Up to 75% of patients given infliximab for Crohn’s disease (CD) will respond.
A number of parameters predicting response have been proposed, but none have been reproduced in an independent cohort.
In this study, researchers aimed to identify markers of response in patients receiving infliximab at the Western General Hospital, Edinburgh, Scotland.
The research team assessed 74 CD patients (42 female, mean age 34 years).
They prospectively collected full clinical data and blood was taken for the inflammatory markers ASCA and ANCA.
Of the 74 patients, 11 had ileal disease, 25 colonic disease and 10 had recurrence following ilesotomy.
|There is a trend towards better response rates in patients with colonic disease.|
Overall, 16 patients had received azathioprine for > 3 months and 5 had received methotrexate.
The team gave the 60 patients with luminal disease single infusions of infliximab (5mg/kg), while 3 infusions were given to the 14 patients with fistulating disease.
They assessed disease activity using the Harvey-Bradshaw index. They defined a response as a reduction of 4 or more points, or a 50% reduction in draining fistula.
The research team determined that patients who smoked more than 5 cigarettes per day for over 6 months were less likely to respond to infliximab than those who did not (52% versus 83%).
The team also found that patients on azathioprine for longer than 3 months at infusion were more likely to respond (94% versus 67%).
In addition, they identified a trend towards better response rates in those with colonic disease, and worse response rates in those with perianal disease.
The team did not find that age at diagnosis, previous surgery, sex, pre-infusion disease activity, CRP, and ASCA/ANCA status influenced response rates in this cohort.
Dr Arnott’s team concluded, “Smoking has a strong adverse effect on response rates to infliximab”.
“Furthermore, patients established on azathioprine for greater than 3 months had greater response rates.”
“Every effort should be made to discourage CD patients from smoking.”
"92% of patients established on azathioprine prior to treatment responded: this has clear implications for clinical practice."