RT Journal Article SR Electronic T1 The identification of asthma phenotypes by categorical PCA: Combinatorial analysis of clinical parameters and dysfunctional blood eosinophils JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP P3006 VO 44 IS Suppl 58 A1 Bart Hilvering A1 Susanne Vijverberg A1 Leo Houben A1 Rene Schweizer A1 Jan-Willem Lammers A1 Leo Koenderman YR 2014 UL http://erj.ersjournals.com/content/44/Suppl_58/P3006.abstract AB Background: The identification of inflammatory asthma phenotypes currently requires sputum analysis. This procedure is invasive, highly variable, time-consuming and a burden for patients. There is a strong need for less-invasive markers to establish asthma phenotypes.Objective: To assess whether a Principal Component Analysis (PCA) of combined clinical parameters and peripheral blood characteristics can identify asthma phenotypes without the need for sputum induction.Materials and Methods: In a prospective study (NCT01611012) 115 adult asthma patients were analysed in terms clinical parameters, sputum phenotype and activation of blood granulocytes. Granulocytes were stained with antibodies against the active CD32 receptor (clones A17/A27) and CD11b in the presence or absence of fMLF, and analysed by flow cytometry. Finally, Categorical PCA was used to reduce dimensions in a combined cellular and clinical dataset.Results: In Figure 1, patients are plotted based on multidimensional cellular and clinical data. The presence of dysfunctional eosinophils (refractory to activation), eosinophil count, FeNO and ACQ scores were important discriminators between eosinophilic and non-eosinophilic asthma.Conclusion: We generated a promising non-invasive model that closely resembles sputum phenotyping based on dimension reduction of routine clinical parameters and blood biomarkers.