivariate Cox proportional hazards model immunomodulator use was associated with a lower risk of surgery (hazard ratio, 0.41; 95% confidence interval 0.21-0.81) after adjustment for propensity score. Similarly, risk of surgery declined with duration of use.

CONCLUSIONS

Immunomodulator use is associated with a decreased risk of first surgery among patients with non-stricturing non-penetrating CD. Early immunomodulator therapy may be beneficial in preventing first surgery in this population that has yet to develop penetrating or fistulizing complications.

Management and prevention of postoperative Crohn's disease

Postoperative Crohn's disease (CD) recurrence is a common occurrence after intestinal resection. Currently, the optimal management of patients who have undergone surgical resection is unknown and treatment remains subjective. Clinicians in conjunction with patients must balance the risks of recurrence against the potential risks associated with treatment. For those at very low risk of recurrence, no therapy may be needed; however, for patients at moderate risk immunomodulators should be considered. For those at highest risk of recurrence, biologic therapy, specifically antitumor necrosis factor agents, have emerged as appropriate treatment. Any postoperative management strategy should include a colonoscopy 6-12 months after surgery to identify recurrence. This review discusses current evidence for various pharmacologic approaches in the prevention of postoperative recurrence and provides guidance for clarifying patient risk.

Predictive value and clinical significance of myenteric plexitis in Crohn's disease

BACKGROUND

Recurrence of Crohn's disease (CD) after ileal or colonic resection is common. Myenteric plexitis in the proximal resection margin of an ileocolonic CD resection specimen may indicate ongoing pathology that relates to disease recurrence. We assessed risk factors for myenteric plexitis, the effect of plexitis on clinical recurrence, and whether preoperative medical therapies affect the intensity of plexitis.

METHODS

Ileocolonic resection specimens from 99 patients with CD were histologically scored for the presence and severity of plexitis. Myenteric plexitis was correlated with immunosuppressive therapy before index surgery. Univariate and multivariate analyses were performed to identify predictive factors for plexitis.

RESULTS

Myenteric plexitis was present in 43% and 85% of cases in the proximal resection margin and the affected resected segments of CD, respectively. Patients with a previous resection were more likely to have plexitis than those with no previous resection (odds ratio [OR] 3.5, 95% confidence interval [CI] 1.21-10.15, P = 0.02), and those with a greater duration of disease were less likely to have plexitis in the proximal resection margin (OR 0.68, 95% CI 0.48-0.96, P = 0.03). Preoperative immunosuppressive therapy was not associated with a lesser incidence of plexitis. Twelve of 40 (30%) patients with plexitis and 9 of 54 (16%) patients without plexitis in the proximal resection margin subsequently developed clinical recurrence (median 10 months; P = 0.17).

CONCLUSIONS

Previous resections and shorter disease duration are associated with plexitis in proximal resection margin of CD. The prognostic value of plexitis in postoperative disease recurrence and risk stratification remain to be prospectively established.

Perianal disease, small bowel disease, smoking, prior steroid or early azathioprine/biological therapy are predictors of disease behavior change in patients with Crohn's disease

AIM

To assess the combined effect of disease phenotype, smoking and medical therapy [steroid, azathioprine (AZA), AZA/biological therapy] on the probability of disease behavior change in a Caucasian cohort of patients with Crohn's disease (CD).

METHODS

Three hundred and forty well-characterized, unrelated, consecutive CD patients were analyzed (M/F: 155/185, duration: 9.4 +/- 7.5 years) with a complete clinical follow-up. Medical records including disease phenotype according to the Montreal classification, extraintestinal manifestations, use of medications and surgical events were analyzed retrospectively. Patients were interviewed on their smoking habits at the time of diagnosis and during the regular follow-up visits.

RESULTS

A change in disease behavior was observed in 30.8% of patients with an initially non-stricturing, non-penetrating disease behavior after a mean disease duration of 9.0 +/- 7.2 years. In a logistic regression analysis corrected for disease duration, perianal disease, smoking, steroid use, early AZA or AZA/biological therapy use were independent predictors of disease behavior change. In a subsequent Kaplan-Meier survival analysis and a proportional Cox regression analysis, disease location (P = 0.001), presence of perianal disease (P < 0.001), prior steroid use (P = 0.006), early AZA (P = 0.005) or AZA/biological therapy (P = 0.002), or smoking (P = 0.032) were independent predictors of disease behavior change.

CONCLUSION

Our data suggest that perianal disease, small bowel disease, smoking, prior steroid use, early AZA or AZA/biological therapy are all predictors of disease behavior change in CD patients.

