Immunomodulation does not alter histology in resected Crohn's disease

The use of immunomodulators (Azathioprine, 6-Mercaptopurine and Methotrexate) and biological agents (Infliximab and adalimumab) for the treatment of Crohn's disease (CD) has increased in the recent years with the aim of treating the inflammatory component of the disease and hoping to change the natural history of the disease. The aim of this study was to determine if the use of immunomodulators or biological agents in the 2 years prior to resection affects the histopathological characteristics of the patient's disease.

A retrospective review was conducted over a 10-year period (1996-2005) of patients who underwent resection for CD. Clinical case notes and histology specimens were reviewed. Patients treated with Azathioprine, 6-Mercaptopurine, Methotrexate or Infliximab for more than 3 months within the 2 years preceding surgery were deemed to have been immunomodulated. The results were also analysed by Montreal phenotype.

A total of 165 patients were identified. 52 patients had been treated with either immunomodulator or biological agent. Of 20 histological features examined, only muscular hypertrophy approached significance (P = 0.05), Montreal A and Montreal L phenotypes were the same regardless on immunomodulators, however, there was a significant difference (P = 0.03) with regard to Montreal B in patients with stricturing disease being more likely to have received an immunomodulator.

In this cohort of patients requiring resection for CD, those with stricturing disease were more likely to receive immunomodulators or biologics than those without stricturing disease. However, there were no significant histological differences in the resected specimens between those who did and those who did not receive these drugs.