Abstract
1. Introduction
The inflammatory bowel diseases (IBD) are chronic inflammatory diseases of the gastrointestinal (GI) tract that are associated with significant morbidity and disability. Over the past few decades, biological therapy with anti-Tumor Necrosis Factor agents (anti TNF-α) has emerged as a corner stone of treatment for IBD. Despite significant response and remission rates, clinicians are often confronted to secondary loss of responses or side effects during long term maintenance. There is emerging data from the literature suggesting that infliximab trough levels might help clinicians tailoring therapy and overcome on-treatment IBD flares.
2. Study aims
To evaluate the indications for trough anti-TNF-α and ADA serum testing, the prevalence of ADA and the therapeutic range of anti-TNF trough level measures and to assess the clinical impact of trough anti-TNF-α and ADA serum levels on routine management of IBD patients
3. Study Design
This is a retrospective study of anti-TNF trough level and ADA serum determinations in IBD patients receiving anti-TNF agents. We included all therapeutic drug monitoring measurements performed from 05.03.2013 to 23.04.2014. A total of 70 patients where included between two tertiary referral centers.
3.1 Inclusion criteria
1. Adult patients affected with CD or UC. 2. Patients for whom an anti-TNF-α trough level and / or anti- drug antibodies were performed at CHUV. 3. Current treatment by anti-TNF- α agents.
3.2. Exclusion criteria
1.No IBD diagnosis. 2. Adults patients suffering from another chronic inflammatory disease requiring treatment with anti-TNF-α such as rheumatoid arthritis. 3. Treatment with anti-TNF-α interrupted before the assays.
Results
In our patients (n=70) appear no male or female predominance and the average age was 40 years. Most tests (n=117) were performed for Crohn's disease (73%). A large subset of our patients had been previously managed with immunomodulators (54.%). However, few cases were on combination therapy (10%). The great majority (79%) for the indication of the determinations were performed as "medical follow up". The percentage of patients with an IFX trough level within the desired range (3-8 μg/ml) is at first determination rather low, but tends to increase during the subsequent determinations. Of 117 total tests assessed the results impacted treatment decisions in approximately 40% of the cases.
Conclusion
Therapetic drug monitoring will guide the induction, the dose titration to prevent disease flares and finally it will guide interventions for cases with loss of response to biologicals. However, some knowledge gaps still need to be addressed to confirm this strategy. We feel that after testing drug and ADA levels, clinicians may gain a sense of saliency in relation to decision-making not only in cases with poor response to biologicals but even in stable case