Effects of active and passive smoking on disease course of Crohn's disease and ulcerative colitis

BACKGROUND

Smoking is a remarkable risk factor for inflammatory bowel disease (IBD), aggravating Crohn's disease (CD) while having beneficial effects on ulcerative colitis (UC). We studied the effects of active and passive smoking in Dutch IBD patients.

METHODS

A questionnaire focusing on cigarette smoke exposure was sent to 820 IBD patients. Returned questionnaires were incorporated into a retrospective chart review, containing details about disease behavior and received therapy.

RESULTS

In all, 675 IBD patients (380 [56%] CD and 295 [44%] UC) responded. At diagnosis there were 52% smokers in CD, 41% in the general population, and 28% in UC. The number of present smokers in CD is lower than in the general population (26% versus 35%). No detrimental effects of active smoking on CD were observed, but passive smokers needed immunosuppressants and infliximab more frequently than nonpassive smokers. Active smoking had beneficial effects on UC, indicated by reduced rates of colectomy, primary sclerosing cholangitis, and backwash-ileitis in active smokers compared to never smokers, and higher daily cigarette dose correlated with less extensive colitis and a lower need for therapy. Furthermore, smoking cessation after diagnosis was detrimental for UC patients, indicated by increased needs for steroids and hospitalizations for patients that stopped smoking after compared to before the diagnosis.

CONCLUSIONS

Active smoking is a risk factor for CD, but does not affect the outcome; passive smoking is detrimental for the outcome of CD patients. In UC, active smoking shows dose-dependent beneficial effects. Our data suggest that passive smoking is a novel risk factor for CD.

Perianal disease, small bowel disease, smoking, prior steroid or early azathioprine/biological therapy are predictors of disease behavior change in patients with Crohn's disease

AIM

To assess the combined effect of disease phenotype, smoking and medical therapy [steroid, azathioprine (AZA), AZA/biological therapy] on the probability of disease behavior change in a Caucasian cohort of patients with Crohn's disease (CD).

METHODS

Three hundred and forty well-characterized, unrelated, consecutive CD patients were analyzed (M/F: 155/185, duration: 9.4 +/- 7.5 years) with a complete clinical follow-up. Medical records including disease phenotype according to the Montreal classification, extraintestinal manifestations, use of medications and surgical events were analyzed retrospectively. Patients were interviewed on their smoking habits at the time of diagnosis and during the regular follow-up visits.

RESULTS

A change in disease behavior was observed in 30.8% of patients with an initially non-stricturing, non-penetrating disease behavior after a mean disease duration of 9.0 +/- 7.2 years. In a logistic regression analysis corrected for disease duration, perianal disease, smoking, steroid use, early AZA or AZA/biological therapy use were independent predictors of disease behavior change. In a subsequent Kaplan-Meier survival analysis and a proportional Cox regression analysis, disease location (P = 0.001), presence of perianal disease (P < 0.001), prior steroid use (P = 0.006), early AZA (P = 0.005) or AZA/biological therapy (P = 0.002), or smoking (P = 0.032) were independent predictors of disease behavior change.

CONCLUSION

Our data suggest that perianal disease, small bowel disease, smoking, prior steroid use, early AZA or AZA/biological therapy are all predictors of disease behavior change in CD patients.

Postoperative Crohn's disease: prevention and treatment

Crohn's disease is a chronic, relapsing-remitting inflammatory disease of the intestinal tract that commonly requires surgical treatment. Unfortunately, the majority of patients will ultimately develop postoperative disease recurrence and require subsequent surgery. A number of medications have been researched for the maintenance of postoperative remission. Of these, few have demonstrated consistent efficacy. A recently published randomized, controlled trial indicated that infliximab is effective in the maintenance of postoperative remission.

Effects of light smoking consumption on the clinical course of Crohn's disease

BACKGROUND

Cigarette smoking is associated with a more severe Crohn's disease (CD) course. However, the effect of light consumption is not known. Our aim was to characterize the effect of a light tobacco consumption on the course of CD.

METHODS

We analyzed the course of CD during the period 1995-2007 from data collected in 2795 consecutive patients in whom smoking habits were recorded. Patients were classified as nonsmokers (n = 1420), light smokers (1-10 cigarettes/day; n = 385), heavy smokers (>10 cigarettes/day; n = 638), and intermittent smokers (change in smoking habits; n = 352). Patient-years while smoking were compared to patient-years without smoking. The analyses considered patient-years regarding annual disease activity and therapeutic requirements.

