Tripterygium agents for the treatment of atopic eczema: A Bayesian analysis of randomized controlled trials

Atopic eczema is a common and recrudescent skin disorder. Tripterygium agents (TA), extracted from Tripterygium wilfordii hook F, a traditional Chinese medicine, have been used as a supplemental therapy for treating eczema empirically in recent years.

To investigate the efficacy and safety of TA for treating atopic eczema.

Systematic review and Bayesian analysis.

PubMed, Embase, Cochrane Central Register of Controlled Trials, CNKI, Chinese Scientific Journals Database, the Wan Fang Database, and Chinese Biomedicine databases were systematically searched from their respective inception dates to October 2, 2018. Randomized controlled trials (RCTs) related to TA used alone or in combination with other drugs were included. Meta-analysis was conducted by RevMan 5.3 software, and Bayesian analysis was performed in Stata 15.0 and R (V.3.4.0) package gemtc software. The Cochrane risk-of-bias tool and Jadad score were applied to assess the quality of all trials.

Thirteen trials involving 1385 patients were analyzed. Meta-analysis showed that, when treating atopic eczema patients, TA combined with other drugs were strongly synergistic (p < 0.00001). Among all combinations, the efficacy of TA combined with Diyin tablet (DYP) and topical glucocorticoids (TG) (RR: 0.06, 95%CI [0.01, 0.53]), as well as with compound glycyrrhizin (CG) (RR: 0.36, 95%CI [0.14,0.94]) was superior. Among the different combined medications, the best curative effect was achieved with TA combined with DYP and TG (98.2%), followed by TA combined with CG (85.3%), with TG (51.0%), or with Fuyang granule (FG) (49.9%). Reproductive system dysfunction was the main adverse events in patients treated with TA (RR: 6.23, 95%CI [1.12, 34.62]). Immunoglobulin E (IgE) levels were significantly decreased, after treatment with TA (p = 0.04). Subgroup analysis indicated no statistically significant difference in eczema-related cytokines (p = 0.44). Recurrence rates of using TA and other drugs were similar (p = 0.40).

TA appear to be effective in some therapies when treating patients with atopic eczema, but with apparent side effects. It cannot be concluded that TA can be generally used for eczema in the clinic, because of the small sample size. Further multi-center studies with large samples, and high-quality RCTs should be conducted to clarify the efficacy and safety of TA for treating eczema.