New perspectives in the treatment of chronic eosinophilic pneumonia in the era of targeted therapies

BackgroundChronic eosinophilic pneumonia (CEP) is a rare, idiopathic inflammatory lung disease characterized by subacute symptoms such as cough, dyspnea, and fever; abnormal chest imaging findings; peripheral eosinophilia; and eosinophilic infiltration of the pulmonary interstitium and alveoli. Eosinophils interact with multiple T helper 2 (Th2) cellular pathways; however, eosinophil recruitment to the lung is primarily mediated by interleukin (IL)-5 and the eotaxin subfamily of chemokines. Standard treatment consists of systemic corticosteroids; however, relapse is frequent after tapering the corticosteroid dose, leading to long-term steroid therapy and its associated adverse effects, including diabetes mellitus, infections, glaucoma, and osteoporosis.ObjectiveThis narrative review aims to summarize the available evidence on the effectiveness and safety of anti–IL-5 biologic therapies (mepolizumab, reslizumab, and benralizumab) in the management of CEP and as steroid-sparing strategies, with particular focus on their role in relapse prevention, which occurs in nearly 50% of cases during systemic corticosteroid tapering.MethodsA narrative review was conducted to identify the real-world advances of anti-IL-5 treatments in CEP. Most of the available literature consists of case series, case reports and observational studies, owing to the lack of controlled clinical trials and guidelines involving this disease and anti–IL-5 therapies.ResultsThe available evidence suggests that anti–IL-5 therapies are effective in controlling disease activity, reducing relapse rates, and enabling corticosteroid tapering or discontinuation.ConclusionsAll the treatments considered were safe and well tolerated, and their use provided significant benefits in terms of symptom control, despite the limited impact on pulmonary function. Owing to their steroid-sparing effects, these agents are useful in reducing the adverse effects associated with long-term corticosteroid use. Anti–IL-5 biologics represent a promising therapeutic option for patients with relapsing or corticosteroid-dependent CEP. Despite encouraging results, larger prospective studies are needed to better define their role in the long-term management of this disease.