A recent study in The Journal of Allergy and Clinical Immunology explores the association between activated sputum eosinophils and exacerbations in asthmatic urban children on mepolizumab.

The MUPPITS-2 controlled trial showed that mepolizumab (an anti-interleukin-5 treatment) lessened both exacerbations and eosinophil levels in children with severe Eosinophilic Asthma in urban settings. However, some patients still faced exacerbation risks post-treatment, indicating the possible presence of different eosinophil subpopulations that could lead to ongoing asthma attacks.


The study found that mepolizumab treatment significantly decreased (58% lower) median sputum eosinophil levels in children with severe Eosinophilic Asthma. However, despite this overall reduction, two subpopulations of sputum eosinophils, CD62Lint and CD62Lhi, exhibited significantly elevated activation markers and eosinophil peroxidase expression, respectively. In mepolizumab-treated participants, CD62Lint and CD62Lhi eosinophils were more abundant in participants who experienced exacerbations than in those who did not.Chart from MUPPITS-2 study comparing eosinophil levels in children with severe asthma treated with mepolizumab, showing three subtypes of eosinophils and their activation states


The study's conclusion noted that children with Eosinophilic Asthma who received mepolizumab treatment showed a marked decrease in sputum eosinophils. Nonetheless, higher levels of CD62Lint and CD62Lhi eosinophil subpopulations in those who experienced asthma exacerbations under treatment indicate that certain eosinophil types may still promote exacerbations despite the use of anti-IL-5 therapy.

For the eosinophilic community, these findings highlight the complexity of Eosinophilic Asthma treatment and suggest that even with targeted therapies like mepolizumab, specific eosinophil subpopulations can still drive exacerbations. This underscores the need for personalised treatment approaches that consider the particular characteristics of eosinophil subpopulations in individuals with this condition.

Meet Jeff, who lives with Eosinophilic Asthma.

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