Dupilumab therapy reduces urinary biopyrrin levels in atopic patients: a new possible biomarker of oxidative status in atopic dermatitis.

Background: Accumulating evidence suggests that oxidative stress is involved in the inflammatory process of atopic dermatitis (AD). Biopyrrins are the end products of the oxidative reaction of bilirubin with reactive oxygen species. The aim of our study was to explore the correlation between urinary biopyrrin levels and AD severity as well as to assess the possible modification of them in AD patients during biologic therapy with human monoclonal antibody dupilumab.

Methods: For this purpose, 25 adult patients with moderate-severe AD who were candidates for dupilumab therapy independently from the study, and 15 healthy control subjects, matched by sex and age, were enrolled. Morning urine samples were collected from all study participants. For AD patients, a collection was planned before starting therapy with dupilumab (WO), after 8, 16, 52 weeks (W8, W16, W52, respectively), and two years (Y2) of treatment. The analysis of urinary levels of biopyrrins was performed by ELISA assay.

Results: Our results demonstrated that urinary biopyrrin levels were significantly augmented in AD patients, and interestingly they correlated with disease severity. Furthermore, dupilumab therapy decreased levels of urinary biopyrrins in AD patients after eight and 16 weeks, maintaining the result after 52 weeks as well as after two years of treatment. The correlation analysis showed a statistically significant positive correlation between the urinary concentration of biopyrrins and EASI Index, circulating total IgE as well as plasma C reactive protein levels.

Conclusions: Dupilumab therapy was able to ameliorate oxidative state in AD patients.