Patients With Inflammatory Bowel Diseases and Higher Visceral Adipose Tissue Burden May Benefit From Higher Infliximab Concentrations to Achieve Remission

INTRODUCTION

In patients with inflammatory bowel diseases (IBDs), high visceral adipose tissue (VAT) burden is associated with a lower response to infliximab, potentially through alterations in volume distribution and/or clearance. Differences in VAT may also explain the heterogeneity in target trough levels of infliximab associated with favorable outcomes. The aim of this study was to assess whether VAT burden may be associated with infliximab cutoffs associated with efficacy in patients with IBD.

METHODS

We conducted a prospective cross-sectional study of patients with IBD receiving maintenance infliximab therapy. We measured baseline body composition parameters (Lunar iDXA), disease activity, trough levels of infliximab, and biomarkers. The primary outcome was steroid-free deep remission. The secondary outcome was endoscopic remission within 8 weeks of infliximab level measurement.

RESULTS

Overall, 142 patients were enrolled. The optimal trough levels of infliximab cutoffs associated with steroid-free deep remission and endoscopic remission were 3.9 mcg/mL (Youden Index [J]: 0.52) for patients in the lowest 2 VAT % quartiles (<1.2%) while optimal infliximab level cutoffs associated with steroid-free deep remission for those patients in the highest 2 VAT % quartiles was 15.3 mcg/mL (J: 0.63). In a multivariable analysis, only VAT % and infliximab level remained independently associated with steroid-free deep remission (odds ratio per % of VAT: 0.3 [95% confidence interval: 0.17-0.64], P < 0.001 and odds ratio per μg/mL: 1.11 [95% confidence interval: 1.05-1.19], P < 0.001).

DISCUSSION

The results may suggest that patients with higher visceral adipose tissue burden may benefit from achieving higher infliximab levels to achieve remission.

Serum trough levels of infliximab are not associated with peripheral arthralgia activity in patients with inflammatory bowel disease

BACKGROUND

Infliximab is an efficacious therapy for inflammatory bowel disease and may play a role in management of some extraintestinal manifestations. While higher trough levels of infliximab are associated with higher rates of disease remission, the association between trough levels of infliximab and arthralgia activity characterised as an extraintestinal manifestation has yet to be defined.

OBJECTIVE

We aimed to assess the association between serum trough levels of infliximab and peripheral arthralgia activity in patients with inflammatory bowel disease.

DESIGN

In this cross-sectional study, we identified patients with inflammatory bowel disease on infliximab therapy with known history of arthralgias attributed to an extraintestinal manifestation. Collected variables included disease phenotype, medications (such as thiopurines or methotrexate), Harvey Bradshaw Index, partial Mayo score, C reactive protein, trough levels of infliximab and anti-infliximab antibodies. The primary outcome was active patient-reported arthralgia.

RESULTS

Out of 267 patients included, 65 (24.4%) had active arthralgias at the time the trough level of infliximab was measured. No significant differences in trough levels were seen between those patients with and without arthralgias. Patients on combination therapy with methotrexate or thiopurines or those with detectable anti-infliximab antibodies were not more likely to have inactive arthralgias (OR 0.99, 95% CI 0.57 to 1.74, p=0.99 and OR 1.94, 95% CI 0.9 to 4.1, p=0.09, respectively).

CONCLUSIONS

This study suggests that although therapeutic drug monitoring of infliximab can have a role in the management of Crohn's disease and ulcerative colitis, it does not seem to be useful in managing arthralgias associated with inflammatory bowel disease.