RESULTS

The percentage of years with active disease was 37% in nonsmokers versus 46% in light smokers (P < 0.001; adjusted hazard ratio 1.30 [1.19-1.43]) and 48% in heavy smokers (P < 0.001; adjusted hazard ratio 1.68 [1.57-1.81]), despite an increased use of immunosuppressants in smokers. Hospitalization rates were also increased in both groups of smokers, with 12% in nonsmokers versus 15% in both groups of smokers (P < 0.001 for both comparisons). The annual rate of intestinal resection was 4.5% in nonsmokers, 5.1% in light smokers, and 5.5% in heavy smokers, with a significant difference observed between nonsmokers and heavy smokers only (P < 0.01).

CONCLUSIONS

Light smokers are doing worse than nonsmokers regarding disease activity and the need for immunosuppressants. Complete smoking cessation should be advised in all smokers with CD.

Does smoking reduce infliximab's effectiveness against Crohn's disease?

Crohn's disease (CD) is an idiopathic inflammatory bowel disease and has no known cure. CD symptoms are treated using an array of medicines, including biological agents such as infliximab. However, infliximab therapy is expensive; therefore, identifying variables that can help predict response to infliximab is worthwhile. The present article reviews the impact of tobacco smoking on the efficacy of infliximab in CD. Earlier studies have speculated that smoking has a negative effect on the response to infliximab in CD, but the current literature is largely unable to identify a significant relationship between the two. Although smoking is known to have a negative effect on the course of CD, as well as other organ systems, presently, a CD patient's smoking status should not influence treatment decisions regarding infliximab therapy.

Infliximab prevents Crohn's disease recurrence after ileal resection

BACKGROUND & AIMS

Crohn's disease commonly recurs after intestinal resection. We evaluated whether the administration of infliximab after resective intestinal surgery for Crohn's disease reduces postoperative recurrence.

METHODS

We randomly assigned 24 patients with Crohn's disease who had undergone ileocolonic resection to receive intravenous infliximab (5 mg/kg), administered within 4 weeks of surgery and continued for 1 year, or placebo. The primary end point was the proportion of patients with endoscopic recurrence at 1 year. Secondary end points were clinical recurrence and remission and histologic recurrence.

RESULTS

The rate of endoscopic recurrence at 1 year was significantly lower in the infliximab group (1 of 11 patients; 9.1%) compared with the placebo group (11 of 13 patients; 84.6%) (P = .0006). There was a nonsignificant higher proportion of patients in clinical remission in the infliximab group (8 of 10; 80.0%) compared with the placebo group (7 of 13; 53.8%) (P = .38). The histologic recurrence rate at 1 year was significantly lower in the infliximab group (3 of 11 patients; 27.3%) compared with the placebo group (11 of 13 patients; 84.6%) (P = .01). The occurrence of adverse events was similar between the placebo and infliximab groups, and none occurred in the immediate postoperative period.

CONCLUSIONS

Administration of infliximab after intestinal resective surgery was effective at preventing endoscopic and histologic recurrence of Crohn's disease.

Azathioprine withdrawal in patients with Crohn's disease maintained on prolonged remission: a high risk of relapse

BACKGROUND & AIMS

Azathioprine (AZA) withdrawal in Crohn's disease after long-term remission under treatment is controversial. In a Groupe d'Etude Thérapeutique des Affections Inflammatoires du tube Digestif randomized, double-blind, placebo-controlled trial, the hypothesis that AZA withdrawal was not inferior to AZA continuation in patients in prolonged clinical remission could not be shown.

METHODS

A cohort of 66 patients in prolonged remission while being treated with AZA who stopped AZA, during or at the end of the randomized controlled trial, underwent long-term follow-up evaluation. The primary end point was clinical relapse. Prognostic factors of relapse were looked for through a proportional hazards model.

RESULTS

Median durations of AZA therapy and of clinical remission were 68.4 months (interquartile range, 52.8-85.2 mo) and 63.6 months (interquartile range, 48.0-55.7 mo), respectively. The median follow-up time after AZA interruption was 54.5 months; 32 of 66 patients had a relapse. The cumulative probabilities +/- SE of relapse at 1, 3, and 5 years were 14.0% +/- 4.3%, 52.8% +/- 7.1%, and 62.7% +/- 7.2%, respectively. C-reactive protein concentration of 20 mg/L or greater (risk, 58.6; 95% confidence interval, 7.5-457; P = .002), hemoglobin level less than 12 g/dL (risk, 4.8; 95% confidence interval, 1.7-13.7; P = .04), and neutrophil count 4 x 10(9)/L or greater (risk, 3.2; 95% confidence interval, 1.6-6.3; P = .003) were associated independently with an increased risk of relapse. Among the 32 relapsing patients, 23 were retreated by AZA alone, all but 1 up to successful remission.

