Study design: Randomized, controlled study.
Objective: To evaluate the effect of infliximab on herniated nucleus pulposus (HNP) resorption.
Summary of background data: Although the effects of tumor necrosis factor alpha (TNF-alpha) on HNP resorption are not fully understood, TNF-alpha appears to be an essential mediator in HNP resorption.
Methods: As part of a substudy of the FIRST II study, magnetic resonance images (MRIs) were obtained from 21 patients who were candidates for discectomy at weeks 0, 2, 12, and 26 after receiving a single infusion of either 5 mg/kg infliximab (11 patients) or placebo (10 patients). The volume (mm3) of HNP, thickness (mm) and extent (%) of rim enhancement, and presence of nerve root edema were assessed.
Results: HNP volume decreased significantly from baseline to 6 months in both treatment groups (P < 0.01), with no difference noted between the infliximab and placebo groups. By week 2, rim enhancement thickness increased significantly in the infliximab group compared with the placebo group (P = 0.003). Two patients in each group required back surgery before the 6-month assessment.
Conclusions: Infliximab did not appear to interfere with disc herniation resorption over a 6-month period.