Influence of immunogenicity on the efficacy of long-term treatment of spondyloarthritis with infliximab
Annals of Rheumatic Diseases, 05/21/2012
Plasencia C et al. – In patients with spondyloarthritis (SpA) treated with Infliximab (IFX), antibodies to infliximab (ATI) formation is associated with a poor clinical response, the appearance of infusion reactions and the discontinuation of treatment.Methods
- 94 patients with SpA treated with IFX from 1999 to 2010 were studied.
- Their clinical characteristics, serum trough IFX levels and ATI status were evaluated for a mean of 6.99 (95% CI:6.28 to 7.7) years.
- Clinical activity and improvement were measured using the Ankylosing Spondylitis Disease Activity Score (ASDAS): inactive <1.3, moderate ≥1.3 and <2.1, high ≥2.1–≤3.5, and very high >3.5 at three time points (6 months, 12 months and >4 years).
- ATI were detected in 24 (25.5%) patients.
- The patients with ATI had higher ASDAS scores than those without ATI (2.55±0.89 vs 1.79±1.04, p=0.038 at 6 months; 1.95±0.67 vs 1.67±0.71, p=0.042 at 1 year; 2.52±0.99 vs 1.53±0.81, p=0.024 at >4 years).
- Eleven patients (12%) developed infusion–related reactions, and of these, ATI were present in eight patients (73%).
- The patients with infusion–related reactions had higher ATI titres (median 12 931 AU/ml, IQR 853–82 437) vs median 2454 AU/ml, IQR 449–7718, p=0.028) and shorter survival (4.25 years vs 8.19 years, p<0.001).
- ATI development occurred more frequently in the patients not receiving methotrexate (20/58 (34.5%) vs 4/36 (11.1%), p=0.011).