CONCLUSIONS

Our results confirm that AZA withdrawal is associated with a high risk of relapse, whatever the duration of remission under this treatment. These data suggest that if AZA is well tolerated, it should not be interrupted.

The effect of smoking after surgery for Crohn's disease: a meta-analysis of observational studies

OBJECTIVE

The aim of the study was to quantify the risk of disease recurrence associated with cigarette smoking for individuals with Crohn's disease after disease-modifying surgery.

DESIGN

Meta-analysis of observational studies.

DATA SOURCES

Medline, Embase, Ovid and the Cochrane database.

MATERIALS AND METHODS

A literature search was performed to identify studies published between 1966 and 2007 comparing outcomes of smokers, ex-smokers and non-smokers with Crohn's disease. Random-effect meta-analytical techniques were employed to assess the risk of medical or surgical recurrence.

RESULTS

Sixteen studies encompassing 2,962 patients including 1,425 non-smokers (48.1%), 1,393 smokers (47.0%) and 137 ex-smokers (4.6%) were included. Smokers had significantly higher clinical post-operative recurrence than non-smokers (odds ratio [OR] = 2.15; 95%CI = 1.42, 3.27; p < 0.001). Smokers were also more likely to experience surgical recurrence by 5 (OR = 1.06; 95%CI = 0.32; 3.53, p = 0.04) and 10 years of follow-up (OR = 2.56; 95%CI = 1.79, 3.67; p < 0.001) compared to non-smokers, although the crude re-operation rate was not statistically significant. When matched for operation and disease site, smokers had significantly higher re-operation rates to non-smokers (OR = 2.3; 95%CI = 1.29, 4.08; p = 0.005). There was no significant difference between ex-smokers and non-smokers in re-operation rate at 10 years (OR = 0.30; 95%CI = 0.09, 1.07; p = 0.10) or in post-operative acute relapses (OR = 1.54; 95%CI = 0.78, 3.02; p = 0.21).

CONCLUSIONS

Patients with Crohn's disease who smoke have a 2.5-fold increased risk of surgical recurrence and a twofold risk of clinical recurrence compared to non-smokers. Patients with Crohn's disease should be encouraged to stop smoking since the risk of disease relapse is minimised upon its cessation.

The effect of smoking after surgery for Crohn's disease: a meta-analysis of observational studies

OBJECTIVE

The aim of the study was to quantify the risk of disease recurrence associated with cigarette smoking for individuals with Crohn's disease after disease-modifying surgery.

DESIGN

Meta-analysis of observational studies.

DATA SOURCES

Medline, Embase, Ovid and the Cochrane database.

MATERIALS AND METHODS

A literature search was performed to identify studies published between 1966 and 2007 comparing outcomes of smokers, ex-smokers and non-smokers with Crohn's disease. Random-effect meta-analytical techniques were employed to assess the risk of medical or surgical recurrence.

RESULTS

Sixteen studies encompassing 2,962 patients including 1,425 non-smokers (48.1%), 1,393 smokers (47.0%) and 137 ex-smokers (4.6%) were included. Smokers had significantly higher clinical post-operative recurrence than non-smokers (odds ratio [OR] = 2.15; 95%CI = 1.42, 3.27; p < 0.001). Smokers were also more likely to experience surgical recurrence by 5 (OR = 1.06; 95%CI = 0.32; 3.53, p = 0.04) and 10 years of follow-up (OR = 2.56; 95%CI = 1.79, 3.67; p < 0.001) compared to non-smokers, although the crude re-operation rate was not statistically significant. When matched for operation and disease site, smokers had significantly higher re-operation rates to non-smokers (OR = 2.3; 95%CI = 1.29, 4.08; p = 0.005). There was no significant difference between ex-smokers and non-smokers in re-operation rate at 10 years (OR = 0.30; 95%CI = 0.09, 1.07; p = 0.10) or in post-operative acute relapses (OR = 1.54; 95%CI = 0.78, 3.02; p = 0.21).

CONCLUSIONS

Patients with Crohn's disease who smoke have a 2.5-fold increased risk of surgical recurrence and a twofold risk of clinical recurrence compared to non-smokers. Patients with Crohn's disease should be encouraged to stop smoking since the risk of disease relapse is minimised upon its cessation.

