[Risk factors for Crohn's disease relapse after treatment of intestinal stenosis]

The influence of CTGF single-nucleotide polymorphisms on outcomes in Crohn's disease

OBJECTIVE

To examine the association between single-nucleotide polymorphisms (SNPs) in CTGF (connective tissue growth factor) and patient outcomes after terminal ileal resection for Crohn's disease.

BACKGROUND

The primary indication for intestinal resection in Crohn's disease is fibrostenotic terminal ileal disease. CTGF is a cytokine overexpressed in the intestine of patients with Crohn's disease that influences outcomes in other disease processes.

METHODS

DNA was extracted from formalin-fixed, paraffin-embedded tissue from 147 patients with Crohn's disease who had undergone terminal ileal resection between 1981 and 2009. Genotyping was performed for 4 CTGF SNPs (rs9402373, rs12526196, rs6918698, and rs9399005), which modulate nuclear factor binding and CTGF production, and a smad3 SNP (rs17293632) involved in the CTGF pathway. Patients were phenotyped using the Montreal Disease Classification.

RESULTS

Sixty-seven of 147 patients (45.6%) were male; the mean age at diagnosis was 30.3 ± 12.6 years and the mean follow-up duration was 8.3 ± 7.1 years. Genotype-phenotype analysis demonstrated that the rs6918698GG genotype was associated with an older age of disease onset [>40 years; 30.6% vs 13.2%; odds ratio (OR): 2.891; 95% confidence interval (CI): 1.170-7.147). The rs9402373CC genotype was positively associated with type B1 disease (50.7% vs 26.3%; OR: 2.876; 95% CI: 1.226-6.743) and negatively associated with B2 disease (37.0% vs 65.0%; OR: 0.317; 95% CI: 0.144-0.699). None of the 5 SNPs assessed influenced clinical or surgical recurrence of Crohn's disease after intestinal resection. On multivariate analysis, male sex odds ratio (OR): 0.235; 95% CI: 0.073-0.755; P = 0.015] and never having smoked tobacco (OR: 0.249; 95% CI: 0.070-0.894; P = 0.033) reduced the risk, whereas having a prior appendectomy increased the risk (OR: 5.048; 95% CI: 1.632-15.617; P = 0.005) of surgical recurrence.

CONCLUSIONS

These data implicate the rs6918698GG genotype with an age of disease onset of greater than 40 years in Crohn's disease whereas the rs9402373CC genotype is associated with a nonstricturing, nonpenetrating disease phenotype. CTGF SNPs do not influence the rate of recurrence after terminal ileal resection for Crohn's disease.

Early symptomatic recurrence after intestinal resection in Crohn's disease is unpredictable

OBJECTIVE

To identify predictors of early symptomatic recurrence of Crohn's disease (CD) after surgical resection.

METHOD

We studied a cohort of 128 patients who had undergone at least one intestinal resection for CD. Factors that might predict early recurrence were documented for analysis using a standardized pro forma. These comprised age, gender, family history, extra-intestinal manifestations, smoking, complicated disease at first presentation, site of disease, preoperative inflammatory markers, involvement of resection margins, orientation and method of anastomosis and postoperative medical therapy. All symptomatic recurrences were confirmed by endoscopic, radiological, or operative means. We defined early recurrence as that which occurred within 36 months of first surgery. Univariate analysis was conducted to compare the distribution of each factor in those who developed early recurrence (n = 48) and those who remained disease free for the first 36 months (n = 50).

RESULTS

Of the 128 patients studied, 98 fulfilled the inclusion criteria of at least 36 months of follow up. Of these patients, 48 (49%) patients developed recurrence. Trends towards fewer early recurrences were seen in patients with colonic disease (33%vs 56%, P = 0.068). Of the current smokers, 60% developed early recurrence compared with 43% of nonsmokers (P = 0.269). All other factors examined were similarly distributed between the two groups. Metronidazole as adjuvant treatment does not appear to protect against early symptomatic recurrence.

CONCLUSION

This study shows that early symptomatic postoperative recurrence of CD remains unpredictable. Against expectation, abstinence from smoking and postoperative adjuvant metronidazole did not appear to protect against early symptomatic recurrence.

Factors affecting recurrence after surgery for Crohn’s disease

Although in Crohn’s disease post-operative recurrence is common, the determinants of disease recurrence remain speculative. The aim of this study was to examine factors affecting post-operative recurrence of Crohn’s disease. A Medline-based literature review was carried out. The following factors were investigated: age at onset of disease, sex, family history of Crohn’s disease, smoking, duration of Crohn’s disease before surgery, prophylactic medical treatment (corticosteroids, 5-amino salicylic acid [5-ASA] and immunosuppressants), anatomical site of involvement, indication for surgery (perforating or non-perforating disease), length of resected bowel, anast-omotic technique, presence of granuloma in the specimen, involvement of disease at the resection margin, blood transfusions and post-operative complications. Smoking significantly increases the risk of recurrence (risk is approximately twice as high), especially in women and heavy smokers. Quitting smoking reduces the post-operative recurrence rate. A number of studies have shown a higher risk when the duration of the disease before surgery was short. There were, however, different definitions of ‘short’ among the studies. Prophylactic cortic-osteroids therapy is not effective in reducing the post-operative recurrence. A number of randomized controlled trials offered evidence of the efficacy of 5-ASA (mesalazine) in reducing post-operative recurrence. Recently, the thera-peutic efficacy of immunosuppressive drugs (azathioprine and 6-mercaptopurine) in the prevention of post-operative recurrence has been investigated and several studies have reported that these drugs might help prevent the recurrence. Further clinical trials would be necessary to evaluate the prophylactic efficacy of immunosuppressants. Several studies showed a higher recurrence rate in patients with perforating disease than in those with non-perforating disease. However, evidence for differing recurrence rates in perforating and non-perforating diseases is inconclusive. A number of retrospective studies reported that a stapled functional end-to-end anastomosis was associated with a lower recurrence rate compared with other types of anastomosis. However, prospective randomized studies would be necessary to draw a definite conclusion. Many studies found no difference in the recurrence rates between patients with radical resection and non-radical resection. Therefore, minimal surgery including strictureplasty has been justified in the management of Crohn’s disease. In this review, the following factors do not seem to be predictive of post-operative recurrence: age at onset of disease, sex, family history of Crohn’s disease, anatomical site of disease, length of resected bowel, presence of granuloma in the specimen, blood transfusions and post-operative complications. The most significant factor affecting post-operative recurrence of Crohn’s disease is smoking. Smoking significantly increases the risk of recurrence. A short disease duration before surgery seems, albeit to a very minor degree, to be associated with a higher recurrence rate. 5-ASA has been shown with some degree of confidence to lead to a lower recurrence rate. The prophylactic efficacy of immunosuppressive drugs should be assessed in future. A wider anastomotic technique after resection may reduce the post-operative recurrence rate, though this should be investigated with prospective randomized controlled trials.

[Surgical treatment for Crohn's disease]

Surgery is mandatory in most patients with Crohn's disease. Crohn's disease refractory to medical treatment represents the main indication for surgery. After intestinal resection, the patient remains exposed to a high risk of recurrence on the remnant bowel. It is the reason why, firstly, intestinal resection for Crohn's disease should be performed without extended resections margins, secondly, it must be restricted to symptomatic lesions, and thirdly, prophylactic therapy should be given postoperatively. The laparoscopic approach is to date more an more proposed in patients with Crohn's disease. It could be the procedure of choice for elective ileocaecal resection. Its use in emergency situations and for more large resections, such as total colectomy followed by ileorectal anastomosis is still under evaluation.