Abstract
Introduction: Infliximab, a monoclonal antibody against tumour necrosis factor alfa (TNFα) has been used succesfully in the treatment of rheumatoid arthritis and Crohn’s disease. Recent animal studies suggest that TNFα also has an important role in the pathogenesis of sciatica. The purpose of this study was to evaluate the efficacy and safety of infliximab in the treatment of sciatic patients.
Methods: 10 patients with acute or subacute severe sciatica (duration of symptoms from 2 to 12 weeks) were included. A disc herniation corresponding to symptoms was confirmed by MRI in each case. Patients with previous back operation or with contraindications for infliximab were excluded. A dose of 3 mg/kg body weight of infliximab in saline was infused intravenously over 2 hours. Leg pain (100-mm Visual Analog Scale) was recorded before and one hour after the infusion, and later at 1 week, 2 weeks, 1 month, 3 months and 6 months. Changes in leg pain were compared statistically with 62 historical controls (saline group in a study of periradicular infiltration) using repeated measures analysis of variance. Changes in back pain, back-related disability on Oswestry Index and clinical status were also assessed.
Results: Mean (SD) leg pain before the infusion was 80 (18) mm in the infliximab group. One hour after the infusion, there was a decrease of 49% in leg pain. At 1 week mean leg pain was 26 (21), at 2 weeks 19 (20), at 1 month 18 (19), at 3 months 10 (16) and at 6 months 13 (8). When compared with the historical controls, the difference was in favour of infliximab for leg pain (19 mm; 95% CI, 6 to 32, P=0.005) and for back-related disability on Oswestry (12%; 95%CI, 4 to 20, P=0.003) over the 6 month follow-up period. At the one-month follow-up every patient in the infliximab group had returned to work compared to 38% of control patients (P=0.02). None of the patients treated with infliximab underwent surgery during the follow-up compared to 14 (23%) in the control group (P=0.09). No immediate or delayed adverse drug reactions were observed.
Conclusions: According to this study, a single infusion of infliximab seems to provide immediate, highly effective and safe treatment of sciatica through 6 months. Rapid return to work appears to be fascilitated, and surgery may possibly be avoided in some patients. There is an urgent need for a randomized trial to verify these results.
Correspondence should be addressed to the editorial secretary: Dr Charles Pither, c/o British Orthopaedic Society, Royal College of Surgeons, 35-43 Lincoln’s Inn Fields, London WC2A 3PN.