Aim: To investigate genetic differences between Crohn's disease (CD) patients with a sustained remission vs relapsers after discontinuing infliximab while in corticosteroid-free remission.
Methods: Forty-eight CD patients received infliximab and were in full corticosteroid-free clinical remission but then discontinued infliximab for reasons other than a loss of response, were identified by review of an electronic database and charts. Infliximab-associated remission was defined as corticosteroid-free plus normalization of clinical disease activity [CD activity index (CDAI) < 150] during follow-up visits based on physician global assessments. A CD relapse (loss of infliximab-induced remission) was clinically defined as a physician visit for symptoms of disease activity (CDAI > 220) and a therapeutic intervention with CD medication(s), or a hospitalization with complications related to active CD. Genetic analyses were performed on samples from 14 patients (n = 6 who had a sustained long term remission after stopping infliximab, n = 8 who rapidly relapsed after stopping infliximab). Nucleotide-binding oligomerization domain 2 (NOD2)/caspase activation recruitment domain 15 (CARD15) polymorphisms (R702W, G908R and L1007fs) and the inflammatory bowel disease 5 (IBD5) polymorphisms (IGR2060a1 and IGR3081a1) were analyzed in each group.
Results: Five single nucleotide polymorphisms of IBD5 and NOD2/CARD15 genes were successfully analyzed for all 14 subjects. There was no significant increase in frequency of the NOD2/CARD15 polymorphisms (R702W, G908R and L1007fs) and the IBD5 polymorphisms (IGR2060a1 and IGR3081a1) in either group of patients; those whose disease relapsed rapidly or those who remained in sustained long term remission following the discontinuation of infliximab. Nearly a third of patients in full clinical remission who stopped infliximab for reasons other than loss of response remained in sustained clinical remission, while two-thirds relapsed rapidly. There was a marked difference in the duration of clinical remission following discontinuance of infliximab between the two groups. The patients who lost remission did so after 1.0 years ± 0.6 years, while those still in remission were at the time of this study, 8.1 years ± 2.6 years post-discontinuation of infliximab, P < 0.001. The 8 patients who had lost remission after discontinuing infliximab had a mean number of 5 infusions (range 3-7), with a mean treatment time of 7.2 mo (range 1.5 mo-15 mo). The mean duration of time from the last infusion of infliximab to the time of loss of remission was 382 d (range 20 d-701 d). The 6 patients who remained in remission after discontinuing infliximab had a mean number of 6 infusions (range 3-12), with a mean treatment duration of 12 mo (range 3.6 mo-32 mo) (P = 0.45 relative to those who lost remission).
Conclusion: There are no IBD5 or NOD2/CARD15 mutations that predict which patients might have sustained remission and which will relapse rapidly after stopping infliximab.
Keywords: Anti-tumor necrosis factor alpha; Crohn’s disease; Genotype; Inflammatory bowel disease; Infliximab.