A collaborative research group led by Dr. Ayano Fukushima-Nomura (Assistant Professor), Dr. Hiroshi Kawasaki (Senior Lecturer), and Prof. Masayuki Amagai of the Department of Dermatology, Keio University School of Medicine; Dr. Akihiko Koseki (Team Director, Laboratory for Developmental Genetics), RIKEN Center for Integrative Medical Sciences; and Takehiro Hasegawa and colleagues at Sysmex Corporation has revealed plasma IL‑22 and IL‑18 levels as potential biomarkers that reflect disease activity over the course of dupilumab treatment in patients with atopic dermatitis.
The levels of serum CCL17 (TARC), a representative type 2 inflammation–related biomarker, are widely utilized in clinical practice in Japan and are useful for assessing disease severity prior to treatment. In this study, the team analyzed plasma cytokine levels from 170 patients with atopic dermatitis and conducted a 6‑month longitudinal evaluation of 24 patients undergoing dupilumab therapy. The results showed that CCL17 levels declined rapidly after treatment initiation, reflecting early treatment response; however, their association with disease activity during treatment tended to be limited. In contrast, IL‑22 and IL‑18 levels demonstrated sustained variability during dupilumab therapy and consistently reflected the severity of cutaneous symptoms throughout the treatment period.
These findings contribute to a reappraisal of monitoring indicators for atopic dermatitis that take into account disease heterogeneity and the phase of treatment. Looking ahead, combining conventional markers such as CCL17 with novel indicators like IL‑22 may enable more precise assessment of disease activity in patients receiving biologic therapies.
This study was published online in the international journal Allergy on February 18, 2026.
