The risk of interstitial lung disease during biological treatment in Japanese patients with psoriasis

Background With the increasing use of biological agents for the treatment of psoriasis, the numbers of patients with interstitial lung disease (ILD) associated with biologics have also increased. Many of these cases were associated with tumour necrosis factor (TNF)-alpha inhibitors, but cases associated with other families of biologics have also been reported in Japan. Aim To analyse the background factors of patients who developed ILD, and to discuss better management of biological treatment. Method We reviewed 246 patients with psoriasis who were treated with biological agents in our department to identify any pulmonary adverse events (AEs). Data on patients who developed ILD were extracted to analyse background factors, clinical type of psoriasis, time to onset of ILD, pre-existing ILD, smoking habit and prescribed drugs. Results Pulmonary AEs were seen in 22 cases, of which 11 were diagnosed as drug-induced ILD. The causative drugs were mainly TNF-alpha inhibitors, accounting for eight cases (six treated with infliximab, two with adalimumab). The remaining three cases were associated with secukinumab, ustekinumab and ixekizumab (n = 1 each). Notably, these three cases also had a history of drug-induced ILD. Conclusion Patients with a history of drug-induced ILD seem to be more susceptible to developing another ILD induced by biologics, even if treated with interleukin-17 inhibitors. Thorough screening of risk factors and evaluation for eligibility, and careful monitoring during treatment are the best solutions to avoid serious pulmonary AE. Early detection and precise diagnosis of pulmonary AEs, especially differentiation from infectious diseases, is essential for managing biological treatment.