Anti-TNF- α agents for refractory intestinal Behcet's disease: case series and meta-analysis

Background: Behcet's disease (BD) is a relapsing systemic immune disorder, and intestinal BD is a significant cause of mortality in patients with BD. Conventional therapeutic strategies for intestinal BD showed unsatisfactory outcomes, especially in those patients with refractory subtypes. In recent years, biologic agents have exhibited promising results in this field. While the sample sizes of existing studies were limited, the results were heterogeneous. Objectives: This study aimed to observe the efficacy of different biologics in clinical symptomatic improvement and intestinal mucosal healing. Design: This is a study including the report of case series and meta-analysis. Data sources and methods: This meta-analysis was conducted following the PRISMA guidelines. Free-text words and subject terms, including `Behcet's Syndrome', `Biologics', `Tumor Necrosis Factor Antagonist', were used to systematically research the relevant studies in the electronic databases (PubMed, Web of Science, Embase, and Cochrane Library). All retrieved articles were from inception to July 2021, and the data from our institution were also included in this meta-analysis. A double arcsine transformation was performed to stabilize the variance of the original ratio. Heterogeneity was evaluated via Q-test and I2 statistics. Randomeffects or fixed-effects model was used to calculate the pooled parameters, and the results were presented as forest plots with 95% confidence intervals. Results: Twelve studies were included, but only antitumor necrosis factor alpha (anti-TNF-a) agents were prescribed as biologicals for refractory intestinal BD. The symptom improvement rates at our institution ranged from 57.1 to 81.8%, and the mucosal healing rates were from 20 to 60% in different therapeutic periods. A total of 514 patients were enrolled in the meta-analysis, and the synthesized ratios showed that 59.8% (n = 377) and 73.7% (n = 317) of patients who received maintenance therapy with anti-TNF-a agents could achieve clinical symptomatic improvement during short-term (10-14 weeks) and long-term (48-54 weeks) periods, respectively. Furthermore, 77.8% (n = 229) of patients with intestinal BD maintained therapeutic efficacy for a longer time (100 weeks). In addition, 60.9% (n = 120) of the patients achieved sustained intestinal mucosal healing during a long-term follow-up (24-52 weeks). Conclusion: Anti-TNF-a treatment is effective in treating refractory intestinal BD but more studies are required to evaluate the effects of new biologics for intestinal BD in the near future.