The following is a summary of “Anti-epithelial-derived cytokines for severe asthma: Systematic review and meta-analysis,” published in the JUNE 2023 issue of Allergy & Immunology by Su, et al.

Therapies targeting epithelial-derived cytokines, known as alarmins, have been investigated in large randomized trials and have shown potential benefits for both type 2 and non-type 2 severe asthma.

A systematic review was conducted by searching multiple databases for relevant studies until March 2022. Randomized controlled trials that evaluated antialarmin therapy in severe asthma were included. A random-effects pairwise meta-analysis was performed, and results were reported as relative risks (RR) with 95% CIs for binary outcomes and as mean differences (MD) with 95% CIs for continuous outcomes. The eosinophil count was used to define high eosinophils (≥300 cells/μL) and low eosinophils (<300 cells/μL). The risk of bias in the trials was assessed using the Cochrane-endorsed RoB 2.0 software, and the certainty of the evidence was evaluated using the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) framework.

A total of 12 randomized trials involving 2,391 patients were included in the analysis. Antialarmin therapy likely reduces the annualized exacerbation rates in patients with high eosinophils (RR 0.33 [95% CI 0.28 to 0.38]; moderate certainty). There is a possibility that antialarmins may also reduce exacerbation rates in patients with low eosinophils (RR 0.59 [95% CI 0.38 to 0.90]; low certainty). Antialarmins significantly improve forced expiratory volume in 1 second (FEV₁) in patients with high eosinophils (MD 218.5 mL [95% CI 160.2 to 276.7]; high certainty). However, in patients with low eosinophils, antialarmin therapy likely does not significantly improve FEV₁ (MD 68.8 mL [95% CI 22.4 to 115.2]; moderate certainty). 

Antialarmins were found to reduce blood eosinophils, total IgE levels, and fractional excretion of nitric oxide in the studied subjects.

Antialarmins have shown effectiveness in improving lung function and likely reduce exacerbations in patients with severe asthma and high blood eosinophil counts (≥300 cells/μL). The effects on patients with lower eosinophil counts are less certain.

Source: jacionline.org/article/S0091-6749(23)00281-6/fulltext