Influence of a polymorphism IL1B gene in the response of rheumatoid arthritis and ankylosing spondylitis patients treated with infliximab

Introduction

Cytokines such as IL1 are central mediators of joint inflammation in patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS) and polymorphism in IL1 has been associated with disease susceptibility and severity.

Aim

To evaluate the role of the polymorphism rs1143634 in the IL1B gene in the pharmacogenetic of RA and AS patients treated with infliximab.

Patients and methods

IL1B genotyping was performed in a subset of 42 RA and 39 AS patients treated with infliximab. Response was assessed at the 3^rd and 6^th month of treatment by EULAR for RA and BASDAI criteria for AS.

Results

According to the EULAR criteria no significant associations were found between IL1B genotypes and response in RA patients. Distribution of IL1B rs1143634 genotype revealed a significant association in AS between the T allele with better response (responders: T 93.5%, C 60.4% vs. non responders: T 6.7%, C 39.6%; p=0.007) and between TT+TC genotypes and better response (CC 52.4% vs. 92.3% TT+TC; p=0.009) at 3 months after treatment commencement according to BASDAI criteria.

Conclusions

rs1143634 seems to influence the response to infliximab treatment in AS but not in AR patients though this finding must be confirmed in a study with larger sample size.