The V249I polymorphism of the CX3CR1 gene is associated with fibrostenotic disease behavior in patients with Crohn's disease

OBJECTIVES

CX3CR1, the receptor of CX3CL1/fractalkine, is involved in regulation of inflammatory response and the CX3CR1-I249-M280 naturally occurring mutants are associated with altered binding to the ligand. Our aim was to evaluate the frequency of CX3CR1 V249I and T280M polymorphisms and NOD2/CARD15 mutations in Crohn's disease patients and to search for a relationship with phenotype.

METHODS

Clinical data were retrospectively collected. V249I and T280M polymorphisms of CX3CR1 gene and NOD2/CARD15 mutations (R702W, G908R, 3020InsC) were identified.

RESULTS

Two hundred and thirty-nine patients (140 females, 39.7+/-14.1 years) were included. About 37.4% were heterozygous and 8.8% were homozygous for the V249I CX3CR1 polymorphism, 18.1% were heterozygous and 1.3% homozygous for the T280M CX3CR1 polymorphism and 35.9% had at least one of the three mutations of NOD2/CARD15. The T280M CX3CR1 polymorphism was not associated with any phenotype. In univariate analysis, stenosis was significantly associated with both V249I CX3CR1 polymorphism and 3020InsC NOD2/CARD15 mutations. In smoker patients carrying the CX3CR1 allele I249, there was a significant increase in the frequency of fibrostenosing disease [P=0.005, odds ratio (OR): 3.25] whereas this relationship disappeared in the group of nonsmokers (P=0.72). In multivariate analysis, 3020InsC NOD2/CARD15 mutations and the V249I CX3CR1 polymorphism were independent risk factors for intestinal stenosis (P=0.046, OR: 1.8 and P=0.044, OR: 2.4, respectively).

CONCLUSION

In Crohn's disease, V249I CX3CR1 polymorphism is associated with intestinal strictures, particularly in smokers. This association is independent of CARD15 mutations.

Inflammatory bowel disease in pregnancy

Active maternal inflammatory bowel disease during pregnancy carries a greater risk to the fetus than appropriate treatment. Careful management is essential to achieve good obstetric outcome

Management of postoperative Crohn's disease

Three-quarters of the patients with Crohn's disease (CD) require surgery involving a resection in the course of their disease. Even if all macroscopically involved bowel is removed, the disease usually recurs proximal to, and at, the anastomosis. This often leads to the recurrent need for treatment of active disease, complications, and reoperation. Ileocolonoscopy has an important place in the assessment of postoperative Crohn's recurrence. The limited available data regarding drug therapy in the postoperative setting suggest that optimal management should include identification of high-risk patients earlier and more widespread use of immunosuppressive therapy than was previously recommended, and colonoscopic monitoring. Such strategies to prevent recurrence then need to be prospectively evaluated. This article examines the evidence for medical prophylaxis of postoperative CD, and proposes a treatment strategy based on current evidence.

Long-term durability of Crohn's disease treatment with infliximab

BACKGROUND

There is a paucity of data providing insight into the durability of Crohn's disease treatment with infliximab for periods longer than 12 months. Our aim was to assess the long-term durability of infliximab therapy.

MATERIALS AND METHODS

A total of 198 Crohn's patients under a maintenance regimen with infliximab, with at least a 30-month follow-up, were evaluated retrospectively. Long-term response maintenance was estimated using Kaplan-Meier analysis. The effect of specific variables was calculated using logistic regression and proportional hazard regression analyses.

RESULTS

Maintenance of response rates at 72 months was estimated to be 66.4% for initial responders and 58.2% for all patients treated. Concurrent immunomodulators enhanced response maintenance in all patients treated, particularly if started >3 months before the initiation of infliximab therapy. Smoking significantly decreased the maintenance of response in initial responders.

CONCLUSIONS

Infliximab treatment of Crohn's disease is reasonably durable beyond 12 months. Concurrent immunosuppressive therapy may increase - and smoking may decrease - long-term response maintenance.

The role of CARD15 mutations and smoking in the course of Crohn's disease in a Mediterranean area

AIM

To evaluate the role of CARD15 mutations and smoking in the main events of Crohn's disease (CD).

PATIENTS AND METHODS

A total of 182 patients with CD were included in a prospective study in order to evaluate the role of CARD15 mutations and smoking in the main outcomes of disease course: first operation and surgical recurrence. The following variables were evaluated in a univariable and multivariable analysis: age, sex, site of disease, pattern, smoking habit, extraintestinal manifestations, duration of disease, and CARD15 mutation. The Kaplan-Meier method for survival curves and Cox model for multivariable analysis were, respectively, used.

