Relationship between serum infliximab levels and acute uveitis attacks in patients with Behcet disease

AIM: To investigate the relationship between the serum concentration of infliximab, a chimeric monoclonal antibody to tumour necrosis factor-α (TNF-α), and its effectiveness in treating uveitis in Behçet disease. METHODS: The authors studied 20 patients with Behçet disease who had been treated with infliximab (5 mg/kg). After informed consent was obtained, samples of the peripheral blood were taken. The authors began collecting blood samples after at least 4 months of infliximab infusions. The first sample was collected at 1 h after an infliximab infusion (Day 0), then after 4 weeks (Week 4), and finally at 1 h prior to the infliximab infusion 8 weeks later (Week 8). The clinical data on uveitis were collected from the clinical charts of the patients. The serum concentration of infliximab was measured by an enzyme-linked immunosorbent assay. RESULTS: The mean serum concentration of infliximab in the 20 patients was 117.4 ± 28.2 μg/ml on Day 0, 11.4 ± 6.8 μg/ml on Week 4 and 6.3 ± 4.8 μg/ml on Week 8. The serum concentration of infliximab in each patient was significantly correlated with its effectiveness in resolving the recurrent episodes of uveitis. CONCLUSION: Monitoring infliximab serum concentrations is useful in determining the effectiveness of infliximab treatments for uveitis in Behçet disease.