PT - JOURNAL ARTICLE AU - K. Samitas AU - E. Zervas AU - S. Vittorakis AU - M. Semitekolou AU - T. Alissafi AU - A. Bossios AU - H. Gogos AU - E. Economidou AU - J. Lötvall AU - G. Xanthou AU - V. Panoutsakopoulou AU - M. Gaga TI - Osteopontin expression and relation to disease severity in human asthma AID - 10.1183/09031936.00017810 DP - 2010 Jan 01 TA - European Respiratory Journal PG - erj00178-2010 4099 - http://erj.ersjournals.com/content/early/2010/06/18/09031936.00017810.short 4100 - http://erj.ersjournals.com/content/early/2010/06/18/09031936.00017810.full AB - Recent studies have associated osteopontin (Opn) with allergic inflammation; however, its role in human asthma remains unclear. We measured Opn levels in serum, bronchoalveolar lavage fluid (BALF) and bronchial tissue of healthy controls and asthmatics, identified cellular sources of Opn and examined possible correlations between Opn expression, disease severity and airway remodeling.Serum samples were obtained from 35 mild-moderate (MMA), 19 severe asthmatics (SA) and 17 healthy controls in steady state and in case of exacerbation. Of these subjects, 29 asthmatics and 9 controls underwent bronchoscopy with endobronchial biopsy and BALF collection. Opn expression was determined by ELISA and immunohistochemistry/immunofluorescence. Reticular basement membrane (RBM) thickness and goblet cell hyperplasia were also determined.Serum and BALF Opn levels were significantly increased in all asthmatics in steady state, while serum levels decreased during exacerbations. Opn was upregulated in the bronchial tissue of all patients and expressed by epithelial, airway and vascular smooth muscle cells, myofibroblasts, T-lymphocytes and mast cells. Opn expression correlated with RBM thickness and was more prominent in subepithelial inflammatory cells in severe compared to mild-moderate asthma.Opn expression is upregulated in human asthma, is associated with remodeling changes and its subepithelial expression correlates to disease severity.