RESULTS

A total of 110 patients were operated on and 32 were reoperated on. The 7-yr cumulative free rate of surgery was 42% (95% CI 34-51%). At multivariate analysis only stricturing and penetrating pattern were predictors of surgery (HR 1.7, 95% CI 1-2.8; HR 3.2, CI 1.8-5.5, respectively). The 7-yr cumulative free rate of reoperation was 75% (95% CI 0.52-0.88). At multivariable analysis in the model with any CARD15 mutation, only smoking habit at diagnosis (HR 3.6, 95% CI 1.4-9.1) was predictive of surgical recurrence. When single mutations were considered in the model smoking (HR 4.2, 95% CI 1.8-10.1) and L1007fs mutation (HR 2.9, 95% CI 1.1-7.3) were predictive of reoperation.

CONCLUSIONS

In CD, smoking predicts recurrence after surgery. The role of CARD15 mutations in the clinical course of CD remains undefined.

Smoking in inflammatory bowel diseases: good, bad or ugly?

Smoking is an important environmental factor in inflammatory bowel disease (IBD), having different effects in ulcerative colitis (UC) and Crohn's disease (CD). A recent meta-analysis partially confirmed previous findings that smoking was found to be protective against ulcerative colitis and, after onset of the disease, might improve its course, decreasing the need for colectomy. However, smoking increases the risk of developing CD and worsens its course, increasing the need for steroids, immunosuppressants and re-operations. Smoking cessation aggravates ulcerative colitis and improves CD. Data are however, largely conflictive as well as the potential mechanisms involved in this dual relationship are still unknown. In this review article, the authors review the role of smoking in inflammatory bowel diseases.

Smoking in inflammatory bowel diseases: good, bad or ugly?

Smoking is an important environmental factor in inflammatory bowel disease (IBD), having different effects in ulcerative colitis (UC) and Crohn's disease (CD). A recent meta-analysis partially confirmed previous findings that smoking was found to be protective against ulcerative colitis and, after onset of the disease, might improve its course, decreasing the need for colectomy. However, smoking increases the risk of developing CD and worsens its course, increasing the need for steroids, immunosuppressants and re-operations. Smoking cessation aggravates ulcerative colitis and improves CD. Data are however, largely conflictive as well as the potential mechanisms involved in this dual relationship are still unknown. In this review article, the authors review the role of smoking in inflammatory bowel diseases.

The role of smoking in Crohn's disease as defined by clinical variables

The development of Crohn's disease (CD) is related to an interaction of genetic and environmental factors, with tobacco smoking being one of the most commonly studied environmental factors. In 1998, the Vienna classification was created to define CD by using three accepted clinical variables: age at diagnosis, disease behavior, and disease location. In this qualitative systematic review, articles examining the relationship between smoking and CD, using variables outlined in the Vienna classification, were identified utilizing multiple health databases. Current smoking was found to be associated with late-onset CD (> or =40 years old) and current smokers were more likely to progress to stricturing or penetrating type CD than were nonsmoking patients. Conflicting evidence exists regarding the relationship between smoking with respect to CD disease location. The Vienna classification is an important tool in permitting comparisons and predicting clinical course among CD cases, especially when smoking status is taken into account.

The long-term efficacy of azathioprine does not wane after four years of continuous treatment in patients with steroid-dependent luminal Crohn's disease

BACKGROUND

The long-term effectiveness of azathioprine, in Crohn's disease (CD) patients remains a matter of debate. This study aims at assessing the effectiveness and safety of azathioprine in patients treated continuously for less or more than 4 years.

METHODS

Patients with steroid-dependent Crohn's disease in remission on azathioprine (2-2.5 mg/kg) for between 2 and 8 years were assigned into two groups. Patients in Group A were being treated continuously for 2 to 4 years whereas patients in Group B for 4 to 8 years. Patients were followed every month for 1 year with physical examination and laboratory tests. Compliance with treatment was also assessed every month. Every 3 months the Crohn's Disease Activity Index (CDAI) was calculated and the quality of life (QOL) Inflammatory Bowel Disease Questionnaire (IBDQ) was completed. Colonoscopy with calculation of the Crohn's Disease Endoscopic Index of Severity (CDEIS) was performed at baseline and at the end of the study. The primary end point was relapse after 1 year. Secondary end points were safety of treatment, QOL, and endoscopic healing.

