4/ Sensitization to certain single components is associated with severity, in particular to nsLTP
In the present study, sensitization to the food components Gal d 1 (ovomucoid) and Cor a 9 (11S seed-storageglobulin) and the airborne dog allergens Can f 1 and Can f 2 (lipocalins) was more frequent among school-age children with SA than those with NSA. These results confirm recent findings that Can f 2 sensitization and multi-sensitization to lipocalins are more frequent among children with SA than those with milder disease (21,22). Interestingly, sensitization to the nsLTPs Cor a 8 and Art v 3 was associated with SA, and sensitization to Pru p 3, a major nsLTP, also tended to be more frequent among SA. In addition, nsLTP sensitization was associated with lower lung function as assessed by the FEV1/FVC <-1.64 z-score. Furthermore, in contrast to the multi-sensitization pattern shown in cluster 5, nsLTP sensitization was a characteristic of the sensitization profile shown in cluster 4, which was the only cluster associated with SA. Among preschoolers, 75% of children from cluster 2, also characterized by nsLTP sensitization, had SRW. This association of nsLTP sensitization with asthma severity has not been described elsewhere. This may result, at least partially, from the high geographical variation in the prevalence of nsLTP sensitization (23). nsLTP have been reported to be the most common food allergens associated with anaphylaxis in Italy and Spain. In parallel with global climate change and the rising spread and allergenicity of pollens, pediatric cases of nsLTP sensitization are increasing (24,25). Sensitization towards nsLTP from pollen and food were observed in this cohort. It is yet to be determined whether sensitization to nsLTP primarily occurs through pollen or food exposure (24). Although these results need confirmation, in particular because of the small size of cluster 4, they highlight how geographical variation might affect asthma severity.