TY - JOUR T1 - Circulating Fibrocytes Are Increased in Children and Young Adults with Pulmonary Hypertension JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/09031936.00072311 SP - erj00723-2011 AU - M.E. Yeager AU - C.M. Nguyen AU - D.D. Belchenko AU - K.L. Colvin AU - S. Takatsuki AU - D.D. Ivy AU - K.R. Stenmark Y1 - 2011/01/01 UR - http://erj.ersjournals.com/content/early/2011/06/20/09031936.00072311.abstract N2 - Chronic inflammation is an important component of the fibroproliferative changes that characterize pulmonary hypertensive vasculopathy. Fibrocytes contribute to tissue remodeling in settings of chronic inflammation, including animal models of pulmonary hypertension. We sought to determine if circulating fibrocytes were increased in children and young adults with pulmonary hypertension.26 individuals with pulmonary hypertension and 10 with normal cardiac anatomy were studied. Fresh blood was analysed by flow cytometry for fibrocytes expressing CD45 and procollagen. Fibrocyte numbers were correlated to clinical and hemodynamic parameters, and circulating CCL2 and CXCL12 levels.We found enrichment of circulating fibrocytes among those with pulmonary hypertension. No differences were observed in fibrocytes among those with idiopathic PH vs. secondary PH. Higher fibrocytes correlated to increasing mean pulmonary artery pressure and age, but not to length or type of treatment. Immunofluorescence analysis confirmed flow sorting specificity. Differences in plasma levels of CCL2 or CXCL12, which could mobilize fibrocytes from the bone marrow, were not found.We conclude that circulating fibrocytes are significantly increased in individuals with pulmonary hypertension compared to controls. We speculate that these cells might play important roles in the vascular remodeling in children and young adults with pulmonary hypertension. ER -