RESULTS

Fifty-eight patients were included in Group A and 42 in Group B. The relapse rates per protocol were 19.6% and 11.9%, respectively (p: not significant). There were no significant differences overall and at each time point of the study between the two treatment groups regarding compliance with and safety of treatment, CDAI, IBDQ, and CDEIS scores. Multifactorial analysis did not identify any factor influencing the remission of disease in any patient group.

CONCLUSIONS

Long-term treatment with azathioprine of steroid-dependent Crohn's disease is efficacious and safe.

Review article: Reproduction in the patient with inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) affects mainly the young population. The effect of IBD and its treatment on fertility and pregnancy is therefore an important clinical consideration.

AIM

To review the best management of IBD in the reproductive and pregnant population.

METHODS

A MEDLINE and an EMBASE search were performed using mainly the search phrases 'pregnancy AND IBD,''sulphasalazine AND male fertility,''abdominal surgery AND female fertility,''AZA AND placenta' and 'infliximab AND pregnancy.' No language or date restrictions were placed. References of review articles were examined.

RESULTS

Overall male and female fertility are not affected by IBD. Sulphasalzine reduces male fertility. No other drugs used in IBD affect significantly fertility in humans. The risk of pregnancy-related complications and the disease behaviour during pregnancy depends mainly on disease activity at time of conception. Proactive treatment for maintenance of disease remission during gestation is recommended. Except for methotrexate, drugs used in IBD appear safe in pregnancy. Breast feeding should be encouraged.

CONCLUSION

The management of IBD in the young and pregnant population remains controversial because the literature comes mostly from retrospective studies. Further studies particularly large prospective trials are needed to guide clinicians in decision making.

Active and passive smoking in childhood is related to the development of inflammatory bowel disease

BACKGROUND

The highest prevalence of smoking in the United States is in Kentucky, where smoking typically begins in childhood. The state has many patients who suffer from inflammatory bowel diseases (IBD). The primary aim of this study was to assess whether exposure to active and/or passive tobacco smoke in childhood is related to the likelihood of developing IBD.

METHODS

Recruited into this prospective study were a total of 672 participants (253 patients with Crohn's disease [CD], 177 patients with ulcerative colitis [UC], and 242 controls), all of whom were asked to complete the Behavioral Risk Factor Surveillance Survey modified by the addition of 4 questions on childhood passive smoke exposure.

RESULTS

Survey response rate was 84%. CD and UC patients were more likely than controls to begin smoking regularly by ages 10 and 15, respectively, suggesting that becoming a regular smoker at a younger age may be associated with a subsequent diagnosis of IBD. Smoking by age 10 was associated with an earlier age at diagnosis with UC, but not with CD. CD patients were more likely than controls to have prenatal smoke exposure (odds ratio [OR], 1.72; 95% confidence interval [CI], 1.1-2.71) and were more likely to have passive smoke exposure during childhood, with 1 or both parents or other household members being smokers (OR, 2.04; 95% CI, 1.28-3.31).

CONCLUSIONS

Passive and active smoke exposure in childhood influences the development of IBD. A high incidence of this disease in a state with a high rate of cigarette smoking underscores the profound role of environmental factors in the etiology of these illnesses.

Does cigarette smoking influence the phenotype of Crohn's disease? Analysis using the Montreal classification

OBJECTIVES

The clinical subclassification of Crohn's disease by phenotype has recently been reevaluated. We have investigated the relationships between smoking habit, age at diagnosis, disease location, and progression to stricturing or penetrating complications using the Montreal classification.

METHODS

408 patients (157 male, median age 29.4 yr) were assessed. Data were collected on smoking habit, age at diagnosis, anatomical distribution, and disease behavior. Follow-up data were available on all patients (median 10 yr).

RESULTS

At diagnosis, ex-smokers (N = 53) were older than nonsmokers (N = 177) or current smokers (N = 178, medians 43.2 vs 28.3 or 28.9 yr, respectively, P < 0.001). Disease location differed according to smoking habit at diagnosis (chi(2)= 24.1, P= 0.02) as current smokers had less colonic (L2) disease than nonsmokers or ex-smokers (30%vs 45%, 50%, respectively). In univariate Kaplan-Meier survival analysis, smoking habit at diagnosis was not associated with time to development of stricturing disease, internal penetrating disease, perianal penetrating disease, or time to first surgery. Patients with isolated colonic (L2) disease were slower to develop strictures (P < 0.001) or internal penetrating disease (P= 0.001) and to require surgery (P < 0.001). Cox models with smoking habit as time-dependent covariates showed that, relative to ileal (L1) location of disease, progression to stricturing disease was less rapid for patients with colonic (L2) disease (HR 0.140, P < 0.001), but not independently affected by smoking habit. Progression to surgery was also slower for colonic (L2) than ileal (L1) disease location (HR 0.273, P < 0.001), but was independent of smoking habit.

