To predict primary failure of infliximab (IFX) therapy in Crohn's disease (CD) and to identify patients who maintain long-term effectiveness to IFX is currently not feasible. Some genetic variations are proposed as potential biomarkers.
We assessed a set of single nucleotide polymorphisms (SNPs) in genes related to the IFX mechanism of action and the presence of HLA-DQA1 * 05 allele on the primary response and long-term durability in CD patients.
A multi-centre cross-sectional study of IFX-exposed adult patients with CD was undertaken. Treatment persistence and time to failure were co-primary endpoints. DNA from the 131 patients was genotyped. Association between SNPs and clinical variables with IFX persistence was assessed.
Failure to IFX was documented in 65 (49.6%) out of 131 patients. IFX persistence was associated either with carrying the TT genotype in ADAM17 rs10929587 (ORa=0.2; 95%CI=0.1-0.8; p = 0.021), or the CC genotype in SLCO1C1 rs3794271 (ORa=0.2; 95%CI=0.1-0.7; p = 0.008), according to multivariate logistic regression. In contrast, previous bowel resection increased the risk of IFX failure (ORa=2.8; 95%CI=1.1-7.3; p = 0.025). Cox regression analysis confirmed these findings and also identified IL23R rs10489629-TT (HRa 0.41; 95%CI=0.22-0.75; p = 0.004) and concomitant immunosuppressants (HRa 0.46; 95%CI=0.27-0.77; p = 0.003) as protection from IFX failure. However, no association between HLA-DQA1 * 05 allele and persistence of IFX therapy was found, with similar failure rates among carriers and non-carriers (52.8% vs. 47.4%, respectively; p = 0.544).
SNPs rs10929587-TT in ADAM17, rs10489629-TT in IL23R and rs3794271-CC in SLCO1C1, together with no previous bowel surgery and concomitant immunosuppression, were identified as protection from failure to IFX.