TY - JOUR T1 - Surfactant protein A in particles in exhaled air (PEx) - A better reflection of small airways in comparison to bronchoalveolar lavage and serum? JF - European Respiratory Journal JO - Eur Respir J VL - 42 IS - Suppl 57 SP - P846 AU - Mona Lärstad AU - Per Larsson AU - Ann-Charlotte Almstrand AU - Ekaterina Mirgorodskaya AU - Gerdt C. Riise AU - Anna-Carin Olin Y1 - 2013/09/01 UR - http://erj.ersjournals.com/content/42/Suppl_57/P846.abstract N2 - Introduction: Particles in exhaled air (PEx) are formed in the small airways during airway reopening after airway closure. Sampling of PEx give the opportunity of measuring biomarkers from the respiratory tract lining fluid noninvasively. Our objective was to investigate if SP-A levels in PEx are correlated to SP-A levels in bronchoalveolar lavage (BAL) and serum.Methods: Consecutive patients undergoing bronchoscopy one year after lung transplantation (n=11), or for investigation of pulmonary fibrosis (IPF)(n=2) and healthy volunteers (n=4) were included. PEx was collected using a method developed in-house. SP-A and albumin were measured in BAL and PEx, and SP-A was measured in serum (ELISA). The absolute (ng) and relative amount of SP-A (%; i.e. ng SP-A/ng PEx) and albumin in PEx (%) were calculated.Results: There was no correlation between SP-A in PEx and SP-A in BAL and serum, nor between albumin in PEx and BAL. SP-A in PEx (ng) was significantly lower in healthy volunteers compared with patients (p<0.05).Conclusion: There was no correlation between SP-A in PEx, BAL and serum. This may reflect different origins since PEx may originate more strictly from the small airways whereas BAL and serum may also reflect the central airways. The fact that SP-A in PEx (ng) was significantly higher in patients may indicate a higher number of PEx in these subjects.View this table:Table 1. Medians, standard deviations and range of concentrations of SP-A in PEx, BAL and serum. ER -