Association of CCL18 levels with clusters of allergic diseases
As we previously have derived clusters of allergic sensitisation20,21, allergic diseases22 and asthma exacerbations23 from children in the MAAS cohort using machine learning, we sought to study the relationship between the chemokine levels and these putative endotypes of allergic diseases.
Children belonging to the multiple early sensitisation cluster20 had significantly higher levels of CCL18 at age 8 compared to non-atopic subjects (Figure 6A). In relation to CRD sensitisation patterns21, circulating levels of CCL18 at age 8 were elevated in individuals sensitised towards multiple allergens as compared to children with predominant grass and tree sensitisation, and as a trend compared to children who were sensitised to a lesser degree (Figure 6B).
There was a trend towards higher levels of CCL18 at age 8 both in the eczema only and the atopic march clusters compared to the cluster consisting of healthy children22 (Figure 6C).
Associating chemokine levels to developmental pattern of asthma exacerbations in the first 8 years of life, children presenting with exacerbations23 showed significantly higher levels of CCL18 at age 8 compared to non-wheezers (Figure 6D).
None of the other chemokines revealed any differences between the investigated clusters.