CONCLUSIONS

Smoking habit was associated with age at diagnosis and disease location in Crohn's disease, while disease location was associated with the rate of development of stricturing complications and requirement for surgery. The pathogenic basis of these observations needs to be explained.

New studies on the role of smoking in inflammatory bowel disease: are we not beating a dead horse?

The role of smoking in inflammatory bowel disease (IBD) has drawn more interest as our understanding of these diseases has moved beyond the simple designations of Crohn's disease (CD) and ulcerative colitis (UC). In this issue of the journal, Aldous et al. present two papers on the role of smoking in the heterogeneity of IBD. They confirm the findings of many, are at odds with the findings of some, and provide novel observations for us all as we try to understand this complex interaction. Do these studies provide more clarity or just add to the noise? As always, the devil is in the details.

Antibodies to saccharomyces cerevisiae in Crohn's disease: higher titers are associated with a greater frequency of mutant NOD2/CARD15 alleles and with a higher probability of complicated disease

BACKGROUND

Both antibodies to Saccharomyces cerevisiae (ASCA) and carriage of two mutated NOD2/CARD15 alleles are associated with ileal Crohn's disease (CD) and complications requiring bowel surgery. We assessed the ASCA titer as a marker of CD clinical behavior.

METHODS

In a cross-sectional study, we phenotyped 117 unrelated CD patients. Titers (Units, U) of ASCA IgG and IgA were measured and patients were genotyped for three high-risk NOD2/CARD15 alleles. Multiple logistic regression and Cox regression analyses were used to assess the association of factors to CD phenotype and time to surgery.

RESULTS

ASCA seropositivity was associated with younger age at diagnosis, ileal disease, and complicated (stricturing or penetrating) behavior. There was a dose-response between the number of mutant NOD2/CARD15 alleles and the prevalence and titers of ASCA. The ASCA titer and tobacco use were associated with ileal disease independently of NOD2/CARD15 status. The ASCA titer (odds ratio (OR): 2.7 per 25 U, 95% confidence interval (CI): 1.5-46.7) and ileal disease were associated with stricturing/penetrating behavior, independently of NOD2/CARD15 status. Patients with ileal CD and ASCA titers of 41 U and 60 U needed 10 and 5 years of disease, respectively, to accumulate a 50% risk of complications.

CONCLUSIONS

ASCA+ patients had a greater frequency of mutant NOD2/CARD15 alleles. Nonetheless, higher ASCA titers were associated with higher probabilities of ileal CD and stricturing/penetrating behavior independently of NOD2/CARD15 status. Higher ASCA titers were associated with more rapid development of complications. This quantitative marker may prove useful in risk-stratifying patients to more aggressive antiinflammatory therapies.

Review article: Altering the natural history of Crohn's disease--evidence for and against current therapies

BACKGROUND

The natural course of Crohn's disease is characterized by flare-ups altered with periods of remission. The majority of Crohn's disease patients need surgery within 10 years of diagnosis. Major advances in treatment options over the past years have made our treatment goals more ambitious and modification of the natural course has become the ultimate endpoint.

AIM

To review the evidence of existing therapies for Crohn's disease for changing the natural history.

METHODS

A Medline search was undertaken by using 'natural history', 'Crohn's disease', 'therapy' (corticosteroids, azathioprine, methotrexate, infliximab and enteral feeding), 'surgery', 'hospitalizations' and 'mucosal healing'.

RESULTS

Corticosteroids do not alter the disease course and maintenance therapy with corticosteroids should be avoided given their side effects. The immunomodulators azathioprine and methotrexate heal the mucosa but their onset of action is slow. Infliximab therapy introduces rapid mucosal healing and is associated with decreased hospitalizations and surgical interventions. Despite the fact that immunomodulators and infliximab are effective in maintaining clinical and endoscopic remission, there is little hard evidence at present that these therapies alter the natural history of the disease. The main reason being the fact that these therapies have so far been used only in refractory patients and that early initiation in the right patient is crucial in order to change the disease course.

CONCLUSION

Prospective studies should validate predictors of complicated disease and randomized studies in high-risk groups should be performed to answer if early introduction of immunomodulators or biological therapies slows down disease progression and alters natural history.