Relationship Between Soluble Urokinase Plasminogen Activator Receptor (suPAR) and Disease Outcome in Adult-Onset Asthma

Taito Niemelä,1 Hannu Kankaanranta,1– 3 Iida Vähätalo,2 Juho Loponen,1,2 Leena E Tuomisto,2 Onni Niemelä,1,4 Mari Hämäläinen,5 Eeva Moilanen,5 Pinja Ilmarinen1,2 1Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland; 2Department of Respiratory Medicine, Seinäjoki Central Hospital, Seinäjoki, Finland; 3Krefting Research Centre, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden; 4Department of Laboratory Medicine, Seinäjoki Central Hospital, Seinäjoki, Finland; 5The Immunopharmacology Research Group, Faculty of Medicine and Health Technology, Tampere University and Tampere University Hospital, Tampere, FinlandCorrespondence: Pinja Ilmarinen, Department of Respiratory Medicine, Seinäjoki Central Hospital, Seinäjoki, Finland, Tel +35 850 420 0596, Email pinja.ilmarinen@epshp.fiBackground: Soluble urokinase plasminogen activator receptor (suPAR) has emerged as a novel biomarker for various inflammatory conditions and has been proposed to associate with the severity of asthma. However, the relationship between suPAR and clinical asthma features is poorly understood.Objective: To examine associations of serum suPAR levels with clinical characteristics of asthma and to define the phenotype with high suPAR levels in patients with adult-onset asthma.Methods: Serum suPAR levels were measured with ELISA from patients with adult-onset asthma participating in the 12-year follow-up visit in the Seinäjoki Adult Asthma Study.Results: In total, 201 patients were divided into quartiles according to suPAR values. High suPAR patients had more severe asthma symptoms and poorer asthma control. They also had higher levels of interleukin 8 (IL-8), interleukin 6 (IL-6), matrix metalloproteinase 9 (MMP-9), and blood neutrophil counts than those with low suPAR levels. The use of high-dose inhaled and oral corticosteroids was more common in patients with elevated suPAR. Such patients also had visited healthcare more frequently during