• adult onset still's disease
• cytokines
• treatment

We would like to thank Dr Lee1 for his interest in our paper2 and for his comments providing futuristic insights into the management of adult-onset Still's disease. As he highlights, conventional disease-modifying antirheumatic drugs (DMARDs) are important options for this disease.3–5 Although the safety of biological agents including tocilizumab have been shown in patients with rheumatoid arthritis, they are more expensive than conventional DMARDs, and the long-term safety of their use in patients with adult-onset Still's disease is still unknown. Some of patients in our trial had a history of not responding to DMARDs such as methotrexate or ciclosporine, but we did not collect precise information about patients’ previous treatment other than glucocorticoids use.

Our trial was a first step, aimed at proving the efficacy of anti-interleukin-6 treatment by a high-levelled evidence rather than case reports. As Dr Lee mentioned, further randomised studies are warranted to determine the optimal management of adult-onset Still's disease, although the rarity and occasional fatal severity of adult-onset Still's disease would hinder determining appropriate endpoints and recruiting active patients who are refractory to glucocorticoids but can tolerate control treatment including placebo or conventional DMARDs. The next step will need worldwide cooperation to establish the optimal management of adult-onset Still’s in clinical studies with a proper design and sample size.